SUNDAY, June 7 (HealthDay News) -- Drugs should be the first line of treatment for diabetics who are also battling heart disease, a new study finds.
Only if further steps are deemed necessary should invasive interventions such as angioplasty or bypass surgery be added, the experts said.
The issue is crucial to millions of Americans, since diabetes is a major risk factor for coronary artery disease and stroke.
But the findings of the study -- to be presented Sunday at the American Diabetes Association annual meeting in New Orleans and released simultaneously online in the New England Journal of Medicine -- may not end the argument over which approach, medicine or surgery, is the best frontline treatment to ward off heart woes.
The trial enlisted almost 2,400 people with type 2 diabetes, the kind that generally develops in adulthood. These patients also had coronary artery blockages. Outcomes for the entire group were tracked for five years after treatment.
All got intensive drug therapy, either with insulin or with drugs such as metformin that increase the body's sensitivity to insulin, while some also had procedures to improve blood flow.
At five years, 87.8 percent of those getting drug therapy alone were still alive, compared to 88.3 percent of those getting drug therapy plus a surgical procedure -- not a significant difference. The incidence of major cardiovascular events such as heart attacks and stroke was also similar, at 75.9 percent in the medical treatment group and 77.2 percent in the drug-plus-procedure group. In the drug-only group, those getting insulin sensitization treatment did slightly better than those who got insulin therapy.
Reacting to the findings, the Society for Cardiovascular Angiography and Interventions issued a statement saying that the trial still "does not answer" the question of whether all diabetic patients with multi-vessel coronary artery disease might be better treated with optimal drug therapy plus angioplasty or bypass.
Results from another ongoing trial "may shed more light" on the issue, the statement added.
What the study did show was that for people with diabetes and stable coronary artery disease, "a strategy of prompt revascularization [surgical opening of arteries] did not benefit patients relative to medical therapy alone," said trial leader Maria Mori Brooks, associate professor of epidemiology at the University of Pittsburgh Graduate School of Public Health.
Increasing severity of disease seemed to matter, however. "For patients who had more severe heart disease, there was a benefit from bypass surgery vs. medical therapy alone," she said.
That benefit was not seen in survival rates, which did not differ much in groups given various treatments. The real gap in outcomes came in the rate at which patients suffered major cardiovascular events such as heart attack and stroke. Those were significantly lower when bypass surgery was added to drug therapy, the researchers found.
The results confirm those of a similar trial reported two years ago, noted Dr. William Boden, a professor of medicine and preventive medicine at the State University of New York, and co-author of an editorial accompanying the journal report. In particular, the new study showed that if a procedure is needed to restore coronary blood flow, "bypass surgery is more likely than angioplasty to reduce the incidence of recurrent heart attacks. No other study to my knowledge has shown that bypass surgery reduces the incidence of myocardial infarction [heart attack]," he said.
Yet dissent arose even on that point.
Dr. Kirk Garratt, director of interventional cardiovascular research at Lenox Hill Hospital in New York City, said that the new trial did not directly compare bypass surgery with angioplasty. Outcomes differed because physicians were free to choose between the two methods of restoring blood flow, and they were more likely to choose bypass surgery for more complex cases, he said.
Brooks agreed that the intent of the study was not to compare bypass and angioplasty. What the study showed was "no more than a 3 percent difference in benefit in terms of one therapy or another," she said.
The results of the new trial are a testament to the ability of new medicines to help people with diabetes avoid heart problems, Boden said.
"We have very powerful medications today," he said. "These are disease-modifying therapies that can alter the course of the disease. We in this country have been enamored of the benefits of angioplasty and stents. It is reassuring to me, and hopefully other physicians, to see what can be accomplished by optimal medical therapy."
There's more on the diabetes-heart disease link at the National Diabetes Information Clearinghouse.
SOURCES: Maria Mori Brooks, Ph.D, associate professor, epidemiology, University of Pittsburgh Graduate School of Public Health; Kirk Garratt, M.D., director, interventional cardiovascular research, Lenox Hill Hospital, New York City; William Boden, M.D., professor, medicine and preventive medicine, State University of New York at Buffalo; June 7, 2009, New England Journal of Medicine online; June 7, 2009, presentation, American Diabetes Association annual meeting, New Orleans