Women undergoing simultaneous heart-kidney transplantation demonstrated an early post-transplant mortality signal concentrated within the first 90 days, without excess long-term risk, underscoring the need for earlier referral and perioperative optimization of high-risk women to improve equity in SHKT outcomes.
Women represented only 19.7% of simultaneous heart-kidney transplantation (SHKT) recipients over the 25-year study period.
Women undergoing SHKT were more likely to have nonischemic cardiomyopathy and higher pulmonary vascular resistance compared to men.
Unadjusted post-transplant survival did not differ significantly between men and women at 1 or 5 years after SHKT.
After multivariable adjustment, sex violated the proportional hazards assumption, necessitating a piecewise constant Cox model that revealed a numerically higher perioperative hazard for women.
In a prespecified 90-day landmark analysis, women had a significantly higher risk of mortality in the first 90 days post-SHKT but not thereafter.
The perioperative mortality disadvantage for women was most pronounced in the contemporary allocation era.
No significant sex interactions were identified across 10 prespecified effect modifiers.
This research analyzed 25 years of national transplant registry data to understand whether men and women have different outcomes after receiving a simultaneous heart and kidney transplant (SHKT). The study included 3,068 adults who received this complex dual-organ transplant between 1999 and 2024, of whom fewer than 1 in 5 (19.7%) were women. Women who received SHKT tended to have different underlying heart disease (more non-ischemic cardiomyopathy), higher pressures in their lung circulation, and were less likely to have been supported by a mechanical heart pump before transplant compared to men. While overall survival rates at 1 and 5 years looked similar between men and women on the surface, more detailed statistical analysis revealed that women faced a significantly higher risk of dying in the first 90 days after the transplant — about 58% higher risk than men during this early window. Importantly, this early disadvantage did not persist: after 90 days, women's survival outcomes were comparable to men's, and no differences were seen at 5 years. This early mortality gap was even more pronounced when looking only at patients transplanted under the most recent organ allocation policies, suggesting the problem has not improved in recent years. This research suggests that the critical period for women undergoing SHKT is the immediate post-transplant phase, and that the long-term outcomes for women who survive this early period are similar to men. The findings highlight a need to identify women who may benefit from SHKT earlier in their disease course and to focus on optimizing their care around the time of surgery, as a means of improving fairness in transplant outcomes between men and women.
Ramu B, Shabbir A, Masotti M, Schultz J, Maharaj V, Alexy T, et al.. (2026). Sex Differences in Simultaneous Heart-Kidney Transplantation: A 25-Year United Network for Organ Sharing Analysis.. Journal of cardiac failure. https://doi.org/10.1016/j.cardfail.2026.06.019