Karnofsky performance status predicts outcomes in candidates for simultaneous liver-kidney transplant

Karnofsky performance status (KPS), a measure of physical frailty, predicts pre-transplant and post-transplant outcomes in liver transplantation, but has not been assessed in simultaneous liver-kidney transplantation (SLKT). We examined the association between KPS and outcomes in SLKT waitlist registrants and recipients (2005-2018) in the UNOS database. KPS was categorized into A (able to work), B (able to provide self-care), and C (unable to provide self-care). Cox regression and competing risk analysis were used to assess the association between KPS groups and outcomes. A total of 10,785 patients were waitlisted (KPS: 19% A, 46% B, 35% C), and 5,516 underwent SLKT (12% A, 36% B, 52% C). One-year waitlist mortality was 17%, 22%, and 32% for KPS A, B, and C, respectively. In adjusted competing risk regression, KPS C was associated with increased waitlist mortality (SHR 1.15, 95%CI 1.04-1.28). One-year post-transplant survival was 92%, 91%, and 87% for KPS A, B, and C, respectively. In adjusted Cox regression, KPS C was associated with increased post-transplant mortality (HR 1.32, 95%CI 1.08-1.61). It was also associated with increased liver and kidney graft losses and with hospital length of stay. Frailty, as assessed by KPS, is associated with poor outcomes in SLKT pre- and post-transplant.