Aim: To evaluate the effect of statins on reducing new-onset atrial fibrillation (AF) in a large real-world post-myocardial infarction (MI) population. Subsequently, to test if different statin doses, various types and compliance affected the incidence of new-onset AF post MI.
Methods: All patients with first-time acute MI between 1997 and 2009 in Denmark and claimed prescriptions of statins after discharge were identified from the Danish nationwide administrative registers. Patients with a history of AF were excluded. Risk of new-onset AF according to statin use were analysed by multivariable time-dependent Cox regressions models adjusted for age, gender, year, concomitant medication, and comorbidity, and additionally in a propensity score-matched analysis.
Results: A total of 89,703 patients with average follow up of 5.0 ± 3.5 years were included in this study. In the 56,044 patients receiving statins, 5698 (10%) had new-onset AF vs. 5010 (15%) in the 33,659 patients serving as controls. The adjusted Cox regression analysis showed significant reduction in new-onset AF (HR 0.83, 95% CI 0.80-0.87, p < 0.001) in statin users. Adjustment for propensity score yielded nearly identical results (HR 0.82, 95% CI 0.78-0.85, p < 0.001). Furthermore, patients compliant to statin treatment had significant reduction in new-onset AF (HR 0.84, 95% CI 0.80-0.87, p < 0.001). Finally, simvastatin and atorvastatin were significantly more effective than pravastatin (both p < 0.01) in reducing new-onset AF.
Conclusions: Statin therapy was significantly associated with less new-onset AF in a nationwide cohort of post-MI patients. Furthermore, statins showed a type-dependent effect in preventing new-onset AF. These results support the beneficial effect of statin therapy beyond lipid lowering in patients with MI and underline the importance of statin adherence and choice of statin type.
Keywords: Inflammation; myocardial infarction; new-onset atrial fibrillation; statins.