Impact of Implantable Cardioverter-Defibrillators on Waitlist Mortality Among Patients Awaiting Heart Transplantation: An UNOS/OPTN Analysis

Objectives This study sought to assess the impact of implantable cardioverter-defibrillators (ICDs) on waitlist mortality in patients listed for heart transplantation (HT). Background The impact of ICDs on preventing sudden cardiac death in patients awaiting HT has not been studied in large multicenter cohorts. Furthermore, whether ICDs benefit patients with a left ventricular assist device (LVAD) is unknown. Methods Adults (age ≥18 years) listed for first-time HT in the United States between January 1, 1999, and September 30, 2014, were retrospectively identified from the United Network for Organ Sharing registry. The primary predictor variable was the presence of an ICD at the time of listing. Primary outcome variable was all-cause waitlist mortality. Results Data on 32,599 patients (mean age 53 ± 12 years, 77% male, 70% Caucasian) were analyzed. During median follow-up of 154 days, 3,638 patients (11%) died on the waitlist (9% in ICD group vs. 15% in no-ICD group; p < 0.0001), whereas 63% underwent HT. Having an ICD at listing was associated with an adjusted 13% relative reduction in mortality (hazard ratio: 0.87; 95% confidence interval: 0.80 to 0.94). In the subgroup of patients with LVAD (n = 9,478), having an ICD was associated with an adjusted 19% relative reduction in mortality (hazard ratio: 0.81; 95% confidence interval: 0.70 to 0.94). Conclusions ICD use was associated with improved survival on the HT waitlist in patients with or without LVADs. These findings strengthen the current guideline recommendations of using ICDs in nonhospitalized patients awaiting HT and provide new insight into the effectiveness of ICDs on survival in LVAD-supported patients.