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.
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,” Chamorro said. “Stroke treatment continues to improve, and getting the right care quickly can make a real difference in a patient’s recovery and return to their everyday life.”
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 clot-busting medication 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. Additionally, they rated themselves higher in mobility, self-care, performing usual activities, lower pain/discomfort and depression/anxiety.
“Mechanical thrombectomy alone is often not enough to fully restore blood flow to the injured brain, even when the blocked artery appears successfully reopened,” Chamorro said. “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.”
The treatment was not significantly more likely to cause a brain bleed (1.4% vs. 0.5%) or death (12.1% vs. 6.4%).
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 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. The PEARL trial used alteplase and had comparable results.
Limitations of the study include the requirement for non-contrast CT scanning during follow-up, which may not provide detailed information about brain tissue injury and recovery. Although the study was conducted only in Spain, participants were from 20 countries across three continents, so results should be generalizable to many populations.
“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.”
