Calculated panel-reactive antibody predicts outcomes on the heart transplant waiting list

Abstract

Background: Sensitized heart transplant candidates spend more time and have higher mortality on the waiting list. Although the calculated panel-reactive antibody (CPRA) value is used to assign allocation priority to kidney transplant candidates in the United States, the relationship between CPRA and outcomes on the heart transplant waiting list is unknown.

Methods: A data set of patients listed for heart transplant with unacceptable human leukocyte antigens (HLA) entered was obtained from the United Network for Organ Sharing. The study cohort was composed of 3,855 adult candidates listed for heart transplant between 2006 and 2013 with active waiting time. The cohort was divided into 5 groups by increasing CPRA. Outcomes were assessed using competing risks and sub-hazard regression analyses.

Results: In each group of successively higher CPRA, the percentage of candidates who received a transplant decreased, whereas the percentage of those who were still waiting for a transplant increased, as did the percentage of those removed from the waiting list or had died. The group of candidates with a CPRA >80% displayed a markedly decreased incidence of transplantation (hazard ratio 0.37) and an increased risk of removal from the waiting list or death (hazard ratio 2.18) as compared to those with CPRA of ≤10%.

Conclusions: Sensitized heart transplant candidates are at high risk of adverse outcomes on the heart transplant waiting list. Clinicians should strive to minimize the CPRA by maximizing specificity in the selection of HLA antigens to exclude. The optimal clinical approach for candidates with high CPRA requires further study.

Keywords: calculated panel reactive antibody; heart transplantation; human leukocyte antigen; sensitization; waiting list; waiting time.