Outcomes after heart transplantation in patients who have undergone a bridge-to-bridge strategy

Abstract

Objectives: We compared posttransplant outcomes between patients bridged from temporary mechanical circulatory support to durable left ventricular assist device before transplant (bridge-to-bridge [BTB] strategy) and patients bridged from temporary mechanical circulatory support directly to transplant (bridge-to-transplant [BTT] strategy).

Methods: We identified adult heart transplant recipients in the Organ Procurement and Transplantation Network database between 2005 and 2020 who were supported with extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary ventricular assist device as a BTB or BTT strategy. Kaplan-Meier survival analysis and Cox regressions were used to assess 1-year, 5-year, and 10-year survival. Posttransplant length of stay and complications were compared as secondary outcomes.

Results: In total, 201 extracorporeal membrane oxygenation (61 BTB, 140 BTT), 1385 intra-aortic balloon pump (460 BTB, 925 BTT), and 234 temporary ventricular assist device (75 BTB, 159 BTT) patients were identified. For patients supported with extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary ventricular assist device, there were no differences in survival between BTB and BTT at 1 and 5 years posttransplant, as well as 10 years posttransplant even after adjusting for baseline characteristics. The extracorporeal membrane oxygenation BTB group had greater rates of acute rejection (32.8% vs 13.6%; P = .002) and lower rates of dialysis (1.6% vs 21.4%; P < .001). For intra-aortic balloon pump and temporary ventricular assist device patients, there were no differences in posttransplant length of stay, acute rejection, airway compromise, stroke, dialysis, or pacemaker insertion between BTB and BTT recipients.

Conclusions: BTB patients have similar short- and midterm posttransplant survival as BTT patients. Future studies should continue to investigate the tradeoff between prolonged temporary mechanical circulatory support versus transitioning to durable mechanical circulatory support.

Keywords: BTB, bridge-to-bridge; BTT, bridge-to-transplant; CO, cardiac output; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; LVAD, left ventricular assist device; MCS, mechanical circulatory support; OPTN, Organ Procurement and Transplantation Network; PA, pulmonary artery; PCWP, pulmonary capillary wedge pressure; TAH, total artificial heart; UNOS, United Network for Organ Sharing; extracorporeal membrane oxygenation; heart transplant; intra-aortic balloon pump; mPAP, mean pulmonary arterial pressure; mechanical circulatory support; tVAD, temporary ventricular assist device; transplant outcomes; ventricular assist devices.

Graphical abstract

Ten-year survival curve for IABP bridge-to-bridge and bridge-to-transplant patients.

Figure 1

Flow diagram showing inclusion and exclusion criteria to generate study population. TAH, Total artificial heart; MCS, mechanical circulatory support; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; tVAD, temporary ventricular assist device; LVAD, left ventricular assist device; BTT, bridge-to-transplant; BTB, bridge-to-bridge.

Figure 2

Ten-year posttransplant survival of bridge-to-bridge versus bridge-to-transplant from extracorporeal membrane oxygenation. Individual plots were truncated when the number at risk fell below 10. 95% confidence intervals (CI) in shaded area.

Figure 3

Ten-year posttransplant survival of bridge-to-bridge versus bridge-to-transplant from intra-aortic balloon pump. Individual plots were truncated when the number at risk fell below 10. 95% confidence intervals (CI) in shaded area.

Figure 4

Ten-year posttransplant survival of bridge-to-bridge versus bridge-to-transplant from temporary ventricular assist device. Individual plots were truncated when the number at risk fell below 10. 95% confidence intervals (CI) in shaded area.

Figure 5

Summary of results of the study. 95% confidence intervals (CI) in shaded area. MCS, Mechanical circulatory support; OPTN, Organ Procurement and Transplantation Network; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; tVAD, temporary ventricular assist device; BTB, bridge-to-bridge; BTT, bridge-to-transplant.

Figure E1

Waitlist outcomes for candidates initially listed with (A) extracorporeal membrane oxygenation (ECMO), (B) intra-aortic balloon pump (IABP), and (C) temporary ventricular assist device (tVAD). 95% confidence intervals (CI) in shaded area.