Each year, millions of people rush to Emergency Rooms complaining of chest pain, and many of those individuals are hospitalized for suspected coronary problems. However, studies have shown that up to three-quarters of patients who present with chest pain are inaccurately diagnosed with a heart attack or unstable angina (chest pain). On the other hand, as many as one-third of all heart attacks go unrecognized.
Researchers at the University of Pennsylvania Medical Center have shown that diagnostic accuracy of chest pain can be dramatically increased--up to 90 percent, in some instances--by using a clinical approach that combines the results of an echocardiogram with a simple blood test that measures a patient's troponin T (TnT) levels. TnT is a protein released by the body during cardiac cell injury or death.
In a prospective study of 100 patients who presented with chest discomfort and were subsequently admitted to a hospital in Indiana, the TnT/echocardiogram combination correctly predicted that 90 percent of those who were not suffering from ischemic heart disease did not need to be admitted and would not return to the hospital with similar ailments. In addition, 90 percent of the patients who sustained acute heart attacks had an increased level of TnT within four hours of entering the ER.
"Our study showed that putting TnT levels together with echocardiograms was a more powerful predictor of subsequent cardiac events in these patients than using either test alone," notes lead author Emile R. Mohler, III, MD, director of vascular medicine at Penn. The study results--published in the February issue of the American Heart Journal--could eventually be applied by Emergency Department physicians to better triage patients and determine which patients should and should not be admitted to the hospital. The study was initiated because--despite physicians' best efforts to pinpoint the cause of chest pain using traditional methods--a large number of patients are being admitted unnecessarily.
"It will also help us make initial diagnoses to determine appropriate medication," adds Mohler. "Most importantly, this research lays the groundwork for a study that will determine the safety of this data. This work represents a unique marriage between cardiac cell biology, medical imaging, and clinical ER triage."
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