Researchers from RCSI and Beaumont Hospital have taken part in a major international study which is set to revolutionise the treatment of stroke.

The study has shown that a clot retrieval procedure, known as endovascular treatment (ET) results in a dramatic improvement in patient outcomes and a reduction in disability and deaths from stroke. The results of this study are published today in the online edition of the New England Journal of Medicine.

The international randomised controlled trial which was led by researchers at the University of Calgary's Hotchkiss Brain Institute (HBI) was carried out at 22 sites worldwide and included patients referred to Beaumont Hospital in Dublin from ten centres across Ireland and from hospitals in Canada, the US, UK and South Korea.

The study involved patients who had suffered an acute ischemic stroke, which is caused by a clot in the brain, and accounts for 80% of all strokes.

Overall, positive outcomes for patients receiving the new ‘clot removal' treatment increased from 30% to 55%. In many cases, instead of suffering major neurological disability, patients went home to resume their lives. The overall mortality rate was reduced by 50%, from two in ten patients for standard treatment of care, to one in ten patients out of those who received the new treatment. Up to now, the current standard treatment involved administering medication to dissolve the clot.

Professor David Williams, Associate Professor in Geriatric and Stroke Medicine, RCSI and Consultant Stroke Physician at Beaumont Hospital and Dr John Thornton, Consultant Neuroradiologist, at Beaumont Hospital were the co-leads in Ireland for the study.

"The results of this study represent the most significant development in stroke treatment in the past 20 years and will impact stroke care in Ireland and around the world. More than 10,000 people in Ireland are admitted to hospital with stroke annually and many of those who survive are left with significant disabilities. This treatment has the potential to improve survival rates and quality of life of more than 15 million people worldwide who suffer a stroke each year. The involvement of RCSI and Beaumont Hospital in this ground-breaking trial demonstrates the world-class expertise of clinical researchers here in Ireland," Professor Williams said.

While the new treatment is improving outcomes, it is still vital that the warning signs of stroke are identified as quickly as possible.

"When removing a clot with this new treatment, as with existing treatments, every minute matters. If you suspect someone is having a stroke, call 999 immediately as many stroke treatments only work if administered within a set period of time. The tell-tale signs of stroke are facial drooping, inability to raise arms over their heads and slurred speech," Professor Williams concluded.

Beaumont Hospital was the largest patient recruiting site for the study outside Canada with 34 patients taking part in the randomised trial over 6 months, recruited by the research team at Beaumont Hospital and followed up by expert research nurses at the RCSI Clinical Research Centre based at Beaumont Hospital.

"There was impressive collaboration between stroke centres; doctors and nurses; and transport services as well as the radiology team in Beaumont where all the procedures were performed,” commented Dr John Thornton.

According to the Irish Heart Foundation, stroke kills more than 2,000 people a year in Ireland - a higher death toll than from breast cancer, prostate cancer and bowel cancer combined. Stroke is the third most common cause of death and the most common cause of acquired physical disability in Ireland. There are more than 30,000 survivors of stroke in Ireland, many of whom have significant disabilities.

The clinical trial, known as ESCAPE (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalisation times), shows there is a marked reduction in both disability and death among patients who receive ET for acute ischemic stroke. Ischemic stroke is caused by a sudden blockage of an artery to the brain that deprives the brain of critical nutrients, such as glucose and oxygen. Currently, the international standard of care based on European and North American guidelines is to administer a drug called tPA when appropriate to bring on a process of thrombolysis. Known as a ‘clot buster', the drug dissolves the blood clot. In the ESCAPE trial, 316 patients who fit the criteria for ET and arrived for treatment within 12 hours of their stroke were randomised to standard medical care (which included the clot-busting drug tPA where appropriate) or standard medical care plus ET.

ET is performed by inserting a thin tube into the artery in the groin, through the body, and into the brain vessels to the clot. This is done under image-guided care using an X-ray. The clot is then removed by a retrievable stent and pulled out, restoring blood flow to the brain.

Endovascular treatments were first developed in the 1990s, but ET has only recently been technically possible. The success of the ESCAPE trial can be credited to very fast treatment and the use of brain and blood vessel imaging. In ESCAPE, researchers were on average two hours faster in opening the blocked blood vessels than in previously reported trials.

ESCAPE is the second ET trial that demonstrates the efficacy of the treatment and the first trial to demonstrate reduced mortality. The previous trial, known as MR. CLEAN (Multi-cenre Randomised Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands), was published in December 2014.

The study was funded by The Heart and Stroke Foundation of Canada, Alberta Innovates-Health Solutions and Medtronic, along with generous donations to the HBI Stroke Team and the Calgary Stroke Programme.

RCSI is the academic partner in RCSI Hospitals Group, which includes Beaumont, Cavan and Monaghan, Connolly, Louth County, Our Lady of Lourdes Drogheda and Rotunda Hospitals.