Alcohol consumption and risk of atrial fibrillation in men and women: The Copenhagen City Heart Study

Background - The relationship of the full range of alcohol consumption with risk of incident atrial fibrillation has been inconsistent in previous, mainly case-control studies. Methods and Results - In a prospective cohort study, we studied the association between self-reported alcohol use and incident atrial fibrillation among 16 415 women and men enrolled in the Copenhagen City Heart Study. We ascertained use of beer, wine, and spirits individually at up to 3 study visits with a structured questionnaire. We identified cases of atrial fibrillation by routine study ECGs and a validated nationwide registry of all hospitalizations. A total of 1071 cases occurred during follow-up. Among both women and men, alcohol consumption throughout the moderate range was not associated with risk of atrial fibrillation. However, consumption of 35 or more drinks per week among men was associated with a hazard ratio of 1.45 (95% CI 1.02 to 2.04); few women consumed this amount of alcohol. Approximately 5% of cases of atrial fibrillation among men were attributable to heavy alcohol use. Further adjustment for blood pressure and incident coronary heart disease and congestive heart failure did not attenuate the association (hazard ratio 1.63; 95% CI 1.15 to 2.31). Conclusions - Heavy alcohol consumption is associated with a higher risk of atrial fibrillation, at least among men. This relationship does not appear to be related to the adverse effects of heavy drinking on coronary heart disease or blood pressure.