Abstract 13387: Effect of Ranolazine on the Incidence of Atrial Fibrillation Following Cardiac Surgery

Abstract

Introduction: Atrial fibrillation (AF) is common following cardiac surgery. Reduction of postoperative AF would decrease average length of stay and improve patient outcomes. Ranolazine has been shown to prevent AF by increasing postrepolarization refractoriness in atrial tissue. This study evaluates prophylactic ranolazine on postoperative AF in cardiac surgery. Hypothesis: To assess the effect of ranolazine as a selective atrial sodium channel blocker on prevention of AF following cardiac surgery. Methods: This double blinded, randomized trial assessed primary prevention of postoperative AF with ranolazine in patients undergoing coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) from 2012-13. Mitral valve surgery was an exclusion criterion. Fifty-four patients were randomly allocated to twice daily ranolazine 1000 mg (n=27) or placebo (n=27) 48 hours prior to surgical intervention and postoperatively for 14 days. Cardiac monitoring for arrhythmias was continued for 2 weeks post discharge using Holter monitor. The primary endpoint was AF up to postoperative day 14. Secondary endpoints included 30 day readmission, complications, and length of stay. (ClinicalTrials.gov: NCT01590979). Results: Fifty-one patients completed the study to 30 days postoperatively. Cohort mean age was 64.3±11.4 years, females were 10(19%), mean ejection fraction was 46.4±14.6%, hypertension 48(89%), dyslipidemia 32(59%) and diabetes 22 (41%), with no difference between the groups. Patients underwent isolated CABG (44, 81%), AVR (4, 7%) and combined AVR/CABG (3, 6%). The incidence of AF was 24%, control 8 (30%) and treated 5 (19%) groups, a 38% reduction, not statistically significant (p=0.530). QT duration was longer in the ranolazine group (p=0.014). The length of stay of patients who developed AF was significantly longer (8.3±5.0 vs. 5.4±2.7, p=0.009), with no drug related adverse events. Conclusion: This study illustrates the prevalence of AF following cardiac surgery. Ranolazine is an antianginal medication that can be used safely in patients to reduce postoperative AF. In conclusion, this study showed a reduction in the incidence of AF by 38%. Although not statistically significant, this indicates a trend towards our hypothesis.