SAN FRANCISCO — Postmenopausal women with coronary heart disease were less likely to develop atrial fibrillation if they were taking statins, a secondary analysis of data on 2,673 patients found.
The prevalence of atrial fibrillation was 65% lower, and the incidence was 55% lower, in women on statin therapy after adjustment for the effects of age, race, heart failure, or history of MI or revascularization. Several previous studies have shown a reduced risk for atrial fibrillation in patients with coronary disease on statins, but those cohorts were 75% male. This is the first study to show a specific benefit in women, Dr. Cara N. Pellegrini of the University of California, San Francisco, and her associates reported at the annual meeting of the Heart Rhythm Society.
The findings are not a reason to use statins specifically to prevent atrial fibrillation in this population, but do provide another reason for women with coronary disease who are on statins to keep taking them, said Dr. Pellegrini, who reported no potential conflicts of interest related to the study.
The data came from the Heart and Estrogen-Progestin Replacement Study (HERS) of 2,763 postmenopausal wom-en with coronary heart disease who were randomized to treatment with hormone replacement therapy or placebo, and followed for cardiovascular outcomes for more than 4 years. The current analysis excluded 90 women because of the presence of other arrhythmias at enrollment.
Compared with the women with no atrial fibrillation, the 88 patients (3%) with atrial fibrillation during the study were significantly more likely to be older (70 years vs. 67 years), have a history of heart failure (35% vs. 12%), and be on an antiarrhythmic medication (5% vs. 1%). In the atrial fibrillation group, 22% were on statins, compared with 37% who did not have atrial fibrillation, a significant difference.
Although statin therapy protected against atrial fibrillation in several previous studies, mostly in men, atrial fibrillation is different in women. They are more likely to have higher heart rates in atrial fibrillation, and to develop paroxysms, thromboembolism, or bleeding, among other differences. Such differences prompted the current study, Dr. Pellegrini said.
An increasing understanding of inflammation's role in atrial fibrillation has increased exploration of nonanti-arrhythmic agents such as statins for prevention of atrial fibrillation. Previous studies linking atrial fibrillation and inflammation focused on men and did not look at community-based populations, which the HERS trial did.