Accuracy of high-sensitivity troponin-T in patients visited emergency department with or without symptoms suggestive of acute myocardial infarction

Objective:
A method of early diagnosis of acute myocardial infarction (AMI) using high-sensitivity cardiac troponin-T (hs-TnT) has been introduced. This study was conducted to evaluate the accuracy of hs-TnT in patients with suspected AMI.
Method:
Patients who were more than 20 years old with symptoms of AMI and who underwent hs-TnT and coronary angiography or echocardiography were included. Risk factors associated with AMI and basic characteristics were collected. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated. The effects of time from symptom onset to emergency department (ED) visit on test accuracy were analyzed.
Results:
The final analysis included 102 patients, of which 37 were AMI. The sensitivity and specificity of the hs-TnT was 59.5% (95% confidence interval [CI], 42.1% to 75.2%) and 67.7% (95% CI, 54.9% to 78.8%), respectively. In patients with typical chest pain, the sensitivity and specificity of the hs-TnT was 58.1% (95% CI, 39.1% to 75.5%) and 73.2% (95% CI, 57.1% to 85.8%), respectively. The NPV and sensitivity increased, and the PPV and specificity decreased as time from symptom onset to ED visit increased.
Conclusion:
The accuracy of the hs-TnT test was not as good in patients who visited the ED for symptoms suggestive of AMI. Therefore, to rule-in or rule-out AMI by using hs-TnT in ED, it is necessary to consider the electrocardiogram and clinical features, or to check variations by repeated measurement of hs-TnT.

Key words: Myocardial infarction; Troponin; Sensitivity and specificity; Emergency service; Hospital; Chest pain