Ayer A, et al. - Given that patients with end-stage renal disease (ESRD) have reduced endothelial function, researchers here assessed if macro- and microvascular endothelial function [evaluated as flow-mediated dilation (FMD) and velocity time integral (VTI), respectively] correlate with baseline risk factors and cardiovascular outcomes. Among 146 participants of the Cardiac, Endothelial Function and Arterial Stiffness in ESRD (CERES) study, impaired VTI was noted to be associated with older age and Black race, as well as female gender, atherosclerosis, and hemodialysis (as opposed to peritoneal dialysis). Impaired VTI was noted in correlation with myocardial injury, measured as high-sensitivity troponin T (hs-TnT), inflammatory markers and N-terminal pro B-type natriuretic peptide (NT-proBNP). As per unadjusted analyses, VTI was significantly associated with the composite outcome, but FMD was not. Association of VTI with the outcome persisted after multivariable adjustment when it was calculated as the ratio of (hyperemic VTI-baseline VTI)/baseline VTI. These findings support the association of microvascular function with higher rates of cardiovascular hospitalizations and all-cause mortality among individuals with ESRD on dialysis.