The impact of angiotensin II type 1 receptor antibodies on post-heart transplantation outcome in Heart Mate II bridged recipients.

OBJECTIVES

Antibodies targeting angiotensin II type 1 receptor (AT1R) have been associated with malignant hypertension, autoimmune diseases and acute rejection and graft loss in solid organ transplantation. The aim of our study was to assess the impact of anti-AT1R antibodies on survival and incidence of acute cellular rejection (ACR) and pathology antibody-mediated rejection (pAMR) in a population of heart transplant recipients who were bridged to transplantation with a durable mechanical assist device Heart Mate II.

METHODS

Sera of 69 consecutive heart transplant recipients transplanted between October 2008 and August 2014 were tested for the presence of angiotensin II type 1 receptor antibodies before Heart Mate II device implantation and at the time of transplantation. Overall survival and post-transplant rejection-free survival were compared between antibody-negative and antibody-positive recipients using Kaplan-Meier and log-rank tests.

RESULTS

Anti-AT1R antibodies were present in 8 patients (11.6%) before Heart Mate II implantation. During the left ventricular assist device (LVAD) bridging, 44 patients (63.8%) who were initially anti-AT1R antibody-negative became positive, leaving 17 (24.6%) anti-AT1R antibody-negative patients at the time of transplantation for all comparisons. One- and 5-year survival was 88 ± 8 and 76 ± 10% for anti-AT1R antibody-negative and 87 ± 5 and 81 ± 7% for anti-AT1R antibody-positive patients, respectively (P = 0.582). Freedom from ACR at 1 year was 68 ± 12% for anti-AT1R-negative and 75 ± 6% for anti-AT1R-positive recipients (P = 0.218). None of the anti-AT1R-negative patients developed AMR 1 year post-transplantation, whereas freedom from pAMR in anti-AT1R-positive recipients was 98 ± 2% (P = 0.198).

CONCLUSIONS

Our data showed no difference in the overall post-heart transplant survival and freedom from acute cellular and antibody-mediated rejection between anti-AT1R-negative and anti-AT1R-positive recipients. Further research is needed to assess the role of anti-AT1R antibodies in the risk stratification of LVAD-bridged recipients on the post-heart transplantation outcomes.