Characteristics And Outcomes Of Patients Bridged To Transplant With Iabps Under Exception Status During New Allocation Era

Purpose The new heart transplant (HT) allocation system prioritizes cardiogenic shock patients on temporary mechanical circulatory support(tMCS). Intra-aortic balloon pumps (IABP) are now frequently used as a bridge to transplant (BTT). Detailed criteria were developed to appropriately categorize patients who qualify for IABP support. Clinicians may request exception status for patients who do not fit the predetermined prioritization criteria. The purpose of our study was to evaluate the clinical characteristics and outcomes of patients BTT with an IABP under an exception status. Methods Adult patients who were supported by IABP and received HT between 10/18/2018 and 12/31/2020 were included in this study. Patients were stratified according to the request for exception status at the time of transplantation. Recipient and donor characteristics were compared between groups. One-year post-transplant survival was calculated with Kaplan-Meier methodology.* Results A total of 1423 patients met our inclusion criteria. Of these 580 (40.7%) patients were transplanted utilizing an exception status. IABP-exception patients were more likely to be Black (27.2% vs. 22.3%, p=0.014), had a higher BMI (27.5±4.9 vs. 26.3±4.8, kg/m2, p=<0.001), more days on the waitlist (18 (7-59) vs. 9 (4-20), p<0.001). IABP-exception patients were more likely to receive a male-donor heart (82.8% vs. 78%, p=0.032), and had a lower frequency of gender mismatch (24.3% vs. 19.1%, p=0.025). There were no differences in age (54.2±12 vs. 54.4±12.5 years, p=0.632), male gender (77.4% vs. 73%, p=0.064), proportion of inotropic use (61.7% vs. 62.7%, p=0.761), or ischemic time (3.6±1 vs 3.5±0.9 hrs., p=0.149). The one-year survival after HT was lower in the IABP-exception group (91% vs. 94.8%, p=0.004) (Figure). Conclusion Forty percent of IABP patients received HT under an exception status. These patients had longer waitlist time and had worse post-transplant survival. Further studies to define the reasons for the use of exception status in the IABP population are required. The new heart transplant (HT) allocation system prioritizes cardiogenic shock patients on temporary mechanical circulatory support(tMCS). Intra-aortic balloon pumps (IABP) are now frequently used as a bridge to transplant (BTT). Detailed criteria were developed to appropriately categorize patients who qualify for IABP support. Clinicians may request exception status for patients who do not fit the predetermined prioritization criteria. The purpose of our study was to evaluate the clinical characteristics and outcomes of patients BTT with an IABP under an exception status. Adult patients who were supported by IABP and received HT between 10/18/2018 and 12/31/2020 were included in this study. Patients were stratified according to the request for exception status at the time of transplantation. Recipient and donor characteristics were compared between groups. One-year post-transplant survival was calculated with Kaplan-Meier methodology.* A total of 1423 patients met our inclusion criteria. Of these 580 (40.7%) patients were transplanted utilizing an exception status. IABP-exception patients were more likely to be Black (27.2% vs. 22.3%, p=0.014), had a higher BMI (27.5±4.9 vs. 26.3±4.8, kg/m2, p=<0.001), more days on the waitlist (18 (7-59) vs. 9 (4-20), p<0.001). IABP-exception patients were more likely to receive a male-donor heart (82.8% vs. 78%, p=0.032), and had a lower frequency of gender mismatch (24.3% vs. 19.1%, p=0.025). There were no differences in age (54.2±12 vs. 54.4±12.5 years, p=0.632), male gender (77.4% vs. 73%, p=0.064), proportion of inotropic use (61.7% vs. 62.7%, p=0.761), or ischemic time (3.6±1 vs 3.5±0.9 hrs., p=0.149). The one-year survival after HT was lower in the IABP-exception group (91% vs. 94.8%, p=0.004) (Figure). Forty percent of IABP patients received HT under an exception status. These patients had longer waitlist time and had worse post-transplant survival. Further studies to define the reasons for the use of exception status in the IABP population are required.