ICD replacement in patients with intermediate left ventricular dysfunction under optimal medical treatment

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Implantable cardioverter-defibrillators (ICD) are crucial for preventing arrhythmias in patients with low ejection fraction.
• The strategy for replacing ICDs in patients with preserved ejection fraction nearing battery life remains debated.

Purpose of the Study:

• To assess long-term arrhythmic outcomes in patients with ICDs or CRT-Ds who have normal or intermediate left ventricular ejection fraction (LVEF) at device replacement.
• To inform decisions regarding device replacement in this patient group.

Main Methods:

• Retrospective analysis of patients with heart failure implanted with ICDs or CRT-Ds for primary prevention (2002-2009).
• Included patients without prior ICD interventions and LVEF ≥35% at average battery replacement time (5-6 years post-implantation).
• Primary outcome was the occurrence of appropriate ICD interventions during long-term follow-up.

Main Results:

• Of 255 patients, 45 (18%) had LVEF ≥35% without interventions at 5 years (10% ICD, 29% CRT-D).
• Long-term appropriate ICD interventions occurred in 27% of the ICD group and 17% of the CRT-D group.
• A significant proportion of patients with preserved LVEF experienced appropriate interventions.

Conclusions:

• Patients with ICDs or CRT-Ds, even with preserved LVEF at battery replacement, remain at risk for significant arrhythmic events.
• These findings support the consideration of device replacement irrespective of the degree of left ventricular dysfunction.