“…Ten studies 15,18,21–24,26,28,32,35 were included in the analysis of current versus never smokers and heart failure (57,180 cases, 3,810,606 participants), nine studies 15,18,21–23,26,28,32,35 were included in the analysis of former smokers and heart failure (57,004 cases, 3,803,792 participants) and 10 studies 15,18,21–23,26–28,32,33 were included in the analysis of ever smokers and heart failure (57,021 cases, 3,833,903 participants). The summary RR (95% CI) was 1.75 (95% CIs: 1.54–1.99, I 2 = 81.4%, P heterogeneity < .0001) (Figure 2(a)) for current smokers, 1.16 (95% CI: 1.08–1.25, I 2 = 50.5%, P heterogeneity = .04) for former smokers (Figure 2(b)) and 1.44 (95% CI: 1.34–1.55, I 2 = 82.5%, P heterogeneity < .0001) for ever smokers (Figure 2(c)).…”