Survival with cardiac-resynchronization therapy in mild heart failure.

Abstract

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.).

• Authors: Ilan Goldenberg, Valentina Kutyifa, Helmut U Klein, David S Cannom, Mary W Brown, Ariela Dan, James P Daubert, N A Mark Estes 3rd, Elyse Foster, Henry Greenberg, Josef Kautzner, Robert Klempfner, Malte Kuniss, Bela Merkely, Marc A Pfeffer, Aurelio Quesada, Sami Viskin, Scott McNitt, Bronislava Polonsky, Ali Ghanem, Scott D Solomon, David Wilber, Wojciech Zareba, Arthur J Moss
• Journal: The New England journal of medicine (N Engl J Med) Vol. 370 Issue 18 Pg. 1694-701 (May 01 2014) ISSN: 1533-4406 [Electronic] United States
• PMID: 24678999 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Topics

• Aged
• Bundle-Branch Block (complications, therapy)
• Cardiac Resynchronization Therapy
• Combined Modality Therapy
• Defibrillators, Implantable
• Female
• Follow-Up Studies
• Heart Failure (complications, mortality, prevention & control, therapy)
• Humans
• Intention to Treat Analysis
• Kaplan-Meier Estimate
• Male
• Middle Aged
• Proportional Hazards Models
• Severity of Illness Index
• Stroke Volume
• Ventricular Dysfunction, Left (complications)