title: Improved detection of minor ischemic myocardial injury with measurement of serum cardiac troponin I.
abstract: This study compared the diagnostic accuracy of the measurement of serum cardiac troponin I (cTnI) with creatine kinase (CK) MB mass in patients with minor myocardial injury whose measured total CK activity did not exceed twice the upper reference limit (300 U/L for men; 200 U/L for women). Forty-eight consecutive patients presenting with chest pain and with in-hospital documentation of myocardial injury were enrolled. Electrocardiogram, echocardiogram, and serial serum CK-MB mass, cTnI, and total CK were measured over 36 h after admission. Peak total CK activity was within normal limits in 28 patients (58%). The mean (+/- SD) peak CK-MB mass and cTnI concentrations were: 16.4 (11.8) micrograms/L and 132 (13.0) micrograms/L; respectively. The peak biochemical marker index (defined as CK-MB or cTnI divided by its respective upper reference limit) was significantly (P < 0.05) higher for cTnI than for CK-MB from 7 to 36 h. The clinical sensitivity for detection of myocardial injury for cTnI was 100% [95% confidence interval (CI): 87.2% to 100%], compared with 81.8% (CI: 67.3% to 91.8%) for CK-MB. Thus, cTnI was more sensitive than CK-MB mass for detection of myocardial injury in patients with small increases of total CK.
authors.affiliation: Clinical Laboratories 812, Hennepin County Medical Center, Minneapolis, MN, USA. fred.apple@co.hennepin.mn.us
authors.forename: F S
authors.initials: FS
authors.lastname: Apple
authors.forename: A
authors.initials: A
authors.lastname: Falahati
authors.forename: P R
authors.initials: PR
authors.lastname: Paulsen
authors.forename: E A
authors.initials: EA
authors.lastname: Miller
authors.forename: S W
authors.initials: SW
authors.lastname: Sharkey
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000175:diagnosis / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase