To evaluate the association between low ankle-brachial index (ABI) and clinical outcome in patients who are undergoing simultaneous coronary and cerebral artery angiography due to atherosclerosis detected on brain imaging studies.

Between January 2009 and April 2019, 11047patients underwent cerebral angiography for atherosclerotic change seen in brain magnetic resonance angiography or computed tomography angiography at a single center. Of these, 543patients who underwent simultaneous coronary and cerebral angiography with ABI checked were enrolled. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE), defined as a composite of all-cause death, myocardial infarction, stroke over 3years.

Of the 542 patients, 480 (88.6%) had normal ABI (>0.9) and 62 (11.4%) had low ABI (<0.9). Low ABI (odds ratio [OR], 3.40;95% confidence index [CI], 1.47-7.88; p=0.004) was the most important predictor for significant coronary artery disease (CAD). The incidence of MACCE (hazard ratio [HR], 2.85; 95% CI, 1.61-5.03; p<0.001) and all-cause death (HR,3.41;95% CI, 1.83-6.38; p<0.001) were significantly higher in the low ABI group. MACCE was independently associated with acute ischemic stroke (HR, 2.87; 95% CI,1.61-5.10; p<0.001), diabetes mellitus (HR, 1.78; 95% CI, 1.03-3.07;p=0.038), previous hyperlipidemia (HR,1.85; 95% CI, 1.08-3.18; p=0.025),significant CAD (HR, 2.50; 95% CI, 1.16-5.36; p=0.019), and low ABI (HR, 1.86;95% CI, 1.03-3.38; p=0.041).

The presence of low ABI was associated with significant CAD and worse clinical outcomes during follow-up. ABI measurement should be considered in patients with cerebral artery atherosclerosis on brain imaging. Especially, patients with low ABI (<0.9) need accurate CAD assessment with coronary angiography.