Australian study will change the way stroke is treated around the world

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A team of Melbourne researchers have found the time to treat ischemic stroke patients can be doubled. One in five people suffer stroke in their sleep and this will be life changing for them.

The EXTEND (Extending the Time for Thrombolysis in Emergency Neurological Deficits) randomised clinical trial found the initial window of 4.5 hours from symptom onset could now be pushed to 9 hours given solid evidence of ‘brain to save’ on advanced brain imaging. The international trial involved 225 participants from a large multi-centre collaboration across 25 hospitals in Australia, New Zealand, Finland and Taiwan, who either received alteplase or placebo.

EXTEND, led by The Royal Melbourne Hospital (RMH), the University of Melbourne and Monash Health, compared the effectiveness of alteplase, a thrombolytic drug used to treat ischemic stroke, versus placebo, for reducing disability after stroke. The research found in most cases if the patient was administered the alteplase between 4.5 to 9 hours after stroke onset it resulted in a high percentage of patients with no or minor neurologic defects than the use of placebo.

RMH neurologist, Director of the Melbourne Brain Centre at RMH and study co-principal investigator Professor Stephen Davis said the study, “Thrombolysis Guided by Perfusion Imaging up to 9 Hours after Onset of Stroke” published in the New England Journal of Medicine found the drug alteplase was life changing in treatment of ischemic stroke. “Our study used imaging of brain blood flow to select patients and showed that alteplase increased the number of patients who were able to return to all their usual activities by 44% compared to placebo, an excellent outcome for our patients,” Professor Davis said.

Professor Bruce Campbell, consultant neurologist and Head of Stroke at the Royal Melbourne Hospital and chair of the Stroke Foundation’s Clinical Council, said that reperfusion therapies, such as intravenous thrombolysis and endovascular thrombectomy, for ischaemic stroke had dramatically reduced disability and revolutionised stroke management.

“Thrombolysis with alteplase is effective when administered to patients with potentially disabling stroke, who are not at high risk of bleeding, within 4.5 hours of the time the patient was last known to be well,” he said. “Emerging evidence suggests that other thrombolytics such as tenecteplase may be even more effective. Treatment may be possible beyond 4.5 hours in patients selected using brain imaging.”

Professor Campbell noted that while 20% of patients with ischaemic stroke are eligible for thrombolysis in the 4.5-hour time window, only about 13% of patients are receiving this treatment. “There is still room to improve the proportion of patients getting thrombolysis,” he said.

Professor Geoffrey Donnan, from the University of Melbourne Professor of Neurology, and the study's co-principal investigator, said a further barrier to reperfusion therapies was inequitable access to stroke units, which was particularly problematic in rural and regional Australia. “We need better access for all Australians to modern stroke care, a national approach to standardised quality care to reduce inequalities, and outcomes monitoring with an expansion of the Australian Stroke Clinical Registry (AuSCR),” he said. The AuSCR is currently in around 80 hospitals Australia-wide.

Professor Donnan went on to say that the results were likely to change stroke treatment guidelines and clinical practice. “This research means that patients who were previously untreatable because they woke up with stroke symptoms or were unavoidably delayed in reaching hospital can now benefit,” he said.

While this breakthrough will lead to sweeping changes in stroke treatment, Professor Davis warns it is still vital for people to seek help as soon as possible as every minute counts when it comes to stroke patients.

“It’s still critical that stroke patients are treated as fast as possible and the proportion of patients who have the favourable brain imaging that allows us to treat them drops rapidly with passing time,” Professor Davis said.

Medical co-ordinator for the EXTEND trial Associate Professor Henry Ma from Monash Health said the research means patients who have a stroke in their sleep will greatly benefit. “These results shift the stroke paradigm from using a clock to determine eligibility for clot-dissolving treatment to using brain imaging to identify whether there is brain tissue that can be saved in the individual patient," he said. “This is terrific for patients and will reduce the burden of stroke-related disability in Australia and worldwide.”