Low, borderline and normal ankle-brachial index as a predictor of incidents outcomes in the Mediterranean based-population ARTPER cohort after 9 years follow-up.

Abstract

BackgroundGuidelines recommended adopting the same cardiovascular risk modification strategies used for coronary disease in case of low Ankle-brachial index (ABI), but here exist few studies on long-term cardiovascular outcomes in patients with borderline ABI and even fewer on the general population.AimThe aim of the present study was to analyze the relationship between long-term cardiovascular events and low, borderline and normal ABI after a 9-year follow up of a Mediterranean population with low cardiovascular risk.Design and settingA population-based prospective cohort study was performed in the province of Barcelona, Spain.MethodA total of 3,786 subjects >49 years were recruited from 2006–2008. Baseline ABI was 1.08 ± 0.16. Subjects were followed from the time of enrollment to the end of follow-up in 2016 via phone calls every 6 months, systematic reviews of primary-care and hospital medical records and analysis of the SIDIAP (Information System for Primary Care Research) database to confirm the possible appearance of cardiovascular events.Results3146 individuals participated in the study. 2,420 (77%) subjects had normal ABI, 524 (17%) had borderline ABI, and 202 (6.4%) had low ABI.In comparison with normal and borderline subjects, patients with lower ABI had more comorbidities, such as hypertension, hypercholesterolemia and diabetes.Cumulative MACE incidence at 9 years was 20% in patients with low ABI, 6% in borderline ABI and 5% in normal ABI.The annual MACE incidence after 9 years follow-up was significantly higher in people with low ABI (26.9/1000py) (p<0.001) than in borderline (6.6/1000py) and in normal ABI (5.6/1000py).Subjects with borderline ABI are at significantly higher risk for coronary disease (HR: 1.58; 95% CI: 1.02–2, 43; p = 0,040) compared to subjects with normal ABI, after adjustment.ConclusionThe results of the present study support that low ABI was independently associated with higher incidence of MACE, ICE, cardiovascular and no cardiovascular mortality; while borderline ABI had significantly moderate risk for coronary disease than normal ABI.