Brain Natriuretic Peptide as a Predictor of Cardioembolism in Acute Ischemic Stroke Patients: Brain Natriuretic Peptide Stroke Prospective Study

Background and Purpose: Our previous retrospective study demonstrated that a brain natriuretic peptide (BNP) level of >140 pg/ml on admission was useful to distinguish cardioembolism (CE) from non-CE. The aim of the present study was to prospectively investigate the utility of this predefined threshold. Method: Two hundred and twenty-one consecutive patients were prospectively enrolled. On admission, the BNP levels of the patients were measured and classified according to low BNP (≤140.0 pg/ml) or high BNP (>140.0 pg/ml) levels. Final diagnosis of stroke subtype on discharge was made using the TOAST criteria. Measured parameters included the sensitivity, specificity, positive predictive value, and negative predictive value for CE in the high BNP group. Results: There were 81 patients in the high BNP group and 140 patients in the low BNP group. A total of 76 (34.4%) patients were diagnosed with CE, including 59 (72.8%) patients in the high BNP group and 17 (12.1%) patients in the low BNP group (p < 0.001). A BNP level >140.0 pg/ml corresponded to a sensitivity of 77.6%, specificity of 84.8%, positive predictive value of 72.8%, and negative predictive value of 87.9% for a diagnosis of CE. Conclusion: A BNP level of >140.0 pg/ml on admission in patients with acute ischemic stroke is a strong biochemical predictor for CE.