Assessment of Ventricular Arrhythmia Risk After CRT-D Replacement for Patients With Primary Prevention Indication

Cardiac resynchronization therapy (CRT) has been shown to reduce heart failure (HF), hospitalizations and death in patients with left ventricular ejection fraction (LVEF) \<35% and wide QRS. CRT provides electromechanical resynchronization and improves LV systolic function. The induced LV reverse remodeling or near normalization in LVEF to ≥45% is associated with a significant reduction in the risk of subsequent life-threatening ventricular tachyarrhythmias (VTA). And at the time of replacement, the need for defibrillator back-up after an event-free first CRT-D service-life for patients with improved LVEF is a controversy question. 80% of Implantable Cardioverter Defibrillator (ICD) patients implanted for primary prevention do not experience VTA during the life-time of their first device. So, regarding patients implanted with a CRT-D for primary prevention at the time of first implantation, the question is will they experience VTA after their device replacement by another CRT-D.

The objective of this study is to describe, in a population of patients who had a primary prevention ICD indication at first implantation of a CRT-D, the relevance defibrillator back-up after the replacement of the first CRT-D. For that, the rate of patients with at least one sustained VTA detected by the CRT-D or a conventional surface ECG will be assessed after the device replacement. Furthermore, the association between the baseline characteristics of the CRT-D population after replacement and the risk of subsequent VTA will be explored after a minimum of two years FU.