Revolutionary Clot-Busting Drugs Show Promise When Administered Within 24 Hours of Stroke Onset

This research brings optimism to stroke patients around the globe, particularly those who might miss the window for clot-dissolving treatment, which is limited to 4.5 hours in places like China, according to Min Lou, M.D., Ph.D., the trial’s lead investigator and a professor at the Second Affiliated Hospital of Zhejiang University in China.

In the United States, alteplase is recommended for stroke treatment within three hours of symptom onset and may be used up to 4.5 hours for certain patients. Additional studies suggest that it may also be effective in some cases even 4.5 to 9 hours after a stroke begins.

The 2019 Guidelines from the American Heart Association/American Stroke Association for managing acute ischemic strokes indicate that administering IV alteplase within 4.5 hours is the standard treatment for most ischemic stroke patients in the U.S.

In this study, 372 stroke patients who exhibited symptoms 4.5 to 24 hours prior were enrolled. CT perfusion imaging, a common brain scanning technique, was employed to determine if these patients still had brain tissue capable of recovery through treatment. The participants were randomly divided into two groups: one received alteplase, while the other was treated with standard stroke care based on antiplatelet therapy as per the Chinese Guidelines for Acute Ischemic Stroke in 2018. Recovery outcomes were analyzed after 90 days.

“We believe these results imply that more individuals might achieve normal or nearly normal lifestyles following a stroke, even with later treatment than previously considered ideal,” Lou stated. “This treatment strategy could set a new standard, particularly in hospitals utilizing CT perfusion imaging, which allows healthcare providers to examine blood flow in various brain areas post-ischemic stroke. This could broaden treatment eligibility to millions more patients worldwide.”

Key findings from the study include:

• 40% of those treated with alteplase reported minimal to no disability after 90 days, contrasted with 26% of those in the standard care group – representing a 54% higher likelihood of functional recovery.
• Fewer than 3% of participants in either group required rescue mechanical clot removal as an additional intervention.
• Mortality rates were identical for both groups at 10.8%.
• The occurrence of brain bleeding was more frequent in those who received alteplase (3.8%) compared to those who did not (0.5%), but this risk is considered manageable by researchers.

“It is essential to further investigate the safety and effectiveness of other clot-dissolving drugs, such as tenecteplase, particularly when administered after a stroke and outside standard treatment windows. Additionally, understanding if our findings are applicable to different demographic groups, especially in regions with varying stroke risk and healthcare systems, is crucial,” Lou elaborated.

However, the study has some limitations, such as both participants and investigators knowing which treatment was administered, potentially introducing bias. Also, the results may not be relevant to populations outside of China.

Study design and details include:

• The trial was a multicenter, prospective, randomized study encompassing 372 stroke patients across 26 stroke centers in China.
• Participants had an average age of 72 years, with 43% being women.
• Thanks to the use of standard CT perfusion imaging, the findings may be more applicable to everyday clinical practices.
• Patients were assigned either to the alteplase group or the standard care group.
• The primary goal was to achieve a score of 0 or 1 on the modified Rankin scale, which assesses disability from 0 (no symptoms) to 6 (death) at the 90-day mark.