Impact of Abnormal Ankle-Brachial Index on Adverse Outcomes in Patients With Acute Coronary Syndrome: A Meta-Analysis

The association between abnormal ankle-brachial index (ABI) and adverse prognosis in patients with acute coronary syndrome (ACS) remains insufficiently characterized. The present meta-analysis aims to assess this association. A systematic search of Web of Science, PubMed, and Embase databases was conducted to identify relevant studies. An abnormal ABI was usually defined as ≤0.9 or >1.4. Pooled adjusted hazard ratios (HR) with 95% confidence intervals (CI) were used to assess the prognostic value of the abnormal ABI. Nine studies comprising 5647 patients were included. Abnormal ABI was significantly associated with an increased risk of major adverse cardiovascular events (MACEs; HR 2.39; 95% CI 1.76-3.23), cardiovascular mortality (HR 2.19; 95% CI 1.27-3.78), and all-cause mortality (HR 2.00; 95% CI 1.57-2.55). An abnormal ABI appears to be a significant predictor for increased mortality and MACEs in ACS patients. While the evidence strongly associates a low ABI with this risk, the current literature lacks explicit comparative data on the prognostic value of a high ABI. A low ABI may help refine risk stratification in ACS patients but requires validation in prospective studies.