From arterial stiffness to kidney graft microvasculature: Mortality and graft survival within a cohort of 220 kidney transplant recipients

BACKGROUND: Aortic stiffness assessed by carotid-femoral pulse wave velocity (CF-PWV) is a predictor of mortality in several populations. However, little is known in kidney transplant recipients. Our objectives were to evaluate the ability of CF-PWV measured 3 months following transplantation to predict mortality, graft loss and its potential links to measured Glomerular Filtration Rate (mGFR) or kidney graft microvasculature parameters. METHODS: The study is based on a monocentric retrospective cohort including 220 adult kidney graft recipients evaluated three months after transplantation. CF-PWV measures, clinical, laboratory and histological data performed at 3 (M3) and 12 months (M12) following transplantation were retrospectively collected. The two primary endpoints were all-cause mortality and occurrence of end stage renal disease (ESRD) defined by initiation of dialysis. RESULTS: After a median follow up of 5.5 years [1.9; 8.8], death and graft loss occurred in 10 and 12 patients respectively. M3 CF-PWV was an independent mortality risk factor (HR = 1.29 [1.03; 1.61]; p = 0.03), despite no aortic stiffness variation during the first year of transplantation. Of notice, M3 CF-PWV was not associated with M12 mGFR or ESRD outcome. Graft microcirculation assessed by Banff vascular fibrous intimal thickening score (cv) worsened between M3 and M12 (p = 0.01), but no link was found with CF-PWV, mGFR or ESRD outcome. Surprisingly, acute rejections at M3 were associated after adjustment with mortality (p = 0.03) but not ESRD. CONCLUSION: Aortic stiffness measured 3 months after kidney transplantation is a strong predictor of mortality with no obvious influence on kidney graft microvasculature or graft loss.