Diabetics with more than one diseased artery fared significantly better if they underwent bypass surgery than those who received drug -coated stents following artery clearing procedures to improve blood flow to the heart, according to data from a five-year study.
The advantages were striking in this trial and could change treatment for thousands of individuals
After five years, the bypass group had a lower combined rate of heart attacks, strokes and deaths of 18.7 per cent versus 26.6 per cent for the stent group in the 1,900-patient study funded by the US National Institutes of Health. The result was deemed to be highly statistically significant, researchers said.
Previous studies had demonstrated the superiority of bypass surgery over the use of bare metal stents – tiny mesh tubes used to prop open cleared arteries. Researchers suspected that newer stents coated with drugs to prevent reclogging might negate some of the bypass advantage but that turned out not to be the case.
“The advantages were striking in this trial and could change treatment recommendations for thousands of individuals with diabetes and heart disease,” said Valentin Fuster, from Mount Sinai School of Medicine in New York, who presented the findings at the American Heart Association scientific meeting in Los Angeles.
There was a higher incidence of stroke in bypass patients – 5.2 per cent versus 2.4 per cent. Stroke is a known risk of the surgical procedure in which a piece of a healthy blood vessel from another part of the body is grafted on to reroute blood flow around a blocked heart artery.
But deaths from any cause were significantly lower with bypass surgery than those who received artery clearing angioplasty and a drug-eluting stent – 10.9 per cent compared with 16.3 per cent. There were also twice as many heart attacks among diabetics in the stent group within five years – 99 vs 48, which Fuster called “very significant”.
More than one million bypass surgeries or stenting procedures are performed in the US each year and some 25 to 30 per cent of those involve diabetics with multiple diseased arteries, researchers said.
If the results of this study alter clinical practice, it could eat into lucrative profits of the companies that sell drug-coated stents.
David Williams of Brigham and Women’s Hospital in Boston, who was not involved in the study, called the results “very convincing”.
“I think the (treatment) guidelines will recognise this and I do think it will be adopted,” he said.