Abstract 14139: Prehospital High-Sensitivity Troponin T Analysis in Patients with Suspected Acute Myocardial Infarction
Prehospital analysis of cardiac troponins (cTn) may accelerate the diagnostic process and improve the triage of patients with suspected of AMI. The aim of the study was to: 1) Evaluate the feasibility of large scale prehospital point of care cTnT testing (POC-cTnT), 2) Evaluate the diagnostic performance of POC-cTnT and 3) Compare the diagnostic accuracy of POC-cTnT with high-sensitivity cTnT measurement (hs-cTnT) for early identification of patients with AMI. Methods We introduced a prehospital POC cTnT assay (Roche cobas h232, Cardiac T) in 25 ambulances, and included 1.099 patients with suspected AMI for analysis. Remaining prehospital blood was stored for comparative laboratory hs-cTnT analysis. The detection limit of the POC-cTnT assay was 0.03µg/l (50ng/l for the hs-cTnT assay). 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 POC-cTnT analysis was successful in 990 patients(90%), of these hs-cTnT data were available for 905 patients. The two assays performed nearly identical at corresponding levels equal to the detection limit of the POC-cTnT: sensitivity = 41% (33-48) for POC-cTnT and and 40% (33-48) for hs-cTnT. At 14 ng/l the hs-cTnT assay yielded a sensitivity of 71% (63-77%). The hs-cTnT showed significantly higher diagnostic accuracy with an AUC of 0.82 (0.79-0.86) vs. 0.68 (0.64-0.72), p<0.0001. Conclusion Our study confirms the reliability and robustness of large scale, routine prehospital POC testing. The present POC-cTnT assay allows identification of 40% of AMI patients on scene. Moreover, we show the improved diagnostic properties of the hs-cTnT assay and, anticipating the development of POC hs-cTnT assays, this improved analytical sensitivity would allow identification of the vast majority of AMI patients already in prehospital phase.
- © 2012 by American Heart Association, Inc.