Ankle-Brachial Index Improves the Classification of Cardiovascular Risk: PERART/ARTPER Study

Introduction and objectives: The sensitivity of cardiovascular risk functions is low because many cardiovascular events occur in low- or intermediate-risk patients. The aim of the present study was to evaluate how the ankle-brachial index (ABI) reclassifies these patients. Methods: We conducted a descriptive, transversal, multicenter study (28 centers) of 3171 randomly selected patients aged > 49 years. We studied demographic variables, clinical history and cardiovascular risk factors, ABI (defined as pathologic if < 0.9) and 10-year cardiovascular risk with the Framingham-Wilson, REGICOR and SCORE equations, dividing risk into three categories: low (Framingham < 10%, REGICOR < 5% and SCORE < 2.5%, intermediate (10-19.9%, 5-9.9% and 2.5-4.9%, respectively) and high (>= 20%, >= 10% and >= 5%, respectively). Low- or intermediate-risk patients were reclassified as high-risk if they presented ABI <0.9. Results: We compared patients with ABI < 0.9 and patients with ABI >= 0.9 and found the former were significantly older, more frequently men, had a worse history and more cardiovascular risk factors, and included more high-risk patients than when the classification used Framingham-Wilson (42.7% vs. 18.5%), REGICOR (25.8% vs. 9.3%) and SCORE (42.2% vs. 15.9%) equations. In men, using ABI led to a 5.8% increase in the high-risk category versus Framingham-Wilson, a 19.1% increase versus REGICOR and a 4.4% increase versus SCORE. In women, the increases were 78.6% versus Framingham-Wilson, 151.6% versus REGICOR and 50.0% versus SCORE. Conclusions: The ABI reclassifies a substantial proportion of patients towards the high-risk category. This is particularly marked in women and by comparison with REGICOR scores. Full English text available from: www.revespcardiol.org (C) 2010 Sociedad Espanola de Cardiologia. Published by Elsevier Espana, S.L. All rights reserved.