Desensitization in Mechanical Circulatory Support Patients Awaiting Heart Transplantation: What is the Post-Transplant Outcome?

Abstract

Sensitization occurs with blood transfusions in recipients of left ventricular assist device (LVAD). 30% of LVAD patients develop a panel reactive antibody (PRA) screen of >= 10%. Highly sensitized patients have an increased morbidity and mortality after heart transplantation. Desensitization therapy is considered for patients with PRAs> 50%. Below are the results of desensitization therapies in mechanical circulatory support (MCS) patients. From 2010-2016, 49 MCS patients who underwent desensitization therapy were compared to a control group who underwent desensitization but did not have MCS support. Desensitization therapy used in both groups included combinations of rituximab/IVIG and plasmapheresis/bortezomib. Baseline PRAs prior to desensitization were repeated 2-4 weeks after treatment. For patients who underwent heart transplantation, outcomes included 1-year survival, freedom from cardiac allograft vasculopathy (CAV), freedom from non-fatal major adverse cardiac events (NF-MACE, defined as myocardial infarction, percutaneous coronary intervention, new congestive heart failure, pacemaker/implantable cardioverter-defibrillator placement, and stroke), and freedom from any treated rejection (ATR), acute cellular rejection (ACR), and antibody-mediated rejection (AMR). Desensitization therapy was successful in both MCS and control groups, resulting in an average of 12% decrease in PRA. When subgrouped into Class 1 versus Class 2 antibodies, Class 1 antibodies appeared to have a better response after desensitization therapy (PRA decrease of 15% in Class 1 versus a decrease of 9% in Class 2). Patients on MCS support appear to have a numerical lower incidence of AMR with comparable first-year survival, freedom from CAV, NF-MACE, ATR, and ACR. Desensitization of MCS patients appeared to be beneficial. Removal of the MCS device at the time of transplant may be a factor in potentially less AMR post-transplant.