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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
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The Addition of a Defibrillator to Resynchronization Therapy Decreases Mortality in Patients With Nonischemic

Bethany Doran1, Chaoqun Mei2, Paul D Varosy3

  • 1Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.

JACC. Heart Failure
|May 16, 2021
PubMed

Insights

Patients with heart failure with reduced ejection fraction (HFrEF) due to nonischemic cardiomyopathy (NICM) benefit from cardiac resynchronization therapy with an implantable cardioverter-defibrillator (CRT-D). Those with ischemic cardiomyopathy (ICM) do not show this survival advantage.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Heart Failure Management

Background:

  • Cardiac resynchronization therapy (CRT) is used for heart failure with reduced ejection fraction (HFrEF).
  • The benefit of adding an implantable cardioverter-defibrillator (ICD) to CRT (CRT-D) versus CRT alone (CRT-P) in nonischemic HFrEF is unclear.
  • Understanding the impact of etiology (ischemic vs. nonischemic) on CRT outcomes is crucial.

Purpose of the Study:

  • To determine if patients with nonischemic heart failure with reduced ejection fraction (HFrEF) benefit from CRT with an ICD (CRT-D) compared to CRT without an ICD (CRT-P).
  • To analyze survival benefits based on the etiology of HFrEF.

Main Methods:

  • Analysis of the COMPANION trial data.
  • Cox proportional hazards modeling stratified by HFrEF etiology: nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM).
  • Primary outcome: all-cause mortality (ACM); Secondary outcomes: cardiovascular mortality/heart failure hospitalization, sudden cardiac death.

Main Results:

  • In the overall CRT population (n=1,212), CRT-D did not significantly reduce all-cause mortality (ACM) compared to CRT-P (HR 0.84).
  • A significant interaction between device type and etiology was observed (p=0.015).
  • In NICM patients (n=555), CRT-D was associated with reduced ACM (HR 0.54), while in ICM patients (n=657), CRT-D showed no significant reduction in ACM (HR 1.05).

Conclusions:

  • Cardiac resynchronization therapy with an ICD (CRT-D) provides a survival benefit in patients with nonischemic cardiomyopathy (NICM).
  • Patients with ischemic cardiomyopathy (ICM) receiving CRT-D did not demonstrate a significant reduction in all-cause mortality compared to CRT-P.
  • The findings highlight the importance of considering HFrEF etiology when selecting CRT therapy.
Abstract

Keywords:
cardiac resynchronization therapyheart failure with reduced ejection fractionimplantable cardioverter-defibrillatornonischemic cardiomyopathy

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