There were 21 studies involving 5008 patients in the meta-analysis for BNP, and the pooled result showed that baseline BNP was significantly higher in patients who experienced AF recurrence post CA compared to those that remained in sinus rhythm (OR 2.91, 95% CI: 1.74–4.88, p < 0.01, Fig. 2). This evidence concerns the gene NPPB and atrial fibrillation.