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Comparison of late mortality after transcatheter aortic valve implantation versus surgical aortic valve replacement: Insights from a meta-analysis

Published:February 04, 2017DOI:https://doi.org/10.1016/j.ejim.2017.01.023

      Highlights

      • TAVI conferred similar late (≥2 years) all-cause mortality compared to SAVR.
      • All-cause mortality differed significantly from randomized control trial and propensity-matched studies.
      • A meta-regression suggested TAVI offered better outcomes with higher age and proportion of coronary artery disease.

      Abstract

      Introduction

      Transcatheter aortic valve implantation (TAVI) has shown non-inferior late mortality in severe aortic stenosis (AS) patients in intermediate to inoperable risk for surgery compared to surgical aortic valve replacement (SAVR). Late outcome of TAVI compared to SAVR is crucial as the number of TAVI continues to increase over the last few years.

      Methods

      A comprehensive literature search of PUBMED and EMBASE were conducted. Inclusion criteria were that [1] study design was a randomized controlled trial (RCT) or a propensity-score matched (PSM) study: [2] outcomes included >2-year all-cause mortality in both TAVI and SAVR. The random-effects model was utilized to calculate an overall effect size of TAVI compared to SAVR in all-cause mortality. Publication bias was assessed quantitatively with Egger's test.

      Results

      A total of 14 studies with 6503 (3292 TAVI and 3211 SAVR, respectively) were included in the meta-analysis. There was no difference in late all-cause mortality between TAVI and SAVR (HR 1.17, 95%CI 0.98–1.41, p = 0.08, I2 = 61%). The sub-group analysis of all-cause mortality of RCT (HR 0.93 95%CI 0.78–1.10, p = 0.38, I2 = 40%) and PSM studies (HR 1.44 95%CI 1.15–1.80, p = 0.02, I2 = 35%) differed significantly (p for subgroup differences = 0.002). Meta-regression implicated that increased age and co-existing CAD may be associated with more advantageous effects of TAVI relative to SAVR on reducing late mortality. There was no evidence of significant publication bias (p = 0.19 for Egger's test).

      Conclusions

      TAVI conferred similar late all-cause mortality compared to SAVR in a meta-analysis of RCT but had worse outcomes in a meta-analysis of PSM.

      Abbreviations:

      AS (aortic stenosis), CAD (coronary artery disease), HR (hazards ratio), NOTION (Nordic Aortic Valve Intervention), OR (odds ratio), PARTNER (Placement of AorRTic TraNscathetER), PSM (propensity-matched), RCT (randomized control trial), SAVR (surgical aortic valve replacement), TAVI (transcatheter aortic valve implantation)

      Keywords

      1. Introduction

      Since the successful first in man case of transcatheter aortic valve implantation (TAVI) in a patient with inoperable, symptomatic severe aortic stenosis (AS) in 2002 by Cribier et al., the number of TAVI performed worldwide has been dramatically increasing [
      • Cribier A.
      • Eltchaninoff H.
      • Bash A.
      • Borenstein N.
      • Tron C.
      • Bauer F.
      • et al.
      Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description.
      ,
      • Reinöhl J.
      • Kaier K.
      • Reinecke H.
      • Schmoor C.
      • Frankenstein L.
      • Vach W.
      • et al.
      Effect of availability of transcatheter aortic-valve replacement on clinical practice.
      ,
      • Holmes Jr., D.R.
      • Nishimura R.A.
      • Grover F.L.
      • Brindis R.G.
      • Carroll J.D.
      • Edwards F.H.
      • et al.
      Annual outcomes with transcatheter valve therapy: from the STS/ACC TVT registry.
      ]. TAVI has shown promising result not only for severe AS patients in high operative risk but also in intermediate surgical risk [
      • Kodali S.K.
      • Williams M.R.
      • Smith C.R.
      • Svensson L.G.
      • Webb J.G.
      • Makkar R.R.
      • et al.
      Two-year outcomes after transcatheter or surgical aortic-valve replacement.
      ,
      • Thourani V.H.
      • Kodali S.
      • Makkar R.R.
      • Herrmann H.C.
      • Williams M.
      • Babaliaros V.
      • et al.
      Transcatheter aortic valve replacement versus surgical valve replacement in intermediate-risk patients: a propensity score analysis.
      ,
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ].
      Patients at intermediate risk are expected to have the longer life expectancy after TAVI compared to those at high or inoperable risk. The data on late outcomes after TAVI is starting to accumulate. Several studies have reported 3 to 7 years of outcome data after TAVI [
      • Ruparelia N.
      • Latib A.
      • Buzzatti N.
      • Giannini F.
      • Figini F.
      • Mangieri A.
      • et al.
      Long-term outcomes after transcatheter aortic valve implantation from a single high-volume center (the Milan experience).
      ,
      • Salinas P.
      • Moreno R.
      • Calvo L.
      • Sánchez-Recalde Á.
      • Jiménez-Valero S.
      • Galeote G.
      • et al.
      Long-term follow-up after transcatheter aortic valve implantation for severe aortic stenosis.
      ,
      • Duncan A.
      • Ludman P.
      • Banya W.
      • Cunningham D.
      • Marlee D.
      • Davies S.
      • et al.
      Long-term outcomes after transcatheter aortic valve replacement in high-risk patients with severe aortic stenosis: the U.K. Transcatheter Aortic Valve Implantation Registry.
      ,
      • Barbanti M.
      • Schiltgen M.
      • Verdoliva S.
      • Bosmans J.
      • Bleiziffer S.
      • Gerckens U.
      • et al.
      Three-year outcomes of transcatheter aortic valve implantation in patients with varying levels of surgical risk (from the CoreValve ADVANCE Study).
      ,
      • Escárcega R.O.
      • Lipinski M.J.
      • Baker N.C.
      • Magalhaes M.A.
      • Minha S.
      • Torguson R.
      • et al.
      Analysis of long-term survival following transcatheter aortic valve implantation from a single high-volume center.
      ,
      • Toggweiler S.
      • Humphries K.H.
      • Lee M.
      • Binder R.K.
      • Moss R.R.
      • Freeman M.
      • et al.
      5-year outcome after transcatheter aortic valve implantation.
      ,
      • Gulino S.
      • Barbanti M.
      • Deste W.
      • Immè S.
      • Aruta P.
      • Bottari V.
      • et al.
      Four-year durability of clinical and haemodynamic outcomes of transcatheter aortic valve implantation with the self-expanding CoreValve.
      ]. However, a number of studies that have reported comparative late outcomes between TAVI and surgical aortic valve replacement (SAVR) are relatively limited. The United States CoreValve Registry showed all-cause mortality favoring TAVI (p = 0.068) during 3 years follow-up, while the Placement of AorRTic TraNscathetER (PARTNER) valve trial have reported similar 5 years all-cause mortality [
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ,
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ].
      Recently, a meta-analysis of long-term outcomes (>1 year) between TAVI and SAVR has been reported using odds ratio (OR) [
      • Gargiulo G.
      • Sannino A.
      • Capodanno D.
      • Barbanti M.
      • Buccheri S.
      • Perrino C.
      • et al.
      Transcatheter aortic valve implantation versus surgical aortic valve replacement: a systematic review and meta-analysis.
      ]. However, an estimate of late outcome is better assessed with hazards ratio (HR) than OR [
      • Deeks J.J.
      • Higgins J.P.
      • Altman D.G.
      Analysing data and undertaking meta-analyses.
      ]. Recent other meta-analyses showed improved mortality in TAVI than SAVR during up to 2 years or median of 2 (range 3 months to 3 years) years follow-up with limited number of studies [
      • Siontis G.C.
      • Praz F.
      • Pilgrim T.
      • Mavridis D.
      • Verma S.
      • Salanti G.
      • et al.
      Transcatheter aortic valve implantation vs. surgical aortic valve replacement for treatment of severe aortic stenosis: a meta-analysis of randomized trials.
      ,
      • Siemieniuk R.A.
      • Agoritsas T.
      • Manja V.
      • Devji T.
      • Chang Y.
      • Bala M.M.
      • et al.
      Transcatheter versus surgical aortic valve replacement in patients with severe aortic stenosis at low and intermediate risk: systematic review and meta-analysis.
      ]. We have previously published meta-analysis of TAVI vs SAVR using propensity-score analysis and concluded that TAVI had worse outcome compared to SAVR [
      • Takagi H.
      • Umemoto T.
      • ALICE (All-Literature Investigation of Cardiovascular Evidence) Group
      Worse survival after transcatheter aortic valve implantation than surgical aortic valve replacement: a meta-analysis of observational studies with a propensity-score analysis.
      ]. In the same report, meta-analysis of 4 randomized clinical trials (RCT) [
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ,
      • Nielsen H.H.
      • Klaaborg K.E.
      • Nissen H.
      • Terp K.
      • Mortensen P.E.
      • Kjeldsen B.J.
      • et al.
      A prospective, randomised trial of transapical transcatheter aortic valve implantation vs. surgical aortic valve replacement in operable elderly patients with aortic stenosis: the STACCATO trial.
      ,
      • Reardon M.J.
      • Adams D.H.
      • Kleiman N.S.
      • Yakubov S.J.
      • Coselli J.S.
      • Deeb G.M.
      • et al.
      2-year outcomes in patients undergoing surgical or self-expanding transcatheter aortic valve replacement.
      ,
      • Thyregod H.G.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Transcatheter versus surgical aortic valve replacement in patients with severe aortic valve stenosis: 1-year results from the all-comers NOTION randomized clinical trial.
      ] was performed. However, our previous report included in that studies, approximately half (10 studies) had follow-up duration <2 years [
      • Takagi H.
      • Umemoto T.
      • ALICE (All-Literature Investigation of Cardiovascular Evidence) Group
      Worse survival after transcatheter aortic valve implantation than surgical aortic valve replacement: a meta-analysis of observational studies with a propensity-score analysis.
      ]. In addition, out of the 4 RCTs included only two had follow-up >2 years [
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ,
      • Reardon M.J.
      • Adams D.H.
      • Kleiman N.S.
      • Yakubov S.J.
      • Coselli J.S.
      • Deeb G.M.
      • et al.
      2-year outcomes in patients undergoing surgical or self-expanding transcatheter aortic valve replacement.
      ]. It is of great clinical importance to assess the comparative late outcomes between TAVI and SAVR to better provide physicians and patients the best available evidence to aid their decisions.
      Therefore, we aimed to compare further late outcomes (≥2 years) through systematic review and meta-analysis using HR to better estimate the effect size of TAVI versus SAVR.

      2. Methods

      2.1 Literature search strategy

      A systematic literature search of PUBMED and EMBASE was performed by two independent reviewers (T.A. and H.T.). There were no language limitations and conference abstracts were excluded. Search was performed on March 23rd, 2016 from January 1st, 2004. Search terms were “aortic valve” AND (percutaneous OR transcatheter OR transluminal OR transarterial OR transapical OR transaortic OR transcarotid OR transaxillary OR transsubclavian OR transiliac OR transfemoral OR transiliofemoral OR “Transcatheter Aortic Valve Replacement” [Mesh]) AND (mortality OR death OR deaths OR survival) AND (propensity OR randomized control). Titles and/or abstracts were screened based on inclusion and exclusion criteria. Studies were included when 1: All-cause mortality was reported for more than two years follow-up in both TAVI and SAVR cohort represented by survival curve 2: HR for all-cause mortality or OR were able to abstract or calculate for late events from the provided information 3: if the study design were either RCT or propensity-matched (PSM) cohort study. Exclusion criteria were 1: single arm study of either TAVI or SAVR. 2: when TAVI outcomes were compared with sutureless aortic valve replacement outcomes and 3: conference abstracts. When more than one study was reported in the same database, the study with the longest study was selected. When the follow-up duration was the same, the study with the most cohorts was selected. The meta-analysis was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines [
      • Moher D.
      • Liberati A.
      • Tetzlaff J.
      • Altman D.G.
      • PRISMA Group
      Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
      ,
      • Stroup D.F.
      • Berlin J.A.
      • Morton S.C.
      • Olkin I.
      • Williamson G.D.
      • Rennie D.
      • et al.
      Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis of Observational Studies in Epidemiology (MOOSE) group.
      ].

      2.2 Study quality assessment

      Quality of the studies was assessed using Cochrane risk of bias tool for RCT's and Newcastle-Ottawa scale for PSM studies [
      • Jüni P.
      • Altman D.G.
      • Egger M.
      Systematic reviews in health care: Assessing the quality of controlled clinical trials.
      ,
      • Kim S.Y.
      • Park J.E.
      • Lee Y.J.
      • Seo H.J.
      • Sheen S.S.
      • Hahn S.
      • et al.
      Testing a tool for assessing the risk of bias for nonrandomized studies showed moderate reliability and promising validity.
      ]. Disagreements were resolved by a discussion by the 2 authors (T.A. and H.T.) to reach a consensus.

      2.3 Statistical analysis

      Categorical values were expressed as percentages and continuous values as a mean ± standard deviation. The generic inverse variance was used to calculate the pooled HR/OR and 95% confidence intervals (CI). When HR was not available from the text, first we used methods proposed by Parmar et al. and when crude event rates were not available, methods proposed by Tierney et al. [
      • Parmar M.K.
      • Torri V.
      • Stewart L.
      Extracting summary statistics to perform meta-analyses of the published literature for survival endpoints.
      ,
      • Tierney J.F.
      • Stewart L.A.
      • Ghersi D.
      • Burdett S.
      • Sydes M.R.
      Practical methods for incorporating summary time-to-event data into meta-analysis.
      ] was utilized to estimate the HR and its 95%CI from the Kaplan-Meier curve analysis. Publication bias was assessed visually from the funnel plot and if concern existed for asymmetry, Egger's test was utilized to quantitatively assess the publication bias. Publication bias was not assessed when <10 studies were included in the meta-analysis for each outcome. Meta-regression analysis was performed by unrestricted maximum likelihood method with continuous variables as a moderator. Variables were pre-specified for the meta-regression analysis. A p-value < 0.05 was considered significant. When 95% CI of either OR or HR for TAVI vs SAVR does not cross one, TAVI (upper limit of 95% CI is below one) or SAVR (lower limit of 95% CI is above on) significantly favors reducing clinical outcomes. Meta-analyses were performed with the Review Manager (RevMan) Version 5.3 (Nordic Cochrane Centre, The Cochrane Collaboration, 2012, Copenhagen, Denmark) and Comprehensive Meta-analysis version 2 and 3 (Biostat, Englewood, NJ)

      3. Results

      Our search result yielded a total of 616 results. Detailed study flow diagram is shown in Table 1. A total of 14 studies including 6503 (3292 TAVI and 3211 SAVR) patients were finally analyzed in this meta-analysis. Four studies [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ,
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ,
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ,
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ] were RCT and 10 were PSM studies [
      • Fraccaro C.
      • Tarantini G.
      • Rosato S.
      • Tellaroli P.
      • D'Errigo P.
      • Tamburino C.
      • et al.
      Early and midterm outcome of propensity-matched intermediate-risk patients aged ≥80 years with aortic stenosis undergoing surgical or transcatheter aortic valve replacement (from the Italian Multicenter OBSERVANT Study).
      ,
      • Fusari M.
      • Bona V.
      • Muratori M.
      • Salvi L.
      • Salis S.
      • Tamborini G.
      • et al.
      Transcatheter vs. surgical aortic valve replacement: a retrospective analysis assessing clinical effectiveness and safety.
      ,
      • Holzhey D.M.
      • Shi W.
      • Rastan A.
      • Borger M.A.
      • Hänsig M.
      • Mohr F.W.
      Transapical versus conventional aortic valve replacement–a propensity-matched comparison.
      ,
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      ,
      • Muneretto C.
      • Alfieri O.
      • Cesana B.M.
      • Bisleri G.
      • De Bonis M.
      • Di Bartolomeo R.
      • et al.
      A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in “real-world” patients with aortic stenosis and intermediate- to high-risk profile.
      ,
      • Papadopoulos N.
      • Schiller N.
      • Fichtlscherer S.
      • Lehmann R.
      • Weber C.F.
      • Moritz A.
      • et al.
      Propensity matched analysis of longterm outcomes following transcatheter based aortic valve implantation versus classic aortic valve replacement in patients with previous cardiac surgery.
      ,
      • Schymik G.
      • Heimeshoff M.
      • Bramlage P.
      • Herbinger T.
      • Würth A.
      • Pilz L.
      • et al.
      A comparison of transcatheter aortic valve implantation and surgical aortic valve replacement in 1,141 patients with severe symptomatic aortic stenosis and less than high risk.
      ,
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      ,
      • Wilbring M.
      • Tugtekin S.M.
      • Alexiou K.
      • Simonis G.
      • Matschke K.
      • Kappert U.
      Transapical transcatheter aortic valve implantation vs conventional aortic valve replacement in high-risk patients with previous cardiac surgery: a propensity-score analysis.
      ,
      • Zweng I.
      • Shi W.Y.
      • Palmer S.
      • MacIsaac A.
      • Whitbourn R.
      • Davis P.
      • et al.
      Transcatheter versus surgical aortic valve replacement in high-risk patients: a propensity-score matched analysis.
      ]. There were few significant baseline characteristic differences in certain studies. Age [
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      ,
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      ], surgical risk score [
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      ], previous coronary artery bypass graft [
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      ,
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      ] and peripheral artery disease [
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      ,
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      ] were higher in TAVI for certain studies while male [
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      ], diabetes [
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ], and peripheral disease [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ] were reported to be more prevalent in SAVR. Characteristics of patients included in each study for TAVI and SAVR are summarized in table 1. Overall, the patients' baselines were well matched in all studies. The flow of the study selection is summarized in Fig. 1.
      Table 1Characteristics summary of included studies.
      AuthorYearDesignCohortAgeMaleSurgical risk score
      TAVISAVRTAVISAVRTAVISAVRTAVISAVR
      Sφndergaard
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      2016RCT14513579.2 ± 4.979.0 ± 4.753.852.62.9 ± 1.6
      Society of thoracic surgeons score.


      8.4 ± 4.0
      Logistic EuroSCORE.
      3.1 ± 1.7
      Society of thoracic surgeons score.


      8.9 ± 5.5
      Logistic EuroSCORE.
      Deeb
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      2016RCT39135983.2 ± 7.183.3 ± 6.452.952.47.3 ± 3.0
      Society of thoracic surgeons score.


      17.7 ± 13.0
      Logistic EuroSCORE.
      7.5 ± 3.3
      Society of thoracic surgeons score.


      18.8 ± 13.2
      Logistic EuroSCORE.
      Fraccaro
      • Fraccaro C.
      • Tarantini G.
      • Rosato S.
      • Tellaroli P.
      • D'Errigo P.
      • Tamburino C.
      • et al.
      Early and midterm outcome of propensity-matched intermediate-risk patients aged ≥80 years with aortic stenosis undergoing surgical or transcatheter aortic valve replacement (from the Italian Multicenter OBSERVANT Study).
      2016PSM41541583.7 ± 2.683.7 ± 2.940.038.19.9 ± 6.9
      Logistic EuroSCORE.
      9.9 ± 6.4
      Logistic EuroSCORE.
      Johansson
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      2016PSM16612580 ± 978 ± 6516323 ± 15
      Logistic EuroSCORE.
      20 ± 14
      Logistic EuroSCORE.
      Leon
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      2016RCT1011102181.5 ± 6.781.7 ± 6.754.254.85.8 ± 2.1
      Society of thoracic surgeons score.
      5.8 ± 1.9
      Society of thoracic surgeons score.
      Mack
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      2015RCT34835183.6 ± 6.884.5 ± 6.457.856.711.8 ± 3.3
      Society of thoracic surgeons score.


      29.3 ± 16.5
      Logistic EuroSCORE.
      11.7 ± 3.5
      Society of thoracic surgeons score.


      29.2 ± 15.6
      Logistic EuroSCORE.
      Muneretto
      • Muneretto C.
      • Alfieri O.
      • Cesana B.M.
      • Bisleri G.
      • De Bonis M.
      • Di Bartolomeo R.
      • et al.
      A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in “real-world” patients with aortic stenosis and intermediate- to high-risk profile.
      2015PSM20420480 ± 280 ± 355.4528.2 ± 4.2
      Society of thoracic surgeons score.


      19.5 ± 6.7
      Logistic EuroSCORE.
      8.3 ± 4.4
      Society of thoracic surgeons score.


      19.2 ± 7.4
      Logistic EuroSCORE.
      Papadopoulos
      • Papadopoulos N.
      • Schiller N.
      • Fichtlscherer S.
      • Lehmann R.
      • Weber C.F.
      • Moritz A.
      • et al.
      Propensity matched analysis of longterm outcomes following transcatheter based aortic valve implantation versus classic aortic valve replacement in patients with previous cardiac surgery.
      2014PSM404081 ± 480 ± 3737311.1 ± 2.8
      Society of thoracic surgeons score.


      24 ± 6
      Logistic EuroSCORE.
      10.4 ± 3
      Society of thoracic surgeons score.


      19 ± 6
      Logistic EuroSCORE.
      Schymik
      • Schymik G.
      • Heimeshoff M.
      • Bramlage P.
      • Herbinger T.
      • Würth A.
      • Pilz L.
      • et al.
      A comparison of transcatheter aortic valve implantation and surgical aortic valve replacement in 1,141 patients with severe symptomatic aortic stenosis and less than high risk.
      2015PSM21621678.3 ± 5.278.2 ± 4.646.351.48.7 ± 2.7
      Logistic EuroSCORE.
      8.8 ± 2.8
      Logistic EuroSCORE.
      Wendt
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      2015PSM625178.7 ± 5.971.1 ± 10.830.625.512.1 ± 10.0
      Society of thoracic surgeons score.


      36.4 ± 17.4
      Logistic EuroSCORE.
      7.1 ± 5.2
      Society of thoracic surgeons score.


      22.2 ± 17.5
      Logistic EuroSCORE.
      Zweng
      • Zweng I.
      • Shi W.Y.
      • Palmer S.
      • MacIsaac A.
      • Whitbourn R.
      • Davis P.
      • et al.
      Transcatheter versus surgical aortic valve replacement in high-risk patients: a propensity-score matched analysis.
      2015PMC444482.3 ± 4.582.2 ± 4.44132NR
      Age, body mass index and surgical risk score is expressed in either mean±standard deviation or interquartile range.
      NR
      Holzhey
      • Holzhey D.M.
      • Shi W.
      • Rastan A.
      • Borger M.A.
      • Hänsig M.
      • Mohr F.W.
      Transapical versus conventional aortic valve replacement–a propensity-matched comparison.
      2012PSM16716780.5 ± 4.679.8 ± 5.435.335.318.7 ± 11.1
      Logistic EuroSCORE.
      18.3 ± 14.0
      Logistic EuroSCORE.
      Fusari
      • Fusari M.
      • Bona V.
      • Muratori M.
      • Salvi L.
      • Salis S.
      • Tamborini G.
      • et al.
      Transcatheter vs. surgical aortic valve replacement: a retrospective analysis assessing clinical effectiveness and safety.
      2012PSM303080.5 (75–83)77.5 (77–81)2046.76.6
      Society of thoracic surgeons score.
      (5.4–10)
      6.1
      Society of thoracic surgeons score.
      (4.8–10.3)
      Wilbring
      • Wilbring M.
      • Tugtekin S.M.
      • Alexiou K.
      • Simonis G.
      • Matschke K.
      • Kappert U.
      Transapical transcatheter aortic valve implantation vs conventional aortic valve replacement in high-risk patients with previous cardiac surgery: a propensity-score analysis.
      2012PSM535378.1 ± 5.577.6 ± 2.7656629.9 ± 14.0
      Logistic EuroSCORE.
      26.4 ± 12.9
      Logistic EuroSCORE.
      AuthorHTN (%)DM (%)PAD (%)Transfemoral (%)Pulmonary disease (%)
      TAVISAVRTAVISAVRTAVISAVRTAVISAVRTAVISAVR
      Sφndergaard
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      71.076.317.920.74.16.796.511.711.9
      Deeb
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      95.196.134.845.141.042.082.8NRNR
      Fraccaro
      • Fraccaro C.
      • Tarantini G.
      • Rosato S.
      • Tellaroli P.
      • D'Errigo P.
      • Tamburino C.
      • et al.
      Early and midterm outcome of propensity-matched intermediate-risk patients aged ≥80 years with aortic stenosis undergoing surgical or transcatheter aortic valve replacement (from the Italian Multicenter OBSERVANT Study).
      NRNR19.318.617.317.3NR17.615.2
      Johansson
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      NRNR24165239451815
      Leon
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      NRNR37.734.227.932.976.331.830.0
      Mack
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      NRNRNR43.241.670.143.743.0
      Muneretto
      • Muneretto C.
      • Alfieri O.
      • Cesana B.M.
      • Bisleri G.
      • De Bonis M.
      • Di Bartolomeo R.
      • et al.
      A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in “real-world” patients with aortic stenosis and intermediate- to high-risk profile.
      63.266.130.326.42122.674.527.426.4
      Papadopoulos
      • Papadopoulos N.
      • Schiller N.
      • Fichtlscherer S.
      • Lehmann R.
      • Weber C.F.
      • Moritz A.
      • et al.
      Propensity matched analysis of longterm outcomes following transcatheter based aortic valve implantation versus classic aortic valve replacement in patients with previous cardiac surgery.
      45404235332702320
      Schymik
      • Schymik G.
      • Heimeshoff M.
      • Bramlage P.
      • Herbinger T.
      • Würth A.
      • Pilz L.
      • et al.
      A comparison of transcatheter aortic valve implantation and surgical aortic valve replacement in 1,141 patients with severe symptomatic aortic stenosis and less than high risk.
      NRNRNRNR5.16.9NR9.38.8
      Wendt
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      91.988.238.743.152.429.4NR25.833.3
      Zweng
      • Zweng I.
      • Shi W.Y.
      • Palmer S.
      • MacIsaac A.
      • Whitbourn R.
      • Davis P.
      • et al.
      Transcatheter versus surgical aortic valve replacement in high-risk patients: a propensity-score matched analysis.
      82843236NRNRNRNRNR
      Holzhey
      • Holzhey D.M.
      • Shi W.
      • Rastan A.
      • Borger M.A.
      • Hänsig M.
      • Mohr F.W.
      Transapical versus conventional aortic valve replacement–a propensity-matched comparison.
      84.487.439.544.327.525.7013.813.8
      Fusari
      • Fusari M.
      • Bona V.
      • Muratori M.
      • Salvi L.
      • Salis S.
      • Tamborini G.
      • et al.
      Transcatheter vs. surgical aortic valve replacement: a retrospective analysis assessing clinical effectiveness and safety.
      93.376.723.36.7403053.33033.3
      Wilbring
      • Wilbring M.
      • Tugtekin S.M.
      • Alexiou K.
      • Simonis G.
      • Matschke K.
      • Kappert U.
      Transapical transcatheter aortic valve implantation vs conventional aortic valve replacement in high-risk patients with previous cardiac surgery: a propensity-score analysis.
      NRNR52.843.4NRNRNR9.47.5
      AuthorPrior CABG (%)BMI (kg/m2)CAD (%)
      TAVISAVRTAVISAVRTAVISAVR
      Sφndergaard
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      NRNRNRNRNRNR
      Deeb
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      29.431.5NRNR75.476.0
      Fraccaro
      • Fraccaro C.
      • Tarantini G.
      • Rosato S.
      • Tellaroli P.
      • D'Errigo P.
      • Tamburino C.
      • et al.
      Early and midterm outcome of propensity-matched intermediate-risk patients aged ≥80 years with aortic stenosis undergoing surgical or transcatheter aortic valve replacement (from the Italian Multicenter OBSERVANT Study).
      4.33.625.9 ± 4.326.2 ± 4.1NRNA
      Johansson
      • Johansson M.
      • Nozohoor S.
      • Bjursten H.
      • Ragnarsson S.
      • Götberg M.
      • Kimblad P.O.
      • et al.
      Late survival and heart failure after transcatheter aortic valve implantation.
      493227 ± 527 ± 4NRNR
      Leon
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      23.625.628.6 ± 6.228.3 ± 6.269.266.5
      Mack
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      42.543.6NRNR74.976.9
      Muneretto
      • Muneretto C.
      • Alfieri O.
      • Cesana B.M.
      • Bisleri G.
      • De Bonis M.
      • Di Bartolomeo R.
      • et al.
      A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in “real-world” patients with aortic stenosis and intermediate- to high-risk profile.
      NRNR26.9 ± 5.326.8 ± 3.225.924.0
      Papadopoulos
      • Papadopoulos N.
      • Schiller N.
      • Fichtlscherer S.
      • Lehmann R.
      • Weber C.F.
      • Moritz A.
      • et al.
      Propensity matched analysis of longterm outcomes following transcatheter based aortic valve implantation versus classic aortic valve replacement in patients with previous cardiac surgery.
      NRNRNRNR83.075.0
      Schymik
      • Schymik G.
      • Heimeshoff M.
      • Bramlage P.
      • Herbinger T.
      • Würth A.
      • Pilz L.
      • et al.
      A comparison of transcatheter aortic valve implantation and surgical aortic valve replacement in 1,141 patients with severe symptomatic aortic stenosis and less than high risk.
      NRNRNRNR48.148.1
      Wendt
      • Wendt D.
      • Al-Rashid F.
      • Kahlert P.
      • El-Chilali K.
      • Demircioglu E.
      • Neuhäuser M.
      • et al.
      Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
      87.164.727.1 ± 4.126.6 ± 3.7NRNR
      Zweng
      • Zweng I.
      • Shi W.Y.
      • Palmer S.
      • MacIsaac A.
      • Whitbourn R.
      • Davis P.
      • et al.
      Transcatheter versus surgical aortic valve replacement in high-risk patients: a propensity-score matched analysis.
      2318NRNRNRNR
      Holzhey
      • Holzhey D.M.
      • Shi W.
      • Rastan A.
      • Borger M.A.
      • Hänsig M.
      • Mohr F.W.
      Transapical versus conventional aortic valve replacement–a propensity-matched comparison.
      NRNR26.3 ± 4.626.3 ± 3.9NRNR
      Fusari
      • Fusari M.
      • Bona V.
      • Muratori M.
      • Salvi L.
      • Salis S.
      • Tamborini G.
      • et al.
      Transcatheter vs. surgical aortic valve replacement: a retrospective analysis assessing clinical effectiveness and safety.
      NRNR24.1 (23.2–26.2)26.3 (22.9–29.4)36.733.3
      Wilbring
      • Wilbring M.
      • Tugtekin S.M.
      • Alexiou K.
      • Simonis G.
      • Matschke K.
      • Kappert U.
      Transapical transcatheter aortic valve implantation vs conventional aortic valve replacement in high-risk patients with previous cardiac surgery: a propensity-score analysis.
      73.669.827.9 ± 4.027.3 ± 4.2100100
      TAVI: transcatheter aortic valve implantation, SAVR: surgical aortic valve replacement, RCT: randomized clinical trial, PSM: propensity matched, HTN, hypertension, DM: diabetes mellitus, PAD: peripheral artery disease, BMI: body mass index, CABG: coronary artery bypass graft, CAD: coronary artery disease NR: not reported, NA: not applicable.
      a Society of thoracic surgeons score.
      b Logistic EuroSCORE.
      c Age, body mass index and surgical risk score is expressed in either mean ± standard deviation or interquartile range.
      All-cause mortality did not differ between TAVI and SAVR (HR 1.17, 95%CI 0.98–1.41, p = 0.08, I2 = 61%). (Fig. 2)
      Fig. 2
      Fig. 2Random-effects model forest plot for all-cause mortality
      RCT: randomized control trial, PSM: propensity-matched.
      Because we observed high heterogeneity, we performed sensitivity analysis. First, we performed a subgroup analysis based on study design, RCT or a PSM study. Meta-analysis of only the RCT (1895 TAVI and 1866 SAVR) did not show the difference in all-cause mortality between TAVI and SAVR (HR 0.93, 95%CI 0.78–1.10, p = 0.38, I2 = 40%). However, pooled HR of only the PSM studies (1397 TAVI and 1345 SAVR) showed significantly worse mortality in TAVI (HR 1.44, 95%CI 1.15–1.80, p = 0.002, I2 = 35%). There was significant heterogeneity between subgroup (I2 = 89.3%, p for subgroup differences = 0.002). This resulted in non-significant heterogeneity in both groups.
      Second, study with the largest weight (19.4% = 10.8% for transfemoral +8.6% for transthoracic) [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ] was removed but did not significantly alter the result (HR 1.23, 95%CI 0.99985–1.51, p = 0.05, I2 = 60%). Third, studies with a cohort of <100 were removed (PMID: 26, 30, 32–34) but the result was consistent (HR 1.19, 95%CI 0.94–1.52, p = 0.16, I2 = 73%). Fourth, every each study was removed once at a time. When a study by Deeb et al. [
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ] was removed, the overall effect was in favor of SAVR (HR 1.23, 95%CI 1.02–1.48, p = 0.03, I2 = 56%). However, when each study was removed at a time for the each subgroup (RCT only meta-analysis and PSM only meta-analysis), it did not significantly affect the result.
      We performed a meta-regression analysis with a pre-specified clinical baseline to further investigate the source of heterogeneity.
      As the age or the prevalence of coronary artery disease (CAD) increases, the HR of late mortality (for TAVI vs SAVR) significantly decreases. This result implicates that TAVI was more effective in reducing the HR of late-mortality compared to SAVR in higher age and patients with CAD. The results of meta-regression for other clinical baselines are summarized in Table 2 and were not significant.
      Table 2Meta-regression analysis.
      VariableNumber of studiesSlopeLower limitUpper limitp-Value
      Age140.0910.150.00330.0021
      Men140.00880.0270.00880.33
      DM120.00820.0310.0150.48
      STS80.0350.0500.120.18
      Logistic EuroSCORE110.0150.0200.0380.53
      Follow up length140.110.0170.240.088
      BMI80.160.400.0740.18
      CAD90.0140.00260.00230.019
      PAD120.00290.0120.00180.70
      Publication year140.0540.290.0890.33
      DM: diabetes, STS: society of thoracic surgeon, BMI: body mass index, CAD: coronary artery disease, PAD: peripheral artery disease.
      Late cardiovascular mortality (1895 and 1866 patients from TAVI and SAVR, respectively, from 4 RCT) did not differ between TAVI and SAVR (OR 1.01, 95%CI 0.78–1.29, p = 0.95, I2 = 43%). From the same 4 RCT studies, late stroke (OR 0.83 95%CI 0.65–1.05, p = 0.13, I2 = 0%) and myocardial infarction (OR 0.83 95%CI 0.57–1.21, p = 0.33, I2 = 0%) were also similar between TAVI and SAVR. There was no significant heterogeneity observed for late cardiovascular mortality, myocardial infarction and stroke. Sensitivity analysis (by omitting one study at a time and recalculating the pooled effect size) did not significantly alter the pooled effect size for cardiovascular mortality, stroke, and myocardial infarction. The results are summarized in Fig. 3.
      Fig. 3
      Fig. 3Random-effects model forest plot for cardiovascular mortality, stroke and myocardial infarction.
      Publication bias was assessed for all-cause mortality including 14 studies and did not show significant publication bias (p = 0.19 for Egger's test).
      For other outcomes, publication bias was not assessed because the included studies were <10.
      Study quality for RCTs showed risk of bias was low for all the studies. Newcastle-Ottawa score showed >7 for all included studies for the PSM studies.

      4. Discussion

      Our major findings of this meta-analysis were that 1: Late (≥2 years) all-cause mortality of TAVI was comparable to SAVR. However, the all-cause mortality of RCT and PSM studies differed significantly. 2: Meta-regression implicated that as the age or proportion of CAD increased, TAVI was more advantageous in reducing mortality.
      Late all-cause mortality in TAVI was comparable to SAVR. However, the all-cause mortality of RCT and PSM studies differed significantly. Siontis et al. reported 13% relative risk reduction in mortality [
      • Siontis G.C.
      • Praz F.
      • Pilgrim T.
      • Mavridis D.
      • Verma S.
      • Salanti G.
      • et al.
      Transcatheter aortic valve implantation vs. surgical aortic valve replacement for treatment of severe aortic stenosis: a meta-analysis of randomized trials.
      ] in TAVI than SAVR with 4 RCTs that reported follow-up duration only up to 2 years [
      • Kodali S.K.
      • Williams M.R.
      • Smith C.R.
      • Svensson L.G.
      • Webb J.G.
      • Makkar R.R.
      • et al.
      Two-year outcomes after transcatheter or surgical aortic-valve replacement.
      ,
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ,
      • Reardon M.J.
      • Adams D.H.
      • Kleiman N.S.
      • Yakubov S.J.
      • Coselli J.S.
      • Deeb G.M.
      • et al.
      2-year outcomes in patients undergoing surgical or self-expanding transcatheter aortic valve replacement.
      ,
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ]. Another recent meta-analysis by Siemieniuk et al. focused mainly on the outcomes of low-intermediate surgical risk cohorts for aortic valve replacement [
      • Siemieniuk R.A.
      • Agoritsas T.
      • Manja V.
      • Devji T.
      • Chang Y.
      • Bala M.M.
      • et al.
      Transcatheter versus surgical aortic valve replacement in patients with severe aortic stenosis at low and intermediate risk: systematic review and meta-analysis.
      ]. They concluded TAVI conferred 21% reduction in mortality risk up to 3 years [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ,
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ,
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ]. We have included the data of longest follow-up duration in order to assess the late-mortality. This is the reason for discrepancy from previous meta-analysis and what makes our results unique and important. TAVI patients included in the RCT generally have more strict inclusion/exclusion criteria than the real world practice where patient candidacy for TAVI is decided by the “heart team” and would likely be one of the main reasons for the discrepancy. There were some clinical features set for exclusion criteria in the RCTs but not in the PSM studies. Severe renal insufficiency and/or chronic dialysis patients, patients with a pre-existing prosthetic heart valve, prior cardiac surgery were excluded from the included RCTs [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ,
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ,
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ,
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ] These clinical features were often included in the PSM studies included in this meta-analysis and also may account for the difference observed between RCT and PSM subgroup meta-analysis. Outcome of TAVI is known to improve with operator/center experience. Several data suggest that roughly 30–80 cases of experiences were required to achieve better outcomes [
      • Arai T.
      • Lefèvre T.
      • Hovasse T.
      • Hayashida K.
      • Watanabe Y.
      • O'Connor S.A.
      • et al.
      Evaluation of the learning curve for transcatheter aortic valve implantation via the transfemoral approach.
      ,
      • Minha S.
      • Waksman R.
      • Satler L.P.
      • Torguson R.
      • Alli O.
      • Rihal C.S.
      • et al.
      Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: success and safety.
      ]. Most of the centers included in the analysis were large volume, highly experienced centers in both TAVI and SAVR. TAVI has increased not only the volume of SAVR but also led to improved outcomes [
      • Patel H.J.
      • Herbert M.A.
      • Paone G.
      • Heiser J.C.
      • Shannon F.L.
      • Theurer P.F.
      • et al.
      The midterm impact of transcatheter aortic valve replacement on surgical aortic valve replacement in Michigan.
      ].
      Sensitivity analysis showed that when the study removed by Deeb et al. [
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ] with the largest weight in favor of TAVI was removed, the pooled HR became significant. The authors have considered the favorable outcome in TAVI to low peri-procedural complications, lower patient-prosthesis mismatch and better improvement in health status. Also, patients with a pre-existing prosthetic heart valve, which could negatively affect TAVI outcomes [
      • Dvir D.
      • Webb J.G.
      • Bleiziffer S.
      • Pasic M.
      • Waksman R.
      • Kodali S.
      • et al.
      Transcatheter aortic valve implantation in failed bioprosthetic surgical valves.
      ], were also excluded in the study by Adams et al. [
      • Adams D.H.
      • Popma J.J.
      • Reardon M.J.
      • Yakubov S.J.
      • Coselli J.S.
      • Deeb G.M.
      • et al.
      Transcatheter aortic-valve replacement with a self-expanding prosthesis.
      ].
      Our meta-regression results suggest that the follow-up duration did not affect mortality of TAVI compared to SAVR. This implies that the follow-up duration did not affect the mortality and TAVI could confer similar long-term mortality compared to SAVR. However, the data for long-term valve durability is still limited for the transcatheter prosthetic valves and further longer follow-up duration could affect the outcomes, although the available data up to 5 years shows similar or even better valve performance than bioprostheses of SAVR [
      • Deeb G.M.
      • Reardon M.J.
      • Chetcuti S.
      • Patel H.J.
      • Grossman P.M.
      • Yakubov S.J.
      • et al.
      3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
      ,
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ].
      Recently, a meta-analysis by Gargiulo et al. reported long-term outcomes in TAVI versus SAVR. They defined long-term mortality as >1 year and used OR to summarize and compare the effect size of TAVI and SAVR for long-term mortality. They reported OR 1.03 and 95%CI 0.65–1.62 for the meta-analysis of RCTs, OR 1.70 and 95%CI 1.23–2.35 for PSM cohort studies and OR 1.28 with 95%CI 0.97–1.69 for the total study included [
      • Gargiulo G.
      • Sannino A.
      • Capodanno D.
      • Barbanti M.
      • Buccheri S.
      • Perrino C.
      • et al.
      Transcatheter aortic valve implantation versus surgical aortic valve replacement: a systematic review and meta-analysis.
      ]. Our study used HR, which better assess, especially outcomes for long-term mortality, and resulted in more narrow 95%CI. In addition, heterogeneity for the meta-analysis for RCT in our study was non-significant as opposed to result by Gargiulo et al. However, the result was the same for both meta-analysis of RCT, PSM, and both study design combined.
      Assessment of long-term outcomes in TAVI is crucial to further expand the indication of TAVI to low surgical risk patients as these patients would have longer life expectancy. The Nordic Aortic Valve Intervention (NOTION) trial included patients at low risk and mean surgical risk was lower than the previous RCTs but the 2-year all-cause mortality was similar between TAVI and SAVR [
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ]. In the exploratory sub-group analysis from the NOTION trial, patients with STS-PROM score < 4%, TAVI conferred similar mortality to SAVR [
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ]. However, Rosato et al. reported worse mortality and the higher rate of major cardiac and cerebrovascular events in TAVI compared to SAVR in patients with EuroSCORE II < 4% [
      • Rosato S.
      • Santini F.
      • Barbanti M.
      • Biancari F.
      • D'Errigo P.
      • Onorati F.
      • et al.
      Transcatheter aortic valve implantation compared with surgical aortic valve replacement in low-risk patients.
      ]. Their study did not exclude subjects on dialysis therapy, history of cardiac surgery and prior stroke and that may have led to the difference from the results of NOTION trial.
      Valve durability is another issue that requires long-term follow-up data. Gulino et al. reported that there was 4.6% of progression of paravalvular regurgitation from mild to moderate and 3.2% developed prosthetic valve failure (moderate/severe restenosis, endocarditis with severe intraprosthetic aortic regurgitation and moderate transvalvular regurgitation) during 4-year follow-up with the CoreValve [
      • Gulino S.
      • Barbanti M.
      • Deste W.
      • Immè S.
      • Aruta P.
      • Bottari V.
      • et al.
      Four-year durability of clinical and haemodynamic outcomes of transcatheter aortic valve implantation with the self-expanding CoreValve.
      ]. Others reported durability on the Sapien valve. Mack et al. demonstrated similar mean valve area and mean gradient between TAVI and SAVR over 5-years follow-up. In addition, there was no case that required surgical intervention for valve deterioration in both groups [
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ]. Although these results appear promising, bioprosthesis used for SAVR have longer durability experience. Bourguignon and colleagues reported 19.7 years of expected valve durability with the Carpentier-Edwards Perimount pericardial bioprosthesis [
      • Bourguignon T.
      • Bouquiaux-Stablo A.L.
      • Candolfi P.
      • Mirza A.
      • Loardi C.
      • May M.A.
      • et al.
      Very long-term outcomes of the Carpentier-Edwards Perimount valve in aortic position.
      ]. Therefore, TAVI still requires data for longer follow-up, especially given recent evidence of similar outcome in intermediate patients [
      • Leon M.B.
      • Smith C.R.
      • Mack M.J.
      • Makkar R.R.
      • Svensson L.G.
      • Kodali S.K.
      • et al.
      Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
      ].
      Meta-regression implicated that increased age and co-existing CAD may be associated with more advantageous effects of TAVI relative to SAVR on reducing late mortality. Considering the less invasiveness of TAVI over SAVR, especially the transfemoral approach, it is understandable that TAVI could be more advantageous than SAVR in higher-age patients. Age has been reported to be associated with worse outcomes in both TAVI and SAVR [
      • Duncan A.
      • Ludman P.
      • Banya W.
      • Cunningham D.
      • Marlee D.
      • Davies S.
      • et al.
      Long-term outcomes after transcatheter aortic valve replacement in high-risk patients with severe aortic stenosis: the U.K. Transcatheter Aortic Valve Implantation Registry.
      ,
      • Unbehaun A.
      • Pasic M.
      • Drews T.
      • Penkalla A.
      • Dreysse S.
      • Klein C.
      • et al.
      Transapical aortic valve implantation: predictors of survival up to 5 years in 730 patients. An update†.
      ,
      • Vasques F.
      • Lucenteforte E.
      • Paone R.
      • Mugelli A.
      • Biancari F.
      Outcome of patients aged ≥80 years undergoing combined aortic valve replacement and coronary artery bypass grafting: a systematic review and meta-analysis of 40 studies.
      ]. Subgroup analysis from the RCT of TAVI vs SAVR did not show the difference in higher age group [
      • Mack M.J.
      • Leon M.B.
      • Smith C.R.
      • Miller D.C.
      • Moses J.W.
      • Tuzcu E.M.
      • et al.
      5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
      ,
      • Søndergaard L.
      • Steinbrüchel D.A.
      • Ihlemann N.
      • Nissen H.
      • Kjeldsen B.J.
      • Petursson P.
      • et al.
      Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
      ]. This discordance may be partially explained by the difference statistical methods utilized. Also, there could be a difference in other comorbidities between TAVI and SAVR in these older patients because it is an ad-hoc analysis. Few studies have suggested comparable outcomes of TAVI in nonagenarian patients [
      • Abramowitz Y.
      • Chakravarty T.
      • Jilaihawi H.
      • Kashif M.
      • Zadikany R.
      • Lee C.
      • et al.
      Comparison of outcomes of transcatheter aortic valve implantation in patients ≥90 years versus <90 years.
      ,
      • Yamamoto M.
      • Meguro K.
      • Mouillet G.
      • Bergoend E.
      • Monin J.L.
      • Lim P.
      • et al.
      Comparison of effectiveness and safety of transcatheter aortic valve implantation in patients aged ≥90 years versus <90 years.
      ]. These studies suggested similar outcomes, however, Arsalan et al. reported worse one-year mortality in nonagenarian (adjusted HR 1.20, p < 0.001) [
      • Arsalan M.
      • Szerlip M.
      • Vemulapalli S.
      • Holper E.M.
      • Arnold S.V.
      • Li Z.
      • et al.
      Should transcatheter aortic valve replacement be performed in nonagenarians?: insights from the STS/ACC TVT registry.
      ].
      CAD has been associated with worse outcomes in SAVR [
      • Beach J.M.
      • Mihaljevic T.
      • Svensson L.G.
      • Rajeswaran J.
      • Marwick T.
      • Griffin B.
      • et al.
      Coronary artery disease and outcomes of aortic valve replacement for severe aortic stenosis.
      ,
      • Aranki S.F.
      • Rizzo R.J.
      • Couper G.S.
      • Adams D.H.
      • Collins Jr., J.J.
      • Gildea J.S.
      • et al.
      Aortic valve replacement in the elderly. Effect of gender and coronary artery disease on operative mortality.
      ] but with conflicting result in TAVI [
      • Ludman P.F.
      • Moat N.
      • de Belder M.A.
      • Blackman D.J.
      • Duncan A.
      • Banya W.
      • et al.
      Transcatheter aortic valve implantation in the United Kingdom: temporal trends, predictors of outcome, and 6-year follow-up: a report from the UK Transcatheter Aortic Valve Implantation (TAVI) Registry, 2007 to 2012.
      ,
      • Gilard M.
      • Eltchaninoff H.
      • Iung B.
      • Donzeau-Gouge P.
      • Chevreul K.
      • Fajadet J.
      • et al.
      Registry of transcatheter aortic-valve implantation in high-risk patients.
      ,
      • Linke A.
      • Wenaweser P.
      • Gerckens U.
      • Tamburino C.
      • Bosmans J.
      • Bleiziffer S.
      • et al.
      Treatment of aortic stenosis with a self-expanding transcatheter valve: the International Multi-centre ADVANCE Study.
      ]. One meta-analysis reported similar mid-term mortality in patients with the history of coronary artery bypass graft surgery in TAVI and SAVR [
      • Ando T.
      • Briasoulis A.
      • Holmes A.A.
      • Afonso L.
      • Schreiber T.
      • Kondur A.
      Transcatheter aortic valve replacement versus surgical aortic valve replacement in patients with previous coronary artery bypass surgery: a systematic review and meta-analysis.
      ]. Although our meta-regression analysis suggests that TAVI may be more effective than SAVR in CAD patients with severe AS, heterogeneity of the definition of CAD and lack of information of the peri-operative revascularization make this result hard to interpret. Therefore, this result should be considered hypothesis generating and confirmed in future studies.
      Our results should be viewed in with several limitations. First, not all the studies included were RCT and the result of the meta-analysis of RCT and PSM differed significantly. This is likely due to the difference in patient selection between RCT and PSM, which more reflects the “real world” practice. This finding may be utilized to improve the outcomes in TAVI compared to SAVR. Although we only included PSM studies as non-randomized studies, PSM studies are more susceptible to confounders and biases. Indeed, there were several differences in baseline comorbidities between TAVI and SAVR cohorts, which may have potentially affected the result. However, the numbers of studies with difference in baseline characteristics were limited. Therefore, our results should be viewed with caution. Meta-regression results are exploratory and the results should be viewed with caution. Second, only 4 RCT were included for other clinical outcomes besides all-cause mortality, hence the results may not be robust to conclude the findings. Third, although relevant articles were searched rigorously and strict inclusion/exclusion criteria were defined, publication bias could not be completely excluded. However, there was no evidence of publication bias on Egger's test. Forth, data on late cardiovascular mortality, stroke and myocardial infarction were available only from the RCTs and therefore 4 studies were included. However, there was no significant heterogeneity and sensitivity analysis showed consistent result, suggesting robust result.
      Lastly, the only maximum of 5 years has been assessed for the follow-up duration and longer TAVI valve durability needs to be observed.

      5. Conclusions

      In this meta-analysis, TAVR was associated with similar late all-cause mortality compared to SAVR in the RCT but had worse all-cause mortality in a meta-analysis from PMS. Exploratory meta-regression suggested that with an increase in age and proportion of CAD, TAVI may be a better mode of aortic valve replacement for severe AS. These findings need to be confirmed with further studies.

      Disclosure

      Authors have no disclosures.

      Conflict of interest statement

      All authors have no conflict of interest to disclose.

      Acknowledgements

      To my wife and daughter for giving me pleasure every day.

      References

        • Cribier A.
        • Eltchaninoff H.
        • Bash A.
        • Borenstein N.
        • Tron C.
        • Bauer F.
        • et al.
        Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description.
        Circulation. 2002; 106: 3006-3008
        • Reinöhl J.
        • Kaier K.
        • Reinecke H.
        • Schmoor C.
        • Frankenstein L.
        • Vach W.
        • et al.
        Effect of availability of transcatheter aortic-valve replacement on clinical practice.
        N Engl J Med. 2015; 373: 2438-2447
        • Holmes Jr., D.R.
        • Nishimura R.A.
        • Grover F.L.
        • Brindis R.G.
        • Carroll J.D.
        • Edwards F.H.
        • et al.
        Annual outcomes with transcatheter valve therapy: from the STS/ACC TVT registry.
        J Am Coll Cardiol. 2015; 66: 2813-2823
        • Kodali S.K.
        • Williams M.R.
        • Smith C.R.
        • Svensson L.G.
        • Webb J.G.
        • Makkar R.R.
        • et al.
        Two-year outcomes after transcatheter or surgical aortic-valve replacement.
        N Engl J Med. 2012; 366: 1686-1695
        • Thourani V.H.
        • Kodali S.
        • Makkar R.R.
        • Herrmann H.C.
        • Williams M.
        • Babaliaros V.
        • et al.
        Transcatheter aortic valve replacement versus surgical valve replacement in intermediate-risk patients: a propensity score analysis.
        Lancet. 2016; 387: 2218-2225
        • Leon M.B.
        • Smith C.R.
        • Mack M.J.
        • Makkar R.R.
        • Svensson L.G.
        • Kodali S.K.
        • et al.
        Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.
        N Engl J Med. 2016; 374: 1609-1620
        • Ruparelia N.
        • Latib A.
        • Buzzatti N.
        • Giannini F.
        • Figini F.
        • Mangieri A.
        • et al.
        Long-term outcomes after transcatheter aortic valve implantation from a single high-volume center (the Milan experience).
        Am J Cardiol. 2016; 117: 813-819
        • Salinas P.
        • Moreno R.
        • Calvo L.
        • Sánchez-Recalde Á.
        • Jiménez-Valero S.
        • Galeote G.
        • et al.
        Long-term follow-up after transcatheter aortic valve implantation for severe aortic stenosis.
        Rev Esp Cardiol (Engl Ed). 2016; 69: 37-44
        • Duncan A.
        • Ludman P.
        • Banya W.
        • Cunningham D.
        • Marlee D.
        • Davies S.
        • et al.
        Long-term outcomes after transcatheter aortic valve replacement in high-risk patients with severe aortic stenosis: the U.K. Transcatheter Aortic Valve Implantation Registry.
        JACC Cardiovasc Interv. 2015; 8: 645-653
        • Barbanti M.
        • Schiltgen M.
        • Verdoliva S.
        • Bosmans J.
        • Bleiziffer S.
        • Gerckens U.
        • et al.
        Three-year outcomes of transcatheter aortic valve implantation in patients with varying levels of surgical risk (from the CoreValve ADVANCE Study).
        Am J Cardiol. 2016; 117: 820-827
        • Escárcega R.O.
        • Lipinski M.J.
        • Baker N.C.
        • Magalhaes M.A.
        • Minha S.
        • Torguson R.
        • et al.
        Analysis of long-term survival following transcatheter aortic valve implantation from a single high-volume center.
        Am J Cardiol. 2015; 116: 256-263
        • Toggweiler S.
        • Humphries K.H.
        • Lee M.
        • Binder R.K.
        • Moss R.R.
        • Freeman M.
        • et al.
        5-year outcome after transcatheter aortic valve implantation.
        J Am Coll Cardiol. 2013; 61: 413-419
        • Gulino S.
        • Barbanti M.
        • Deste W.
        • Immè S.
        • Aruta P.
        • Bottari V.
        • et al.
        Four-year durability of clinical and haemodynamic outcomes of transcatheter aortic valve implantation with the self-expanding CoreValve.
        EuroIntervention. 2015; 11 (pii: 20140923-06)
        • Deeb G.M.
        • Reardon M.J.
        • Chetcuti S.
        • Patel H.J.
        • Grossman P.M.
        • Yakubov S.J.
        • et al.
        3-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement.
        J Am Coll Cardiol. 2016; 67: 2565-2574
        • Mack M.J.
        • Leon M.B.
        • Smith C.R.
        • Miller D.C.
        • Moses J.W.
        • Tuzcu E.M.
        • et al.
        5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial.
        Lancet. 2015; 385: 2477-2484
        • Gargiulo G.
        • Sannino A.
        • Capodanno D.
        • Barbanti M.
        • Buccheri S.
        • Perrino C.
        • et al.
        Transcatheter aortic valve implantation versus surgical aortic valve replacement: a systematic review and meta-analysis.
        Ann Intern Med. 2016 Jun 7;
        • Deeks J.J.
        • Higgins J.P.
        • Altman D.G.
        Analysing data and undertaking meta-analyses.
        in: Higgins J.P. Green S. Cochrane handbook for systematic reviews of interventions version 5.1.0. The Cochrane Collaboration. 2011 ([updated March 2011, Chapter 9, Available from: www.cochrane-handbook.org])
        • Siontis G.C.
        • Praz F.
        • Pilgrim T.
        • Mavridis D.
        • Verma S.
        • Salanti G.
        • et al.
        Transcatheter aortic valve implantation vs. surgical aortic valve replacement for treatment of severe aortic stenosis: a meta-analysis of randomized trials.
        Eur Heart J. 2016 Jul 7;
        • Siemieniuk R.A.
        • Agoritsas T.
        • Manja V.
        • Devji T.
        • Chang Y.
        • Bala M.M.
        • et al.
        Transcatheter versus surgical aortic valve replacement in patients with severe aortic stenosis at low and intermediate risk: systematic review and meta-analysis.
        BMJ. 2016; 28: i5130
        • Takagi H.
        • Umemoto T.
        • ALICE (All-Literature Investigation of Cardiovascular Evidence) Group
        Worse survival after transcatheter aortic valve implantation than surgical aortic valve replacement: a meta-analysis of observational studies with a propensity-score analysis.
        Int J Cardiol. 2016; 220: 320-327
        • Nielsen H.H.
        • Klaaborg K.E.
        • Nissen H.
        • Terp K.
        • Mortensen P.E.
        • Kjeldsen B.J.
        • et al.
        A prospective, randomised trial of transapical transcatheter aortic valve implantation vs. surgical aortic valve replacement in operable elderly patients with aortic stenosis: the STACCATO trial.
        EuroIntervention. 2012; 8: 383-389
        • Reardon M.J.
        • Adams D.H.
        • Kleiman N.S.
        • Yakubov S.J.
        • Coselli J.S.
        • Deeb G.M.
        • et al.
        2-year outcomes in patients undergoing surgical or self-expanding transcatheter aortic valve replacement.
        J Am Coll Cardiol. 2015; 66: 113-121
        • Thyregod H.G.
        • Steinbrüchel D.A.
        • Ihlemann N.
        • Nissen H.
        • Kjeldsen B.J.
        • Petursson P.
        • et al.
        Transcatheter versus surgical aortic valve replacement in patients with severe aortic valve stenosis: 1-year results from the all-comers NOTION randomized clinical trial.
        J Am Coll Cardiol. 2015; 65: 2184-2194
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        • PRISMA Group
        Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        Ann Intern Med. 2009; 151: 264-269
        • Stroup D.F.
        • Berlin J.A.
        • Morton S.C.
        • Olkin I.
        • Williamson G.D.
        • Rennie D.
        • et al.
        Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis of Observational Studies in Epidemiology (MOOSE) group.
        JAMA. 2000; 283: 2008-2012
        • Jüni P.
        • Altman D.G.
        • Egger M.
        Systematic reviews in health care: Assessing the quality of controlled clinical trials.
        BMJ. 2001; 323: 42-46
        • Kim S.Y.
        • Park J.E.
        • Lee Y.J.
        • Seo H.J.
        • Sheen S.S.
        • Hahn S.
        • et al.
        Testing a tool for assessing the risk of bias for nonrandomized studies showed moderate reliability and promising validity.
        J Clin Epidemiol. 2013; 66: 408-414
        • Parmar M.K.
        • Torri V.
        • Stewart L.
        Extracting summary statistics to perform meta-analyses of the published literature for survival endpoints.
        Stat Med. 1998; 17: 2815-2834
        • Tierney J.F.
        • Stewart L.A.
        • Ghersi D.
        • Burdett S.
        • Sydes M.R.
        Practical methods for incorporating summary time-to-event data into meta-analysis.
        Trials. 2007 Jun 7; 8: 16
        • Søndergaard L.
        • Steinbrüchel D.A.
        • Ihlemann N.
        • Nissen H.
        • Kjeldsen B.J.
        • Petursson P.
        • et al.
        Two-year outcomes in patients with severe aortic valve stenosis randomized to transcatheter versus surgical aortic valve replacement: the all-comers Nordic aortic valve intervention randomized clinical trial.
        Circ Cardiovasc Interv. 2016 Jun; 9 ([pii: e003665])
        • Fraccaro C.
        • Tarantini G.
        • Rosato S.
        • Tellaroli P.
        • D'Errigo P.
        • Tamburino C.
        • et al.
        Early and midterm outcome of propensity-matched intermediate-risk patients aged ≥80 years with aortic stenosis undergoing surgical or transcatheter aortic valve replacement (from the Italian Multicenter OBSERVANT Study).
        Am J Cardiol. 2016; 117: 1494-1501
        • Fusari M.
        • Bona V.
        • Muratori M.
        • Salvi L.
        • Salis S.
        • Tamborini G.
        • et al.
        Transcatheter vs. surgical aortic valve replacement: a retrospective analysis assessing clinical effectiveness and safety.
        J Cardiovasc Med (Hagerstown). 2012; 13: 229-241
        • Holzhey D.M.
        • Shi W.
        • Rastan A.
        • Borger M.A.
        • Hänsig M.
        • Mohr F.W.
        Transapical versus conventional aortic valve replacement–a propensity-matched comparison.
        Heart Surg Forum. 2012; 15: E4-E8
        • Johansson M.
        • Nozohoor S.
        • Bjursten H.
        • Ragnarsson S.
        • Götberg M.
        • Kimblad P.O.
        • et al.
        Late survival and heart failure after transcatheter aortic valve implantation.
        Asian Cardiovasc Thorac Ann. 2016; 24: 318-235
        • Muneretto C.
        • Alfieri O.
        • Cesana B.M.
        • Bisleri G.
        • De Bonis M.
        • Di Bartolomeo R.
        • et al.
        A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in “real-world” patients with aortic stenosis and intermediate- to high-risk profile.
        J Thorac Cardiovasc Surg. 2015; 150: 1570-1577
        • Papadopoulos N.
        • Schiller N.
        • Fichtlscherer S.
        • Lehmann R.
        • Weber C.F.
        • Moritz A.
        • et al.
        Propensity matched analysis of longterm outcomes following transcatheter based aortic valve implantation versus classic aortic valve replacement in patients with previous cardiac surgery.
        J Cardiothorac Surg. 2014; 9: 99
        • Schymik G.
        • Heimeshoff M.
        • Bramlage P.
        • Herbinger T.
        • Würth A.
        • Pilz L.
        • et al.
        A comparison of transcatheter aortic valve implantation and surgical aortic valve replacement in 1,141 patients with severe symptomatic aortic stenosis and less than high risk.
        Catheter Cardiovasc Interv. 2015; 86: 738-744
        • Wendt D.
        • Al-Rashid F.
        • Kahlert P.
        • El-Chilali K.
        • Demircioglu E.
        • Neuhäuser M.
        • et al.
        Conventional aortic valve replacement or transcatheter aortic valve implantation in patients with previous cardiac surgery.
        J Cardiol. 2015; 66: 292-297
        • Wilbring M.
        • Tugtekin S.M.
        • Alexiou K.
        • Simonis G.
        • Matschke K.
        • Kappert U.
        Transapical transcatheter aortic valve implantation vs conventional aortic valve replacement in high-risk patients with previous cardiac surgery: a propensity-score analysis.
        Eur J Cardiothorac Surg. 2013; 44: 42-47
        • Zweng I.
        • Shi W.Y.
        • Palmer S.
        • MacIsaac A.
        • Whitbourn R.
        • Davis P.
        • et al.
        Transcatheter versus surgical aortic valve replacement in high-risk patients: a propensity-score matched analysis.
        Heart Lung Circ. 2016; 25: 661-667
        • Arai T.
        • Lefèvre T.
        • Hovasse T.
        • Hayashida K.
        • Watanabe Y.
        • O'Connor S.A.
        • et al.
        Evaluation of the learning curve for transcatheter aortic valve implantation via the transfemoral approach.
        Int J Cardiol. 2016; 203: 491-497
        • Minha S.
        • Waksman R.
        • Satler L.P.
        • Torguson R.
        • Alli O.
        • Rihal C.S.
        • et al.
        Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: success and safety.
        Catheter Cardiovasc Interv. 2016; 87: 165-175
        • Patel H.J.
        • Herbert M.A.
        • Paone G.
        • Heiser J.C.
        • Shannon F.L.
        • Theurer P.F.
        • et al.
        The midterm impact of transcatheter aortic valve replacement on surgical aortic valve replacement in Michigan.
        Ann Thorac Surg. 2016; 102: 728-734
        • Dvir D.
        • Webb J.G.
        • Bleiziffer S.
        • Pasic M.
        • Waksman R.
        • Kodali S.
        • et al.
        Transcatheter aortic valve implantation in failed bioprosthetic surgical valves.
        JAMA. 2014; 312: 162-170
        • Adams D.H.
        • Popma J.J.
        • Reardon M.J.
        • Yakubov S.J.
        • Coselli J.S.
        • Deeb G.M.
        • et al.
        Transcatheter aortic-valve replacement with a self-expanding prosthesis.
        N Engl J Med. 2014; 370: 1790-1798
        • Rosato S.
        • Santini F.
        • Barbanti M.
        • Biancari F.
        • D'Errigo P.
        • Onorati F.
        • et al.
        Transcatheter aortic valve implantation compared with surgical aortic valve replacement in low-risk patients.
        Circ Cardiovasc Interv. 2016; 9e003326
        • Bourguignon T.
        • Bouquiaux-Stablo A.L.
        • Candolfi P.
        • Mirza A.
        • Loardi C.
        • May M.A.
        • et al.
        Very long-term outcomes of the Carpentier-Edwards Perimount valve in aortic position.
        Ann Thorac Surg. 2015; 99: 831-837
        • Unbehaun A.
        • Pasic M.
        • Drews T.
        • Penkalla A.
        • Dreysse S.
        • Klein C.
        • et al.
        Transapical aortic valve implantation: predictors of survival up to 5 years in 730 patients. An update†.
        Eur J Cardiothorac Surg. 2015; 47: 281-290
        • Vasques F.
        • Lucenteforte E.
        • Paone R.
        • Mugelli A.
        • Biancari F.
        Outcome of patients aged ≥80 years undergoing combined aortic valve replacement and coronary artery bypass grafting: a systematic review and meta-analysis of 40 studies.
        Am Heart J. 2012; 164: 410-418
        • Abramowitz Y.
        • Chakravarty T.
        • Jilaihawi H.
        • Kashif M.
        • Zadikany R.
        • Lee C.
        • et al.
        Comparison of outcomes of transcatheter aortic valve implantation in patients ≥90 years versus <90 years.
        Am J Cardiol. 2015; 116: 1110-1115
        • Yamamoto M.
        • Meguro K.
        • Mouillet G.
        • Bergoend E.
        • Monin J.L.
        • Lim P.
        • et al.
        Comparison of effectiveness and safety of transcatheter aortic valve implantation in patients aged ≥90 years versus <90 years.
        Am J Cardiol. 2012; 110: 1156-1163
        • Arsalan M.
        • Szerlip M.
        • Vemulapalli S.
        • Holper E.M.
        • Arnold S.V.
        • Li Z.
        • et al.
        Should transcatheter aortic valve replacement be performed in nonagenarians?: insights from the STS/ACC TVT registry.
        J Am Coll Cardiol. 2016; 67: 1387-1395
        • Beach J.M.
        • Mihaljevic T.
        • Svensson L.G.
        • Rajeswaran J.
        • Marwick T.
        • Griffin B.
        • et al.
        Coronary artery disease and outcomes of aortic valve replacement for severe aortic stenosis.
        J Am Coll Cardiol. 2013; 61: 837-848
        • Aranki S.F.
        • Rizzo R.J.
        • Couper G.S.
        • Adams D.H.
        • Collins Jr., J.J.
        • Gildea J.S.
        • et al.
        Aortic valve replacement in the elderly. Effect of gender and coronary artery disease on operative mortality.
        Circulation. 1993; 88: II17-II23
        • Ludman P.F.
        • Moat N.
        • de Belder M.A.
        • Blackman D.J.
        • Duncan A.
        • Banya W.
        • et al.
        Transcatheter aortic valve implantation in the United Kingdom: temporal trends, predictors of outcome, and 6-year follow-up: a report from the UK Transcatheter Aortic Valve Implantation (TAVI) Registry, 2007 to 2012.
        Circulation. 2015; 131: 1181-1190
        • Gilard M.
        • Eltchaninoff H.
        • Iung B.
        • Donzeau-Gouge P.
        • Chevreul K.
        • Fajadet J.
        • et al.
        Registry of transcatheter aortic-valve implantation in high-risk patients.
        N Engl J Med. 2012; 366: 1705-1715
        • Linke A.
        • Wenaweser P.
        • Gerckens U.
        • Tamburino C.
        • Bosmans J.
        • Bleiziffer S.
        • et al.
        Treatment of aortic stenosis with a self-expanding transcatheter valve: the International Multi-centre ADVANCE Study.
        Eur Heart J. 2014; 35: 2672-2684
        • Ando T.
        • Briasoulis A.
        • Holmes A.A.
        • Afonso L.
        • Schreiber T.
        • Kondur A.
        Transcatheter aortic valve replacement versus surgical aortic valve replacement in patients with previous coronary artery bypass surgery: a systematic review and meta-analysis.
        Int J Cardiol. 2016; 215: 14-19