RESUMO
BACKGROUND: Smoking cessation is an important factor in the primary and secondary prevention of cardiac events. Although multiple clinical trials have examined the efficacy of various smoking cessation aids, a systematic review of the efficacy and safety of smoking cessation aids has not been done. METHODS: This paper reviews the effects of smoking on coronary artery disease. In addition, we identify randomized controlled trials examining the efficacy and safety of smoking cessation aids from the years 1970 to 2004. We then pooled the trial results for 6- and 12-month rates of continuous smoking abstinence. RESULTS: The 4 principal mechanisms of cardiovascular damage caused by cigarette smoking are induction of a hypercoagulable state, reduction of oxygen delivery because of carbon monoxide, coronary vasoconstriction, and nicotine-induced hemodynamic effects. Our review of clinical trials suggests that each smoking cessation aid improved continuous smoking abstinence rates at both 6 and 12 months compared with placebo. The 12-month abstinence rates for the active versus placebo treatments were the following: nicotine patch 11.1% versus 5.5%, nicotine gum 27.3% versus 16.5%, nicotine inhaler 16.9% versus 9.1%, bupropion 18.5% versus 6.6%, and behavioral therapy 20.0% versus 13.9%. CONCLUSIONS: Several smoking-related mechanisms are responsible for the development of atherosclerosis and the induction of cardiac events. Smoking cessation aids effect a modest increase in smoking abstinence at 12 months compared with placebo. In spite the apparent success of cessation aids, smoking relapse rates are quite high.
