Abstract
RATIONALE & OBJECTIVE: The effects of successful kidney transplant (KT) on cognitive function remain unclear. To clarify how the presence or absence of pre-KT mild cognitive impairment (MCI) affects cognitive changes (overall and domain) after KT. To determine whether the cognitive improvement after KT is associated with improved cardiac function. STUDY DESIGN: A hybrid retrospective and prospective observational cohort study. SETTING & PARTICIPANTS: We obtained data from 70 recipients who underwent living donor KT (2017-2021). PREDICTORS: Pre-KT MCI status and left ventricular (LV) remodeling. OUTCOMES: Changes in mean Montreal cognitive assessment (MoCA) scores before and after KT. STATISTICAL ANALYSIS: We evaluated whether the presence or absence of pre-KT MCI modified the effect of KT (total and each domain). We also evaluated the association between changes in MoCA total score and LV reverse remodeling effect. RESULTS: MoCA total score: no significant change was observed in the non-MCI group (27.6 ± 1.2 to 27.6 ± 1.6, P = 0.81). In contrast, the score in the MCI group improved from 22.9 ± 2.0 to 24.7 ± 2.0 (P < 0.001; P (int) < 0.001). MoCA domain score: the effect of KT varied between the non-MCI group and the MCI group in each domain; the visuospatial and executive domains increased for the MCI group but not non-MCI group (P (int) = 0.01). Cognitive and cardiac function: improvement in MoCA score was positively correlated with the effect of LV reverse remodeling (P = 0.02), even after adjusting for age and tacrolimus trough level. LIMITATIONS: Incomplete cerebral blood flow data. CONCLUSIONS: The effect of KT was changed by pre-KT MCI status. Heterogeneous cognitive improvement after KT can be explained by the LV reverse remodeling effect.