P1219Statins and the risk of major adverse cardiac events in patients with atrial fibrillation without coronary artery disease: a propensity score adjusted analysis

Abstract

Background: In addition to being a well-recognized risk factor for stroke, atrial fibrillation (AF) also confers a significant risk of major adverse cardiac events (MACE), including myocardial infarction (MI) and cardiac death. Recently, findings from a large multinational European registry reported a significant reduction in the risk of MACE and all-cause death in the general population of AF patients treated with statins. Purpose: We aimed to assess whether statin treatment reduces the 5-year risk of MACE in a primary prevention cohort of AF patients without overt coronary artery disease (CAD) at baseline. Methods: a prospective, observational study including non-valvular AF patients free of CAD, treated at a tertiary cardiology center (2010 through 2016). At inclusion, CAD was excluded based on medical records and diagnostic tests (i.e. stress-exercise echocardiography and/or coronary angiography). Also, data on clinical and medication history were collected. Statins were prescribed by treating physicians prior to enrollment, or at study inclusion according to patients' serum lipid levels and cardiovascular risk. The study outcome was the composite MACE including non-fatal/fatal (death within first 30 days) MI, coronary artery revascularization (percutaneous/surgical) and cardiac death. The association between statins and the risk of MACE was first analyzed in a conventional Cox univariable and multivariable models and then in a Cox model adjusted for the propensity score for using statins (C-statistic for differentiation of statin use, 0.870) and other potential confounders. Results: of 843 enrolled AF patients (mean age 62.5612.2 years 61.4% male), 363 (43.1%) received statins. Patients taking statins were older, and more often had a higher body mass index, hypertension, diabetes, prior stroke, and higher glucose, total cholesterol, and triglyceride levels (all P<0.05). At 5-year follow-up, the composite MACE occurred in 118 patients (2.8%/year). The event-rate of MACE was significantly lower in statin users (Figure 1). In a univariable analysis, statins were associated with a hazard ratio (HR) of 0.59 (95% confidence interval [CI], 0.41-0.87; P<0.001) for MACE. This association persisted following adjustment for age, sex, comorbidities, and medical treatment in a conventional multivariable model (adjusted HR, 0.73 95% CI, 0.57-0.97 P=0.001). The association was confirmed after adjustment for the propensity for statin treatment (propensity-adjusted HR, 0.76 95% CI, 0.63-0.97 P=0.008). Conclusion: Our results suggest that statins reduce the 5-year risk of MACE (i.e. coronary events and cardiac death) by 25% in AF patients free of CAD at baseline. While awaiting further confirmation in randomized trials, this observation supports a consideration of statin therapy in AF patients at high cardiovascular risk for primary prevention of adverse cardiovascular outcomes.