Time - Dependent Diagnostic Value of TROPTR TNT Rapid Assay in Patients with Ischemic Chest Pain

Abstract

A prospective study was carried out to evaluate the validity of TROPT troponin T rapid assay in early diagnosis of acute myocardial infarction(AMI) in patients with ischemic chest pain, in comparison with conventional diagnostic tools such as serum troponin T(c-TnT) level, creatine Kinase(CK), CK-MB level and initial EKG finding. The study was performed at the emergency department(ED) of Yong Dong Severance hospital from March 1st 1996 to February 28th 1997. One hundred eighty one patients visiting ED with chief complaint of atraumatic chest pain within 24 hours of visit were eligible for the study. Those who lacked enough data collection and those who had chest paint of noncardiac origin and EKG of PSVT were excluded from the study. The overall study population was a total of 131 patients. Initial EKG, TROPT rapid assay, CK, CK-MB and c-TnT level were obtained simultaneously. Diagnosis of AMI was made according to the international diagnostic criteria for AMI. Of the 131 patients 61 patients(46.6%) were diagnosed as AMI. Within 4 hours of their symptom onset, initial EKG showed the highest sensitivity(63.2%) whereas the sensitivities of TROPT rapid assay, c-TnT, CK and CK-MB were poor(0-0.7%). From 4-8 hours, the sensitivities of c-TnT, CK and CK-MB were higher than that of TROPT rapid assay(80% vs. 30%). The sensitivites of TROPT rapid assay, c-TnT, CK and CK-MB rose over time and reached 100% after 8 hours symptom onset. The specificities of the TROPT rapid assay, c-TnT, CK & CK-MB and EKG were all 100% within 8 hours after symptom onset. Discrepancy between TROPT rapid assay and c-TnT was noted in nine patients(6.9%). In this study TROPT rapid assay was valuable in the diagnosis of AMI after 8 hours of symptom onset.