Potential clotting risk
One reason for the lack of observed benefit with tranexamic acid may be an inappropriate sample size, said Dr. Liu. Patient recruitment was difficult, especially in centers that used the spot sign as an inclusion criterion.
“We think a positive result could be seen in a substantially larger sample size,” said Dr. Liu. “Furthermore, we infer from our subgroup analysis that a more specified patient selection and shorter treatment window may be required for better effect.”
In some of their subgroup analyses, the researchers found a trend toward an increased effect in patients with moderate-size hematoma who received treatment in an earlier window. “That could be the targeted population for future studies,” said Dr. Liu. “We are working on further analysis of the population and possibly international collaboration.”
But tranexamic acid also entails risks, said Louis R. Caplan, MD, professor of neurology at Harvard Medical School, Boston, who provided independent commentary on the findings. “Tranexamic acid works on the thrombolytic system, so it increases clotting, and it does have a risk in people who are older and have risk factors for coronary disease and pulmonary embolism.”
As in ischemic stroke, time to treatment is a crucial consideration. Patients with ICH may receive treatment within 5 or 6 hours of onset, but most hemorrhages have reached their maximum size at that point. “The number of people that you can actually help by reducing the size is small,” said Dr. Caplan. “And then reducing the size in most hemorrhages doesn’t make any clinical difference.”
Stereotactic drainage, in which fluid is physically removed, is more likely to lead to long-term improvement for some patients with hemorrhage than limiting expansion, said Dr. Caplan. “That seems to be a more promising therapy,” he added.
The study was supported by the National Key R&D program of China, the National Natural Science Foundation of China, and the Beijing Science and Technology Commission. Dr. Liu and Dr. Caplan have disclosed no relevant financial relationshps.
A version of this article first appeared on Medscape.com.