Serum B-type natriuretic peptide level and timing of its measurement as a predictor of acute ischemic stroke outcome.

An increased B-type natriuretic peptide (BNP) level is associated with cardioembolic stroke because of atrial fibrillation. However, data associating the measurement time of BNP and clinical influence of BNP are limited. Herein, we examined the utility of BNP level for prediction of stroke severity when accounting for measurement time. We retrospectively registered 327 patients admitted within 7 days from onset of ischemic stroke. We collected information on patients' background, stroke risk factors, subtype and severity, and outcome at discharge. Measurement of BNP was performed by chemiluminescent enzyme immunoassay. Patients were divided into 3 groups according to the time of BNP measurement from disease onset. Multivariate analyses were performed to evaluate the association of BNP value with outcome after patients were grouped according to BNP measurement time. Of the 327 patients, the numbers of patients whose BNP was measured within 24 h of symptom onset, between 24 and 48 h of symptom onset, and after 48 h of symptom onset were 102, 92, and 133, respectively. Favourable outcome at discharge was negatively correlated with BNP value in patients with a BNP level measured within 24 h of stroke onset. BNP value may be useful for prediction of stroke outcome if measured within 24 h after stroke onset.