Objective: To determine the independent risk factors for atrial fibrillation.
Design: Cohort study.
Setting: The Framingham Heart Study.
Subjects: A total of 2090 men and 2641 women members of the original cohort, free of a history of atrial fibrillation, between the ages of 55 and 94 years.
Main outcome measures: Sex-specific multiple logistic regression models to identify independent risk factors for atrial fibrillation, including age, smoking, diabetes, electrocardiographic left ventricular hypertrophy, hypertension, myocardial infarction, congestive heart failure, and valve disease.
Results: During up to 38 years of follow-up, 264 men and 298 women developed atrial fibrillation. After adjusting for age and other risk factors for atrial fibrillation, men had a 1.5 times greater risk of developing atrial fibrillation than women. In the full multivariable model, the odds ratio (OR) of atrial fibrillation for each decade of advancing age was 2.1 for men and 2.2 for women (P < .0001). In addition, after multivariable adjustment, diabetes (OR, 1.4 for men and 1.6 for women), hypertension (OR, 1.5 for men and 1.4 for women), congestive heart failure (OR, 4.5 for men and 5.9 for women), and valve disease (OR, 1.8 for men and 3.4 for women) were significantly associated with risk for atrial fibrillation in both sexes. Myocardial infarction (OR, 1.4) was significantly associated with the development of atrial fibrillation in men. Women were significantly more likely than men to have valvular heart disease as a risk factor for atrial fibrillation. The multivariable models were largely unchanged after eliminating subjects with valvular heart disease.
Conclusion: In addition to intrinsic cardiac causes such as valve disease and congestive heart failure, risk factors for cardiovascular disease also predispose to atrial fibrillation. Modification of risk factors for cardiovascular disease may have the added benefit of diminishing the incidence of atrial fibrillation.