February 25, 2010
International study finds novel SickKids-developed technique reduces the size of heart attacks by up to 50 per cent
To view a video of Dr. Andrew Redington discussing the discovery, click here.
TORONTO – An international research group coordinated by The Hospital for Sick Children (SickKids) shows that a novel use of a common medical device, found in every ambulance, doctor’s office and even in many homes, can reduce the size of adult heart attacks by as much as 50 per cent. The medical device is a standard blood pressure cuff and the method, called remote ischemic preconditioning, has been shown to protect the heart during a heart attack. The study is published in the February 26 edition of The Lancet.
Dr. Andrew Redington, Division Head of Cardiology and Senior Associate Scientist at SickKids, and Professor in the Department of Paediatrics at the University of Toronto, led a transatlantic team of scientists from Aarhus, Denmark and Oxford, UK.
The randomized study looked at 333 Danish adult patients, who were having heart attacks. Half the patients received remote ischemic preconditioning in the ambulance on the way to the hospital. The SickKids-developed preconditioning method consists of using a regular blood pressure cuff to transiently cut off blood flow to the arm; the cuff was inflated for five minutes, then deflated for five minutes, four times. At the hospital, the patients received routine heart attack treatment including angioplasty (a procedure to mechanically open narrowed or blocked blood vessels to the heart). Compared to the control group, the size of the heart attack was reduced by about 30 per cent overall in patients who were preconditioned. In patients having the largest heart attacks, the size was reduced by about 50 per cent.
“This is a good example of how research leads to clinical benefits,” says Redington. “Remote ischemic preconditioning could be one of the most effective treatments for evolving heart attacks that we have. While it’s too early to say whether this will be applicable in all cases, these results are extremely promising.”
Ischemic preconditioning is a powerful innate mechanism the body uses to protect all its tissues – not only the heart – from the effects of lack of blood flow. While this is not a new phenomenon, it was Redington and Dr. Rajesh Kharbanda from the UK, who developed the method to harness this natural mechanism in 2001. They found that reducing the blood flow in the arm sends a warning message to the body and the heart, by releasing substances in the blood that protect the body and the heart from subsequent injury.
In the first human study performed at SickKids and reported in 2006, Redington showed that preconditioning also helps to reduce heart damage in children undergoing heart surgery. Others have shown this to also be true in adults undergoing cardiac and vascular surgery, and elective coronary angioplasty.
The current study evolved from previous research performed by the international team, where the preconditioning was performed prior to the procedure. In 2007, the researchers showed that preconditioning during a heart attack may have similar benefits in lab animals. This led to the current study in humans, showing dramatic results.
“This is just the beginning – we would like to see more studies with larger groups of patients,” says Redington. “While the reduced heart attack is an important benefit, we would like to determine whether this will lead to improved survival rates, patient well-being and quality of life.”
Redington and colleagues are also working on developing an automated cuff that would make it easier and more efficient for health-care workers to use. SickKids has licensed intellectual property and is working with a Canadian company to develop the product.
About The Hospital for Sick Children
The Hospital for Sick Children (SickKids) is recognized as one of the world’s foremost paediatric health-care institutions and is Canada’s leading centre dedicated to advancing children’s health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada’s most research-intensive hospitals and has generated discoveries that have helped children globally. Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system. SickKids is proud of its vision of Healthier Children. A Better World.™ For more information, please visit www.sickkids.ca.
About SickKids Centre for Research and Learning
The SickKids Centre for Research and Learning will bring together researchers from different scientific disciplines and a variety of clinical perspectives, to accelerate discoveries, new knowledge and their application to child health — a different concept from traditional research building designs. The facility will physically connect SickKids science, discovery and learning activities to its clinical operations. Designed by award-winning architects Diamond + Schmitt Inc. and HDR Inc. with a goal to achieve LEED® Gold Certification for sustainable design, the Centre will create an architectural landmark as the eastern gateway to Toronto’s Discovery District. The SickKids Centre for Research and Learning is funded by a grant from the Canada Foundation for Innovation, the Government of Ontario, philanthropist Peter Gilgan and community support for the ongoing fundraising campaign. For more information, please visit www.sickkidsfoundation.com/bepartofit.
The Hospital for Sick Children
The Hospital for Sick Children
Phone: 416-813-7654 ext. 2059