By Margarita Nahapetyan
There is a new evidence that coronary bypass surgery might be a better solution than artery-opening angioplasty, for patients who are older than 65, and individuals who suffer major heart artery blockages and diabetes. For other people, there is not much difference between the two.
The largest-ever international study to assess the two rival procedures, based its findings on a vast compilation of the life-or-death results from the world's major clinical trials of heart disease treatment. Mark Hlatky, professor of health research and policy and cardiovascular medicine at Stanford University in California, and colleagues analyzed data from 10 different international trials that involved 7,812 patients. Each of the patients suffered multi-vessel coronary disease and was enrolled in a clinical trial of bypass surgery and angioplasty.
Both bypass surgery and angioplasty are aimed to prevent heart attack. In bypass surgery, a vein is grafted to route blood around a clogged artery which leads to the heart. Angioplasty is a less invasive procedure in which a tiny wire called a catheter is inserted into the artery to break up the clot and prevent blockage. In most cases, a mesh tiny tube called a stent, is being used to prop open the artery and keep it from squeezing shut again.
Over a median follow-up of nearly six years, the experts found that patients with diabetes were 30 per cent less likely to die if given coronary artery bypass graft surgery (CABG), than if given percutaneous coronary intervention (PCI). The death rate for these patients was 12 per cent for those who had (CABG), compared with 20 per cent of those who had angioplasty. For the patients between the ages of 65 and 75, overall mortality rate was 11 per cent for those who had bypass, compared with 15 per cent for those who had angioplasty.
However, patients aged younger that 55 years, who had bypass surgery, were 25 per cent more likely to pass away, compared to individuals who had angioplasty. For those with the ages between 55 and 64, CABG patients had an 8 per cent mortality rate compared with 9 per cent among angioplasty patients. The study found no significant difference between men and women, racial or ethnic groups, or people who had 2 or 3 clogged vessels. The overall mortality was similar whether individuals received bypass or angioplasty. Of all the patients who had CABG, 15 per cent died over the course of a study, compared to 16 per cent for PCI.
"Long-term mortality is similar after both procedures in most patient subgroups with multi-vessel coronary artery disease, so choice of treatment should depend on patient preferences for other outcomes," the experts wrote.
The new study is a prime example of the relatively new approach called comparative effectiveness research, Dr. Hlatky said. The majority of controlled trials study the effects of whether giving a treatment to the patient or giving no treatment, he said. The new approach is to figure out the most effective treatment for every individual case, he added. Dr. Hlatky described the reported benefit of surgery in older people as "somewhat surprising, because you would think that, as people grow older, the risk of surgery goes up - so this is the opposite of what you would predict," concluded the scientist.
The findings are reported in the latest issue of The Lancet medical journal.