Abstract 15382: The Value of Prehospital and Inhospital High-Sensitivity Troponin T Analysis for Rapid Rule in and Rule out of Patients with Acute Myocardial Infarction
Reliable prehospital identification of patients with AMI is essential to initiate rapid and appropriate treatment. Development of the high-sensitivity cardiac troponin assays (hs-cTnT) has stimulated studies on early rule-in and rule-out of patients with a presumed AMI based on a single admission sample. The aim of the study was to investigate the diagnostic performance of hs-cTnT values in a prehospital sample, at admission and in later inhospital samples. Methods We obtained prehospital blood samples from 998 patients with suspected AMI for laboratory hs-cTnT analysis. The diagnostic properties of hs-cTnT for the AMI diagnosis were calculated for this prehospital sample and for the routine inhospital admission- and highest-value samples. The diagnosis of AMI was established in accordance with the Universal MI definition using ischemic findings and routine inhospital hs-cTnT with 14ng/l (99th percentile of the URL) as decision cut-point for AMI. Results Prehospital and inhospital serial hs-cTnT meassurements were available for 728 patients. The prehospital sample was drawn a median of 89 minutes (IQR: 59-135) and 547 minutes (135-876) before the admission- and highest-value samples. For the prehospital-, admission and highest-value samples the diagnostic accuracy of hs-cTnT, measured by ROC curve AUC was 0.82, 0.89, and 0.97 (P<0.001). Using 14ng/l as cut point, diagnostic sensitivity was 70%, 90% and 100%, specificity was 79%, 74% and 69%, the positive predictive value was 50%, 51% and 50% and the negative predictive value was 90%, 96% and 100% Conclusion This study demonstrates the potential value of early single hs-cTnT testing on rule-in of patients with presumed AMI and shows that the vast majority of patients with AMI could be identified already in the prehospital setting. However, at least two inhospital samples are needed to reach a sensitivity of 100% and likewise, single samples cannot be used for safe and rapid rule-out of patients without AMI.
- © 2012 by American Heart Association, Inc.