Gender mismatch and outcomes following heart transplantation in the United States

Available literature indicates the possible detrimental effect of gender mismatching on mortality in patients undergoing heart transplantion. Our objective was to examine the role of gender mismatching on mortality and graft rejection in patients undergoing heart transplantation in the US.

Data on adult patients January who underwent heart transplantation between January 2015 and October 2021, was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were all-cause mortality, 1-year all-cause mortality and treated acute rejection.

A total of 19,805 adult patients underwent heart transplant during the study period. Approximately, one out of ten patients in the M-F group had a PHM mismatch<25%, while only four out of ten patients had such a mismatch in the F-M group. In both M-M and F-F groups, seven out of ten patients had a PHM mismatch<25% (p=0.122). Proportion of PHM mismatch was similar throughout the study period. Unadjusted analysis showed that M-F was associated with increased risk for all-cause mortality (HR: 1.13; 95% CI: 1.02, 1.27; p=0.026) and 1-year mortality (HR: 1.26; 95% CI: 1.09, 1.45; p=0.002) compared to M-M. Graft failure incidence was higher in the M-F group compared to M-M (HR: 1.12; 95% CI: 1.01, 1.25; p=0.041).

Gender mismatching is associated with post-transplant mortality with transplantation of female donor grafts to male recipients demonstrating worse outcomes. Further research is required to elucidate pathways involved and possible changes in clinical practice.

Type of funding sources: None.