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

RATIONALE AND OBJECTIVE: The EVOCIT study was designed to evaluate dialyzer performance during hemodialysis with and without systemic anticoagulation.

STUDY DESIGN: Randomized, crossover, non-inferiority trial. Noninferiority was defined as a difference of ≤10% for the primary outcome.

SETTING AND PARTICIPANTS: Single hemodialysis center; 26 prevalent patients treated with 617 hemodialysis sessions.

INTERVENTIONS: Hemodialysis using a heparin-grafted dialyzer combined with a 1.0 mmol/L citrate-enriched dialysate ("Evocit") without systemic anticoagulation was compared to 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.

OUTCOMES: The primary end point was the difference in Kt/Vurea between Evocit and Evohep. Secondary end points were urea reduction ratio (RR), middle molecule removal, treatment time, thrombin generation and reduction in dialyzer blood compartment volume.

RESULTS: The estimated difference in Kt/Vurea between Evocit and Evohep was -0.03 (95%CI, -0.06 to -0.007) establishing non-inferiority with mean Kt/Vurea of 1.47±0.05 (SE) for Evocit and 1.50±0.05 for Evohep. Non-inferiority was also established for urea RR and beta-2 microglobulin RR. 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.

LIMITATIONS: The effects of avoiding systemic anticoagulation on clinical outcomes were not evaluated.

CONCLUSIONS: Evocit is non-inferior to Evohep with respect to solute clearance but results in a greater number of shortened treatments, more membrane clotting and greater thrombin generation.