(Toronto - Nov. 4, 2012) - An international, clinical research trial has shown that patients with diabetes whose multi-vessel coronary artery disease is treated with bypass surgery live longer and are less likely to suffer severe complications like heart attacks than those who undergo angioplasty.
The findings are published online today in The New England Journal of Medicine (10.1056/NEJMoa1211585). The study - co-led by researchers at New York's Mount Sinai Hospital and Toronto's Peter Munk Cardiac Centre, University Health Network (UHN) - is known as the FREEDOM trial.
"We've shown that bypass surgery saves one extra life for every 20 patients with diabetes who are treated for multi-vessel coronary artery disease," says lead author, Dr. Michael Farkouh, Chair of the Peter Munk Centre of Excellence in Multinational Clinical Trials, Peter Munk Cardiac Centre, UHN.
Five years after treatment, patients who received coronary artery bypass grafts (CABG) had lower combined rates of strokes, heart attacks, and deaths (18.7 percent) than those who underwent angioplasty (26.6 percent). Strokes were slightly more common among the CABG group (5.2 percent) than in the angioplasty group (2.4 percent), however, more angioplasty patients died from any cause (16.3 percent) than CABG patients (10.9 percent).
"Based on these results, we believe that coronary artery bypass surgery should be standard therapy for the millions of patients worldwide with diabetes who have more than one diseased vessel," says Dr. Farkouh, who is the Chair of Cardiology Research and an associate professor of medicine at the University of Toronto.
Coronary artery disease is the buildup of plaque in the coronary arteries. It's the most common form of heart disease and can lead to chest pain, heart failure and heart attack. According to the Public Health Agency of Canada, almost 2.4 million Canadians live with diabetes.1
A total of 1,900 patients were enrolled at 140 international centers from 2005-2010. All participants had diabetes and more than one diseased artery, and 83% had three-vessel disease. Half the participants received bypass surgery and the other group received angioplasty - which includes percutaneous coronary intervention and drug-eluting stents. The study followed patients for a median of four years and a minimum of two. Patients in both streams of the study were prescribed optimal medical management for control of high LDL cholesterol, high blood sugar levels and high blood pressure. The result assessed all-cause mortality, non-fatal heart attacks, and non-fatal stroke.
"This study will challenge the prevailing ambiguity between bypass surgery and angioplasty for multi-vessel coronary artery disease," says Dr. Farkouh. "Bypass surgery saves lives and reduces the chance of complications in a high-risk group of patients with diabetes."
The study focused on diabetes because patients with diabetes have cardiac events more often than patients who do not have diabetes, and require more follow-up care than other patients. Cardiovascular disease is a major complication of diabetes and the leading cause of early death among people with this disease -- about 65 percent of people with diabetes die from heart disease and stroke. Adults with diabetes are two to four times more likely to have heart disease or suffer a stroke than people without diabetes.
"The benefits of bypass surgery are so significant that they're what you'd expect to see between a patient who is and a patient who isn't taking medication to control cholesterol," says Dr. Farkouh.
The research was supported by U01 grants #01HL071988 and #01HL092989 from the National Heart, Lung, and Blood Institute with provision of stents from Cordis, Johnson and Johnson and Boston Scientific, provision of abciximab and an unrestricted research grant from Eli Lilly and provision of clopidogrel from Sanofi-Aventis and Bristol Myers Squibb. Dr. Farkouh's research is also supported by Toronto General and Western Hospital Foundation's Peter Munk Cardiac Centre campaign.
About The Peter Munk Cardiac Centre
The Peter Munk Cardiac Centre is the premier cardiac centre in Canada. Since it opened in 1997, the Centre has saved and improved the lives of cardiac and vascular patients from around the world. Each year, approximately 55,000 patients receive innovative and compassionate care from multidisciplinary teams in the Peter Munk Cardiac Centre. The Centre trains more cardiologists, cardiovascular surgeons and vascular surgeons than any other hospital in Canada. Based at the Toronto General Hospital and the Toronto Western Hospital - members of University Health Network, which also includes the Princess Margaret Cancer Centre and Toronto Rehabilitation Institute. All four sites are research hospitals affiliated with the University of Toronto. For more information please visit www.petermunkcardiaccentre.ca
Public Affairs, Peter Munk Cardiac Centre