A Better Test for Heart Attacks
Perfusion imaging prevents unnecessary hospitalizations
TUESDAY, Dec. 3, 2002 (HealthDayNews) -- A test that measures blood flow to the heart can avoid unnecessary hospitalizations for people brought to the emergency room with chest pain.
The test is called myocardial perfusion imaging. It is done routinely for non-emergency patients who undergo stress tests. In a study of nearly 2,500 patients who came to emergency rooms with suspected heart attacks, the test reduced unnecessary hospital admissions by 16 percent, says a report in tomorrow's issue of the Journal of the American Medical Association.
"By incorporating this information, the emergency room physician can make a decision about who should be in the hospital and who should go home," says Dr. James E. Udelson, associate chief of cardiology at Tufts-New England Medical Center in Boston and leader of the study.
The study included 2,475 people who came to New England emergency rooms with chest pain or other symptoms of a possible heart attack, but whose electrocardiograms and blood enzyme tests gave no clear-cut indication of a heart attack. Half got the usual evaluation of their condition, and the other half had myocardial perfusion imaging.
"The patient is injected with an isotope in the emergency room and then is taken to the nuclear medicine department where a camera takes a picture showing what blood flow to the heart is," Udelson says.
The test did not bar hospitalization for those patients who needed it -- 97 percent of patients who had heart attacks and got the test were admitted, compared to 96 percent who did not get the test. However, for those people who were eventually found not to have had heart attacks, 42 percent who had myocardial perfusion imaging were hospitalized, compared to 52 percent who did not have the test.
Dr. Raymond J. Gibbons, a professor of medicine at the Mayo Clinic and author of an accompanying editorial in the journal, calls the study "an important step forward."
"This is not a trivial bit of evidence," Gibbons says. "It is a study that has been very carefully done and that gives new information on a very important topic. It offers substantial evidence in favor of this option in treating patients."
However, the study raises "a lot of issues that have to be thought about," Gibbons says, such as what happens with patients who come to the emergency room at night or those who come to small hospitals.
"The logistics of the nighttime use of perfusion imaging are formidable for most hospitals," he writes in the editorial. "This approach also cannot be easily implemented in hospitals that do not currently have on-site nuclear imaging facilities."
It's also not clear that using the test would be cost-effective, Gibbons adds.
In the study, 11.3 patients had to undergo perfusion imaging to prevent one hospital admission, he calculates. A hospital admission would have to cost more than $5,500 for the test to pay for itself, Gibbons says. And "the magnitude of the cost savings is uncertain, as some of the unnecessary admissions were less-expensive stays in a chest pain unit, with costs that were likely well below this break-even point," he says.
Udelson says money is just one of the issues to be weighed.
"The situation gets beyond cost-benefit analysis," he says. "Even a few beds taken up by people who don't need them can compound a problem. Emergency rooms are increasingly crowded, hospitals are crowded. If a patient doesn't need a hospital bed, wouldn't it be nice to find that out faster?"
Gibbons says myocardial perfusion imaging "certainly will have a positive effect in reducing admissions. But one cannot assume that it will save money. That may not be the case."
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