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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
Cardiac resynchronization therapy in pacemaker-dependent patients with left ventricular dysfunction.
John Gierula1, Richard M Cubbon, Haqeel A Jamil
1Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK.
Summary
Cardiac resynchronization therapy (CRT) significantly improves heart function and quality of life in pacemaker patients with left ventricular systolic dysfunction (LVSD) and right ventricular (RV) pacing. This intervention, performed during pulse generator replacement (PGR), offers substantial benefits over standard pacing.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Permanent pacemakers often lead to left ventricular (LV) systolic dysfunction (LVSD) due to unavoidable right ventricular (RV) pacing.
- Existing treatments for heart failure in these patients are limited, especially when severe symptoms are absent.
Purpose of the Study:
- To evaluate the efficacy of cardiac resynchronization therapy (CRT) during pulse generator replacement (PGR) in patients with RV pacing and LVSD.
- To assess if CRT improves cardiac function and clinical outcomes in this specific patient population.
Main Methods:
- A randomized controlled trial involving 50 patients with unavoidable RV pacing and LVSD undergoing PGR.
- Patients were randomized to either standard RV-PGR or CRT.
- Primary endpoint: change in LV ejection fraction (LVEF) at 6 months; secondary endpoints included exercise capacity, quality of life, and NT-proBNP levels.
Main Results:
- CRT significantly improved LVEF by 9% compared to a decrease of -1.5% in the RV-PGR group (P < 0.0001).
- CRT also led to improvements in peak oxygen consumption (P = 0.007), quality of life (P = 0.03), and NT-proBNP levels (P = 0.007).
- Long-term follow-up showed fewer hospitalizations in the CRT group, and two patients in the RV-PGR arm required CRT for worsening heart failure.
Conclusions:
- Performing CRT during PGR in pacemaker patients with RV pacing and LVSD, even without severe symptoms, enhances cardiac function.
- CRT improves exercise capacity, quality of life, and reduces NT-proBNP levels in this patient cohort.
- This strategy offers a significant clinical benefit for patients with pacemaker-induced LVSD.
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