Donor-Recipient Sex Mismatch is Associated with Severe Primary Graft Dysfunction after Heart Transplantation

The association between sex and primary graft dysfunction after heart transplantation (HT) remains unclear. We evaluated whether recipient sex and donor-recipient sex matching are associated with severe primary graft dysfunction (PGD) in a contemporary, multicenter cohort.

We analyzed data from the International PGD Consortium comprised of adult HTs from 2010 to 2024 across 14 centers. Associations between sex-related variables and severe PGD were assessed using multivariable logistic regression, and adjusted for ischemic time, pre-transplant durable left ventricular assist device (LVAD), dialysis, congenital heart disease, and predicted heart mass (PHM) ratio.

Among 3,994 recipients, 1,030 (25.8%) were female. Female recipients were younger (54 vs. 57 years) with fewer comorbidities, and less frequently bridged on a durable LVAD (19.8% vs. 29.1%). Although female recipients had a lower incidence of PGD than male recipients (7.1% vs. 9.4%), recipient sex was not independently associated with PGD after multivariable adjustment. Female donor to male recipient sex mismatching had the highest PGD incidence of 11.5% and was associated with a 43% increase in the odds of severe PGD (p=0.030). While sex-mismatch was associated with an increased incidence of PGD, size mismatch by PHM ratio was not an independent predictor.

In this large international registry, donor-recipient sex mismatch, specifically among male recipients of female donor hearts, was independently associated with severe PGD, even when appropriately size matched. These findings inform risk stratification for development of severe PGD after HT.