ISSN 2996-8215
International Journal of Cardiology | Vol. 2, No. 7, July 2011 | pp. 49–56
DOI: 10.46882/2011/IJC/000028
Original Research Article
Diagnostic Utility of High-Sensitivity Cardiac Troponin T for Early Rule-Out of Myocardial Infarction in the Emergency Department
Chloe Bennett¹, Thomas Wright¹, Oliver Harrison²
¹Emergency Department, St Vincent's Hospital, Sydney, New South Wales, Australia
²School of Medicine, University of Queensland, Brisbane, Queensland, Australia
Abstract:
Rapid identification or exclusion of acute myocardial infarction (AMI) in patients presenting with chest pain is vital for emergency department (ED) throughput. High-sensitivity cardiac troponin T (hs-cTnT) assays allow for lower detection limits but may compromise specificity. This study sought to evaluate the diagnostic utility of a 0-hour/2-hour accelerated diagnostic protocol utilizing hs-cTnT for rapid AMI rule-out. We prospectively evaluated 412 consecutive patients presenting to the ED with acute chest pain suggestive of acute coronary syndrome. Blood samples for hs-cTnT were drawn at presentation (0h) and 2 hours later. The final diagnosis of AMI was adjudicated by an independent committee using the universal definition. AMI was diagnosed in 58 patients (14.1%). A baseline hs-cTnT level below the limit of blank (less than 5 ng/L) coupled with an absolute change of less than 3 ng/L within 2 hours successfully ruled out AMI in 238 patients (57.8%). This 0h/2h protocol yielded a diagnostic sensitivity of 98.3% (95% CI: 90.8%–99.9%) and an exceptional negative predictive value (NPV) of 99.6% (95% CI: 97.7%–99.9%). The specificity and positive predictive value (PPV) were 66.7% and 32.6%, respectively. No patient classified as safe for early rule-out experienced an un-adjudicated myocardial infarction or cardiac death within a 30-day safety follow-up. An accelerated diagnostic protocol incorporating baseline and 2-hour hs-cTnT assays allows for rapid, exceptionally safe exclusion of acute myocardial infarction in over half of presenting ED chest pain patients.
Keywords: High-sensitivity cardiac troponin T, Acute myocardial infarction, Emergency department, Diagnosis, Chest pain, Negative predictive value
Received: April 02, 2011; Revised: May 15, 2011; Accepted: June 08, 2011; Published: July 22, 2011
Citation: International Journal of Cardiology, 2011, Vol. 2, No. 7, pp. 49–56, DOI: 10.46882/2011/IJC/000028