Abstract 10897: Effect of High-Dose Atorvastatin on Risk of Atrial Fibrillation in Patients with Prior Stroke or Transient Ischemic Attack: Analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial
Background: Observational analyses and short-term randomized trials after cardiac surgery or cardioversion have suggested that statins reduce occurrence or recurrence of atrial fibrillation. We tested the hypothesis that long-term treatment with high-dose atorvastatin reduces the occurrence of atrial fibrillation in patients with prior stroke or transient ischemic attack.
Methods: The Stroke Prevention with Aggressive Reduction in Cholesterol Levels (SPARCL) trial compared atorvastatin 80 mg daily with placebo in 4731 patients with prior stroke or transient ischemic attack. Patients who had chronic or paroxysmal atrial fibrillation or were taking medications for the treatment or prophylaxis of atrial fibrillation at the time of enrollment were excluded. In a pre-specified analysis, we examined development of new atrial fibrillation in SPARCL. Atrial fibrillation was identified from protocol-specified electrocardiograms (ECGs) submitted to a blinded central ECG Laboratory and from investigators' adverse event reports. The primary efficacy measure was time from randomization to first occurrence of new atrial fibrillation.
Results: Patients were followed for a median of 4.8 years, corresponding to over 10,000 patient-years of observation in each treatment group, with a median of 5 ECGs per patient. The time to first occurrence of atrial fibrillation did not differ between treatment groups. By intention-to-treat, there were 139 cases of new atrial fibrillation in the atorvastatin group and 122 cases in the placebo group, corresponding to incidence rates of 1.32 and 1.14 cases per 100 patient-years of observation (hazard ratio 1.15, 95% CI 0.90–1.46, p=0.26). On-treatment analysis yielded similar findings, with incidence rates of 1.26 and 1.01 cases per 100 patient-years of observation in the atorvastatin and placebo groups, respectively (hazard ratio 1.25, 95% CI 0.94–1.67, p=0.12).
Conclusions: High dose atorvastatin does not prevent development of atrial fibrillation in patients with prior stroke or transient ischemic attack.
- © 2010 by American Heart Association, Inc.