MONDAY, Jan. 23, 2006 (HealthDay News) -- Doctors are using more and more tests and procedures to help detect and treat heart disease, even though the incidence of the illness isn't rising all that much, new studies show.
"I do believe that some of it is being done needlessly," said F. Lee Lucas, associate director of the Maine Medical Center's Outcomes Research and Evaluation, and lead author of a report in the Jan. 24 issue of Circulation.
Looking at Medicare records, Lucas and her colleagues found that from 1993 to 2001, U.S. doctors charted a nearly three-fold increase in the number of imaging stress tests ordered and more than a seven-fold increase in the use of coronary stents, the flexible tubes used to open narrow blood vessels in the heart.
"However, heart attack, by contrast, has not been increasing in any dramatic way," Lucas said. "So, we do not believe that the large increase in cardiac procedures reflects an underlying increase in coronary heart disease."
A report in the same journal on a study led by physicians at the University of Toronto found that annual costs for cardiac tests and bypass surgery nearly doubled in Canada between 1992 and 2001, outstripping "both demographic shifts and changes in the prevalence of coronary artery disease."
"The proliferation of cardiac testing challenges the sustainability of Medicare in Canada, especially given uncertainty as to whether the accompanying incremental rise in total expenditures translates into significant outcome benefits in the population," the researchers wrote.
In the United States, there has been a slight decrease in bypass surgery, Lucas said. "The rate has leveled off and will stay leveled off," she said.
But other procedures -- such as the insertion of catheters, flexible tubes used to open arteries, and stents, metal tubes designed to keep arteries open -- are being done more often, Lucas said.
"My basic feeling is that the rate of catheterization and coronary procedures such as stenting continues to increase," she said. "Some analyses show more than a linear increase. The trend is accelerating. Although this paper doesn't say so, I don't expect to see any leveling off based on what we see in the data."
The belief that many procedures are being done needlessly comes from a related study by the Maine group, Lucas said. "What we were able to show was that in areas where the rate is higher, the extra procedures are not targeted at the people who need them most," she said. "People get them equally, despite their risk."
The American Heart Association and the American College of Cardiology have separated patients into several classes, Lucas noted. "Class three includes those in whom the procedures are contraindicated, such as the terminally ill, who do not derive benefit from the procedure," she said. "What we showed is that the rate at which cardiac catheterizations are being given is higher among all the subgroups, including those for whom it is contraindicated."
However, these two studies don't show whether the procedures are overused or done on patients who don't really need them, said Dr. Sidney C. Smith Jr., professor of medicine at the University of North Carolina and a spokesman for the American Heart Association.
"Nothing in either paper deals directly with appropriateness," Smith said, adding, "We need to be sure that we use these procedures appropriately and that all who might benefit from them receive them."
Until further studies are done to determine whether too many procedures are being done, prevention still should be key, he said.
"Cardiovascular disease is largely preventable," Smith said. "The issue can be resolved by better and increased use of preventive measures -- exercise, control of blood pressure, control of lipid abnormalities, weight loss when necessary. We wouldn't have to worry about the need for extensive procedures if these measures were taken by more people."
For more on a range of cardiac tests, visit the U.S. National Heart, Lung, and Blood Institute.