Prospective survey of serial Troponin T requesting in an acute teaching hospital

BACKGROUND: Requests for troponin T, a biomarker for myocardial infarction, may be sent in a variety of clinical situations. In most cases, a single sample 12 hours or more after symptom onset should be sufficient for diagnosis. We chose to investigate how troponin T testing is used in our hospital with emphasis on those who had serial rather than single troponin measurements during their hospital stay. METHODS: Prospective survey of 50 patients with serial troponin T requests out of a total of 321 patients who had troponin T levels measured during the same time period. RESULTS: The time of symptom onset could be clearly identified in 40/50 patients. In 22 of these the first troponin was taken prior to 12 hours after symptom onset. For the 18 patients whose first troponin was taken after 12 hours, the second result remained in the same category (normal or high) as the first in all cases. This was not the case for 3/10 patients whose first troponin was sent within 12 hours and was normal. Early troponin results rarely affected immediate patient management and did not inform decisions about fibrinolytic therapy. CONCLUSIONS: Serial troponin testing was most commonly due to a sample being sent within 12 hours of symptom onset or to unnecessary repetition of an appropriately timed sample. Patient management was rarely enhanced by early troponin testing.