Ability of B-type natriuretic peptide in predicting postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting.

OBJECTIVES: Atrial fibrillation (AF) is still the most frequent rhythm disturbance after coronary artery surgery. Our aim was to evaluate the predictive value of preoperative brain natriuretic peptide (BNP) levels for determining postoperative new-onset AF in patients undergoing isolated first-time coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB).

METHODS: We recruited 144 consecutive patients (51 women and 93 men) who underwent isolated CABG. Preoperative and postoperative data were collected. Preoperative BNP levels were measured the day before surgery.

RESULTS: The median preoperative BNP level was 68 pg/mL. Postoperative AF occurred in 36 (25%) of the patients. Univariate analyses showed that both advanced age and median preoperative BNP levels were associated with postoperative AF (63.9 +/- 8 years versus 57.3 +/- 9.8 years, P < .001; 226 pg/mL versus 65.2 pg/mL, P <.001). Both variables remained independent predictors of postoperative AF after multivariate logistic regression analyses. For advanced age, the odds ratio was 1.074 (95% confidence interval [CI], 1.019-1.131; P = .008); for preoperative BNP level, the odds ratio was 1.004 (95% CI, 1.001-1.006; P = .002). A receiver operating characteristic (ROC) curve demonstrated that preoperative BNP level was a predictor of postoperative AF, with an area under the ROC curve of 0.750. A cutoff value of 135 pg/mL for AF demonstrated a 72.2% sensitivity, a 71.2% specificity, a 45.6% positive predictive value, a 88.5% negative predictive value, and a 71.5% accuracy for predicting postoperative AF.

CONCLUSIONS: Elevated preoperative BNP levels and advanced age together are significant predictors for the development of postoperative AF in patients undergoing isolated CABG with CPB.