New Study Shows Stroke Treatment Window Can Extend Beyond 4.5 Hours with Advanced Imaging

A recent comprehensive study published in JAMA Network Open challenges the traditional 4.5-hour treatment window for ischemic stroke patients receiving clot-dissolving medication. Dr. Roni Eichel, head of neurology at Shaare Zedek Medical Center, explains that stroke causes acute blood flow disruption in the brain, leading to irreversible damage as neurons die by the millions each minute. Historically, intravenous thrombolytic therapy (IV tPA) was limited to within 4.5 hours of symptom onset, but nearly 25% of stroke patients wake up with symptoms, making exact timing unclear.

The new meta-analysis combined data from 14 randomized clinical trials involving 4,174 ischemic stroke patients treated with thrombolytics beyond 4.5 hours or after unknown onset times. Advanced brain imaging (MRI and CT) was used to identify salvageable brain tissue, allowing treatment up to 24 hours after stroke onset in some cases. Results showed a 22% higher chance of excellent functional recovery and a 12% higher chance of good recovery at 90 days compared to controls. However, symptomatic intracranial hemorrhage risk increased 2.44 times, though mortality rates did not differ significantly.

Dr. Eichel emphasizes that patient selection must be meticulous due to bleeding risks, requiring sophisticated imaging and clinical expertise. While mechanical thrombectomy (clot removal via catheter) is effective up to 24 hours in selected patients, only about 17% of ischemic stroke patients in Israel currently receive reperfusion therapies, partly due to late hospital arrival and limited specialist availability.

The study supports expanding treatment eligibility using advanced imaging to identify patients who can benefit beyond the conventional time limits. Dr. Eichel calls for increased specialist training and resources in Israel to improve access to these life-saving interventions and reduce stroke-related disability.