Introduction: Hypothermic machine perfusion (HMP) is widely used to preserve and assess deceased donor kidneys, with machine-measured renal resistance (MMRR) often guiding utilization. High MMRR (≥0.4 mmHg/mL/min) is associated with delayed graft function (DGF) in the overall transplant population, leading many centers to decline such grafts. However, not all high MMRR kidneys are created equal as some perform exceptionally well. This study evaluated outcomes among high-resistance kidneys, focusing on donor and histologic predictors of success.
Methods: We retrospectively analyzed 317 deceased donor renal transplants performed between 12/23/2020 and 4/29/2024, all undergoing HMP. Logistic regression examined associations between donor factors (age, terminal creatinine, DCD status, KDPI) and biopsy findings (glomerulosclerosis, interstitial fibrosis, nephrosclerosis) with DGF and 1-year eGFR. Analyses were performed for the overall cohort and the high-resistance subgroup (n = 68). Fisher’s Exact test compared outcomes by composite donor risk profile. Significance was set at p ≤ 0.05. 
Results: In the overall cohort, resistance ≥0.4 was associated with higher odds of DGF (OR = 1.92, p = 0.034). Within the high-resistance subgroup, donor age (OR = 1.00, p = 0.88), terminal creatinine (OR = 0.90, p = 0.56), and DCD status (OR = 0.88, p = 0.84) were not associated with DGF (Figure 1A), whereas lower donor age (OR = 0.95, p = 0.006), lower KDPI (OR = 0.98, p = 0.036), absence of ≥10% interstitial fibrosis (OR = 0.05, p = 0.006), and absence of ≥10% nephrosclerosis (OR = 0.12, p = 0.014) were associated with higher odds of achieving eGFR ≥ 60 at 1 year (Figure 1B). High-MMRR kidneys from donors <60 with <10% interstitial fibrosis had better outcomes, with 67% achieving eGFR ≥ 60 at 1 year compared to 16% in donors ≥60 or with ≥10% fibrosis (p = 0.001), with no significant difference in DGF (Figure 2). 
Conclusions: In the overall cohort, high MMRR was associated with increased DGF, but in high-resistance kidneys, younger donor age and minimal interstitial fibrosis strongly predicted excellent 1-year function. High MMRR alone should not preclude use—donor age and biopsy findings provide critical context for safe expansion of kidney utilization.