Targeting the Right Metrics for Kidney Transplantation Success

Wang and colleagues1 provide an insightful analysis that fine-tunes important metric measurements of transplant center performance. Compared with the traditional end point of 1-year allograft failure, a composite 1-year end point that incorporates a measure of suboptimal allograft function (eGFR of <30 ml/min per 1.73 m2 is widely used internationally) or graft loss provides improved differentiation between transplant programs with respect to long-term deceased-donor graft outcomes. Although sole reliance on binary indications of graft survival provides insufficient granularity regarding program performance, unintended consequences with any change must be appreciated, which the authors briefly touch upon. Specifically, balancing legitimate regulatory oversight for unexpected 1-year graft outcomes, where this composite outcome metric will be particularly useful, versus expected 1-year graft outcomes when using marginal kidneys is challenging. If transplant professionals are fearful of regulatory consequences relating to suboptimal 1-year graft function, the risk-versus-reward calculation will skew toward risk aversion and further exacerbate the problem of organ utilization.2 If patients have a hypothetical choice between two deceased-donor kidneys, a marginal expanded-criteria kidney that may have suboptimal kidney function at 1 year versus a standard-criteria offer, clearly the best decision is to choose the latter option. However, this is a false dichotomy and kidney transplant candidates do not face this hypothetical luxury of choosing between simultaneous kidney offers. Their reality is a choice to proceed with a kidney offer versus declining and remaining on the waiting list. Decision making here becomes different, illustrated with the example of diabetic donor kidneys. Recipients of diabetic donor kidneys have higher rates of all-cause allograft failure (hazard ratio [HR], 1.21; 95% CI, 1.16 to 1.26) and death (HR, 1.19; 95% CI, 1.13 to 1.24) compared with receiving nondiabetic donor kidneys.3 However, recipients of diabetic donor kidneys have lower mortality compared with the options of remaining on the waiting list and/or transplantation later with a nondiabetic donor kidney (adjusted HR, 0.91; 95% CI, 0.84 to 0.98).4 Younger waitlisted patients (aged <40 years) have no survival benefit from transplantation with diabetic donor kidneys, but patients with diabetes who have longer waiting-list times attain the greatest survival benefit. Wang and colleagues1 correctly identify "a robust monitoring plan will need to be in place to detect whether it [policy change] is resulting in unwanted effects." Although their work is commendable for improving post-transplant metrics distinguishing transplant center performance, prioritizing the new pretransplant metrics, including offer acceptance and waiting-list mortality, should have greater importance. Getting more patients with kidney failure transplanted quicker will save more lives compared with modifying post-transplant metrics. Disclosures A. Sharif reports serving on speakers bureaus hosted by Astellas, Chiesi, and Novartis; serving in an advisory or leadership role for Atara Biotheraputics, Boehringer Ingelheim/Lilly Alliance, and Novartis Pharmaceuticals; having consultancy agreements with, and receiving research funding from, Chiesi Pharmaceuticals; and receiving honoraria from Chiesi Pharmaceuticals, Napp Pharmaceuticals, Novartis, and Sandoz. Funding None.