Effects of smoking cessation on coronary endothelial function in patients with recent myocardial infarction

Background Smoking is associated with an increased risk and extent of advanced atherosclerotic vascular disease, but few studies have examined the clinical effect of smoking cessation on human coronary endothelial function. Objectives We sought to determine the effects of smoking cessation on endothelial function in patients with recent myocardial infarction. Methods Infarcted-not-related coronary arteries of 53 patients with acute myocardial infarction undergoing successful angioplasty were examined in two groups: smoking cessation group (n = 35, 28 males, mean age 56 years) and non-smoking group (n = 18, 10 males, mean age 65 years). We infused acetylcholine into the coronary artery and the diameter was assessed by quantitative angiography at baseline and 6 months after PTCA. Results The mean % diameter change from baseline was significantly more constricted in the smoking cessation group than in the non-smoking group (38% ± 5 vs. 19% ± 5, p < 0.05). However, the response after six months was significantly decreased after smoking cessation (from 38% ± 5 to 28% ± 4, p < 0.01). Multiple regression analysis showed smoking cessation (p = 0.03) was a significant determinant factor for improvement of endothelial function. Conclusions These findings suggest that just 6 months of smoking cessation improves coronary endothelial function in patients with recent myocardial infarction.