Combined Multiorgan Heart and Kidney Transplants With Single Donor Allografts: Simultaneous Versus Staged?

Multiorgan heart and kidney transplants (HKTx) performed for patients with end-stage heart failure and chronic kidney disease have increased in recent years. However, no established protocols exist on whether a heart and kidney from the same donor should be transplanted in the same operation versus 1-2 days apart.

Using SRTR data 1993-2023, we compared same-donor HKTx recipients with both transplants performed on the same day ("simultaneous") to recipients with kidney transplants performed within 1 day of the heart transplant ("staged"). We examined differences in weighted post-transplant clinical characteristics using average treatment effect. Post-transplant mortality and graft failure was also assessed using Kaplan-Meier curves and instrumental variable analysis adjusted for recipient characteristics and year of transplant.

The proportion of staged HKTx increased from 20.7% in 2015 to 58.8% in 2023. Recipients of simultaneous versus staged HKTx had similar rates of stroke (3.4% vs. 4.1%, p = 0.3), permanent pacemaker prior to discharge (2.0% vs. 1.8%, p = 0.7), and kidney primary non-function (2.7% vs. 2.6%, p = 0.8). However, simultaneous HKTx recipients had shorter kidney cold ischemic time (median (IQR) (h) 10.0 (7.5 vs. 14.6) versus 20.3 (15.9, 24.8), p < 0.001) and a lower weighted hospital stay compared to staged HKTx recipients (_1.08 1.09 _1.11, p < 0.001). Weighted patient mortality, all cause heart failure (ACHF), and all cause kidney failure (ACKF) 4 years post-transplant were slightly lower for simultaneous versus staged HKTx recipients (17.1% vs. 19.9%, 17.2% vs. 20.1%, 20.8% vs. 24.7%). However, instrumental variable analysis found no meaningful differences in adjusted patient survival, ACHF, or ACKF by HKTx type.

Simultaneous HKTx recipients have shorter hospital stays, decreased mortality, and higher rates of graft survival post-transplant compared to staged HKTx recipients, which may reflect favorable patient factors that enable both operations to be performed on the same day rather than an inherent benefit of simultaneous HKTx, given equivalent adjusted patient mortality, ACHF, and ACKF.