Effect of statin dose on incidence of atrial fibrillation: Data from the Pravastatin or Atorvastatin Evaluation and Infection Therapy–Thrombolysis in Myocardial Infarction 22 (PROVE IT–TIMI 22) and Aggrastat to Zocor (A to Z) trials

BackgroundInflammation has been suggested as a factor in the initiation and maintenance of atrial fibrillation (AF). Several observational studies have suggested that statins, presumably through their anti-inflammatory properties, decrease the risk of AF.MethodsWe analyzed 2 large, randomized trials, PROVE IT–TIMI 22 and phase Z of the A to Z trial, which compared lower- versus higher-intensity statin therapy to evaluate whether higher-intensity statin therapy lowered the risk of AF onset during the 2 years of follow-up. We hypothesized that higher-intensity statin therapy would decrease the risk of AF when compared to lower-intensity statin therapy. From each trial, patients experiencing the onset of AF during follow-up were identified from the adverse event reports.ResultsNeither study showed a decreased AF risk with higher-dose statin. In PROVE IT–TIMI 22, 2.9% versus 3.3% in the high- versus standard-dose statin therapy, respectively, experienced the onset of AF over 2 years (OR 0.86, 95% CI 0.61-1.23, P = .41). In A to Z, rates were 1.6% versus 0.99%, respectively (OR 1.58, 95% CI 0.92-2.70, P = .096). In both trials, C-reactive protein levels (plasma or serum) tended to be higher among patients experiencing the onset of AF.ConclusionOur randomized comparison among 8659 patients found that higher-dose statin therapy did not reduce the short term incidence of AF among patients after acute coronary syndromes when compared with standard dose statin treatment.