The Association Of Intra-aortic Balloon Pump Or Impella Duration Of Support With Waitlist And Post-heart Transplant Outcomes

Background Patients listed for heart transplantation (HT) supported by intra-aortic balloon pump (IABP) or Impella (Abiomed, Danvers, MA) are accorded a higher waitlist status under the new 2018 heart allocation system. The effect of device duration of support on waitlist or post-transplant outcomes is unclear. The purpose of this study is to investigate the association of IABP or Impella duration of support with waitlist and post-transplant outcomes in patients listed for HT. Methods The United Network for Organ Sharing database was queried for adults listed for HT who were supported with an IABP or Impella (2.5, 5.0, CP, or RP) between October 2018 and March 2020. Patients were stratified into tertiles according to duration of support by device type. Competing risks analysis was used to examine the risk of waitlist mortality or delisting, accounting for HT. One year post-HT stroke, dialysis, and acute rejection were analyzed using logistic regression models. Survival at 1-year was analyzed using Cox proportional hazards modeling. Results A total of 2823 listed patients were supported with an IABP (n=2494) or Impella (n=329) during the study period. The median [IQR] duration of device support was 9 [5, 17] days with IABP and 12 [6, 24.5] days with Impella. There were no differences in waitlist mortality/delisting by duration of support according to device type (IABP: >13 days ref., 6-13 days HR 1.18, 95% CI 0.41-3.40, <6 days HR 1.89, 95% CI 0.70-5.11; Impella: >18 days ref., 8-18 days HR 0.34, 95% CI 0.09-1.28; <6 days HR 0.26, 95% CI 0.06-1.20). Patients in the longest tertile of device support were less likely to receive transplant compared to patients in the shortest and middle tertiles (Figure, p<0.001 for IABP and Impella). Among those who successfully reached HT after support with an IABP (n=2418, 97%) or Impella (n=298, 90.6%), rates of stroke, need for dialysis, and acute rejection post-HT were similar between the IABP groups and the Impella groups. There were no differences in post-HT survival by duration of support at 1 year among patients with IABP (>13 days ref., 6-13 days HR 0.97, 95% CI 0.83 - 1.13, <6 days HR 0.94, 95% CI 0.80-1.10) or Impella (>18 days ref., 8-18 days HR 0.82, 95% CI 0.49-1.36, <6 days HR 0.86, 95% CI 0.49-1.52). Conclusions Waitlist mortality and post-HT outcomes are comparable regardless of duration of support in patients supported by IABP, as well as those supported by Impella. Patients listed for heart transplantation (HT) supported by intra-aortic balloon pump (IABP) or Impella (Abiomed, Danvers, MA) are accorded a higher waitlist status under the new 2018 heart allocation system. The effect of device duration of support on waitlist or post-transplant outcomes is unclear. The purpose of this study is to investigate the association of IABP or Impella duration of support with waitlist and post-transplant outcomes in patients listed for HT. The United Network for Organ Sharing database was queried for adults listed for HT who were supported with an IABP or Impella (2.5, 5.0, CP, or RP) between October 2018 and March 2020. Patients were stratified into tertiles according to duration of support by device type. Competing risks analysis was used to examine the risk of waitlist mortality or delisting, accounting for HT. One year post-HT stroke, dialysis, and acute rejection were analyzed using logistic regression models. Survival at 1-year was analyzed using Cox proportional hazards modeling. A total of 2823 listed patients were supported with an IABP (n=2494) or Impella (n=329) during the study period. The median [IQR] duration of device support was 9 [5, 17] days with IABP and 12 [6, 24.5] days with Impella. There were no differences in waitlist mortality/delisting by duration of support according to device type (IABP: >13 days ref., 6-13 days HR 1.18, 95% CI 0.41-3.40, <6 days HR 1.89, 95% CI 0.70-5.11; Impella: >18 days ref., 8-18 days HR 0.34, 95% CI 0.09-1.28; <6 days HR 0.26, 95% CI 0.06-1.20). Patients in the longest tertile of device support were less likely to receive transplant compared to patients in the shortest and middle tertiles (Figure, p<0.001 for IABP and Impella). Among those who successfully reached HT after support with an IABP (n=2418, 97%) or Impella (n=298, 90.6%), rates of stroke, need for dialysis, and acute rejection post-HT were similar between the IABP groups and the Impella groups. There were no differences in post-HT survival by duration of support at 1 year among patients with IABP (>13 days ref., 6-13 days HR 0.97, 95% CI 0.83 - 1.13, <6 days HR 0.94, 95% CI 0.80-1.10) or Impella (>18 days ref., 8-18 days HR 0.82, 95% CI 0.49-1.36, <6 days HR 0.86, 95% CI 0.49-1.52). Waitlist mortality and post-HT outcomes are comparable regardless of duration of support in patients supported by IABP, as well as those supported by Impella.