Brain natriuretic peptide as a predictor of delayed atrial fibrillation after ischaemic stroke and transient ischaemic attack.

BACKGROUND AND PURPOSE

We investigated whether the brain natriuretic peptide (BNP) level can serve as a predictive biological marker of delayed atrial fibrillation (AF).

METHODS

Two hundred and thirty seven consecutive patients admitted to our institution with acute ischaemic stroke or transient ischaemic attack (TIA) within 24 h of onset were enrolled. The patients were classified according to the presence or absence of AF upon admission [AF and sinus rhythm (SR) groups]. The SR group was subdivided based on the development of AF after admission (new- and non-AF groups). We compared the characteristics between the AF and SR groups, and between the new- and non-AF groups. The factors associated with new-AF were investigated by multivariate logistic regression analysis.

RESULTS

Amongst the enrolled patients, 72 (30.4%) had AF upon admission (AF group), and 13 (5.5%) developed AF thereafter (new-AF group). The plasma BNP level was significantly higher in the AF, than in the SR group (401.7 vs. 92.1 pg/ml, P < 0.001). Moreover, the plasma BNP level was significantly higher in the new-, than in the non-AF group (184.7 vs. 84.1 pg/ml, P < 0.001). The optimal cutoff BNP level required to distinguish new-, from non-AF groups was 85.0 pg/ml, and the sensitivity and specificity was 83.3% and 76.2%, respectively. On multivariate logistic regression analysis, plasma BNP level >85.0 pg/ml (odds ratio, 7.20; 95% confidence interval, 1.71 to 30.43, P = 0.007) was an independent factor associated with new-AF.

CONCLUSION

High plasma BNP level should be a strong predictor of delayed AF after ischaemic stroke or TIA.