Abstract 13790: Is There a Difference in Benefits from Cardiac Resynchronization Therapy in Ischemic and Non-Ischemic Cardiomyopathy Patients?
Background---Cardiac resynchronization therapy (CRT) is an effective adjunct to pharmacologic management to reduce mortality and heart failure hospitalization rates but reports conflict regarding consistency of benefit based on underlying cardiac condition. Even large randomized control trials have differing outcomes in CRT treated patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM) and previous meta-analyses have not specifically answered this question.
Methods---We conducted a systematic review and meta-analysis of the published randomized trials that reported combined mortality and heart failure or cardiovascular hospitalization for patients with ICM and NICM treated with CRT with or without defibrillator. All the studies reported hazard ratios, which were adjusted for confounding variables (including age, race, gender, ejection fraction, QRS duration, New York Heart Association class and prior myocardial infarction) and generic inverse variance using log-hazard ratios was used to combine them.
Results---There was no significant heterogeneity among studies (the Q test heterogeneity p value >0.1) and a random effect model was used for all analysis for stringency. Five studies with 6561 patients were included in this study. The combined death and heart failure or cardiovascular hospitalization rate for CRT (with or without a defibrillator) Vs. no CRT (whether on optimal medical therapy alone or medical therapy along with a standard defibrillator) was similar across both ischemic (Hazard ratio [HR]- 0.71, 95% confidence interval [CI]- 0.64-0.79, p<0.001) and non-ischemic subgroups (HR- 0.72, 95% CI-0.60-0.86, p<0.001). Using the Welch's t-test, (to compare unpaired samples with unequal variance), no difference in the reported hazard ratios was noted (p = 0.8).
Conclusion---CRT is seen to have a similar effect on the composite endpoint of death and heart failure or cardiovascular hospitalization regardless of whether the cardiomyopathy is ischemic or not.
- © 2012 by American Heart Association, Inc.