Differences in cardiovascular mortality in smokers, past-smokers and non-smokers: findings from the FRENA registry

The influence of smoking on outcome in patients with coronary artery disease (CAD) is controversial. Even less is known about its influence in patients with cerebrovascular (CVD), or peripheral artery (PAD) disease.

FRENA is an ongoing, observational registry of consecutive outpatients with symptomatic CAD, CVD, or PAD. We reviewed their cardiovascular mortality according to smoking status.

As of May 2008, 2501 patients had been enrolled in FRENA. Of these, 439 (18%) were current smokers, 1086 (43%) past-smokers, 976 (39%) had never smoked. Current- and past-smokers were 10 years younger, more often males, and more likely to have chronic lung disease, but had diabetes, hypertension, heart failure, or renal insufficiency less often than non-smokers. Over a mean follow-up of 14 months, 123 patients died (cardiovascular death, 68). On univariate analysis, current smokers had a significantly lower rate of cardiovascular death: 1.1 (95% CI: 0.4-2.4) per 100 patient-years in current smokers; 1.9 (95% CI: 1.2-2.8) in past-smokers; 3.5 (95% CI: 2.5-4.7) in non-smokers, with no differences between patients with CAD, CVD or PAD. Mean age at cardiovascular death was 82+/-6.4; 70+/-9.9 and 67+/-15 years, respectively. On multivariate analysis, smoking status was not independently associated with a lower risk for cardiovascular death.

Current and past-smokers with CAD, CVD or PAD had a less than half cardiovascular mortality than those who never smoked, but this may be explained by the confounding effect of additional variables. They died over 10 years younger than non-smokers.