De-Novo Human Leukocyte Antigen Allosensitization on HeartMate 3 versus HeartMate II Left Ventricular Assist Device Recipients

Abstract

MOMENTUM 3 trial demonstrated superiority of Heartmate 3 (HM 3) compared to Heartmate II (HM 2) with regards to hemocompatibility, however, their differential effects on de-novo HLA allosensitization, which may create a challenge for future transplantation, remains unknown. Patients who underwent HM2 or HM3 implantation and had no prior HLA antibodies by solid-phase assay (Luminex) testing at a major academic center were included for the study. Complement dependent cytotoxicity (CDC) panel reactive antibody (PRA) levels as well as Luminex antibody profiles were followed until cardiac transplantation, device explantation, or death. 34 HM3 and 34 HM2 patients with no HLA antibodies by Luminex testing prior to LVAD implant were identified with a mean follow-up duration of 1.71 ± 1.1 years on device support. HM3 and HM2 groups had similar age at implant (56.1±8.6 vs 54.7±12.0, p=0.575), female gender (11.8% vs. 14.7%, p=0.720), ischemic HF etiology (38.2% vs 35.3%, p=0.801), and bridge strategy at implant (44.1% vs 58.8%, p=0.225). Over the follow-up period, 41.2% of HM3 and 47.1% of HM2 patients had detectable HLA antibodies by Luminex testing (p=0.625). Development of high level (MFI>10, 000) Class I HLA antibodies were significantly lower in HM3 patients (2.9% vs 17.9%, p=0.046) compared to high-level Class II HLA antibodies which were similar in two device groups (2.9% vs 5.9%, p=0.555). CDC PRA testing showed lower proportion of HM3 patients with a positive result (PRA >0%) for T cell (32.4% vs. 55.9%, p=0.050) compared to positive B cell panel which was comparable in two groups (32.4% vs 47.1%, p=0.215). Peak PRA levels in patients who turned positive was comparable for T cell (5.8% vs 6.5%, p=0.775) and B cell (10.2% vs. 12.4%, p=0.568) in HM3 vs. HM2 patients. Our findings suggest that HM3 is associated with a lower likelihood of de-novo HLA sensitization than HM2 specifically against Class I antigens.