CT scans, cardiac stress tests don’t help in ruling out heart attack.

Patients who go to the emergency room (ER) with chest pain often receive unnecessary tests to evaluate whether they are having a heart attack, a practice that provides no clinical benefit and adds hundreds of dollars in health-care costs, according to a new study from researchers at Washington University School of Medicine in St. Louis.

Specifically, computed tomography (CT) scans and cardiac stress tests are overused in the ER for patients with chest pain and provide no information to determine whether a patient is in the midst of a heart attack, the researchers found.

The study appeared November 14, in JAMA Internal Medicine journal, which coincided with a presentation of the study at the American Heart Association’s Scientific Sessions.

A typical clinical evaluation includes a medical history, physical exam, electrocardiogram and blood test for a protein that becomes elevated after the heart is damaged. In addition, many patients also are given a CT scan of the arteries that deliver blood to the heart or a cardiac stress test. A stress test measures heart function during exercise.

“Our study suggests that in the emergency room, stress testing and CT scans are unnecessary for evaluating chest pain in possible heart attack patients,” said cardiologist and senior author David L. Brown, MD, a professor of medicine. “Patients don’t do any better when given these additional tests. Our study is not a definitive randomized clinical trial, but it does suggest that we are over-testing and over-treating these patients.”

In recent years, Brown said doctors can more accurately diagnose heart attacks largely because of advances in the blood test that measures levels of a protein called troponin. High troponin levels signal injury to the heart.

“This troponin test is super-sensitive,” Brown said. “But earlier blood tests were much less accurate. A patient could be having a heart attack and these older tests often would come back normal. Doctors didn’t trust the tests, so they looked for other ways to evaluate the patient. CT scans and stress tests were among the methods used. But now that the blood testing method is so much better, there is less reason to continue doing these screening tests in the emergency room.”

The investigators evaluated data from 1,000 patients treated at nine medical centers across the country, including Washington University School of Medicine, that were a part of the Rule Out Myocardial Ischemia/Infarction by Computer Assisted Tomography (ROMICAT-II) clinical trial. The current study revisited data from that trial, looking for any differences in outcomes for patients who received a clinical evaluation alone (118 patients) compared with those who received a clinical evaluation plus either a CT scan or a stress test (882 patients). In the study, 88% of patients received the extra testing. Nationwide, the overwhelming majority of patients evaluated for chest pain in the ER get such extra tests, Brown said.

During the nearly month-long follow-up period, there were no differences between the two groups in the percentages of patients that had a stent placed to open an artery, underwent coronary artery bypass surgery, returned to the emergency room or experienced a major cardiac event, such as heart attack.

While providing no clear health benefit to emergency room patients, the extra tests also led patients to stay in the hospital longer than may have been necessary and exposed them to radiation from testing that was not required to diagnose a heart attack. Length-of-stay for patients who received less testing was, on average, 20 hours compared with 28 hours for those who did receive either of the two additional tests.

The analysis also showed that, on average, a patient receiving more testing accrued $500 more in health-care costs during the ER visit. Patients who received m