MONDAY, Jan. 26, 2015 (HealthDay News) -- For patients seen in emergency rooms solely for chest pain, noninvasive screening tests may not always predict future heart trouble, a new study suggests.
Such tests include:
- electrocardiograms, which measure the heart's electrical activity,
- echocardiograms, which measure how well blood is flowing in the heart using ultrasound,
- and CT scans of the heart.
All three tests are recommended for chest pain under current guidelines, the study authors said.
"It may be safe to defer early cardiac stress testing in patients with chest pain but no evidence of a heart attack," said lead researcher Dr. Andrew Foy, an assistant professor of medicine and public health sciences at the Penn State Milton S. Hershey Medical Center in Hershey, Pa.
Foy doesn't think these tests are overused, but may not be needed in all cases. "Furthermore, early cardiac stress testing appears to result in unnecessary, additional tests and invasive treatments," he added.
Around 6 million patients go to the emergency room with chest pain each year in the United States, Foy said. "Therefore, these findings could impact the care of a large number of patients," he said.
Foy said that for patients with chest pain not brought on by a heart attack, it seems safe to defer early cardiac stress tests.
"We would recommend they follow up closely with their primary care provider or cardiologist [for the best advice on what to do after chest pain]. If the pain returns, then cardiac stress testing may certainly be reasonable, depending on the nature of the pain and their other risk factors for heart disease," he said.
The report was published online Jan. 26 in the journal JAMA Internal Medicine.
For the study, Foy and his colleagues used health insurance claims from a group of almost 700,000 privately insured patients seen in emergency rooms for chest pain in 2011.
From this group, they identified almost 422,000 patients, of which more than 293,000 did not receive noninvasive tests and close to 128,000 did. The most common test used was a myocardial perfusion scintigraphy -- a scan that shows blood flow in the heart.
According to Foy, the percentage of patients hospitalized for a heart attack was only 0.11 percent a week after being seen in the emergency room and only 0.33 percent 190 days after being seen.
Patients who did not have initial noninvasive tests were no more likely to have a heart attack than those who did receive testing, the researchers found.
Patients who received these tests, however, were more likely to have invasive procedures such as angioplasty. Yet these procedures did not improve the odds against having a heart attack, Foy said.
In an editor's note that accompanied the study, Dr. Rita Redberg, editor-in-chief of JAMA Internal Medicine, said such tests in low-risk patients are unnecessary and prolong time spent in the ER.
"It is time to change our guidelines and practice for treatment of chest pain in low-risk patients," Redberg wrote. "Such patients should be given a close follow-up appointment with a primary care physician who can determine, based on the patient's condition, whether further evaluation is necessary."
But Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said since the study researchers looked back at patients who went to the emergency room and used data from insurance companies, the true value of these tests can't be definitively determined.
Studies looking at patients in real time need to be done to identify the value of these tests for low-risk chest pain patients, he added.
Visit the U.S. National Heart, Lung, and Blood Institute for more on heart attacks.