Survival Benefit In Single Organ Heart Transplant Supported By Intra-aortic Balloon Pump

Abstract

Background The intra-aortic balloon pump (IABP) is the most commonly used mechanical circulatory support device for adults with cardiogenic shock awaiting heart transplantation (HT). Historical data suggest worse outcomes for these patients and it's yet to be seen how the revision in the United Network for Organ Sharing (UNOS) donor allocation scheme in October 2018 may have influenced outcomes. Given this, we sought to identity the impact of IABP use on outcomes after HT in the era prior to the revision. Methods We identified adults listed for HT with IABP at time of listing (excluding patients receiving VAD or ECMO) utilizing the Scientific Registry of Transplant Recipients database between 2000 and 2018. The patients were followed until death, transplant or end of data availability. Waitlist mortality and successful HT were compared between groups using a Fine and Gray competing risk hazard regression model adjusted for known risk factors. 30- and 90-day post-HT mortality was assessed using adjusted Cox proportional hazards regression. Results 25,325 patients were identified and 5% (N = 1256) were supported with an IABP at the time of listing. Those supported with an IABP had lower creatinine clearance, cardiac output and index, higher pulmonary capillary wedge, pulmonary artery systolic, diastolic and mean pressures (p < 0.01 for all). Unadjusted 30 day survival [mortality for IABP = 5.2% & no IABP = 4.4%; Log rank p = 0.0875] and 90 day survival [mortality for IABP = 7.7% & no IABP = 6.6%; Log rank p = 0.0503] post-transplant was worse in the IABP group (figure 1A & 1C). After adjustment, IABP use at the time of listing was significantly associated with a lower 30 day (HR 0.59, 95% CI 0.44-00.80; p=0.0008) and 90 day mortality (HR 0.63, 95% CI 00.49-0.80; p = 0.0002) (figure 1B and 1D). Conclusion Among adults who successfully underwent HT, IABP support significantly decreased 30 and 90 day mortality. This suggests an important role for IABP support in HT even after the revision in the UNOS donor allocation scheme. Systematic efforts should be made to identify the cohort which will derive this benefit while awaiting HT. The intra-aortic balloon pump (IABP) is the most commonly used mechanical circulatory support device for adults with cardiogenic shock awaiting heart transplantation (HT). Historical data suggest worse outcomes for these patients and it's yet to be seen how the revision in the United Network for Organ Sharing (UNOS) donor allocation scheme in October 2018 may have influenced outcomes. Given this, we sought to identity the impact of IABP use on outcomes after HT in the era prior to the revision. We identified adults listed for HT with IABP at time of listing (excluding patients receiving VAD or ECMO) utilizing the Scientific Registry of Transplant Recipients database between 2000 and 2018. The patients were followed until death, transplant or end of data availability. Waitlist mortality and successful HT were compared between groups using a Fine and Gray competing risk hazard regression model adjusted for known risk factors. 30- and 90-day post-HT mortality was assessed using adjusted Cox proportional hazards regression. 25,325 patients were identified and 5% (N = 1256) were supported with an IABP at the time of listing. Those supported with an IABP had lower creatinine clearance, cardiac output and index, higher pulmonary capillary wedge, pulmonary artery systolic, diastolic and mean pressures (p < 0.01 for all). Unadjusted 30 day survival [mortality for IABP = 5.2% & no IABP = 4.4%; Log rank p = 0.0875] and 90 day survival [mortality for IABP = 7.7% & no IABP = 6.6%; Log rank p = 0.0503] post-transplant was worse in the IABP group (figure 1A & 1C). After adjustment, IABP use at the time of listing was significantly associated with a lower 30 day (HR 0.59, 95% CI 0.44-00.80; p=0.0008) and 90 day mortality (HR 0.63, 95% CI 00.49-0.80; p = 0.0002) (figure 1B and 1D). Among adults who successfully underwent HT, IABP support significantly decreased 30 and 90 day mortality. This suggests an important role for IABP support in HT even after the revision in the UNOS donor allocation scheme. Systematic efforts should be made to identify the cohort which will derive this benefit while awaiting HT.