Abstract 4136036: Five-year Outcomes of Heart-Kidney Transplant Recipients Bridged with Durable Mechanical Circulatory Support: Less AMR Better Survival?

Introduction: Despite the increased risk of sensitization in patients receiving pre-transplant durable mechanical circulatory support (D-MCS), it has been suggested that removing D-MCS at the time of transplant may lead to a drop in HLA-antibody levels. Whether this may reduce rejection rates and improve long-term outcomes in patients undergoing heart-kidney transplantation (HKTx) has not been widely investigated. Therefore, we aim to investigate the impact of pre-transplant D-MCS on 5-year clinical outcomes of patients undergoing HKTx. Methods: We included 98 patients undergoing HKTx between 2010 and 2018 at a single center. Recipient pre-transplant characteristics and clinical outcomes were compared between patients receiving D-MCS (n=24) versus non-D-MCS patients (n=74). The D-MCS cohort included those who received total artificial heart (n=13), left ventricular assist device (n=8), and biventricular assist devices (n=3). Endpoints included 1- and 5-year survival, 1-year-freedom from acute cellular rejection (defined as grade 2R or 3R), 1-year-freedom from antibody-mediated rejection (AMR, defined as pathologic AMR of grade ≥1), 5-year freedom from cardiac allograft vasculopathy (CAV, stenosis ≥30% by angiography), 5-year freedom from non-fatal major adverse cardiac events (NF-MACE including myocardial infarction, new congestive heart failure, percutaneous coronary intervention, implantable cardioverter defibrillator/pacemaker implant, stroke), and 5-year freedom from left ventricular dysfunction (LVEF ≤40). Results: At 1 year, freedom for AMR was numerically higher in the D-MCS group (100 vs. 90.2%, P=0.12). Additionally, the 5-year post-transplant survival rate was higher in the D-MCS group (95.8% vs. 80.8%), but it did not reach statistical significance (P=0.091). Comparable outcomes were noted for other outcomes, including 5-year freedom from CAV, NF-MACE, or LVD (Table 1 ). Conclusion: The current study hints at better 5-year survival in HTKx recipients receiving pre-transplant D-MCS, which could be attributed to lower rates of AMR in this population. Future larger studies are warranted to further validate these findings.