Influence of Smoking Status on Risk of Incident Heart Failure: A Systematic Review and Meta-Analysis of Prospective Cohort Studies.

Smoking is a well-known risk factor for atherosclerotic cardiovascular disease. However, there are insufficient data regarding the predictive influence of smoking status on the risk of incident heart failure (HF). This study involved a systematic review and meta-analysis of prospective cohort studies to identify the association of smoking status with incident risk of HF. Peer-reviewed articles published in PubMed, Embase, Web of Science, Cochrane, and CINAHL up to May 2019 were identified. Seven studies, based on 42,759 participants and 4826 HF cases, were included. Pooled hazard ratios (HRs) and their 95% confidence intervals (CI) were estimated using the fixed effects model. Subgroup analyses were conducted to define possible sources of heterogeneity. Current smokers aged 18 years and over had a greater risk of HF incidence compared with non-smokers (never or former smokers) (HR = 1.609, 95% CI, 1.470-1.761). Additionally, former smokers had a greater risk of HF incidence compared with never smokers (HR = 1.209, 95% CI, 1.084-1.348). The present study highlighted that never smokers have more obvious cardiovascular benefits than current or former smokers. Therefore, health professionals should support cessation at the earliest among current smokers and encourage young people and non-smokers not to start smoking.