Advertisement

Hyponatremia in hospitalised patients with heart failure in internal medicine: Analysis of the Spanish national minimum basic data set (MBDS) (2005–2011)

      Highlights

      • Hyponatremia with acute heart failure has increased in internal medicine lately.
      • Hyponatremia was most frequently observed in patients with comorbidities.
      • Hyponatremia was associated to readmission and longer hospital stay.
      • Hyponatremia was an independent risk factor for mortality in acute heart failure.

      Abstract

      Objective

      Hyponatremia is the most common electrolyte disorder seen in clinical practice. Numerous studies have reported increased inhospital mortality associated to this condition, which is also an independent predictor of comorbidity in patients admitted with heart failure (HF). The objective of this study is to assess the incidence, average length of stay, associated comorbidities, readmissions and mortality caused by hyponatremia in admissions for acute heart failure from the Spanish national minimum basic data set (MBDS).

      Materials and methods

      Data from the Spanish national minimum basic data set (MBDS) of discharged patients who were initially diagnosed with heart failure (HF) from all internal medicine (IM) departments of Spanish National Health System (SNS) hospitals between 2005 and 2011 were analysed (ICD-9: 428; DRGs 127 and 544). A descriptive data analysis was conducted comparing the diagnosis codes and administrative variables of heart failure patients with and without hyponatremia. The chi-square test was used for qualitative variables and the Student's t test for quantitative variables. A bivariate analysis was used to detect statistical differences in the mortality of both groups, as well as mean age, Charlson index, average length of stay and readmissions. A multivariate logistic regression analysis was performed, taking intrahospital mortality and hospital readmissions as dependent variables, and age, gender, comorbidity according to the Charlson index and hyponatremia as independent variables.

      Results

      A total of 504,860 patients with acute heart failure were identified, of whom 11,095 (2.2%) presented with HNa. A gradual year-on-year increase of hyponatremia codification (both primary and secondary diagnosis) was observed at discharge throughout the study period (from 1.6% in 2005 to 2.8% in 2011; p < 0.0001). Overall mortality due to any cause in patients with hyponatremia was 17% (1937 patients) versus 11% in non-hyponatremic patients (53,820 patients). The probability of readmission for patients with hyponatremia was 22% versus 17% in the non-hyponatremic group. Hyponatremia was associated to a higher rate of mortality during hospitalisation for acute heart failure with an odds ratio (OR) of 1.58, 95% CI, 1.50–1.66 (p < 0.05). Hyponatremia maintained statistical significance in the regression model after adjusting for gender, OR 0.919 (95% CI 0.902–0.936); age, OR 1.061 (95% CI 1.060–1.062); and Charlson index, OR 1.388 (95% CI 1.361–1.461).

      Conclusions

      Hyponatremia is associated to an increased rate of mortality and readmission in patients admitted for acute heart failure in SNS hospitals. Our study identified a statistically significant association between hyponatremia and increased intrahospital mortality independent of age, gender and the Charlson comorbidity index. During the defined follow-up period the discharge reports showed an increased codification of hyponatremia.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to European Journal of Internal Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Clyde W.Y.
        • Jessup M.
        • Bozkurt B.
        • Butler J.
        • Casey D.J.
        • Mark H.
        • et al.
        ACCF/AHA Guideline for the Management of Heart Failure: Executive Summary: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guideline.
        Circulation. 2013; 128: 240-327
        • Filippatos Theodosios D.
        • Elisaf Moses S.
        Hyponatremia in patients with heart failure.
        World J Cardiol. Sep 26, 2013; 5: 317-328
        • Verbalis J.G.
        • Goldsmith S.R.
        • Greenberg A.
        • Schrier R.W.
        • Sterns R.H.
        Hyponatremia treatment guidelines 2007: expert panel recommendations.
        Am J Med. 2007; 120: S1
        • Goldsmith S.R.
        • Gheorghiade M.
        Vasopressin antagonism in heart failure.
        J Am Coll Cardiol. 2005; 46: 1785-1791
        • Rose B.D.
        • Sterns R.H.
        • Colucci W.S.
        • Forman J.P.
        Hyponatremia in patients with heart failure. UpToDate. Version 19.1.
        January 2011
        • Sato N.
        • Gheorghiade M.
        • Kajimoto K.
        • Munakata R.
        • Minami Y.
        • Mizuno M.
        • et al.
        ATTEND Investigators Hyponatremia and in-hospital mortality in patients admitted for heart failure (from the ATTEND registry).
        Am J Cardiol. Apr 1 2013; 111: 1019-1025
        • Gheorghiade M.
        • Abraham W.T.
        • Albert N.M.
        • Gattis Stough W.
        • Greenberg B.H.
        • O'Connor C.M.
        • et al.
        Relationship between admission serum sodium concentration and clinical outcomes in patients hospitalized for heart failure: an analysis from the OPTIMIZE-HF registry.
        Eur Heart J. 2007; 28: 980-988
        • Bavishi C.
        • Ather S.
        • Bambhroliya A.
        • Jneid H.
        • Virani S.S.
        • Bozkurt B.
        • et al.
        Prognostic significance of hyponatremia among ambulatory patients with heart failure and preserved and reduced ejection fractions.
        Am J Cardiol. Jun 1 2014; 113: 1834-1838
        • Konstam M.A.
        • Gheorghiade M.
        • Burnett Jr., J.C.
        • Grinfeld L.
        • Maggioni A.P.
        • Swedberg K.
        • et al.
        Effects of oral tolvaptan in patients hospitalized for worsening heart failure: the EVEREST Outcome Trial.
        JAMA. 2007; 297: 1319
      1. Statistical analysis of the Spanish National Minimum Basic Hospital Data Set. Methodological note. State standard..
        ([accessed 01/09/13])
        • Instituto Nacional de la Salud
        • Ministerio de Sanidad y Consumo
        CMBD Insalud. Análisis de los GRDs. Year 2000.
        (Available at:) ([accessed 22])
        • Madan VD I.
        • Novak E.
        • Rich M.W.
        Impact of change in serum sodium concentration on mortality in patients hospitalized with heart failure and hyponatremia.
        Circ Heart Fail. Sep 2011; 4: 637-643
        • Corona G.
        • Giuliani C.
        • Parenti G.
        • Norello D.
        • Verbalis J.G.
        • Forti G.
        • et al.
        Moderate hyponatremia is associated with increased risk of mortality: evidence from a meta-analysis.
        PLoS One. 2013; 8: e80451
        • Rusinaru D.
        • Tribouilloy C.
        • Berry C.
        • Richards A.M.
        • Whalley G.A.
        • Earle N.
        • et al.
        MAGGIC Investigators Relationship of serum sodium concentration to mortality in a wide spectrum of heart failure patients with preserved and with reduced ejection fraction: an individual patient data meta-analysis(†): Meta-Analysis Global Group in Chronic heart failure (MAGGIC).
        Eur J Heart Fail. Oct 2012; 14: 1139-1146
        • Aaronson K.D.
        • Schwartz J.S.
        • Chen T.M.
        • Wong K.L.
        • Goin J.E.
        • Mancini D.M.
        Development and prospective validation of a clinical index to predict survival in ambulatory patients referred for cardiac transplant evaluation.
        Circulation. 1997; 95: 2660-2667
        • Lee D.S.
        • Austin P.C.
        • Rouleau J.L.
        • Liu P.P.
        • Naimark D.
        • Tu J.V.
        Predicting mortality among patients hospitalized for heart failure derivation and validation of a clinical model.
        JAMA. 2003; 290: 2581-2587
        • Levy W.C.
        • Mozaffarian D.
        • Linker D.T.
        • Sutradhar S.C.
        • Anker S.D.
        • Cropp A.B.
        • et al.
        The Seattle heart failure model: prediction of survival in heart failure.
        Circulation. 2006; 113: 1424-1433
        • Arévalo Lorido J.C.
        • Carretero Gómez J.
        • Formiga F.
        • Montero Pérez-Barquero M.
        • Trullás Vila J.C.
        • Aramburu Bodas O.
        • et al.
        RICA Investigators. Hyponatremia as predictor of worse outcome in real world patients admitted with acute heart failure.
        Cardiol J. 2013; 20: 506-512
        • Casademont J.
        • Francia E.
        • Torres O.
        Age of patients admitted to Internal Medicine departments in Spain: a twenty years perspective.
        Med Clin (Barc.). Mar 24 2012; 138: 289-292
        • Ruiz-Laiglesia F.J.
        • Sánchez-Marteles M.
        • Pérez-Calvo J.I.
        • Formiga F.
        • Bartolomé-Satué J.A.
        • Armengou-Arxé A.
        • et al.
        Comorbidity in heart failure. Results of the Spanish RICA Registry.
        QJM. Dec 2014; 107: 989-994
        • Marco J.
        • Barba R.
        • Matía P.
        • Plaza S.
        • Méndez M.
        • Canora J.
        • et al.
        Low prevalence of hyponatremia codification in departments of internal medicine and its prognostic implications.
        Curr Med Res Opin. Dec 2013; 29: 1757-1762
        • Registry Adhere
        Insights from the Adhere Registry: data from over 100,000 patient cases.
        2005
        • Konstam M.A.
        • Gheorghiade M.
        • Burnett Jr., J.C.
        • Grinfeld L.
        • Maggioni A.P.
        • Swedberg K.
        • et al.
        Effects of oral tolvaptan in patients hospitalized for worsening heart failure: the EVEREST outcome trial.
        JAMA. 2007; 297: 1319-1331
        • Cumming K.
        • Hoyle G.E.
        • Hutchison J.D.
        • Soiza R.L.
        Prevalence, incidence and etiology of hyponatremia in elderly patients with fragility fractures.
        PLoS One. Feb 5 2014; 9: e88272
        • Herrero-Puente P.
        • Marino-Genicio R.
        • Martín-Sánchez F.J.
        • Vázquez-Alvarez J.
        • Jacob J.
        • Bermudez M.
        • et al.
        Characteristics of acute heart failure in very elderly patients — EVE study (EAHFE very elderly).
        Eur J Intern Med. May 15, 2014; 25: 463-470
        • Gosch M.
        • Joosten-Gstrein B.
        • Heppner H.J.
        • Gerontology Lechleitner M.
        Hyponatremia in geriatric inhospital patients: effects on results of a comprehensive geriatric assessment.
        . 2012; 58: 430-440
        • Spasovski Goce
        • Vanholder Raymond
        • Allolio Bruno
        • Annane Djillali
        • Ball Steve
        • Bichet Daniel
        • et al.
        Clinical practice guideline on diagnosis and treatment of hyponatraemia.
        Eur J Endocrinol. March 1, 2014; 170: G1-G47
        • Amin A.
        • Deitelzweig S.
        • Christian R.
        • Friend K.
        • Lin J.
        • Belk K.
        • et al.
        Evaluation of incremental healthcare resource burden and readmission rates associated with hospitalized hyponatraemic patients in the US.
        J Hosp Med. Oct 2012; 7: 634-639
        • Shchekochikhin Dmitry Y.
        • Schrier Robert W.
        • Lindenfeld JoAnn
        • Lyn Price Lori
        • Jaber Bertrand L.
        • Madias Nicolaos E.
        Outcome differences in community- versus hospital-acquired hyponatremia in patients with a diagnosis of heart failure.
        Circ Heart Fail. 2013; 6: 379-386