Evaluation of point-of-care test systems using the new definition of myocardial infarction

Objectives To examine the proportion of patients admitted to CCU because of chest pain with a negative quantitative troponin t-test (Cardiac reader; Roche), who despite the negative test, would fulfil the new myocardial infarction criteria. A second aim was to evaluate the clinical utility of troponin I. Design and methods Troponin T (Cardiac reader; Roche) was measured 12 h after the last chest pain episode. If Troponin T was negative the subjects were included in the study. All included subjects were also examined with troponin I (Stratus CS; Dade Behring) and troponin T at the central laboratory (Elecsys 2010) at the same time. 187 patients were included. CKMB was also measured 6 h after the last chest pain (Stratus CS; Dade Behring). Results Fifth teen patients (8.0%) fulfilled the criteria of myocardial infarction, despite a negative Troponin T (Cardiac reader; Roche). CKMB measures did not add useful diagnostic information. The sensitivity and specificity were 100% and 95.3%, respectively for troponin I, when 0.2 μg/L was used as cut off level for myocardial infarction. Conclusion In this low risk group, eight percent of the patients with a negative Troponin T (Cardiac reader; Roche) fulfilled the new criteria of myocardial infarction. Troponin I (Stratus CS; Dade Behring) appeared to be a reliable method in this group.