Smoking Cessation Reduces the Risk of Heart Failure: A Nationwide Cohort Study

Background: There is a lack of data for the incidence of heart failure (HF) according to changes in smoking behaviors. Objectives: The authors aimed to investigate the effects of smoking behavior change on development of HF. Methods: In this population-based, retrospective cohort study using the Korean National Health Insurance System database, the authors identified 778,608 current smokers who participated in a health screening program in 2009 and in a follow-up screening in 2011. Participants were categorized into quitters, reducers I (≥50% reduction) and II (<50% reduction), sustainers, and increasers. Results: During a median follow-up of 6.3 years, there were 23,329 HF events (4.8 per 1,000 person-years). Compared with sustainers, the risk of HF was increased among increasers (adjusted hazard ratio [aHR]: 1.06 [95% CI: 1.02-1.10]). By contrast, quitters had a reduced risk for HF (aHR: 0.86 [95% CI: 0.83-0.90]). Even heavy smokers who quit smoking had a lower risk for HF than those who sustained heavy smoking (aHR: 0.90 [95% CI: 0.85-0.95]). In reducers, the risk of HF was not reduced but rather increased slightly (≥50% reduction, aHR: 1.06 [95% CI: 1.01-1.11]; <50% reduction, aHR: 1.04 [95% CI: 1.00-1.08]). Conclusions: Current smokers who increased their smoking amount were associated with a higher risk for HF development compared to sustainers, whereas self-reported smoking cessation was associated with a lower risk of HF. There was no benefit from reduction in smoking amount. Self-reported smoking cessation should be reinforced whenever possible to prevent HF.