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Is CRT pro-arrhythmic? A comparative analysis of the occurrence of ventricular arrhythmias between patients implanted
A B Gopalamurugan1, G Ganesha Babu1, Dominic P Rogers1
1Department of Cardiac Electrophysiology, The Heart Hospital, Institute of Cardiovascular Sciences, University College London UK.
Insights
Cardiac resynchronization therapy (CRT) with defibrillators (CRT-D) did not increase ventricular arrhythmias (VA) compared to implantable cardioverter-defibrillators (ICD) alone. This study found no evidence that CRT is pro-arrhythmic in primary prevention patients.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Cardiac resynchronization therapy (CRT) offers symptomatic and mortality benefits.
- Anecdotal evidence suggests CRT may be pro-arrhythmic in some patients.
- Large trials show CRT improves mortality and morbidity.
Purpose of the Study:
- To compare the incidence of ventricular arrhythmias (VA) in patients receiving CRT with defibrillators (CRT-D) versus implantable cardioverter-defibrillators (ICD) for primary prevention.
- To investigate the hypothesis that CRT is not pro-arrhythmic, aligning with existing mortality and morbidity data.
Main Methods:
- Retrospective analysis of 180 patients with cardiomyopathy receiving CRT-D or ICD for primary prevention between 2005-2007.
- Patients had no prior history of sustained VA.
- VA episodes were identified from stored electrograms and classified as sustained (VT/VF) or non-sustained (NSVT).
Main Results:
- No significant difference in the overall incidence of VA between CRT-D (35.0%) and ICD (38.1%) groups (p=0.74).
- Similar rates of sustained VT (21.3% vs 28.5%, p=0.36) and NSVT (12.8% vs 9.5%, p=0.63) were observed.
- Therapy delivery for VT/VF, including anti-tachycardia pacing and shocks, was comparable between groups.
Conclusions:
- In patients receiving CRT-D or ICD for primary prevention, there was no significant difference in VA incidence.
- This single-center retrospective analysis does not support the notion that cardiac resynchronization therapy is pro-arrhythmic.
Unlabelled:
Aim and Hypothesis: Despite the proven symptomatic and mortality benefit of cardiac resynchronization therapy (CRT), there is anecdotal evidence it may be pro-arrhythmic in some patients. We aimed to identify if there were significant differences in the incidence of ventricular arrhythmias (VAs) in patients undergoing CRT-D and implantable cardioverter-defibrillators (ICD) implantation for primary prevention indication. We hypothesized that CRT is unlikely to be pro-arrhythmic based on the positive mortality and morbidity data from large randomized trials.
Methods And Results:
A retrospective analysis of device therapies for VA in a primary prevention device cohort was performed. Patients with ischemic (IHD) and non-ischemic (DCM) cardiomyopathy and ICD or CRT+ICD devices (CRT-D) implanted between 2005 and 2007 without prior history of sustained VA were included for analysis. VA episodes were identified from stored electrograms and defined as sustained (VT/VF) if therapy [anti-tachycardia pacing (ATP) or shocks] was delivered or non-sustained (NSVT) if not. Of a total of 180 patients, 117 (68% male) were in the CRT-D group, 42% IHD, ejection fraction (EF) 24.5 ± 8.2% and mean follow-up 23.9 ± 9.8 months. 63 patients (84% male) were in the ICD group, 60% IHD, EF 27.7 ± 7.2% and mean follow-up 24.6 ± 10.8 months. Overall, there was no significant difference in the incidence of VA (35.0 vs. 38.1%, p = 0.74), sustained VT (21.3 vs. 28.5%, p = 0.36) or NSVT (12.8 vs. 9.5%, p = 0.63) and no significant difference in type of therapy received for VT/VF: ATP (68 vs. 66.6%, p = 0.73) and shocks (32 vs. 33.3%, p = 0.71) between the CRT-D and ICD groups, respectively.
Conclusion:
In patients with cardiomyopathy receiving CRT-D and ICDs for primary prophylaxis, there was no significant difference in the incidence of VA. From this single center retrospective analysis, there is no evidence to support cardiac resynchronization causing pro-arrhythmia.
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