Ability of NT-pro-BNP to Diagnose Cardioembolic Etiology in Patients with Acute Ischemic Stroke.

Background Cardioembolic stroke (CE) is usually associated with a larger ischemic area leading to higher morbidity and mortality rates. No biomarkers for CE are available, which causes difficulty in differential diagnosis of CE from other subtypes of acute ischemic stroke.

Methods: We prospectively evaluated consecutive patients with acute ischemic stroke to identify biomarkers that could distinguish between CE and other subtypes of acute ischemic stroke. Etiological diagnoses were identified according to the National Institute of Neurological Disorders and Stroke (NINDS) 111 classification using clinical examinations, computed tomography (CT), magnetic resonance imaging (MRI), cardiac evaluations, and other tests. The biomarkers N-terminal pro-brain natriuretic peptide (NT-pro-BNP), Thrombin-Antithrombin III Complex (TAT), and D-dimer were determined in blood samples collected within 48 hours of onset and compared between groups with and without CE. Non- CE consisted of atherothrombotic brain infarction (ATBI), lacunar infarction (LI), and other stroke subtypes of unknown cause (other).

Results: This study included 279 patients diagnosed with acute ischemic stroke. Serum levels of NT-pro- BNP were significantly higher in those with than in those without CE stroke (p<0.0001). Analysis of receiver operating characteristics (ROC) curves indicated that an NT-pro-BNP cutoff of 332 pg/mL provided optimal sensitivity (98.3%) and specificity (75.8%) for distinguishing CE from non-CE.

Conclusions: Serum levels of NT-pro-BNP may help in diagnosis of CE during the acute phase and thus allow appropriate therapy t6 prevent subsequent cardiogenic stroke.