Infectious outcomes in heart-after-liver transplantation with or without domino (HALT+/-D): A case series with comparison to isolated heart and isolated liver transplantation.

Heart-after-liver transplantation with or without domino (HALT+/-D) has emerged as a strategy to expand access for highly sensitized patients who face limited transplant options due to donor-specific antibodies (DSAs). While the liver's immunoprotective effect may mitigate antibody-mediated rejection, the infectious risks of this approach remain poorly defined. We performed a retrospective single-center case series of all HALT+/-D recipients (n = 4) at the University of Washington, with detailed characterization of infectious complications. For context, we compared outcomes to highly sensitized (cPRA ≥ 89%) isolated heart (n = 6) and liver (n = 5) transplant recipients. All 4 HALT+/-D recipients were female with extreme allosensitization (median cPRA 99%) and prolonged pre-transplant hospitalization (mean 64 days). Median time for the first post-transplant infection was 29 days (range 6-52). Three of four (75%) developed Clostridioides difficile infection, associated with broad-spectrum antibiotic use. HALT+/-D recipients had median infection-related hospital days of 37, vs 7 in heart and 0 in liver transplant recipients. All 4 patients survived to one year with functioning grafts. HALT+/-D recipients experience a substantial infectious burden, particularly CDI. This case series provides clinical information to guide infection management. Prospective multicenter studies are needed to optimize protocols.