By Mary Ellen Schneider
Tranexamic acid was not effective in preventing bleeding when added to routine transfusion therapy in patients undergoing treatment for hematologic malignancy, according to findings presented at the annual meeting of the American Society of Hematology.
But researchers cautioned that the clot stabilizer has been shown to be effective in other situations.
“This study looked only at tranexamic acid as an adjunct to routine prophylactic platelet transfusion in preventing bleeding,” said Terry B. Gernsheimer, MD, of the University of Washington School of Medicine in Seattle. “We cannot rule out the usefulness of tranexamic acid in other settings of thrombocytopenia, such as the treatment of active bleeding, refractoriness to platelet transfusion, or prophylaxis for procedure.”
Dr. Gernsheimer presented findings from the American Trial Using Tranexamic Acid in Thrombocytopenia (A-TREAT) trial, which sought to determine if the high rate of World Health Organization grade 2 or greater bleeding in patients undergoing therapy for hematologic malignancy — which ranges from about 40%-70% — could be decreased through the inhibition of fibrinolysis (Abstract 2).
The trial included 330 adult patients undergoing treatment for a hematologic malignancy who had a platelet count of less than 10,000/µL for at least 5 days. Patients were randomized to tranexamic acid or placebo, and treatment was started when platelets were less than 30,000/µL. Patients were excluded from the trial for several reasons, including if they had a history of thromboembolism or a thrombotic cardiac event, were on anticoagulant therapy or were deemed to be at high risk for thrombosis, or if there were other etiologies for thrombocytopenia.
Overall, tranexamic acid administered prophylactically in addition to routine platelet transfusion did not decrease the rate of bleeding in severely thrombocytopenic patients undergoing therapy for hematologic malignancies. The primary outcome – the proportion of World Health Organization grade 2 or greater bleeding – was 48.8% in the placebo group and 45.4% in the tranexamic acid group (Odds Ratio 0.86, 0.52-1.38). This difference is similar to what has been observed in other studies and is not statistically significant, Dr. Gernsheimer said.
Mean days alive without bleeding and mean numbers of platelet transfusions also did not differ between the groups (P=0.94 for both). There was no difference between the groups in terms of red blood cell transfusions, even when adjusted for thrombocytopenic day, Dr. Gernsheimer reported.
A post-hoc analysis of grade 3 and 4 bleeding “showed these events to be rare, without an obvious trend towards improvement with tranexamic acid,” she said.
Researchers observed an increased incidence in central line occlusion in the tranexamic acid arm, but there was no difference in other thrombotic events or mortality. The percentage of patients experiencing line occlusion was 6.7% with placebo versus 16.5% for tranexamic acid. However, the percentage of patients experiencing non-catheter thrombotic events were 5.5% for placebo versus 3.7% for tranexamic acid.