Utility of the Immediate 2-Dimensional Echocardiography and Troponin T Test Combination for Diagnosing Non-ST Elevation Acute Coronary Syndromes in Patients with T-Wave Negative and Non-Diagnostic Electrocardiogram

Introduction: In a cohort of patients with chest pain and a negative troponin T (TnT) test, a mortality rate of 1.4 % during a mean follow-up of 9–10 weeks was recently reported. The mortality was greater in patients with evidence of ischaemic ECG changes and a negative TnT test (1.6– 4.4 %). Few studies have examined the efficacy of two-dimensional echocardiography (2DE) in patients with chest pain. The purpose of the present study was to determine the clinical utility, sensitivity, and specificity of the combination of TnT levels and 2DE in patients presenting with chest pain, T-wave negative and non-diagnostic ECG on the entry ECG. Methods: 88 consecutive patients with chest pain and the presence of T-wave inversion, and non-diagnostic ECG, an acceptable 2DE window, evidence or no evidence of alterations of the segmentary motion, a negative or positive TnT test, and normal value of CK, CK-MB, were enrolled. 2DE, blood CK, CK-MB, and TnT levels were controlled at entry and subsequent samples were obtained every 4 h for the first 12 h and then every 12 h. A haemodynamic study was performed in all patients within 12–72 h of admission. Percutaneous transluminal coronary angioplasty or coronary artery bypass graft were performed according to angiographic findings and left ventricular function. Results: A total of 88 patients, who met the entry criteria, were divided as follows: group 1: T-wave inversion (36 patients); and group 2: nondiagnostic ECG (52 patients). The combination of positive TnT and wall motion alterations showed a higher sensitivity and higher predictive values in comparison with TnT alone. Patients with concordance between TnT and 2DE were at higher risk. Patients with a negative combination in all groups (50 patients) showed a moderate incidence of critical coronary stenosis (20 %), as well as a negative 2DE alone (52 patients) (10 %). Patients with a negative TnT (70 patients) showed higher incidence of critical coronary stenosis (28 patients). Conclusion: Our results suggest that the combination of a negative TnT test and negative 2DE in patients presenting to emergency department with chest pain and T-wave inversion or without ECG changes is a useful tool to identify those who can be discharged safely. On the other hand, our data is important to identify the high risk (when positive) patients, and to reduce the number of false negative diagnoses. J Clin Basic Cardiol 2005; 8: 37–42.