Low ankle-brachial index is a predictive factor for initial severity of acute ischemic stroke

Abstract

A low ankle-brachial index (ABI) is predictive of peripheral arterial disease (PAD). For unknown reasons, patients with PAD demonstrate higher vascular mortality during follow-up than do those without. Initial stroke severity is a strong predictor of long-term outcome, and so we investigated whether a low ABI was associated with severe stroke presentation. We enrolled 1,156 consecutive first-ever ischemic stroke patients who underwent ABI measurements during hospitalization. Patients were categorized into the normal (≥ 0.90) or the abnormal (< 0.90) ABI group. Baseline characteristics and initial National Institutes of Health Stroke Scale (NIHSS) scores were compared between the groups. We also compared the degrees of improvement in NIHSS score during the first week after hospitalization and components of the NIHSS subscales in these groups. ABI was abnormal in 85 (7.4%) patients. Mean initial NIHSS score was higher in the abnormal ABI group (6.61 ± 6.56) than the normal ABI group (4.36 ± 4.89)(p=0.003). Improvement in the NIHSS score was smaller in the abnormal ABI group between days 3 and 7. Low ABI was independently associated with higher NIHSS score in a multivariate analysis. In the abnormal ABI group, leg weakness was more severe than it was in the normal ABI group, and the contribution of leg weakness to the initial NIHSS score was higher. Patients with low ABI values presented with more severe ischemic stroke. Poor clinical outcomes in patients with PAD may be partially explained by their increased likelihood for severe stroke.