Implications of Early and Late Pacemaker Implantation After Heart Transplantation

Variables associated with permanent pacemaker (PPM) implantation after heart transplantation and the relationship between PPM placement and mortality are poorly understood. This study evaluates factors contributing to PPM insertion and subsequent mortality rates, with emphasis on the timing of implantation.

The United Network for Organ Sharing registry was queried for adult heart transplant recipients from 2010 to 2023. A multistate model was constructed, assessing the probability of 3 transitions: transplant to pacemaker, pacemaker to death, and transplant to death. Multivariable Cox proportional hazards models evaluated clinical factors influencing transitions, including early (≤30 days) and late (>30 days) PPM implantation.

Of the 30,566 patients included in the model, 1698 (5.6%) received a PPM, with most occurring in the late period (n = 1354 [79.7%]). At 5 years, late PPM recipients had a significantly higher cardiac allograft vasculopathy burden (30.3%) than non-PPM (14.9%) and early PPM (15.7%) recipients. Factors associated with increased probability of PPM insertion included antiarrhythmic use (hazard ratio [HR], 1.19 [1.02-1.40]), ischemia time (HR, 1.08 per hour [1.03-1.12]), and older donor age (HR, 1.02 per year [1.01-1.02]). Bicaval anastomosis decreased the likelihood of PPM insertion (HR, 0.69 [0.62-0.78]). Factors associated with increased probability of transition from PPM to death included late PPM insertion (HR, 2.58 [1.93-3.46]), recipient diabetes (HR, 1.29 [1.05-1.58]), and ischemic cardiomyopathy (HR, 1.25 [1.01-1.54]).

Longer ischemia time and antiarrhythmic use increased PPM likelihood. Late PPM recipients had a significantly higher probability of transitioning from implantation to death, warranting further investigation into contributing factors and its relationship with cardiac allograft vasculopathy.