Prophylactic implantable cardioverter defibrillators for primary prevention: From implantation to heart transplantation

Abstract

The frequency, characteristics and outcomes of primary prevention implantable cardioverter defibrillator (ICD) recipients who eventually undergo heart transplantation (HT) during follow-up have not been well described. In a cohort of patients with heart failure implanted with an ICD for primary prevention of sudden cardiac death, to identify those at high risk of subsequent HT and evaluate ICD usefulness. Between 2002 and 2012, 5539 patients received a primary prevention ICD across 12 centers, and were enrolled in the DAI-PP programme, including 5427 with full HT information available. During a median follow-up of 1024 days (interquartile range 484-1702 days), 176 (3.2%) patients underwent HT. Median duration between ICD implantation and HT was 484 days (IQR 169-1117 days). Among those aged≤65 years (theoretical age limit for HT registration in France), the overall incidence per 1000 person-years was 18.03 (95% confidence interval [CI]: 15.32-20.74). Left ventricular ejection fraction<25% (hazard ratio [HR]: 3.43, 95% CI: 2.34-5.04; P<0.0001), younger age (HR: 0.95, 95% CI: 0.93-0.96; P<0.0001), New York Heart Association (NYHA) class III-IV (HR: 2.67, 95% CI: 1.79-4.00; P<0.0001) and no cardiac resynchronization therapy (HR: 2.09, 95% CI: 1.39-3.14; P=0.0004) were independently associated with HT. Patients with these three characteristics (excluding age) had a 1-year HT rate of 15.2%. Incidence of appropriate ICD therapies was 92.7 per 1000 person-years for patients who underwent HT versus 76.1 for those who did not (P=0.64). The overall incidence of HT in this primary prevention population was relatively high, especially among young patients with a very low ejection fraction, an advanced NYHA class and were unsuitable for cardiac resynchronization therapy (up to 15% annually). Patients awaiting HT experienced a significant rate of appropriate ICD therapies, reinforcing the importance of specific cardiac rhythm management in these patients.