NPPB and atrial fibrillation: During the short-term period, diabetes mellitus, frequent AF episodes (≥1 per week), and the BNP level at baseline were the predictors of AF recurrence in the univariate analysis (hazard ratio 2.639 (95% confidence interval 1.174–5.932), p = 0.019; 4.038 (1.545–10.557), p = 0.004; and 1.054 (1.029–1.081), p <0.0001, respectively), and frequent AF episodes and BNP level were the independent predictors in the multivariate analysis (3.868 (1.475–10.143), p = 0.006 and 1.049 (1.017–1.082), p = 0.002, respectively).