Ankle-Brachial Index and Cardiovascular Outcome.

Abstract

We read the article ‘‘The Ankle-Brachial Index is Associated With Cardiovascular Complications After Noncardiac Surgery’’ by Carmo et al with interest. They evaluated the role of ankle–brachial index (ABI) as a predictor of cardiovascular (CV) complications in patients with and without an abnormal ABI submitted to noncardiac surgery. An ABI 0.9 indicated a >7-fold chance for the occurrence of the primary outcome. Patients with symptomatic and asymptomatic atherosclerosis or several risk factors have relatively high rates of CV events. Additionally, several studies demonstrated an independent positive association between asymptomatic peripheral artery disease (PAD) and CV events, including stroke, transient ischemic attack, myocardial infarction, and death among patients with previous stroke. Serena et al analyzed the adjusted predictive capacity of the ABI together with additional markers of atherothrombotic disease as predictors of CV events. In the ARTICO stroke population, symptomatic PAD and particularly the association of both symptomatic PAD and ABI 0.9 with internal carotid artery stenosis >50% were independently associated with a 3.72 and 4.39 times increased risk of new vascular events. The ABI is a relatively simple, easy, noninvasive, and inexpensive test, and it is >90% sensitive and specific compared with angiography, the gold standard. Although the ABI provides several benefits, it also has limitations. For example, 10% of the general population have a congenital absence of the dorsalis pedis or posterior tibial artery meaning that ABI would not be accurate. In conclusion, Carmo et al describe the ABI as a predictor of CV complications in patients with noncardiac surgery. This relationship needs to be evaluated in large-scale prospective randomized clinical trials.