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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
Impact of implantable defibrillators and resynchronization therapy on outcome in patients with left ventricular
Jawdat Abdulla1, Jens Haarbo, Lars Køber
1Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark. ja@heart.dk
Insights
Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillators (ICD) reduce mortality and hospitalizations in patients with left ventricular systolic dysfunction (LVSD). Combined CRT and ICD therapy further lowers all-cause mortality in select LVSD patients.
Area of Science:
- Cardiology
- Medical Devices
- Clinical Trials
Background:
- The clinical efficacy of cardiac resynchronization therapy (CRT) and prophylactic implantable cardioverter defibrillators (ICD) for patients with left ventricular systolic dysfunction (LVSD) remains a subject of debate.
- Left ventricular systolic dysfunction (LVSD) affects a significant patient population, necessitating effective therapeutic strategies.
Purpose of the Study:
- To conduct a meta-analysis evaluating the impact of CRT and prophylactic ICD therapy on patients diagnosed with LVSD.
- To synthesize evidence from multiple clinical trials to provide a comprehensive understanding of device therapy benefits.
Main Methods:
- A meta-analysis was performed on eligible trials comparing CRT versus no-CRT, ICD versus no-ICD, and the addition of ICD to CRT versus no-ICD.
- Key outcomes assessed included all-cause mortality, cardiac mortality, heart failure hospitalizations, exercise tolerance, and New York Heart Association (NYHA) functional class.
Main Results:
- CRT implantation significantly reduced all-cause mortality (OR=0.73) and heart failure hospitalizations (OR=0.60), while improving exercise tolerance and NYHA class.
- ICD implantation demonstrated a reduction in all-cause mortality (OR=0.75) and cardiac mortality (OR=0.63).
- The combination of ICD with CRT further decreased all-cause mortality (OR=0.69) in patients with LVSD.
Conclusions:
- Certain patients with LVSD derive significant clinical benefits from CRT, ICD, or a combination of both therapies.
- Further research is warranted to precisely identify patient subgroups who will most benefit from single or combined device implantation strategies.
Background:
The clinical benefits of cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter defibrillator (ICD) in patients with left ventricular systolic dysfunction (LVSD) are debated.
Objective:
To evaluate by a meta-analysis the effect of CRT and prophylactic ICD therapy in patients with LVSD.
Methods:
Eligible trials evaluating the effect of CRT vs. no-CRT, ICD vs. no-ICD and adding ICD to CRT vs. no-ICD were selected and meta-analyzed. The outcomes were: all cause mortality, cardiac mortality, hospitalization for heart failure and change in exercise tolerance and New York Heart Association class.
Results:
Implantation of CRT reduced all cause mortality odds ratio (OR) = 0.73 (0.60-0.89) p = 0.002 and hospitalization for heart failure OR = 0.60 (0.45, 0.80) p = 0.001, increased peak oxygen consumption by 1.77 (0.32-3.22) ml/kg/min p = 0.017 and improved New York Heart Association class by at least one class with OR = 1.52 (1.30, 1.77) p < 0.0001. Implantation of ICD reduced all-cause mortality OR = 0.75 (0.59-0.96) p = 0.025 and cardiac mortality OR = 0.63 (0.48, 0.82) p = 0.001. Adding ICD to CRT reduced all cause mortality OR = 0.69 (0.53-0.91) p = 0.008.
Conclusion:
Selective patients with LVSD benefit from CRT, ICD or both. Further investigations are necessary to clarify which patients benefit most from a single or combined device implantation.
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