Positive response to cardiac resynchronization therapy reduces arrhythmic events after elective generator change in
Frederic A Sebag1, Nicolas Lellouche, Zhong Chen
1Fédération de cardiologie, Hôpital Henri Mondor, Assistance Publique Hôpitaux de Paris et INSERMU955, Créteil, France; Division of Cardiovascular Medicine, St. Thomas' Hospital, Guy's and Saint Thomas NHS Trust, London, UK.
Insights
Many patients receiving CRT-D therapy for heart failure may no longer need an ICD at device replacement due to improved heart function. This study found that absence of theoretical ICD indication is common and associated with low appropriate therapy rates.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) and implantable cardioverter-defibrillators (ICD) are established treatments for heart failure (HF) patients with cardiac dyssynchrony.
- Positive remodeling from CRT can improve left ventricular ejection fraction (LVEF), potentially diminishing the need for ICD therapy in primary prevention patients.
Purpose of the Study:
- To evaluate the outcomes of CRT-defibrillator (CRT-D) patients at the time of device replacement (DR).
- To determine the incidence of patients no longer meeting criteria for ICD indication after CRT.
- To assess appropriate therapy rates in CRT-D patients without ongoing ICD indication at DR.
Main Methods:
- Prospective enrollment of 107 primary prevention CRT-D patients undergoing DR across two centers (November 2007 - March 2011).
- CRT response defined as ≥1 NYHA class improvement and ≥10% LVEF increase.
- Patients without theoretical ongoing ICD indication (TOII) at DR had LVEF ≥40% and no appropriate ICD therapy during the first device service life.
Main Results:
- 57% of patients were CRT responders.
- At DR, 37% of patients did not meet criteria for TOII.
- Among patients without TOII, 95% remained free of appropriate therapy during follow-up, compared to 72% with TOII (P = 0.007).
- Absence of TOII was the only independent predictor of appropriate therapy post-DR.
Conclusions:
- Over one-third of CRT-D patients undergoing DR may lack a theoretical ICD indication.
- The rate of appropriate therapy is low in this subgroup, suggesting potential for de-escalation of therapy.
- Device replacement evaluations should consider LVEF improvement and patient response to CRT.
Introduction:
Cardiac resynchronization therapy (CRT) and implantable cardioverter-defibrillators (ICD) are effective therapies for heart failure (HF) patients with cardiac dyssynchrony. Patients receiving primary prevention CRT-defibrillator that positively remodel might no longer qualify for ICD indication due to CRT-induced left ventricular ejection fraction (LVEF) improvement. We aimed to evaluate the outcome of CRT-D patients at the time of device replacement (DR).
Methods And Results:
Patients undergoing primary prevention CRT-D DR were prospectively included from November 2007 to March 2011 in 2 centers. CRT response was as defined as ≥1 NYHA class improvement and an increase in LVEF ≥10%. Before DR, all patients underwent echocardiography and device interrogation. Patients without theoretical ongoing ICD indication (TOII) at DR were defined as those with LVEF ≥40% without appropriate ICD therapy (appropriate therapy) during the first ICD service-life. A total of 107 consecutive patients were enrolled. Sixty-one patients (57%) were considered CRT responders after the index procedure. At the time of DR (56.4 ± 14.4 months from initial implant), 87% of CRT responders were free of appropriate therapy, compared with 70% of CRT nonresponders (P = 0.02). Thirty-nine patients (37%) did not meet the criteria for TOII. During follow-up (mean 26.4 ± 14.4 months after DR), 37 patients (95%) without TOII were free of appropriate therapy versus 49 of 68 patients (72%) with ongoing TOII (P = 0.007). By multivariable analysis, the only independent predictor of appropriate therapy after DR was TOII (hazard ratio = 6.43; P = 0.01).
Conclusion:
Absence of theoretical ICD indication occurs in more than one-third of CRT-D patients undergoing DR. In addition, appropriate therapy rate is relatively low (2.2% per year) in this subgroup of patients.
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