Implications of routinely measuring Ankle-Brachial Index (ABI) among patients attending at a Lipid Clinic

Abstract 

Background

Low (≤ 0.90) Ankle Brachial Index (ABI) values identify patients at high risk for cardiovascular (CV) disease and mortality. Implications for CV risk classification from routinely measuring ABI in the context of a Lipid Clinic have not been fully investigated. We aimed to evaluate whether and to what extent routine ABI determination on top of conventional risk prediction models may modify CV risk classification.

Methods

Consecutive asymptomatic non-diabetic individuals free from previous CV events attending for a first visit at a Lipid Clinic underwent routine ABI determination and conventional CV risk classification according either to national CUORE model (including age, gender, smoking, total and high density lipoprotein cholesterol, systolic blood pressure and current use of blood pressure lowering drugs) and SCORE model for low risk countries.

Results

In the overall sample (320 subjects, mean age 64.8 years) 77 subjects (24.1%) were found to have low ABI value. Forty-two of 250 subjects (16.8%) and 47 of 215 individuals (21.3%) at low or moderate risk according to the CUORE and SCORE models, respectively, were found to have low ABI values, and should be reclassified at high risk.

Conclusion

In a series of consecutive asymptomatic individuals in a Lipid Clinic, we observed a high prevalence of low ABI values among subjects deemed at low or moderate risk on conventional prediction models, leading to CV high-risk reclassification of roughly one fifth of patients. These findings reinforce recommendations for routine determination of ABI at least within referral primary prevention settings.

Keywords: Ankle-brachial index, Cardiovascular risk, Cardiovascular prevention, Peripheral artery disease