CRT-D reduced the 7-year rate of death from any cause compared to defibrillator therapy alone in patients with mild heart failure and LBBB (18% vs 29%; HR 0.59; 95% CI 0.43-0.80; P<0.001).
RCT (n=1,691)
Randomly assigned
Yes
Does early intervention with CRT-D improve long-term survival in patients with mild heart failure and left ventricular dysfunction compared to defibrillator therapy alone?
In patients with mild heart failure, left ventricular dysfunction, and left bundle-branch block, early intervention with CRT-D provides a significant long-term survival benefit compared to defibrillator therapy alone.
Hazard Ratio: 0.59 (95% CI 0.43–0.8)
Absolute Event Rate: 18% vs 29%
p-value: p=<0.001
BACKGROUND: The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) showed that early intervention with cardiac-resynchronization therapy with a defibrillator (CRT-D) in patients with an electrocardiographic pattern showing left bundle-branch block was associated with a significant reduction in heart-failure events over a median follow-up of 2.4 years, as compared with defibrillator therapy alone. METHODS: We evaluated the effect of CRT-D on long-term survival in the MADIT-CRT population. Post-trial follow-up over a median period of 5.6 years was assessed among all 1691 surviving patients (phase 1) and subsequently among 854 patients who were enrolled in post-trial registries (phase 2). All reported analyses were performed on an intention-to-treat basis. RESULTS: At 7 years of follow-up after initial enrollment, the cumulative rate of death from any cause among patients with left bundle-branch block was 18% among patients randomly assigned to CRT-D, as compared with 29% among those randomly assigned to defibrillator therapy alone (adjusted hazard ratio in the CRT-D group, 0.59; 95% confidence interval CI, 0.43 to 0.80; P<0.001). The long-term survival benefit of CRT-D in patients with left bundle-branch block did not differ significantly according to sex, cause of cardiomyopathy, or QRS duration. In contrast, CRT-D was not associated with any clinical benefit and possibly with harm in patients without left bundle-branch block (adjusted hazard ratio for death from any cause, 1.57; 95% CI, 1.03 to 2.39; P=0.04; P<0.001 for interaction of treatment with QRS morphologic findings). CONCLUSIONS: Our findings indicate that in patients with mild heart-failure symptoms, left ventricular dysfunction, and left bundle-branch block, early intervention with CRT-D was associated with a significant long-term survival benefit. (Funded by Boston Scientific; ClinicalTrials.gov numbers, NCT00180271, NCT01294449, and NCT02060110.).
Goldenberg et al. (2014) conducted an RCT in Mild heart failure (n=1,691). Cardiac-resynchronization therapy with a defibrillator (CRT-D) vs. Defibrillator therapy alone was evaluated on Death from any cause (HR 0.59, 95% CI 0.43 to 0.80, p=<0.001). CRT-D reduced the 7-year rate of death from any cause compared to defibrillator therapy alone in patients with mild heart failure and LBBB (18% vs 29%; HR 0.59; 95% CI 0.43-0.80; P<0.001).