Low Ankle-Brachial Index Is Associated With Stroke Recurrence in Ischemic Stroke Patients With Atrial Fibrillation

Introduction: Cardioembolic stroke (CE) has poor outcomes and high recurrence rates. A low ankle-brachial index (ABI <0.9) is associated with atrial fibrillation (AF) and poor stroke outcomes. We investigated whether a low ABI is associated with stroke recurrence, major adverse cardiovascular events (MACE), and mortality in patients with CE and whether this association is affected by AF. Methods: We enrolled patients with CE who underwent ABI measurements during hospitalization. Recurrent stroke was defined based on newly developed neurologic symptoms with relevant lesions 7 days after the index stroke. MACE comprised stroke recurrence, myocardial infarction, or death. Results: Of 775 patients, 427 (55.1%) were AF patients and 348 (44.9%) were non-AF patients. Patients were followed up for a median of 33.6 (IQR, 18.0-51.6) months. In total, 194 (25.0%) patients experienced MACE, including 77 (9.9%) patients with stroke recurrence and 101 (13.0%) patients with mortality, during the study period. Multivariable Cox regression analysis showed that an ABI <0.9 was independently associated with MACE (AF patients: hazard ratio [HR] = 2.327, 95% confidence interval [CI] = 1.371-3.949, non-AF patients: HR = 3.116, 95% CI = 1.465-6.629) and mortality (AF patients: HR = 2.659, 95% CI = 1.483-4.767, non-AF patients: HR = 3.645, 95% CI = 1.623-8.187). Stroke recurrence was independently associated with an ABI <0.9 in AF patients (HR = 3.559, 95% CI = 1.570-8.066), but not in non-AF patients (HR = 1.186, 95% CI = 0.156-8.989). Conclusions: We found that a low ABI is associated with stroke recurrence, MACE, and mortality in patients with CE. In particular, the association between ABI and recurrent stroke is only present in AF patients. A low ABI may be a useful prognostic marker in patients with CE, especially in AF patients.