- Background: Recent studies have shown conflicting results regarding a protective effect of statin therapy on atrial fibrillation (AF). Hypothesis: We sought to determine whether statins are effective in reducing the risk of developing arrhythmia in a cohort of 264 patients (49% women, mean age [± standard deviation] 71 [± 12] years) with permanent pacemakers who are at high risk for AF. Methods: All patients who underwent implantation of a permanent pacemaker over a 3 -year period were eligible for inclusion in the study. We excluded patients with AF at implantation, incomplete medication information, or less than a yearly follow-up visit. Atrial fibrillation was diagnosed by ECG documentation, pacemaker interrogation, and Holter monitoring. Statin treatment was verified through a central pharmacy-computerized database (for most patients) or by chart review. Of the 264 patients, 36% had coronary artery disease. Results: Atrial fibrillation developed in 70 patients (26%) at a median of 359 days post pacemaker implantation. The incidence rate for the first occurrence of AF post pacemaker implantation among patients treated and not treated with statins was 10.5 versus 9.8 events per 100 patient-years, respectively (p = 0.81). Even after controlling for baseline differences, the hazard ratio (HR) for developing AF among statin users did notachieve statistical significance (HR = 0.59 [0.31-1.12]). Conclusions: We could not demonstrate that statin therapy had a protective effect against the risk of AF in patients implanted with a permanent pacemaker. The low prevalence of coronary artery disease in our patients may partly explain our results.