A: At least one Canadian researcher is on this track. Dr. Ruth McPherson, director of the Lipid Clinic and AtheroGenetics Laboratory at the University of Ottawa Heart Institute (UOHI), has identified a common genetic variation on chromosome 9 that increases the risk of developing premature heart disease. McPherson’s research team used a technique known as genome-wide scanning to compare the DNA of 1,800 Ottawa patients with premature heart disease to the DNA of 1,800 healthy Ottawa seniors and to pinpoint crucial differences.
McPherson's landmark 2007 study showed that about 25 per cent of Caucasian Canadians carry two copies of this flawed stretch of DNA, which increases their heart disease risk by 50 per cent. A further 50 per cent of Caucasians carry one copy, which increases their risk by 25 per cent. This discovery could lead to better genetic tests to assess future heart disease risk, allowing people to take preventive action through exercise, diet and drugs. "Within five years we hope to have a simple blood test that uses up to 10 genetic variants to give an accurate assessment of heart disease risk," she says.
Q: Time is of the essence when someone has a heart attack. Are there any systemwide efforts in Canada to speed up the response time to get treatment?
A: That's also in the works at the UOHI. When a person in Ottawa calls 911 complaining of chest pain, a crew of advanced care paramedics is immediately dispatched. These paramedics are trained to interpret the results of an electrocardiogram and recognize the deadliest form of attack, known as a STEMI (ST-Elevation Myocardial Infarction). If a STEMI is detected, paramedics bypass emergency departments and route the patient directly to the UOHI, where a team performs an emergency angioplasty (a procedure using a balloon to clear blocked arteries).
A 2008 study in the New England Journal of Medicine showed that such a streamlined approach cut the death rate in half, from 10 per cent to less than five per cent. "Patients leave the hospital sooner and they also have fewer complications," says Dr. Michel Le May of the UOHI, who authored the study.
The citywide emergency system cuts the "door-to-balloon time" – the time from hospital arrival to first balloon inflation – to only 69 minutes (the average for patients referred through emergency departments is 123 minutes).
Elsewhere, hospitals in Calgary and Vancouver are also helping to shorten the time to treatment by transmitting electrocardiograms from the ambulance to emergency physicians.
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