EMJ: ER docs have good first instincts in diagnosing heart attacks
Researchers at Wake Forest University Baptist Medical Center in in Winston-Salem, N.C., have demonstrated that emergency room doctors correctly identify patients who are having a heart attack, even when laboratory tests have not yet confirmed it, according to a study in the July issue of Emergency Medicine Journal.

The study used data from the registry, i*trACS, and analyzed MI patients symptoms who were admitted to emergency departments (EDs) in eight participating U.S. centers.

“One of the most common complaints we see in the emergency department is chest pain,” said lead author Chadwick Miller, MD, assistant professor of emergency medicine at Wake Forest. “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.”

The MI patients were divided into three groups, which were determined by a blood test that measured levels of the protein troponin, which increases when the heart muscle is damaged from a heart attack.

According to the researchers, 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 MI happened several hours or even days before coming to 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.

The study focused primarily on EMI patients: when a patient was admitted into the ED with MI symptoms, doctors at centers participating in the i*trACS registry would record their initial impressions of the symptoms exhibited by the patient.

According to the study results, the initial impression of the physicians showed that a higher percentage of them assigned a higher risk of heart attack to the EMI (76 percent) and NSTEMI (71 percent) patients, than the No MI (52 percent) 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 authors wrote.

”This study suggests that although we are relying on better medical technology to diagnose patients, the clinical impression is still very important,” Miller said.

“It is reassuring to see that the admission patterns among the EMI patients were more aggressive than with the No MI patients, even though in both groups the patients' troponin results were not elevated. This suggests that clinicians are not allowing the non-elevated troponin results to overshadow their clinical impression,” Miller added.

The i*trACS registry was compiled over a period of 26 months with ore than 17,000 patients were enrolled, the authors wrote. However, only 4,136 of those patients were included in the analysis, primarily because patients had to have two troponin results within 12 hours to be included. Patients were also excluded from the i*trACS registry if they were pregnant, or under 18 years old.