Alcohol consumption, atherosclerotic progression, and prognosis among patients with coronary artery bypass grafts

Background: Although moderate drinking has been associated with lower mortality among patients after myocardial infarction, its relationship with prognosis and graft obstruction among patients with coronary artery bypass grafts is unknown. Methods: We studied 1351 patients enrolled in the Post-CABG trial, who had undergone coronary bypass surgery 1 to 11 years before entry. Participants were randomly assigned to lovastatin in low or high doses and to low-dose warfarin or placebo in a factorial design. Participants underwent coronary angiography at baseline and after a mean follow-up of 4.3 years and were followed up for a composite end point of death, myocardial infarction, stroke, bypass surgery, or angioplasty. We categorized reported weekly alcohol intake as abstention (<1 drink), light (1-6 drinks), moderate (7-13 drinks), and heavier (≥14 drinks). Results: During follow-up, 238 participants sustained a clinical event. Moderate drinking was associated with a trend toward both fewer clinical events (hazard ratio 0.7, 95% CI 0.4-1.1) and less angiographic progression (odds ratio 0.7, 95% CI 0.5-1.1), although neither of these effects were statistically significant. High-density lipoprotein cholesterol appeared to account for one third of the trend toward lower risk among moderate drinkers. Conclusion: We did not demonstrate statistically significant differences in prognosis according to alcohol intake in this study, although there were inverse trends between moderate drinking and both morbidity and graft progression of a magnitude similar to studies in other populations. Larger studies of alcohol intake among patients with coronary artery bypass grafts are needed.