Low Toe–Brachial Index Is Associated With Stroke Outcome Despite Normal Ankle–Brachial Index

Abstract

Introduction: We investigated whether the toe–brachial index (TBI) is associated with stroke prognosis and evaluated this association in patients with normal ankle–brachial index (ABI).

Methods: Acute ischemic stroke patients who underwent TBI measurements were enrolled. Poor functional outcome was defined as modified Rankin Scale score ≥3. Major adverse cardiovascular event (MACE) was defined as stroke recurrence, myocardial infarction, or death. Normal ABI was defined as 0.9 ≤ ABI ≤ 1.4.

Results: A total of 1,697 patients were enrolled and followed up for a median 39.7 (interquartile range, 25.7–54.6) months. During the period, 305 patients suffered MACE (18.0%), including 171 (10.1%) stroke recurrences. TBI was associated with hypertension, diabetes, atrial fibrillation, aortic plaque score, ABI, and brachial–ankle pulse wave velocity (all p < 0.05). In multivariable logistic regression, TBI was inversely associated with poor functional outcome in all patients [odds ratio (OR) 0.294, 95% confidence interval (CI) 0.114–0.759], even in patients with normal ABI (OR 0.293, 95% CI 0.095–0.906). In multivariable Cox regression, TBI < 0.6 was associated with stroke recurrence [hazard ratio (HR) 1.651, 95% CI 1.135–2.400], all-cause mortality (HR 2.105, 95% CI 1.343–3.298), and MACE (HR 1.838, 95% CI 1.396–2.419) in all patients. TBI < 0.6 was also associated with stroke recurrence (HR 1.681, 95% CI 1.080–2.618), all-cause mortality (HR 2.075, 95% CI 1.180–3.651), and MACE (HR 1.619, 95% CI 1.149–2.281) in patients with normal ABI.

Conclusions: Low TBI is independently associated with poor short- and long-term outcomes in acute ischemic stroke patients despite normal ABI.