The baseline levels of ln BNP were significantly associated with rhythm at blood collection, age, sex, and left atrial diameter, and left ventricular ejection fraction (P < 0.05).The subgroup analysis showed a significant interaction on the risk of AF recurrence between ln BNP, sex difference, and rhythm at blood collection (P for interaction < 0.05). The gene discussed is NPPB; the disease is atrial fibrillation.