Brain Natriuretic Peptide in Acute Ischemic Stroke

Elevated serum brain natriuretic peptide (BNP) levels are associated with cardioembolic stroke mainly because of atrial fibrillation (AF). However, the mechanisms of increased serum BNP levels are hitherto unclear. We aimed to identify the factors associated with increased BNP levels in patients with acute ischemic stroke. We measured serum BNP levels in consecutive patients aged 18 years or older. Stroke subtypes were classified using the Trial of ORG 10172 in Acute Stroke Treatment criteria. Categorical variables included age, sex, smoking status, alcohol consumption status, hypertension, diabetes mellitus, dyslipidemia, coronary artery disease (CAD), AF, antiplatelet therapy, and anticoagulant therapy. Continuous variables included hemoglobin, creatinine (Cr), β-thromboglobulin, platelet factor 4, thrombin–antithrombin complex, and d-dimer levels. We further determined the relationship between serum BNP and intima–media thickness, left ventricular ejection fraction, size of infarction, National Institutes of Health Stroke Scale score on admission, and modified Rankin Scale (mRS) score at discharge. Of the 231 patients (mean age, 71 ± 12 years) with acute ischemic stroke (AIS), 36% were women. Serum BNP levels significantly correlated with CAD, AF, Cr, mRS, and cardioembolism (CE) (Dunnett method, P = .004). BNP levels were significantly higher in patients with larger infarcts, higher mRS scores, and higher CHADS 2 scores. The levels were higher in patients with larger infarcts, higher mRS scores at discharge, and higher CHADS 2 scores among AF patients.