A new study has found that the clot-dissolving drug alteplase can significantly improve stroke recovery even when given up to 24 hours after a stroke begins.
The results, presented at the American Stroke Association’s International Stroke Conference 2025, suggest that many more stroke patients worldwide could benefit from this treatment, even if they miss the currently approved treatment window.
Expanding Treatment Options for Stroke Patients
Alteplase is already used to treat ischemic strokes, which occur when a blood clot blocks blood flow to the brain. In the U.S., it is approved for use within three hours of a stroke and is recommended for some patients up to 4.5 hours.
In China, the approved window is also 4.5 hours. However, past research has suggested that alteplase might still work beyond this time frame in select patients.
The new study, led by Dr. Min Lou from Zhejiang University in China, tested this idea in 372 stroke patients who arrived at the hospital between 4.5 and 24 hours after their symptoms began. All participants underwent a special brain scan called CT perfusion imaging, which helped doctors determine if they still had brain tissue that could recover with treatment.
The patients were then randomly assigned to two groups: one group received alteplase, while the other received standard stroke care, which included antiplatelet therapy based on Chinese stroke guidelines. Researchers assessed their recovery after 90 days.
Key Findings
- Better Recovery: 40% of patients who received alteplase had little to no disability after 90 days, compared to 26% in the standard treatment group. This means alteplase improved the chances of a good recovery by 54%.
- Low Need for Additional Treatment: Less than 3% of patients in either group needed an extra procedure to remove the clot mechanically.
- Similar Death Rates: About 10.8% of patients in both groups died, suggesting that alteplase did not increase the overall risk of death.
- Increased Bleeding Risk: 3.8% of alteplase patients experienced brain bleeding compared to 0.5% in the standard treatment group. However, researchers believe this is a manageable risk.
What This Means for Stroke Treatment
Dr. Lou believes these results could change the way stroke patients are treated, especially in hospitals that use CT perfusion imaging. This technology allows doctors to see how blood flows in different parts of the brain and identify patients who might still benefit from clot-dissolving medication, even many hours after a stroke starts.
“If these findings are confirmed in larger studies, more people may return to normal or near-normal lives after a stroke, even if they receive treatment later than originally thought beneficial,” Lou said.
Future Research Needed
The study highlights the need for further research on alteplase and other clot-dissolving drugs like tenecteplase to determine how effective and safe they are beyond standard time limits. Additionally, researchers want to see if these results apply to other populations, especially in countries with different stroke risks and healthcare resources.
Study Considerations
The study was conducted in 26 stroke centers in China, and the average age of participants was 72, with 43% being women. A limitation of the research is that both doctors and patients knew which treatment was being given, which could have influenced the results. Additionally, the findings may not apply to stroke patients in other countries with different healthcare systems.
Still, this study offers hope that alteplase could help many more stroke patients recover, even if they arrive at the hospital long after the usual treatment window.
If you care about stroke, please read studies about how to eat to prevent stroke, and eating eggs could help prevent stroke.
For more health information, please read studies about how to eat to prevent stroke, and diets high in flavonoids could help reduce stroke risk.
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