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Updated: Jun 14, 2026
Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Which patients with chronic heart failure should be referred for CRT-D implantation? Practical implications of
Wojciech Zareba1, Karolina M Zareba
1Cardiology Division, University of Rochester Medical Center, Rochester, New York, USA. wojciech_zareba@urmc.rochester.edu
Insights
Cardiac resynchronization therapy (CRT) with defibrillators (CRT-D) benefits heart failure patients. Early CRT-D use in less advanced heart failure may slow disease progression.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) is a key treatment for heart failure.
- Implantable cardioverter-defibrillators (ICD) are standard for preventing mortality in cardiomyopathy.
- CRT-defibrillator (CRT-D) devices combine both therapies for eligible patients.
Purpose of the Study:
- To evaluate the benefits of CRT-D in heart failure patients.
- To assess the efficacy of CRT-D in patients with less advanced heart failure.
- To determine if a proactive approach with CRT-D can reduce heart failure progression.
Main Methods:
- Review of randomized clinical trials and data from the MADIT-CRT trial.
- Analysis of patient subgroups based on heart failure severity (NYHA class), ejection fraction (EF), and QRS duration.
- Comparison of CRT-D outcomes against optimal pharmacological therapy.
Main Results:
- CRT-D significantly decreases heart failure progression in patients with NYHA class III or IV, EF ≤35%, and QRS ≥120 ms.
- MADIT-CRT data show benefits in less advanced heart failure (NYHA class I/II, EF ≤30%, QRS ≥130 ms).
Conclusions:
- CRT-D is beneficial for heart failure patients across various disease stages.
- Consideration of CRT-D in patients with less advanced heart failure may be warranted for proactive management.
- Early intervention with CRT-D could help mitigate long-term heart failure progression.
Abstract:
Over the last decade, cardiac resynchronization therapy (CRT) has emerged as an important treatment modality in patients with heart failure. Primary prevention of mortality with implantable cardioverter-defibrillator (ICD) in patients with ischemic and nonischemic cardiomyopathy and left ventricular dysfunction (ejection fraction [EF] < or =35%) has become the standard of care. A growing number of patients with indications for ICD are also eligible for CRT, receiving resynchronization pacing-defibrillator devices (CRT-D). Randomized clinical trials have provided evidence that cardiac resynchronization therapy is beneficial in heart failure patients and contributes to a significant decrease in heart failure progression on top of administering optimal pharmacological therapy. Currently approved indications for CRT-D include utilizing this treatment modality in heart failure patients with New York Heart Association (NYHA) class III or IV, EF < or =35%, and QRS > or =120 ms. New data from MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) document that patients with less advanced heart failure (ischemic cardiomyopathy in NYHA class I or II and nonischemic cardiomyopathy class II), EF < or =30%, and QRS > or =130 ms also benefit from CRT. These findings indicate that a more proactive approach should be considered regarding the management of heart failure patients with less advanced disease to decrease progression of heart failure with CRT-D therapy.
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