Outcomes of Premature Ventricular Contraction-Cardiomyopathy in the Veteran Population: ASecondary Analysis of the CHF-STAT Study.

Abstract

This study sought to assess the rate and outcomes of premature ventricular contractions (PVC)-cardiomyopathy from the CHF-STAT (Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure) trial, a population with cardiomyopathy (left ventricular [LV] ejection fraction of<40%) and frequent PVCs (>10 PVCs per hour). PVCs are associated with heart failure and PVC-cardiomyopathy. The prevalence of PVC-cardiomyopathy and outcome benefits of PVC suppression are not clear. A secondary analysis of the CHF-STAT study was performed to compare the rate of successful PVC suppression (≥80% PVC reduction), LV recovery (defined as improvement in LV ejection fraction of≥10% points), and PVC-cardiomyopathy between amiodarone and placebo groups at 6months. PVC-cardiomyopathy was defined if both PVC reduction of≥80% and LV ejection fraction improvement of≥10% were present at 6months. Cardiac events (death or resuscitated cardiac arrest) were compared between PVC-cardiomyopathy versus non-PVC-cardiomyopathy during a 5-year follow-up. The rates of successful PVC suppression and LV recovery were significantly higher in the amiodarone (72% and 39%, respectively) when compared to the placebo group (12% and 16%, respectively; p<0.001), regardless of cardiomyopathy etiology. PVC-cardiomyopathy was present in 29% and 1.8% of patients in the amiodarone and placebo groups, respectively (p<0.001). Similar PVC-cardiomyopathy rates were found in ischemic (24% amiodarone vs. 2% placebo; p<0.001) and nonischemic populations (41% amiodarone vs. 1.5% placebo; p<0.001). Death and resuscitated cardiac arrest were significantly lower in patients with PVC-cardiomyopathy and those treated with amiodarone. The overall prevalence of PVC-cardiomyopathy in the CHF-STAT study was significant regardless of ischemic substrate (29%, overall population; 41%, nonischemic cardiomyopathy). Treatment of PVC-cardiomyopathy with amiodarone is likely to improve survival in this high-risk population.