Landmark research study provides real answers...

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Landmark research study provides real answers for appropriate treatment of stroke patientsLONDON, ON (Nov. 11, 1998) -- The second phase of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), run by Dr. Henry Barnett, has been completed and will be reported in the prestigious New England Journal of Medicine tomorrow. The study provides definitive step-by-step procedures to follow with Stroke patients in order to ascertain if they should have medical or surgical treatment for narrowing of the carotid arteries. It will be an important algorithm used by neurologists all around the world. NASCET is a large multi-centre clinical trial, centred at The John P. Robarts Research Institute, involving physicians from 100 different sites and 2,900 patients around the globe. Of all the sites participating in the trial, London Health Sciences Centre made the largest contribution entering 10% of the patients. The study began in 1987, and the first phase was completed in 1991, proving that a surgical procedure to clean out clogged neck arteries--called a carotid endarterectomy--was beneficial in patients with severe blockage of the carotid artery. The carotid arteries, located on either side of the neck, provide blood to the eye and the brain, and when blocked, can cause Stroke. The study showed that those with Stroke symptoms and severe blockage-- 70-99% narrowing of the artery--clearly should be treated with the carotid endarterectomy procedure. The second phase looked at those patients with symptoms and moderate blockage--30-69% narrowing. This group was more difficult to analyse, and the study concluded that there was only moderate reduction in risk of stroke after the procedure. It also identified a number of groups of these moderate patients who were not candidates for the procedure. Principal Investigator of the study, Dr. Henry Barnett, explains: "We found that in moderate cases, three groups shouldn't be given high priority: 1) female patients, 2) those who have preliminary symptoms that are just Transient Ischemic Attacks (TIA's) and 3) patients with retinal symptoms. None of these patients will benefit from surgery and should be given proper medical treatment."The second phase of the study also showed that the procedure carried a higher operative risk for patients who were not taking aspirin, who were Diabetic, who had evidence of damage to the brain on the same side as the blocked artery on a CT scan, who had evidence of a clot in the artery at angiography, or who had narrowing of the left artery. However, despite the higher risk, the surgery is beneficial in these patients.Commenting on the surgery which involves opening the neck artery up and cleaning it out, Dr. Barnett says: "It is a very delicate procedure and must be done by extremely skilled surgeons in order to ensure the procedure helps--not hinders. Our final results do not justify a great increase in the procedure. Without excellent surgery, the treatment could end up causing what you're trying to prevent...Stroke."The impact of the phase one study was that surgeons began to do more of these tricky procedures on severe symptomatic cases and the number more than doubled between 1990 and 1997. With the second phase reporting a lesser benefit in moderate cases, care must be taken that only centres with skilled surgeons perform the procedure. Being lesser risk, the margin between risk and benefit is narrower. Dr. Mark Poznansky, President and Scientific Director of Robarts says: "The study was funded by the National Institute of Health (NIH) in the United States. Funding totalled $35 Million US over the 11 years the study has run. That this type of funding came to London, and to Canada is outstanding. It brought not only money and jobs to this city, but it altered the practice of how certain patients at risk of Stroke are treated around the world. Dr. Barnett has been an international champion for evidence-based medicine, and has shown us in spades, how research can lead to the most effective use of the health care dollar."Chair of the Board, Bill Brady, comments "On behalf of the Board and the staff at Robarts, I would like to congratulate Dr. Barnett for marshalling this definitve study. The Founding President and Scientific Director of the Institute, Dr. Barnett's lifetime work in the area of Stroke has been a boon to medical colleagues and countless pateints around the world. Robarts has good reason to be proud of the marvellous achievements of the NASCET Group."The NASCET steering committee included Co-Principal Investigators; Dr. Gary Ferguson (Associate Scientist at Robarts and Surgeon at London Health Sciences Centre), Dr. Wayne Taylor (Biostatistician at McMaster), Dr. Brian Haynes (Epidemiologist/Internist at McMaster), Dr. Allan Fox (Associate Scientist at Robarts and Chief of Neuroradiology at LHSC) and Dr. Vladimir Hachinski (Associate Scientist at Robarts and Chair of CNS at The University of Western Ontario). Other key members of the committee were Dr. Hugh Barr (Associate Scientist at Robarts and Surgeon at LHSC), Dr. Pat Clagett (Vascular Surgeon at the University of Texas Southwestern Medical Centre in Dallas), Dr. Michael Eliasziw (Scientist at Robarts and Data Manager/Statistician for NASCET), Heather Meldrum (NASCET Director at Robarts), Dr. Richard Rankin (Associate Scientist at Robarts and Radiologist at LHSC), Dr. David Sackett (Epidemiologist/Physician at Oxford University, England), Dr. David Spence (Robarts Scientist and Neurologist at LHSC) and Dr. Kevin Thorpe (Biostatistician at McMaster).The Robarts Research Institute was officially opened in 1986 and is Canada's only privately operated medical research facility. The Institute is comprised of some 365 highly qualified individuals, including scientists, hospital clinicians and technical specialists. They are actively researching many of the major causes of death and disability. For more information, please contact:Irene Posliff, Communications Officer, The John P. Robarts Research Institute, (519) 663-3021