Abstract 4137135: Trends in Mechanical Circulatory Support After the New Heart Allocation Policy

Background: In October 2018 a new heart allocation policy (NHAP) was implemented, which resulted in patients with Intra-aortic balloon pumps (IABP) being upgraded to status-two. We sought to determine practice pattern changes in mechanical circulatory support (MCS) use as a result of the NHAP. Hypothesis: Changes in the new heart allocation policy may lead to shifts in choice of mechanical circulatory support. Methods: A retrospective analysis was conducted using the National Inpatient Sample (NIS) between 2017–2020. Hospitalizations for cardiogenic shock were identified, and stratified based on whether the patients were admitted before or after the NHAP. Baseline characteristics were compared between these cohorts, and the primary outcome of interest was the use of MCS and transplant before and after the NHAP. Subgroup analyses included patients only in transplant centers, non-transplant centers, and those who eventually underwent transplant. Results: A total of 689,935 hospitalizations were included in the final analysis, of which 279,230 (40.5%) were before the NHAP, and 410,705 (59.5%) were after. In allcomers, hospitalizations after the NHAP were less likely to undergo IABP (Adjusted odds ratio [OR] 0.81, p<0.01) and LVAD (Adjusted OR 0.73, p<0.01). These findings were consistent in most subgroup analyses. Patients who underwent transplant after the NHAP however were more than twice as likely to have received a IABP compared to those admitted prior to the NHAP (adjusted OR 2.58; p<0.01). Conclusion: IABP placement after the NHAP increased in patients who underwent transplant, as opposed to allcomers or patients who did not undergo transplant. This change in utilization of MCS may be reflective of perceived benefits and biases in regards to transplantation candidacy.