Giving the clot-busting medication alteplase at the site of a blocked brain artery after blood clot removal may increase the number of patients who fully recover, according to preliminary late-breaking science presented at the American Stroke Association’s International Stroke Conference 2026. The meeting, Feb. 4 - 6, 2026, in New Orleans, is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.
Large-artery ischemic (clot-caused) strokes account for about 1 in 4 ischemic strokes, according to study author Ángel Chamorro, M.D., Ph.D., professor of neurology at the University of Barcelona and head of the Comprehensive Stroke Center Hospital Clinic in Barcelona. These types of strokes can cause death and long-term disability because they block large arteries that supply blood to significant areas of the brain.
The 2026 Guideline for the Early Management of Patients With Acute Ischemic Stroke, from the American Stroke Association, a division of the American Heart Association, notes that removing clots directly from blocked brain arteries, a procedure called thrombectomy, is a powerful treatment for major strokes caused by large-vessel blockages in select patients. However, more than half of stroke survivors who have their large artery successfully cleared do not achieve full recovery 90 days later.
In the CHOICE2 trial, more than 400 adults with large-artery ischemic stroke were treated at stroke centers in Spain within 4.5 to 24 hours of their first stroke symptoms. Patients were randomized to receive either clot removal (219 people) or clot removal plus infusion of alteplase into the artery (214 people). At 90 days after treatment, participants who received alteplase in addition to clot removal were significantly more likely to achieve excellent functional outcome (57.5% vs. 42.5%), with an absolute improvement of 15 percentage points. They were also less likely (28.6% vs. 50.5%) to have inadequate blood flow in small vessels of the brain revealed by imaging, with a decline of 22 percentage points. Patients rated themselves higher in mobility, self-care, performing usual activities, lower pain/discomfort and depression/anxiety. Importantly, they were not significantly more likely to have a brain bleed (1.4% vs. 0.5%) or to die (12.1% vs. 6.4%).
“Mechanical thrombectomy alone is often not enough to fully restore blood flow to the injured brain, even when the blocked artery appears successfully reopened. Standard imaging can miss persistent blockages in the brain’s smallest blood vessels. Intra-arterial alteplase given after successful thrombectomy significantly increased the chances of an excellent recovery,” Chamorro said.
In an earlier study, preliminary results from CHOICE, published in 2022, revealed significantly better outcomes in stroke survivors who were treated with alteplase in addition to thrombectomy. However, the number of patients in the study was relatively small (121), and the trial was halted early due to the COVID-19 pandemic. Similar research (the ANGEL-TNK trial) that used the clot-dissolving agent tenecteplase was presented last year at the International Stroke Conference and had comparable results.
“These results are practice-informing but not yet practice-changing on their own,” Chamorro said. “While CHOICE2 strengthens the evidence that intra-arterial alteplase given after successful thrombectomy can improve recovery, broader adoption will require confirmation in additional studies, guideline review and careful consideration of patient selection. Importantly, this approach should not be viewed as a ’one-size-fits-all’ treatment.”
The study was conducted only in Spain, but participants were from 20 countries across three continents, suggesting the results should be generalizable to many populations. Future research will focus on ways to treat the underlying causes leading to the disruption of blood flow in the microcirculation.
