Abstract 14093: Primary Prevention Cardiac Resynchronization Defibrillator Therapy Is Associated With Lower Risk for Ventricular Arrhythmias or Death Compared to a Cardioverter Defibrillator Alone: Results From MADIT-RIT
Background: Benefits of cardiac resynchronization defibrillator therapy (CRT-D) vs. an implantable cardioverter defibrillator (ICD) alone to prevent ventricular tachycardia (VT), ventricular fibrillation (VF) or death remains uncertain.
Objective: We aimed to compare monitored non-treated sustained (>30 beats) or ICD-treated VT, VF, or death end points in patients receiving an ICD alone or CRT-D in the MADIT-RIT Trial.
Methods: Kaplan-Meier survival analyses and multivariate Cox proportional hazards regression models were utilized to compare the incidence and the risk of monitored non-treated sustained, or treated VT, VF, or death in the ICD and CRT-D subgroups.
Results: Multivariate analyses accounted for significantly different baseline clinical characteristics (age, gender, ischemic etiology, and NYHA class at enrolment) and covariates predicting outcome (MADIT-RIT programming arm, diabetes, heart rate, and systolic blood pressure at enrolment). Of the ICD (n=742) and CRT-D (n=757) patients enrolled, risk of death was significantly lower in the CRT-D vs. ICD subgroup (HR=0.41, 95% CI: 0.23-0.72, p<0.002). The risk of monitored sustained or treated VT, VF or death was lower in CRT-D vs. ICD patients (Figure) (HR for the overall difference 0.65, 95% CI: 0.48-0.88, p=0.005). The significantly lower mortality and the lower risk of monitored sustained or treated VT/VF beyond 6 months follow-up (HR=0.58, 95% CI: 0.38-0.88, p=0.011) in patients with CRT-D vs. ICD contributed to this difference.
Conclusions: Implantation of a primary prevention CRT-D is associated with lower risk for VT/VF and death vs. an ICD alone. The benefit of CRT-D concerning VT/VF emerges 6 months after device implantation.
- Resynchronization therapy
- Implantable cardioconvert defibrillator
- Ventricular tachycardia
- Ventricular fibrillation
- © 2013 by American Heart Association, Inc.