Risk of Heart Failure and Death After Prolonged Smoking Cessation: Role of Amount and Duration of Prior Smoking

Abstract

Background: According to the 2004 Surgeon General's Report on Health Consequences of Smoking, after >15 years of abstinence, the cardiovascular risk of former smokers becomes similar to that of never-smokers. Whether this health benefit of smoking cessation varies by amount and duration of prior smoking remains unclear.

Methods and results: Of the 4482 adults ≥65 years without prevalent heart failure (HF) in the Cardiovascular Health Study, 2556 were never-smokers, 629 current smokers, and 1297 former smokers with >15 years of cessation, of whom 312 were heavy smokers (highest quartile; ≥32 pack-years). Age-sex-race-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for centrally adjudicated incident HF and mortality during 13 years of follow-up were estimated using Cox regression models. Compared with never-smokers, former smokers as a group had similar risk for incident HF (aHR, 0.99; 95% CI, 0.85-1.16) and all-cause mortality (aHR, 1.08; 95% CI, 0.96-1.20), but former heavy smokers had higher risk for both HF (aHR, 1.45; 95% CI, 1.15-1.83) and mortality (aHR, 1.38; 95% CI, 1.17-1.64). However, when compared with current smokers, former heavy smokers had lower risk of death (aHR, 0.64; 95% CI, 0.53-0.77), but not of HF (aHR, 0.97; 95% CI, 0.74-1.28).

Conclusions: After >15 years of smoking cessation, the risk of HF and death for most former smokers becomes similar to that of never-smokers. Although this benefit of smoking cessation is not extended to those with ≥32 pack-years of prior smoking, they have lower risk of death relative to current smokers.

Keywords: heart failure; mortality; smoking.

Figure 1

Flow chart displaying assembly of study cohort based on the public-use copy of the Cardiovascular Health Study (CHS) data

Figure 2

Age-sex-race-adjusted survival plots for incident heart failure for never-smokers, former smokers who quit smoking over 15 years ago, stratified by quartiles of pack-years (PY) of prior smoking, and current smokers

Figure 3

Age-sex-race-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for incident heart failure for never-smokers and former smokers who quit smoking over 15 years ago, stratified by quartiles of pack-years (PY) of prior smoking, relative to current smokers. The red dotted line is the line of reference, and the green dotted line intersects the aHR for never-smokers

Figure 4

Age-sex-race-adjusted survival plots for all-cause mortality for never-smokers, former smokers who quit smoking over 15 years ago, stratified by quartiles of pack-years (PY) of prior smoking, and current smokers

Figure 5

Age-sex-race-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for all-cause mortality for never-smokers and former smokers who quit smoking over 15 years ago, stratified by quartiles of pack-years (PY) of prior smoking, relative to current smokers. The red dotted line is the line of reference, and the green dotted line intersects the aHR for never-smokers