Haemodialysis in patients treated with oral anticoagulant: should we heparinize?

Background. Anticoagulation for the haemodialysis circuit in patients treated with oral anticoagulation poses additional haemorrhagic risk. The few available data suggest that tapering or even stopping heparinization is feasible and the HeprAN membrane with grafted heparin was developed to decrease heparin dose. The objective of our study was to evaluate the need for additional anticoagulation in patients on long-term oral anticoagulation, according to the type of membrane used. Methods. This is a prospective, randomized, crossover bifactorial trial in haemodialysed patients on oral anticoagulation. Each patient had four haemodialysis sessions with two different membranes [HeprAN or polysulphone (PS)] and with or without enoxaparin. Clinical coagulation was evaluated by the need for premature ending and by a visual score (Janssen scale). Coagulation activation markers were also measured: D-dimers, prothrombin fragments 1+2, thrombin–antithrombin complexes, tissue factor pathway inhibitor and platelet factor-4. Results. Ten patients were included (M/F = 4/6, mean age 63 ± 15 years). None of the 40 sessions ended prematurely. The clotting scores were similar with or without enoxaparin (dialyser: 1.49 ± 0.19 versus 1.53 ± 0.17, P = 0.97; bubble trap: 0.75 ± 0.19 versus 0.78 ± 0.22, P = 0.62) and with the polysulphone or the HeprAN membrane (dialyser: 1.54 ± 0.20 versus 1.47 ± 0.16, P = 0.65; bubble trap: 0.74 ± 0.22 versus 0.79 ± 0.19, P = 0.58). There was no significant difference in coagulation activation markers between dialysis modalities; however, dialysis efficacy was significantly greater with the PS membrane (1.58 ± 0.07 versus 1.43 ± 0.06, P = 0.02). Conclusions. These results suggest that haemodialysis without additional anticoagulation is possible in patients with oral anticoagulation. The HeprAN membrane did not provide any additional benefit compared with a PS membrane.