Statins lower risk of AF in women with CHD
Giving statins to women with established coronary disease reduces their odds of developing atrial fibrillation (AF), a large observational study has shown.
The study cohort was taken from the Heart and Estrogen/Progestin Replacement Study (HERS). In total, 2,673 postmenopausal women with stable coronary disease were enrolled. The main outcome measure was AF prevalence at baseline and incident AF over a mean follow-up of four years.
The results identified 29 women with AF at baseline and 59 during follow-up. Those with AF were significantly less likely to be taking a statin at enrolment compared with those without AF (22% vs. 37%, p = 0.003). This was associated with a 65% lower odds of having AF in women taking statins, which persisted after adjustment for potential confounding factors such as age, race, history of myocardial infarction or revascularisation and history of heart failure (OR 0.35, 95% CI 0.13 - 0.93, p = 0.04).
At a mean follow up of four years those who were taking statins at enrolment were 55% less likely to develop AF than those who were not (hazard ratio 0.45, 95% CI 0.26 - 0.78, p = 0.004). Therefore, overall 69 of 1,697 women (4%) not taking statins at baseline or during follow-up had AF compared with 19 of 976 (2%) taking statins.
However, the limitations of this study must be noted. It was an observational study and the study population had a lower than expected prevalence and incidence of AF. Furthermore, the diagnosis of AF was based on computer algorithms. In addition the dose of statin was not defined nor was the temporal relationship between statin use and the onset of AF.
AF is a growing problem and current clinical practice focuses on thromboprophylaxis, rate and rhythm control. The concept of preventing AF by pharmacological means is interesting and not surprisingly statins could have a role. The mechanism is likely to be due to the pleiomorphic actions of statins such as antioxidant and anti-inflammatory effects, and changes to cellular and endothelial function.
This study provides a further reason to use statins in women with coronary disease although is not enough to recommend statins for AF prevention in all patients. Randomised controlled trials will be needed to inform clinical practice further.
Pellegrini CN, Vittinghoff E, Lin F et al Statin use is associated with lower risk of atrial fibrillation in women with coronary disease: the HERS trial Heart 2009;95:704-708Reviewer
Dr Peter Savill