After more than 15 years of smoking cessation, the risk for HF and death among former mild smokers appears similar to the risks faced by people who have never smoked, researchers reported in a recent study.
Researchers evaluated 4,482 individuals aged 65 years and older without prevalent HF. All were enrolled in the ongoing, prospective Cardiovascular Health Study of CV risk factors among older, community-dwelling adults in the United States.
More than half of the participants (57%) reported never smoking, 29% previously smoked but quit more than 15 years prior and 14% were current smokers. Researchers classified the former smokers by pre-cessation pack-years of smoking: light smokers (< 8 pack-years: n = 383); moderate smokers (8 to 15 pack-years: n = 250; 16 to 31 pack-years: n = 352); and heavy smokers (≥ 32 pack-years: n = 312).
The primary outcome was incident HF and all-cause mortality during 13 years of follow-up.
According to the findings, former smokers and never-smokers had similar risks for incident HF (adjusted HR = 0.99; 95% CI, 0.85-1.16) and all-cause mortality (adjusted HR = 1.08; 95% CI, 0.96-1.2). This finding “was driven by former light and moderate smokers who had a similar risk to that of never-smokers,” the researchers wrote.
Among former heavy smokers, the risks for incident HF (adjusted HR = 1.45; 95% CI, 1.15-1.83) and all-cause mortality (adjusted HR = 1.38; 95% CI, 1.17-1.64) were higher compared with never-smokers. However, compared with current smokers, the risk for incident HF was similar to that of current smokers (adjusted HR = 0.97; 95% CI, 0.74-1.28), but the risk for all-cause mortality was decreased (adjusted HR = 0.64; 95% CI, 0.53-0.77).
In other results, former smokers had similar risks for CV mortality (adjusted HR = 1; 95% CI, 0.84-1.18) and incident acute MI (adjusted HR = 1.08; 95% CI, 0.88-1.33) compared with never-smokers. However, compared with never-smokers, former heavy smokers had increased risks for CV mortality (adjusted HR = 1.37; 95% CI, 1.06-1.77), non-CV mortality (adjusted HR = 1.4; 95% CI, 1.12-1.75) and acute MI (adjusted HR = 1.65; 95% CI, 1.22-2.22).
According to the researchers, the findings of this study suggest a benefit to smoking cessation, particularly for mild and moderate former smokers, but also for heavy smokers.
“Although HF risk for former heavy smokers was similar to that of current smokers, they had significantly lower risks for all-cause and non-cardiovascular deaths, and a trend toward lower cardiovascular death,” the researchers wrote. “These data support the overall conclusions of the U.S. Surgeon General about the health benefits of prolonged smoking cessation and provide additional insights about how this benefit may be modified by the amount and duration of prior smokers.” – by Jennifer Byrne
Disclosure: The researchers report no relevant financial disclosures.