ASA: Alteplase Improves Outcomes 4.5 to 24 Hours After Acute Ischemic Stroke Onset

On Tuesday, February 18, 2025, new findings were revealed concerning the treatment of acute ischemic stroke (AIS) patients whose symptoms began between 4.5 to 24 hours prior. The study, presented at the American Stroke Association International Stroke Conference in Los Angeles, demonstrated that alteplase, a thrombolytic agent, significantly enhances the likelihood of patients attaining favorable outcomes 90 days post-stroke.

The research, led by Dr. Min Lou from the Second Affiliated Hospital of Zhejiang University School of Medicine in China, was a prospective, randomized trial conducted across 26 stroke centers in China. It involved patients exhibiting clinical symptoms of AIS within the 4.5 to 24-hour window and possessing salvageable brain tissue as indicated by perfusion imaging. Participants were randomized to receive either intravenous alteplase or standard medical care, with each group consisting of 186 patients.

The primary objective of the study was to assess the proportion of patients achieving a score of 0 or 1 on the modified Rankin scale after 90 days, indicating no symptoms or slight symptoms respectively. The results revealed that 40.3 percent of the patients treated with alteplase reached this primary outcome, compared to 26.3 percent in the standard treatment group. This corresponds to a relative rate of 1.40, with a 95 percent confidence interval ranging from 1.05 to 1.87.

Despite the promising results in functional outcomes, mortality rates at 90 days post-treatment were identical for both groups at 10.8 percent. However, the incidence of symptomatic intracerebral hemorrhage within 36 hours of treatment was notably higher in the alteplase group at 3.8 percent, compared to 0.5 percent in those who received standard medical treatment.

Endovascular thrombectomy was rarely performed among the participants, with three patients in the alteplase group and seven in the standard treatment group undergoing the procedure. This relatively low incidence suggests that the findings primarily reflect the effects of alteplase itself as opposed to other interventions.

These findings suggest a potential shift in how clinicians might approach treatment for AIS, particularly concerning the treatment window for thrombolytic therapy. Dr. Lou expressed optimism about the impact of the study, stating that more individuals might recover to normal or near-normal lives post-stroke, even with treatment initiated later than traditionally considered beneficial.

In summary, this study highlights the potential for alteplase to improve long-term outcomes for AIS patients when administered within 4.5 to 24 hours of symptom onset. While challenges such as an increased risk of hemorrhage remain, the overall enhancement in recovery prospects could influence future treatment protocols and guidelines.