Ankle-brachial index and cardiovascular outcomes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial.

BACKGROUND: Peripheral arterial disease increases cardiovascular risk in many patient populations. The risks associated with an abnormal ankle-brachial index (ABI) in patients with type 2 diabetes and stable coronary artery disease have not been well described with respect to thresholds and types of cardiovascular events. METHODS: We examined 2,368 patients in the BARI 2D trial who underwent ABI assessment at baseline. Death and major cardiovascular events (death, myocardial infarction and stroke) during follow-up (average 4.3 years) were assessed across the ABI spectrum and by categorized ABI: low (≤0.90), normal (0.91-1.3), high (>1.3), or noncompressible. RESULTS: A total of 12,568 person-years were available for mortality analysis. During follow-up, 316 patients died, and 549 had major cardiovascular events. After adjustment for potential confounders, with normal ABI as the referent group, a low ABI conferred an increased risk of death (relative risk [RR] 1.6, CI 1.2-2.2, P = .0005) and major cardiovascular events (RR 1.4, CI 1.1-1.7, P = .004). Patients with a high ABI had similar outcomes as patients with a normal ABI, but risk again increased in patients with a noncompressible ABI with a risk of death (RR 1.9, CI 1.3-2.8, P = .001) and major cardiovascular event (RR 1.5, CI 1.1-2.1, P = .01). CONCLUSIONS: In patients with coronary artery disease and type 2 diabetes, ABI screening and identification of ABI abnormalities including a low ABI (<1.0) or noncompressible artery provide incremental prognostic information.

The prevalence and predictors of an abnormal ankle-brachial index in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial.

OBJECTIVE: To examine ankle-brachial index (ABI) abnormalities in patients with type 2 diabetes and coronary artery disease (CAD). RESEARCH DESIGN AND METHODS: An ABI was obtained in 2,240 patients in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Trial. ABIs were classified as: normal, 0.91-1.3; low, ≤ 0.9; high, >1.3; or noncompressible artery (NC). Baseline characteristics were examined according to ABI and by multivariate analysis. RESULTS ABI was normal in 66%, low in 19%, and high in 8% of patients, and 6% of patients had NC. Of the low ABI patients, 68% were asymptomatic. Using normal ABI as referent, low ABI was independently associated with smoking, female sex, black race, hypertension, age, C-reactive protein, diabetes duration, and lower BMI. High ABI was associated with male sex, nonblack race, and higher BMI; and NC artery was associated with diabetes duration, higher BMI, and hypertension. CONCLUSIONS: ABI abnormalities are common and often asymptomatic in patients with type 2 diabetes and CAD.