Reoperative sternotomy is associated with increased early mortality after cardiac transplantation

Objectives: Outcomes of cardiac transplantation in patients undergoing reoperative sternotomy are often worse than primary transplants. However, the risks imposed by a prior sternotomy, left ventricular assist device (LVAD) or retransplantation have not been independently analysed.

Methods: Using the United Network for Organ Sharing (UNOS) database, a retrospective propensity-matched cohort analysis was performed on 14 730 patients who received a heart transplant between 2005 and 2017. Of 7365 patients who underwent a reoperative sternotomy, 4526 (61%) patients had previous cardiac surgery, 2364 (32%) patients had an LVAD and 475 (6%) patients had a previous transplant. Baseline characteristics were compared, and survival was analysed using a Cox model.

Results: Compared to patients who underwent a primary transplant, patients with a prior sternotomy had a worse long-term survival (P < 0.001). There was no significant difference in survival between patients who had an LVAD and those who had a previous cardiac operation. However, all subgroups had better survival compared to patients who underwent a retransplant (P < 0.05). On the multivariable analysis, prior sternotomy and radiation demonstrated an increased risk of death compared to primary transplants [prior cardiac surgery: hazard ratio (HR) 1.13, 95% confidence interval (CI) 1.05-1.22; P = 0.001; LVAD: HR 1.19, 95% CI 1.08-1.32; P = 0.001; retransplant: HR 1.68, 95% CI 1.42-1.99; P < 0.001; radiation: HR 1.82, 95% CI 1.00-3.30; P = 0.04]. When excluding patients who died in the first year, there were no significant differences in survival between the primary transplant, prior cardiac surgery, LVAD and retransplant groups.

Conclusions: Prior sternotomy is a risk factor for worse survival after cardiac transplantation, mainly due to increased early postoperative mortality. A history of prior transplant confers the greatest risk compared to those who received an LVAD or had prior cardiac surgery.