Abstract 18639: Implantable Cardioverter-defibrillator Use is Associated With Improved Survival on the Waitlist for Heart Transplantation: A UNOS/ OPTN Registry Analysis of 36,397 Patients

Background: Current guidelines do not support routine use of implantable cardioverter-defibrillators (ICDs) in patients (pts) with end-stage heart failure (HF), unless these pts are awaiting advanced HF therapies such as left ventricular assist devices (LVADs) or a heart transplantation (HT). Whether ICDs improve survival in end-stage HF pts awaiting HT has not been previously examined in a large, multicenter cohort. Hypothesis: Presence of ICDs at time of listing for HT is associated with lower waitlist mortality. Methods: The United Network for Organ Sharing registry was used to identify adults (≥18 years) listed for HT between January 4, 1999 & September 30, 2014. Pts with congenital heart disease, total artificial heart, restrictive cardiomyopathy, prior HT, or missing covariates were excluded. Cox regression analysis was used to assess the impact of an ICD at the time of listing on waitlist mortality. Results: The analysis included 36,397 pts (mean age 53±12; 77% males) listed for HT. The prevalence of ICDs at listing has steadily increased over time before reaching a plateau in 2006 (27% in 1999, and range 76-82% between 2006-2014). In the unadjusted model, ICD use was associated with a 36% reduction in waitlist mortality (HR 0.64, 95% CI 0.60-0.68, p<0.001). After adjustment for covariates such as age, sex, race, creatinine, ischemic cardiomyopathy, and listing status, this association was nearly unchanged (HR 0.67, 95% CI 0.62-0.72, p<0.001). Test for interaction by listing era (pre- and post-2006) was non-significant (p=0.28). In the final adjusted model, that included listing era and LVAD status in addition to the above listed covariates, ICD use continued to remain associated with a mortality benefit on the waitlist for HT (HR 0.84, 95% CI 0.78-0.91, p<0.001). Conclusion: ICDs are increasingly prevalent in pts listed for HT; however many pts are still listed for HT without these devices. The presence of an ICD at the time of listing is associated with lower mortality on the waitlist. Although the magnitude of ICD efficacy diminishes slightly, its benefit continues to remain significant even after adjustment for listing era and LVAD use. Further analyses are required to identify specific sub-groups of pts where ICD use is most beneficial and appropriate.