Perspective:

Ever since the COMPANION trial, which was not powered to compare CRT-P with CRT-D, there has been an ongoing debate about to what extent an ICD provides greater protection from mortality than a CRT device alone. CRT on its own accord reduces the risk for sudden cardiac death through reverse left ventricular remodeling. Medical therapy for heart failure has advanced with the addition of new heart failure therapies such as angiotensin receptor–neprilysin inhibitors (ARNIs) and sodium–glucose co-transporter 2 (SGLT2) inhibitors, both of which reverse remodeling of the left ventricle and reduce ventricular arrhythmia compared with controls. The DANISH trial showed no benefit for CRT-D over CRT-P devices in patients with nonischemic cardiomyopathy.

The current study is a large retrospective observational study. In the unadjusted analysis, treatment with CRT-P was associated with a higher incidence of all-cause death. However, CRT-P patients were on average 6.7 years older than CRT-D patients, and age differences accounted for the greatest part of the survival difference. After adjustment for age, there was no mortality difference between CRT-P and CRT-D. While still not providing a definitive answer, the findings of the current study suggest that the addition of a defibrillator may not be associated with improved mortality. The ongoing randomized RESET-CRT (Re-evaluation of Optimal Re-synchronization Therapy in Patients With Chronic Heart Failure) project should provide more insight into this clinical dilemma.