Emergency Physicians Instinctively Diagnose Heart Attacks

A new study has demonstrated that emergency room doctors are correctly identifying patients who are having a heart attack, even when laboratory tests have not yet confirmed the event.

Researchers at Wake Forest University Baptist Medical Center (WFUBMC, Winston-Salem, NC, USA) used data from 4,136 patients in the i*trACS registry, and analyzed patients with myocardial infarction (MI) symptoms who were admitted to emergency departments (EDs) in eight participating centers in the United States. The patients were divided into three groups: no myocardial infarction (No MI), non-ST segment elevation myocardial infarction (NSTEMI), or evolving myocardial infarction (EMI); the groups were determined by a blood test that measured levels of troponin, a protein that has elevated levels when the heart muscle is damaged. When a patient was admitted into the ED with heart attack symptoms, doctors at participating centers would record their initial impressions of the symptoms exhibited by the patient.

The study showed that the initial impression of the physicians showed that a higher percentage of doctors assigned a higher risk of heart attack to the EMI (76%) and NSTEMI (71%) patients, than the No MI (52%) group. As a result, the EMI patients were triaged to higher levels of care than the no MI group, despite the initial negative troponin results. The study was published in the August 2008, issue of the Emergency Medicine Journal.

"There has been a lot of concern that clinicians either aren't spending enough time getting clinical history from patients or are not using the information they obtain,” said lead author Chadwick Miller, M.D., an assistant professor of emergency medicine at WFUBMC. "Patients with EMI are at particular risk for being evaluated less aggressively because their initial troponin result is normal, even though they have had a heart attack. This study suggests that although we are relying on better medical technology to diagnose patients, the clinical impression is still very important."

Patients classified as NSTEMI show elevated troponin levels when first admitted, usually because the MI occurred several hours or even days before coming to the ED. Patients classified as EMI, on the other hand, do not initially show elevated troponin levels when presenting to the ED, but showed evidence of heart damage up to 12 hours later. Patients who do not have an MI may have had symptoms but, according to the troponin levels throughout their hospital stay, do not actually have a heart attack.

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Wake Forest University Baptist Medical Center