The Value of Procalcitonin, a Novel Inflammatory Marker, in the Diagnosis of Myocardial Infarction and Evaluation of Acute Coronary Syndrome Patients

Abstract

Background Procalcitonin is a calcitonin precursor that is used as an inflammatory biomarker in the plasma of patients with sepsis. Objective The aim of this study was to determine the diagnostic accuracy of emergency department (ED) point-of-care blood procalcitonin testing in identifying myocardial infarction (MI) in patients with chest pain of presumed ischemic origin. Methods Patients over 18 years of age who presented to the ED with MI-typical chest pain of presumed ischemic origin were included in the study. An initial point-of-care blood sample was drawn from each study patient for testing procalcitonin, troponin T, myoglobin, and creatine kinase-MB levels. A second sample was taken 4 h after admission for a procalcitonin test. Finally, a 6-h post-admission blood sample was taken to measure troponin T, myoglobin, and creatine kinase-MB levels in each study patient who had an initial negative cardiac marker test. Results A total of 1008 patients with chest pain were admitted to the ED during the study period, and a total of 141 patients met study criteria and were entered into the study. ED point-of-care blood procalcitonin testing to identify myocardial infarction in patients with chest pain of presumed ischemic origin had a sensitivity of 38.3% (95% confidence interval [CI] 28.8–47.3%) and a specificity of 77.8% (95% CI 70.0–84.4%), a positive likelihood ratio (LR+) of 1.725 and a negative likelihood ratio (LR−) of 0.792. The 4th hour diagnostic values (sensitivity, specificity, LR+ and LR−) of procalcitonin semi-quantitative (PCT-Q) testing were 90% (95% CI 80.9−95.7%), 59.3% (95% CI 52.5−63.5%), 2.2, and 0.16, respectively. Conclusion ED point-of-care testing for procalcitonin had poor diagnostic accuracy for predicting myocardial infarction.