Incidence, predictors, and temporal trends of sudden cardiac death after heart transplantation

Background Sudden cardiac death (SCD) has been reported to be a significant mode of death after heart transplantation (HT) in small case series. However, the incidence, timing, and predictors of SCD have not been examined in a large multicenter HT cohort. Objective The purpose of this study was to examine the incidence, timing, predictors, and temporal trends of SCD after HT. Methods Adults (≥18 years) who underwent first-time HT in the United States between 1987 and 2012 were retrospectively identified from the United Network for Organ Sharing (UNOS) registry. Patients with sudden cardiac arrest as the primary cause of death constituted the SCD group. Results Data on 37,492 HT recipients (mean age 51.9 ± 11.7 years, 77% male, 78% Caucasian) were analyzed. During mean follow-up of 6.5 ± 5.7 years, there were 17,324 (46%) deaths, of which 1659 (9.6%) were SCD. On multivariate Cox regression analysis, left ventricular ejection fraction (LVEF) ≤40% (hazard ratio [HR] 3.67, 95% confidence interval [CI] 3.23-4.17, P <.0001), allograft rejection (HR 1.51, 95% CI 1.35-1.70, P <.0001), and donor age (HR 1.17, 95% CI 1.13-1.23, P <.0001) were associated with increased risk of SCD, whereas recipient age (HR 0.90, 95% CI 0.86-0.95, P <.0001) and Caucasian race (HR 0.61, 95% CI 0.54-0.69, P <.0001) were associated with reduced risk. The incidence of SCD has shown no significant temporal improvement since 1987 (log-rank P =.84). Conclusion Approximately 10% of deaths after HT are due to SCD. Allograft rejection and LVEF ≤40% are strong predictors of SCD in adult HT patients. Whether implantable cardioverter-defibrillators would reduce mortality in these patients with a relative higher risk of non-SCD remains to be determined.