Cigarette smoking exposure and heart failure risk in older adults: The Health, Aging, and Body Composition Study

BackgroundAlthough there is evidence linking smoking and heart failure (HF), the association between lifetime smoking exposure and HF in older adults and the strength of this association among current and past smokers is not well known.MethodsWe examined the association between smoking status, pack-years of exposure, and incident HF risk in 2,125 participants of the Health, Aging, and Body Composition Study (age 73.6 ± 2.9 years, 69.7% women, 54.2% whites) using proportional hazard models.ResultsAt inception, 54.8% of participants were nonsmokers, 34.8% were past smokers, and 10.4% were current smokers. During follow-up (median 9.4 years), HF incidence was 11.4 per 1,000 person-years in nonsmokers, 15.2 in past smokers (hazard ratio [HR] vs nonsmokers 1.33, 95% CI 1.01-1.76, P = .045), and 21.9 in current smokers (HR 1.93, 95% CI 1.30-2.84, P = .001). After adjusting for HF risk factors, incident coronary events, and competing risk for death, a dose-effect association between pack-years of exposure and HF risk was observed (HR 1.09, 95% CI 1.05-1.14, P < .001 per 10 pack-years). Heart failure risk was not modulated by pack-years of exposure in current smokers. In past smokers, HR for HF was 1.05 (95% CI 0.64-1.72) for 1 to 11 pack-years, 1.23 (95% CI 0.82-1.83) for 12 to 35 pack-years, and 1.64 (95% CI 1.11-2.42) for >35 pack-years of exposure in fully adjusted models (P < .001 for trend) compared with nonsmokers.ConclusionsIn older adults, both current and past cigarette smoking increase HF risk. In current smokers, this risk is high irrespective of pack-years of exposure, whereas in past smokers, there was a dose-effect association