Low ankle–brachial index is a predictive factor for initial severity of acute ischaemic 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 may be different between patients with and without PAD. Thus, we investigated whether a low ABI was associated with severe stroke presentation. We enrolled 1147 first-ever ischaemic 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 further analysed components of the NIHSS subscales in these groups. Ankle-brachial index was abnormal in 85 (7.4%) patients. Mean initial NIHSS score was higher in the abnormal ABI group (6.61 ± 6.56) than in the normal ABI group (4.36 ± 4.90) (P = 0.003). A 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 ischaemic stroke. Contribution of pre-existing PAD to leg weakness may play a role in the initial severity of stroke in patients with PAD. Our findings suggest that poor clinical outcomes in patients with PAD may be partially explained by their increased likelihood for severe stroke.