Brain natriuretic peptide levels as a predictor for new atrial fibrillation during hospitalization in patients with acute ischemic stroke.

The aim of this study was to investigate the relation between brain natriuretic peptide (BNP) levels and the detection rate of new documented atrial fibrillation (AF) after ischemic stroke. Consecutive patients with ischemic stroke prospectively enrolled within 24 hours of onset. Patients with AF on admission electrocardiography or with histories of AF were excluded. The plasma BNP level was measured on admission, and the factors associated with new documented AF were investigated by multivariate logistic regression analysis. Furthermore, the detection rates of AF according to BNP level were evaluated. A total of 584 patients were enrolled. AF was detected in 40 patients (new AF group; 6.8%). The median BNP level of the new AF group was significantly higher than for the non-AF group (186.6 pg/ml [interquartile range 68.7 to 386.3] vs 35.2 pg/ml [interquartile range 15.9 to 80.1], p <0.0001). The cut-off level, sensitivity, and specificity of BNP levels to distinguish the new AF group from the non-AF group were 65.0 pg/ml, 80%, and 70%, respectively. Multivariate logistic regression analysis demonstrated that National Institutes of Health Stroke Scale score >7 (odds ratio 3.4, 95% confidence interval 1.685 to 7.006, p = 0.0007) and a plasma BNP level >65.0 pg/ml (odds ratio 6.8, 95% confidence interval 2.975 to 15.359, p <0.0001) were independently associated with new AF. The detection rates of AF according to BNP level were as follows: 2% of patients with <50 pg/ml, 4% of those with 50 to <100 pg/ml, 12% of those with 100 to <200 pg/ml, 26% of those with 200 to <400 pg/ml, and 38% of those with ≥400 pg/ml. In conclusion, BNP levels can predict new AF in patients with acute ischemic stroke. Elevated BNP levels result in an increase in the frequency of detection of new AF.