The NT-proBNP level was significantly associated with the incidence of documented AF/AT recurrence within the three-month blanking period after catheter ablation (HR, 1.84, 95% CI, 1.06–3.19, p = 0.030), but the MR-proANP level was not (HR, 2.87, 95% CI, 0.86–9.50, p = 0.085). This evidence concerns the gene NPPA and atrial fibrillation.