ORLANDO, Fla. — “Interestingly, clotting events only occurred in patients on heparin-free hemodialysis and warfarin,” said Graham Abra, MD, here at the Annual Dialysis Conference.

“As we are all well-aware, patients receive heparin during hemodialysis to prevent clotting of the dialysis circuit to allow proper clearance of uremic toxins,” Abra said. “Additionally, some patients on hemodialysis are on oral anticoagulation for a variety of conditions including atrial fib and venous thrombosis.”

There is no standard for heparin dosing of patients on oral anticoagulants and Abra’s small study looked heparin-free hemodialysis in patients taking oral anticoagulants.

There was an initial 2-week period of patients taking heparin followed by a 2-week period of no heparin. In the 2-week period when patients were off heparin, saline-flushing was not used.

Graham Abra, MD

Inclusion criteria were adult patients who were treated with warfarin, dabigatran, apixaban, or rivaroxaban and intradialytic heparin; end-stage renal disease and currently undergoing in-center hemodialysis; could understand English; and had the willingness to sign an informed consent. Patients who were excluded had been admitted to the hospital 7 days or fewer and had a recent INR of less than 1.8 on warfarin.

According to Abra, the primary outcome was clinically significant clotting “which we defined as dialyzed or dialysis circuit complete clotting.”

The study was conducted at two hemodialysis centers and included eight patients (six patients were on warfarin and two patients were on apixaban). Four patients were receiving oral anticoagulation because of atrial fibrillation and the remaining were due to stroke and venous thrombosis risk.

“During the on-heparin period, there were no clotting events over the course of 41 hemodialysis treatments,” Abra said and also noted that during the no-heparin period, there were two clotting events during the course of 43 hemodialysis events.

“Significant here – both of the clotting events occurred in patients on warfarin. Neither of the patients who had a clotting event had a documented INR prior to the clotting event occurring,” Abra said. “Also interesting is that five of the six patients on warfarin had no documented INR during the 4 weeks of the study … highlighting the fact that Coumadin management is often sporadic in patients who are on hemodialysis,” he said.

He also said there was similar time to access hemostasis and hemoglobin on and off heparin.

Abra acknowledged this was a small, exploratory pilot study that was too small to draw conclusions and that further research is needed.  – by Joan-Marie Stiglich, ELS


Abra G. Heparin-free dialysis for patients on oral anticoagulants. Presented at: Annual Dialysis Conference; March 3-6, 2018; Orlando, Fla.

 Disclosure: Abra reports he is an employee of Satellite Health, a non-profit dialysis provider.