Infusion of clot-buster medication after clot removal may improve stroke recovery

Research Highlights:

• Even after a blood clot is removed from a large artery in the brain via a minimally invasive procedure to treat a clot-caused stroke, delivering the clot-busting medication alteplase to the area may improve stroke recovery, according to a trial conducted at stroke centers in Spain.
• The two-pronged treatment approach may increase the number of people who fully recover from stroke due to a blockage in a large brain artery.
• Note: The study featured in this news release is a research abstract. Abstracts presented at the American Heart Association's scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

Embargoed until 11:45 a.m. CT/12:45 p.m. ET Wednesday, Feb. 4, 2026

NEW ORLEANS, Feb. 4, 2026 - 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.

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. Even when doctors successfully reopen a blocked brain artery, novel treatment strategies such as adding alteplase to thrombectomy can further improve outcomes after a stroke."

In the CHOICE2 trial reported today, 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, making it possible to both remove the clot in the large artery and to have the option of treatment with alteplase to the same location immediately after. 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;
• were less likely (28.6% vs. 50.5% for those treated with only thrombectomy) to have inadequate blood flow in small vessels of the brain revealed by imaging, with a decline of 22 percentage points;
• rated themselves higher in mobility, self-care, performing usual activities, lower pain/discomfort and depression/anxiety; and
• 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, which interfered with patient recruitment and the supply of placebos.

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.

The limitations of this study include the requirement for non-contrast CT scanning during the follow-up period, which reflects real-world clinical practice but 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; therefore, the 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. Importantly, this approach should not be viewed as a 'one-size-fits-all' treatment. It is most likely to benefit patients who, despite large-vessel reopening, have evidence of inadequate blood flow in their microcirculation. However, if future studies and meta-analyses confirm the safety of this strategy, it may eventually reduce the need to rely on advanced imaging techniques to identify patients with persistent perfusion abnormalities appropriate for this treatment."

In addition to confirming the findings of CHOICE2, future research will focus on ways to treat the underlying causes leading to the disruption of blood flow in the microcirculation.

Study details, background and design:

• Participants were 433 adults (median age 76 years; 51% women; 95% white) who experienced an ischemic (clot-caused) stroke in a large brain artery and were treated at one of 14 stroke centers in Spain between December 2023 and August 2025.
• All study participants were treated with mechanical thrombectomy (a minimally invasive procedure to physically remove the blood clot), and blood flow through the artery was successfully restored. All were treated quickly enough that the clot-busting medication alteplase could be delivered within 24 hours of the time the patient was last seen well.
• In this Phase 3 trial, CHOICE2 (CHemical OptImization of Cerebral Embolectomy 2), after a successful thrombectomy, patients were randomized to receive either usual care of mechanical clot removal (219 patients) or usual care plus a 15-minute infusion of alteplase directly into the affected brain artery (214 patients).
• None of the participants had any serious neurological problems before their strokes, and None had a stroke classified as "very severe" on a scale of stroke severity.
• In the primary determination of treatment success, patients functional recovery at 90 days was evaluated using the modified Rankin Scale to quantify disability, and the proportion of patients with little or no disability was quantified. Other outcomes assessed at 90 days included independence in performing basic activities of daily living and patients' self-reported quality of life using the EuroQuol 5 dimensions, 5-level questionnaire.
• The safety of the treatment was evaluated by the occurrence of bleeding in the brain (symptomatic intracranial hemorrhage) within 24 hours of treatment and death from any cause by 90 days.
• In an earlier study, preliminary results from CHOICE, published in 2022, revealed significantly better outcomes in stroke survivors who had also received 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, which interfered with patient recruitment and the supply of placebos.

Study co-authors, their disclosures, and study funding are available in the abstract.

Statements and conclusions of studies that are presented at the American Heart Association/American Stroke Association's scientific meetings are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association's scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

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Additional Resources:

• Multimedia is available on the right column of release link.
• Link to abstract in the American Stroke Association International Stroke Conference 2026 Online Program Planner
• American Heart Association information: 2026 Acute Ischemic Stroke Guideline Resources
• American Heart Association health information: Large-Core Ischemic Stroke Endovascular Treatment
• American Heart Association news release: Mechanical blood clot removal led to good recovery in half of stroke patients (Feb. 2022)
• According to the American Heart Association's 2026 Heart Disease and Stroke Statistics, stroke is now the #4 leading cause of death in the U.S. Learn more at www.stroke.org.
• For more news at American Stroke Association International Stroke Conference 2026, follow us on X @HeartNews #ISC26

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About the American Stroke Association

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