Objectives: The aim of this study was to evaluate the impact of smoking in patients with left ventricular dysfunction.
Background: The impact of smoking in patients with left ventricular dysfunction has not been well-studied.
Methods: We compared the incidence of death, hospitalization due to heart failure and myocardial infarction (MI) in current smokers to ex-smokers of < or =2 years and ex-smokers of >2 years duration to never-smokers among participants of the Study Of Left Ventricular Dysfunction (SOLVD) Prevention and Intervention trials. Participants all had left ventricular ejection fraction (LVEF) <35% and follow-up was over a mean of 41 months.
Results: Complete smoking status and outcome data were available in 6,704 subjects. There were 1,562 current smokers, 1,317 ex-smokers of < or =2 years, 2,354 ex-smokers of >2 years and 1,471 never-smokers. After adjusting for baseline differences of age, LVEF, race and etiology of heart failure, current smoking was associated with a significantly increased all-cause mortality (relative risk [RR]: 1.41, 95% confidence interval [CI]: 1.25 to 1.58, p < 0.001) compared with ex-smokers and never-smokers. The incidence of death or recurrent congestive heart failure requiring hospitalization or MI was significantly greater (RR: 1.39, 95% CI: 1.26 to 1.52, p < 0.001) in current smokers compared with ex-smokers and never-smokers. There were no significant differences in the number of deaths or hospitalizations due to heart failure between ex-smokers and never-smokers. This effect was consistent across both the SOLVD Prevention and Treatment trials.
Conclusions: Current smoking is a powerful independent predictor of morbidity (recurrent heart failure and MI) and mortality in patients with left ventricular dysfunction. Quitting smoking appears to have a substantial and early effect (within two years) on decreasing morbidity and mortality in patients with left ventricular dysfunction, which is at least as large as proven drug treatments recommended in patients with left ventricular dysfunction.