A study conducted by Wake Forest University Baptist Medical Center, Winston-Salem, NC shows emergency room doctors are correctly identifying patients who are having a heart attack—even when lab tests have not yet confirmed it, according to the Emergency Medicine Journal.

Employing data from the i*trACS registry, it analyzed patients with heart attack symptoms who were admitted to emergency departments (EDs) in eight participating US centers.

“One of the most common complaints we see in the emergency department is chest pain,” said Chadwick Miller, MD, lead author and assistant professor of emergency medicine at the facility. “That’s why it is so important to figure out if we’re doing a good job of diagnosing and treating heart attacks, or if there’s a better way to do it.”

Patients in the registry were divided into three groups: no myocardial infarction (No MI), non-ST segment elevation myocardial infarction (NSTEMI), or evolving myocardial infarction (EMI). Groups were determined by a blood test measuring levels of the protein troponin, which increases when the heart muscle is damaged from a heart attack.

Patients classified as No MI may have had symptoms but did not have a heart attack. Patients classified as NSTEMI showed elevated troponin levels when first admitted, usually because their heart attack happened hours or days before arriving at the ED. Patients classified as EMI did not initially show elevated troponin levels when presenting to the ED, but showed evidence of heart damage up to 12 hours later.

EMI patients were the study’s main focus. When a patient was admitted into the ED with heart attack symptoms, doctors at centers participating in the registry would record their first impressions of the patient’s symptoms. The initial impression of physicians shows that a higher percentage of them 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.

“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,” Miller said. “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.”

The i*trACS registry was compiled over a period of 26 months, and more than 17,000 patients were enrolled.