Dialyzer Performance During Hemodialysis Without Systemic Anticoagulation Using a Heparin-Grafted Dialyzer Combined With a Citrate-Enriched Dialysate: Results of the Randomized Crossover Noninferiority EvoCit Study

The EvoCit study was designed to evaluate performance of a heparin-grafted dialyzer during hemodialysis with and without systemic anticoagulation. Randomized, crossover, noninferiority trial. Noninferiority was defined as a difference of ≤10% for the primary outcome. Single hemodialysis center; 26 prevalent patients treated with 617 hemodialysis sessions. Hemodialysis using a heparin-grafted dialyzer combined with a 1.0 mmol/L citrate-enriched dialysate (“EvoCit”) without systemic anticoagulation compared with hemodialysis performed with a heparin-grafted dialyzer with systemic heparin (“EvoHep”). Patients were randomly allocated to a first period of 4 weeks and crossed over to the alternative strategy for a second period of 4 weeks. The primary end point was the difference in Kt/V urea between EvoCit and EvoHep. Secondary end points were urea reduction ratio, middle molecule removal, treatment time, thrombin generation, and reduction in dialyzer blood compartment volume. The estimated difference in Kt/V urea between EvoCit and EvoHep was −0.03 (95% CI, −0.06 to −0.007), establishing noninferiority with mean Kt/V urea of 1.47 ± 0.05 (SE) for EvoCit and 1.50 ± 0.05 for EvoHep. Noninferiority was also established for reduction ratios of urea and β 2 -microglobulin. Premature discontinuation of dialysis was required for 4.2% of sessions among 6 patients during EvoCit and no sessions during EvoHep. Effective treatment time was 236 ± 5 minutes for EvoCit and 238 ± 1 minutes for EvoHep. Thrombin generation was increased and there was greater reduction in dialyzer blood compartment volume after treatments with EvoCit compared with EvoHep. The effects of avoiding systemic anticoagulation on clinical outcomes were not evaluated. EvoCit is noninferior to EvoHep with respect to solute clearance but results in a greater number of shortened treatments, more membrane clotting, and greater thrombin generation Registered at ClinicalTrials.gov with study number NCT03887468.