Classification and risk stratification of patients with acute chest pain using a low discriminatory level of cardiac troponin T

摘要

Background: Cardiac troponins are the biochemical markers of choice for the evaluation of acute coronary syndromes (ACS). Using the first‐generation test, most studies related adverse outcome to > 0.20 or 0.10 μg/l cardiac troponin T (cTnT) levels. With the highly sensitive and specific second‐ and third‐generation assays, cTnT is undetectable in most healthy individuals. Hypothesis: We evaluated whether a lower cTnT level, within 24 h of admission, could indicate an increased risk of future complications. Methods: During 1998–1999, clinical data were collected in 260 patients with ACS. Cardiac troponin T was measured at arrival, and 4, 8, and 12–24 h thereafter. The maximum cTnT value was then used to assess, over a 15‐month follow‐up period, the cumulative risk of death or myocardial infarction (MI), as well as rates of events according to quartiles of cTnT values. Results: Patients with ≤ 0.03 μg/l cTnT levels had the lowest rate of adverse events and the best Kaplan‐Meier event‐free survival curve. Increasing cTnT levels were associated with stepwise increases in mortality rates and with a constant 10fold increase in MI rates during follow‐up. Conclusions: A low threshold cTnT elevation is recommended to assess the risk of ACS. All cTnT elevations > 0.03 μg/l predict a higher risk of MI during follow‐up, whereas increasing values predict mortality in relation to the amount of elevation.