Objective: To determine the value in daily practice of a troponin assay for triage of patients with chest pain.
Design: Retrospective and descriptive.
Method: All patients in whom troponin T was measured after at least six hours after complaints began during the first three months of 2001 in the cardiac emergency unit of the Isala Clinics, location Weezenlanden, Zwolle, the Netherlands, were included. Cardiac events occurring within 30 days after the troponin assay were recorded retrospectively.
Results: All 350 included patients were followed for 30 days. An elevated troponin level was found in 51 patients (15%). At 30 days, 27 of these 51 patients had had a myocardial infarction or had died. Apart from these 27 patients, a revascularisation procedure was performed in nine patients. In the remaining 15 patients with an elevated troponin level, another reason for myocardial damage was found. In 40 patients in whom the troponin assay was negative, coronary artery disease was diagnosed later. The negative predictive value for myocardial infarction or death within 30 days was 98%.
Conclusion: A troponin assay, performed six hours or more after the onset of cardiac symptoms, appears to be a safe method to exclude patients with severe coronary artery disease resulting in myocardial necrosis and an elevated risk of death. An elevated troponin level was always associated with myocardial damage, but not always with coronary artery disease. Therefore, there must be a clear indication for requesting a troponin assay, and one should always keep in mind that a normal troponin level does not exclude coronary artery disease.