Cardiac Resynchronization With or Without Defibrillator in Nonischemic Cardiomyopathy: A Nationwide Cohort Study...

Area of Science:

• Cardiology
• Medical Devices
• Clinical Trials

Background:

• Evolving therapies for heart failure with reduced ejection fraction necessitate clarity on defibrillator benefits during cardiac resynchronization therapy (CRT).
• The specific impact of defibrillators in nonischemic cardiomyopathy (NICM) patients undergoing CRT remains uncertain.
• This study addresses the long-term survival outcomes for NICM patients treated with CRT defibrillator (CRT-D) versus CRT pacemaker (CRT-P).

Purpose of the Study:

• To evaluate the long-term survival rates of patients with nonischemic cardiomyopathy (NICM) receiving CRT defibrillator (CRT-D) compared to CRT pacemaker (CRT-P).
• To assess secondary outcomes including generator replacement, device infections, heart failure hospitalizations, and ventricular arrhythmias in NICM patients undergoing CRT.

Main Methods:

• A multicenter cohort study (DECIDE-CRT) analyzed data from 170 US Veterans Affairs hospitals.
• Patients with NICM receiving primary-prevention CRT-P or CRT-D between 2006 and 2020 were identified.
• Propensity score weighting and inverse probability of treatment weighting were used to balance baseline characteristics and estimate all-cause mortality hazards.

Main Results:

• Of 3965 NICM patients, 3158 received CRT-D and 807 received CRT-P.
• After a median follow-up of 5.2 years, the adjusted hazard ratio for all-cause mortality was 0.90 (95% CI, 0.71-1.13; P=0.34), showing no significant difference.
• The CRT-D group experienced higher rates of generator replacement and device-related infections, with no significant difference in heart failure hospitalization rates.

Conclusions:

• This nationwide observational study did not find a clear survival advantage for adding a defibrillator to CRT in NICM patients.
• Residual confounding cannot be excluded, highlighting the need for further investigation.
• A randomized trial is recommended to definitively test the incremental value of CRT-D over CRT-P in the NICM population.