Effects of cessation of smoking after myocardial infarction.

Smoking is an important risk factor for myocardial infarction, but not for uncomplicated angina pectoris. However, angina patients who smoke have a greater risk of later infarction or death than do those who do not smoke. Most patients who suffer an infarction are moderate smokers. Non-smokers who suffer an infarction tend to be afflicted by more other risk factors than are smokers. The mechanism of infarction in smokers most often seems to be thrombosis in less atherosclerotic arteries. Stopping smoking is associated with lower mortality among patients after infarction and resuscitation from cardiac arrest. After coronary surgery re-infarction as well as new infarctions and angina pectoris are less common among patients who stop smoking than they are among those who continue to smoke. Factors such as an increase in body weight after stopping smoking are not associated with any increase in mortality among post-infarct patients. There are some psychosocial differences between those who stop smoking and those who continue to smoke after an infarction, but it is improbable that these differences explain the rapid effect on re-infarction and mortality rates of stopping smoking.