C onsiderable clinical decision making revolves around the use of left ventricular ejection fraction (LVEF) for prognosis and for indications for use of both implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT). Guidelines support implantation for CRT for heart failure (HF) patients with LVEF ≤30% with left bundle-branch block (LBBB), sinus rhythm, and New York Heart Association (NYHA) class II, class III, and ambulatory class IV HF symptoms (Class IA recommendation). Similarly, guidelines support implantation of an ICD in postmyocardial infarction patients with LVEF ≤35% (Class IA recommendation) and in nonischemic cardiomyopathy HF Background-Appropriate guideline criteria for use of implantable cardioverter-defibrillators (ICDs) do not take into account potential recovery of left ventricular ejection fraction (LVEF) in patients treated with CRT-defibrillator. Methods and Results-Patients randomized to CRT-defibrillator from the Multicenter Automatic Defibrillator ImplantationTrial With Cardiac Resynchronization Therapy (MADIT-CRT) trial who survived and had paired echocardiograms at enrollment and at 12 months (n=752) were included. Patients were evaluated by LVEF recovery in 3 groups (LVEF ≤35% [reference], 36%-50%, and >50%) on outcomes of ventricular tachyarrhythmias (VTAs), VTA ≥200 bpm, ICD shock, heart failure or death, and inappropriate ICD therapy by multivariable Cox models. A total of 7.3% achieved LVEF normalization (>50%). The average follow-up was 2.2±0.8 years.

In patients with terminal conditions who are at risk for imminent death, active management of the patient's ICD, including timely discussions regarding ICD deactivation, may reduce the risk of ICD shocks during the end of life.