SMOKING DOES NOT PREDICT CARDIOVASCULAR DEATH!

NEW YORK (Reuters Health) Sep 21 - Could it be good news for smokers? Current and past-smokers with coronary artery disease, cerebrovascular disease, or peripheral artery disease have less than half the cardiovascular mortality than never-smokers, the initial findings from a new study suggest.

But don't be so quick to tell your patients to light up: After accounting for potential confounders, the association was not statistically significant.

"The relationship between smoking habit and outcome in patients with established arterial disease remains controversial," Dr. M. Monreal, of Hospital Universitari Germans Trias i Pujol, Barcelona, Spain, and colleagues write in the September issue of the European Journal of Internal Medicine.

"Some studies have found that smoking may be associated with a better outcome among patients with acute coronary disease," they note. "As for patients with cerebrovascular disease or peripheral artery disease, there is little information on the influence of smoking on outcome."

The researchers used data from FRENA, an ongoing, observational registry of consecutive outpatients with symptomatic coronary artery disease, cerebrovascular disease, or peripheral artery disease, to compare the incidence of cardiovascular death during follow-up of all enrolled patients according to their smoking status.

A total of 2501 patients from 24 participating Spanish hospitals had been enrolled in FRENA as of May 2008. Of these, 439 (18%) were current smokers, 1086 (43%) were past-smokers, and 976 (39%) never smoked.

Compared to never-smokers, current and past-smokers were younger, more often male, and more likely to have chronic lung disease. Diabetes, hypertension, and heart failure were less common in current- and past-smokers.

There were a total of 250 major cardiovascular events in 239 patients (9.6% of the original 2501) over a mean follow-up of 14 months. A total of 123 (4.9%) patients died (cardiovascular death, 68) during follow-up.

Significantly lower cardiovascular mortality was observed among current smokers and past-smokers compared to non-smokers (1.1 per 100 patient-years in current smokers, 1.9 in past-smokers, and 3.5 in non-smokers). Similar results were found when patients with coronary artery disease, cerebrovascular disease, or peripheral artery disease were considered separately.

The mean age at cardiovascular death was 82 years for never-smokers, 70 years for past-smokers, and 67 years for current smokers. The mean age for non-cardiovascular death was 79, 74, and 69 years, respectively.

"On univariate analysis, age >70 years, body mass index >28, chronic lung disease, heart failure, diabetes, prior history of artery disease, non-smoking status, atrial fibrillation, renal insufficiency, and the use of some drugs were significantly associated with an increased cardiovascular mortality," Dr. Monreal and colleagues write. However, on multivariate analysis, none of the variables, including smoking status, were independent predictors of cardiovascular death.