Evaluation of a Rapid Whole Blood ELISA for Quantification of Troponin I in Patients with Acute Chest Pain

BACKGROUND: Troponin I (cTnI) provides important prognostic information in patients with chest pain. We wished to evaluate a rapid, whole-blood analyzer for quantitative point-of-care testing. METHODS: A quantitative point-of-care test system (Stratus CS((R)); Dade-Behring) for cTnI with an incorporated centrifuge was evaluated in 412 patients with chest pain less than 12 h. RESULTS: Results were available within 15 min. CVs were 4.5% at 0.1 microgram/L, 4.2% at 0.25 microgram/L, and 6.5% at 0.82 microgram/L. The detection limit was 0. 01 microgram/L. The 97.5% percentile in a healthy population was 0.08 microgram/L. Based on ROC curve analysis, a threshold of 0.15 microgram/L was calculated for the detection of acute myocardial infarction (AMI). With it, sensitivity for the detection of patients with AMI (n = 62) was 63% at arrival and 98% after 4 h (Stratus II((R)), 48% and 85%, respectively; P <0.01). In 42% of patients with unstable angina (n = 121), cTnI was >/=0.08 microgram/L (Stratus II, 28%; P <0. 01). During 30 days, death or AMI occurred in 25.5% of these cTnI-positive vs 2.9% of cTnI-negative patients (Stratus II, 29.4% vs 5.8%). CONCLUSION: The Stratus CS provided better analytical performance and comparable or better prognostic information than the Stratus II.