Variations in Antithrombotic Use Affect Bleeding Risk in Hemodialysis

The data from a large international study of patients receiving hemodialysis show a wide variation in antithrombotic therapy, along with an increased risk of bleeding among patients receiving oral anticoagulants (OACs), reports Kidney International.

In more than 48,000 patients enrolled in the worldwide Dialysis Outcomes and Practice Patterns Study, the researchers assessed variations in antithrombotic therapy and major bleeding events. The study also sought to identify risk factors for stroke and bleeding events in this very large hemodialysis population.

The use of all categories of antithrombotic agents varied widely among countries: from 0.3 percent to 18 percent for OACs, 3 percent to 25 percent for antiplatelet agents (APAs), and 8 percent to 36 percent for aspirin. The rates of major bleeding events also varied widely: from 0.05 to 0.22 events per year. In adjusted analyses, patients receiving OACs were at increased risk of all-cause and cardiovascular mortality as well as bleeding events requiring hospitalization. Antiplatelet agents were also associated with increased all-cause and cardiovascular mortality.

In patients with atrial fibrillation, the CHADS2 score was a significant predictor of stroke risk. Gastrointestinal bleeding within the past year was a strong predictor of bleeding risk: for patients with such a history, the bleeding rate was at least twice as high as the stroke rate. This was so at all levels of CHADS2 score and among patients at high risk of stroke.

The results show a wide variation in the use of antithrombotic agents in patients receiving hemodialysis, with increased bleeding risk in patients receiving OACs. Both OACs and APAs are associated with increased mortality. “Appropriate risk stratification and a cautious approach should be considered before OAC use in the dialysis population,” the researchers conclude [Sood MM, et al. Major bleeding events and risk stratification of antithrombotic agents in hemodialysis: results from the DOPPS. Kidney Int 2013; 84:600–608].