Reported June 08, 2009

For people with Type 2 diabetes and stable heart disease, drug treatments are as effective as angioplasty or bypass surgery in some cases, a new study suggests.

It's an important issue given that adults with Type 2 diabetes are two to four times more likely to develop heart disease, and heart attacks and strokes are more likely to be fatal, the researchers said.

When doctors decide angioplasty and a stent (a wire mesh scaffold that props open an artery) are needed to restore blood flow and reduce chest pain, the latest results suggest it's safe to use drug treatments.

But for people with extensive coronary artery disease, getting invasive bypass surgery right away may help to prevent a future heart attack.

The study, which appears in Sunday's online issue of the New England Journal of Medicine and was presented at the American Diabetes Association annual scientific meeting in New Orleans, does not resolve the question of whether drugs or surgery is the best preventive approach, in part since newer stents are now available.

The study involved 2,368 patients with diabetes and an average age of 62 living in the United States, Canada, Brazil, Mexico, the Czech Republic and Austria. Participants either got treated right away with angioplasty, usually with a stent, and drugs, or drugs alone.

Overall, the researchers found no significant difference in the rates of death, heart attack or stroke after five years.

At five years, 87.8 per cent of those getting drug therapy alone were still alive, compared with 88.3 per cent of those getting drug therapy plus a surgical procedure.

The incidence of major cardiovascular events such as heart attacks and stroke was also similar: 75.9 per cent in the medical treatment group and 77.2 per cent in the drug-plus-procedure group.

Insulin treatments compared

In the drug-only group, those getting newer insulin sensitization treatment (metformin or glitazones) that lower the body's resistance to insulin did slightly better than those who got insulin therapy (insulin itself or sulfonylureas) that stimulates the body to make more of the hormone.

About 60 per cent of subjects in the insulin-sensitizing group took rosiglitazone or Avandia, the researcher said.

"We found some indications that insulin-sensitizing drugs might be beneficial for certain patients with diabetes, especially those with more extensive coronary artery disease who undergo bypass surgery, but more research is needed," Sheryl Kelsey, a professor of epidemiology at the University of Pittsburgh Graduate School of Public Health, and the study's principal investigator, said in a release.

Among those in the study, about two-thirds were considered suitable candidates for elective angioplasty and the rest were candidates for elective bypass surgery.

Best way to restore blood flow?

A journal commentary accompanying the study questioned why so many diabetics undergo angioplasty.

"The continued high rate of use of [angioplasty] (1.24 million procedures per year in the U.S.) and the high rate of drug-eluting stent usage strongly suggests that we critically reassess our approach to revascularization, if needed, in diabetics with coronary disease," wrote Dr. William Boden of the University at Buffalo in New York.

Of the 798 participants selected by their doctors to receive prompt angioplasty, 91 per cent had a stent inserted, of whom about one-third received a newer drug-eluting stent.

Many of the study's authors and Boden reported receiving lecture or consulting fees from pharmaceutical companies or served on their advisory boards.

The study was funded by the U.S. National Heart, Lung and Blood Institute, the U.S. National Institute of Diabetes and Digestive, and several makers of diabetes drugs and devices.