Low Ankle-Brachial Index is a Simple Physical Exam Sign Predicting Intracranial Atherosclerotic Stenosis in Ischemic Stroke Patients

BackgroundThe investigation of ischemic stroke etiology is commonly limited to the heart and extracranial vessels. Nevertheless, the diagnosis of intracranial stenosis may carry important therapeutic implications. The aims of this study were to determine the prevalence and clinical predictors of intracranial atherosclerotic stenosis (ICAS) in a sample of patients with ischemic stroke.MethodsConsecutive patients admitted to a university-based outpatient stroke clinic underwent CT angiography of the intracranial and extracranial brain vessels. Clinical, demographic, and laboratory characteristics were compared between patients with increasing levels of stenosis. Ankle-brachial index (ABI) was measured to quantify peripheral arterial disease, defined as an ABI less than or equal to .9. Multivariable ordinal logistic regression was constructed to predict increasing stenosis grades (none, 1%-49%-mild, 50%-69%-moderate, 70%-100%-severe).ResultsWe studied 106 subjects, mean age 62 ± 15 years, 54% female. ICAS was present in 38 (36%) patients: 19 (50%) mild, 7 (18%) moderate, and 12 (32%) severe. Of 74 patients where ABI was measured, low ABI was found more frequently with increasing ICAS severity (26%, 42%, 67%, and 89% of patients with none, mild, moderate, and severe ICAS, respectively). In univariable analysis, higher age, presence of diabetes, abdominal obesity, and low ABI correlated with increasing stenosis grades. In multivariable analysis, only low ABI remained independently associated with increasing stenosis grades.ConclusionsThe ABI is independently associated with increasing severity of ICAS, making it a potentially useful triaging tool for more invasive test selection.