Role of Low Ankle-Brachial Index in Cardiovascular and Mortality Risk Compared with Major Risk Conditions

Cardiovascular prevention is of particular interest in persons with asymptomatic peripheral arterial disease. We aimed to quantify its association with mortality and cardiovascular outcomes, compared to other indicators of high risk. We performed a retrospective cohort study using the Database of the Catalan primary care system (SIDIAP^Q), for 2006-2015, including 35-85-year-old patients with an ankle-brachial index (ABI) measurement, classified according to the presence of diabetes, cardiovascular disease, and low ABI (<0.9). We calculated the incidences and hazard ratios (HRs) for all-cause mortality, acute myocardial infarction, and ischemic stroke. During a median follow-up of 5.9 years, we analyzed 58,118 persons. The mean (SD) age was 66.6 (10.7) years and 53.4% were men. Compared to the reference group with no diabetes, no previous cardiovascular disease, and normal ankle-brachial index, the HR for all-cause mortality was 1.42 (1.25-1.63) in the group with low ABI, 1.35 (1.26-1.45) in those with diabetes, 1.50 (1.34-1.69) in those with previous cardiovascular disease, and 1.84 (1.68-2.01) in those with low ABI and diabetes. In conclusion, participants with low ABI showed increased mortality, acute myocardial infarction, and ischemic stroke incidence in all the subgroups. Patients with low ankle-brachial index plus diabetes presented increased mortality, acute myocardial infarction, and ischemic stroke risk, all at rates similar to those with previous cardiovascular disease.