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

Abstract

Background Peripheral arterial disease (PAD) increases cardiovascular risk in many patient populations. The risks associated with an abnormal ankle-brachial index (ABI) in patients with type 2 diabetes (T2D) and stable coronary artery disease (CAD) have not been well described with respect to thresholds and types of cardiovascular events. Methods We examined 2368 patients in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial that underwent ABIassessment at baseline. Death and major cardiovascular events (death, myocardial infarction (MI) and stroke) during follow-up (average 4.3 years) were assessed across the ABI spectrum and by categorizedABI: low (≤0.90), normal (0.91–1.3), high (>1.3), or non-compressible. Results A total of 12,568 person-years were available for mortality analysis. During follow-up, 316 patients died and 549 suffered 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; C.I. 1.2, 2.2; p=.0005) and major cardiovascular events (RR 1.4; C.I. 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 non-compressible ABI with a risk of death (RR1.9; C.I. 1.3, 2.8; p=.001) and major cardiovascular event (RR 1.5, C.I. 1.1, 2.1; p=.01). Conclusions In patients with CAD and T2D ABI screening and identification of ABI abnormalities including a low ABI (<1.0) or non-compressible artery provide incremental prognostic information.

Prognostic Value of the Ankle-Brachial Index in Patients Undergoing Drug-Eluting Stent Implantation

“…There were also significant differences in the cumulative event rate between the patients with an ABI of 0.9-1.056 vs. an ABI of ≥ 1.057 in this study. These results are in agreement with the findings of prior studies 5,[22][23][24] . Although an ABI of ≥ 0.9 assessed according to dichotomous categorization is usually classified as indicating 'no disease', many studies have shown an increase in risk proportional to a decrease in ABI, even among patients with an ABI of ≥ 0.9.…”

“…Likewise, a meta-analysis demonstrated that the risk of mortality increases consistently with decreases in the ABI for values of ABI 1.1 22) . Moreover, among 2,368 patients with documented CAD, Abbott et al noted a higher risk of cardiovascular events at an ABI of 0.91-1.00 compared with an ABI of 1.01-1.10 24) . Collectively, these findings, including the present data, suggest that the use of the traditional cut-off value of ABI 0.9 to define high-and low-risk groups may not allow for optimal risk stratification.…”

Toe–brachial index as a predictor of cardiovascular disease and all-cause mortality in people with type 2 diabetes and microalbuminuria

“…The Fremantle Diabetes Study followed 1294 individuals with type 2 diabetes and previous CVD and demonstrated that low (≤0.90) compared with normal (0.91-1.40) ABI was associated with cardiovascular mortality [6]. In 2368 people with type 2 diabetes and coronary artery disease included in the Bypass Angioplasty Revascularization Investigation 2 Diabetes Trial, low ABI (<1.0) conferred an increased risk of mortality and major cardiovascular events during follow-up of a median 5.2 years [24].…”

Microvascular and Macrovascular Disease and Risk for Major Peripheral Arterial Disease in Patients With Type 2 Diabetes

“…In the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) clinical trial, the incidence of PAD was comparable to the incidence of major coronary events and stroke (6). PAD is associated with poor outcomes, leading to a high rate of amputation and death (7), and has been associated with an increased risk of cardiovascular morbidity and mortality (8,9). PAD mainly affects the infrapopliteal arteries and may induce more damage in small than in large vessels in patients with type 2 diabetes (7,10).…”