Novel high-sensitivity troponin assay requires higher cut-off value to separate acute myocardial infarction from non-acute myocardial infarction in a high-risk population

• Published in: Canadian journal of physiology and pharmacology 2015-10, Vol.93 (10), p.873-877
• Main Authors: Wassef, Anthony Wafik Aziz, Hiebert, Brett, Saeed, Mahwash F, Tam, James W
• Format: Article
• Language: English
• Subjects: Aged; Algorithms; Biochemical assays; Biological markers; Biomarkers - blood; Diagnosis; Female; Heart attack; Heart attacks; Hospitalization; Humans; Identification and classification; Male; Methods; Myocardial Infarction - blood; Myocardial Infarction - diagnosis; Myocardial Infarction - pathology; Proteins; Retrospective Studies; Risk factors; ROC Curve; Sensitivity and Specificity; Severity of Illness Index; Troponin T - blood
• ISSN: 0008-4212; 1205-7541
• DOI: 10.1139/cjpp-2014-0473

The novel high-sensitivity troponin T assay (hs-cTnT) has been validated for diagnosing AMI in the emergency room. However its utility in high-risk in-patient populations is unknown. We retrospectively reviewed admissions to a general cardiology unit that had 2 hs-cTnT measurements in the first 12 h of presentation. We assessed 8 diagnostic algorithms that used hs-cTnT concentration and changes in concentration (including the 99th percentile cut-off of 14 ng/L) for their diagnostic utility in separating AMI patients from cardiac/nonACS and non-cardiac chest-pain patients. UA was excluded. There were 233 patients (mean age 67 years, 153 were males (66%)) admitted over a 2 month period, with AMI diagnosed in 118 of these patients (51%). The recommended 99th percentile cut-off had modest accuracy (65%), good sensitivity (88%), and poor specificity (25%); a higher cut-off of 75 ng/L had a better diagnostic accuracy of 73%, p < 0.05. While some hs-cTnT algorithms were either highly sensitive or specific, none were both. In high-risk cardiology in-patients, no hs-cTnT concentration cut-off or change more accurately diagnosed and excluded AMI, although higher cut-offs had better diagnostic utility.