title: Improved identification of acute coronary syndromes with second generation cardiac troponin I assay: utility of 2-hour delta cTnI > or = +0.02 ng/mL.
abstract: It has been shown that the 2-h Stratus II delta creatine kinase-MB (CK-MB) is more sensitive and is equally specific compared to a 2-h Stratus II CK-MB and to a 2-h Stratus II delta cardiac troponin-I (DeltacTnI) for identification of acute myocardial infarction and adverse outcome (AO). Because the newest generation of Stratus (Stratus CS) cTnI assay has an analytical sensitivity of 0.03 ng/mL, compared to 0.35 ng/mL for the first generation assay, we undertook a small pilot study of 120 chest pain patients to compare sensitivities and specificities for 30-day AO of the Stratus CS DeltacTnI immunoassay to the DeltaCK-MB and DeltacTnI, as measured by the Abbott Axsym immunoassay, and to the DeltaCK-MB, as measured by the Stratus CS. A Stratus CS DeltacTnI > or = +0.02 ng/mL in 2 h was more sensitive (61.9%) than an Axsym DeltaCK-MB > or = +1.3 ng/mL (38.1%; p = 0.03), a Stratus CS DeltaCK-MB > or = +0.4 ng/mL (38.1%; p = 0.03), and an Axsym DeltacTnI > or = +0.3 ng/mL (33.3%; p = 0.03) for 30-day AO. There were no differences in specificities. Our data support enhanced identification of ACS with a second generation cTnI assay. Pending larger studies, patients with a rise in DeltacTnI of > or = +0.02 ng/mL in 2 h, as measured by the Stratus CS immunoassay, should receive consideration for aggressive anti-ischemic therapy and further diagnostic testing prior to making an exclusionary diagnosis of non-ischemic chest pain.
authors.affiliation: Department of Emergency Medicine and Heart-Stroke Center, Erlanger Medical Center, University of Tennessee College of Medicine, 37405, Chattanooga, Tennessee, USA
authors.forename: Francis M
authors.initials: FM
authors.lastname: Fesmire
authors.forename: Connie E
authors.initials: CE
authors.lastname: Fesmire
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D010865:Pilot Projects; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013997:Time Factors; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form