Long-term outcomes and clinical predictors for pacemaker-requiring bradyarrhythmias after cardiac transplantation: analysis of the UNOS/OPTN cardiac transplant database

Background: Pacemaker-requiring bradyarrhythmias after cardiac transplantation are common, and rarely can lead to sudden cardiac death. Prior outcomes studies have been limited to single-center data.

Objective: This study sought to define the long-term outcomes and clinical predictors for pacemaker-requiring bradyarrhythmias in the cardiac transplant population.

Methods: This study used multivariable analysis of the United Network for Organ Sharing/Organ Procurement and Transplantation Network (UNOS/OPTN) database of sequential U.S. cardiac transplant recipients from 1997 to 2007 stratified by postoperative bradyarrhythmias requiring a pacemaker. The primary end point was all-cause mortality.

Results: Among 35,987 cardiac transplant recipients (age 46.1 ± 18.3 years, 76% male, 22% bicaval technique) with a follow-up of 6.3 ± 4.7 years, pacemaker-requiring bradyarrhythmias occurred in 3,940 patients (10.9%). Pacemaker recipients demonstrated improved survival (median 8.0 years vs. 5.2 years, P < .001), decreased 5-year mortality (13.8% vs. 17.7%, P < .001), and overall crude mortality (42.9% vs. 45.9%, P < .001). Multivariable propensity-score-adjusted analysis demonstrated improved survival among pacemaker recipients (adjusted hazard ratio 0.84, 95% confidence interval [CI] 0.80 to 0.88, P < .001) after adjustment for donor/recipient age, UNOS listing status, donor heart ischemic time, surgical technique, graft rejection, and other common comorbidities. The bicaval surgical technique was strongly protective against a postoperative pacemaker requirement (odds ratio [OR] 0.33, 95% CI 0.29 to 0.36, P < .001) in multivariable analysis. Among the other variables studied, only increasing donor age (OR 1.04, 95% CI 1.00 to 1.09, P < .001) and recipient age (OR 1.09, 95% CI 1.0 to 1.12, P < .001) were associated with a permanent pacemaker requirement.

Conclusion: Cardiac transplant recipients with pacemaker-requiring bradyarrhythmias have an excellent long-term prognosis. Increased mortality in the nonpacemaker group merits further investigation. Biatrial surgical technique and increasing donor/recipient age are associated with postoperative pacemaker requirement.