A subsequently performed multivariable regression analysis searching for independent predictors of postoperative AF identified only increased preoperative BNP levels (being in the two highest quartiles of BNP) as predictor of this arrhythmia after adjustment for age (above or below the median value), CRP levels, postoperative beta-blockers administration, gender, HTN, smoking, and “off-pump” operation, with odds ratio (OR) of 0.56 (95% CI = 0.32–0.96; P = 0.036). This evidence concerns the gene NPPB and atrial fibrillation.