NPPB and atrial flutter: The results of the secondary outcome analysis showed that increased BNP was associated with a significantly increased risk of IHD [HR 1.21 (1.09–1.35)], AMI [HR 1.20 (1.08–1.34)], HF [HR 1.43 (1.28–1.60)], atrial fibrillation and flutter [HR 1.20 (1.06–1.34)], and all-cause mortality [HR 1.28 (1.20–1.37)] (Figure 3 and Table S6).