S-troponin T in suspected ischemic myocardial injury compared with mass and catalytic concentrations of S-creatine kinase isoenzyme MB.
In a multicenter study we compared three tests for ischemic myocardial injury (IMI): a new, automated enzyme immunoassay for S-troponin T (S-TNT; Boehringer Mannheim) and two S-creatine kinase (CK) isoenzyme MB assays (mass and catalytic concentrations). For critical evaluation of clinical sensitivity, we studied 243 cases with an IMI prevalence of 43% and an 18% prevalence of cases with unstable angina. Relative peak values of S-TNT and S-CK-MB (mass) after onset of pain were four- to fivefold higher than S-CK-MB (catalytic) results. Increases of S-TNT and S-CK-MB (mass), even though still within their reference ranges, indicated minor myocardial damage in about one-third of the cases primarily classified as unstable angina. The diagnostic window for S-TNT ranged from hours to weeks after the acute episode. The time courses were frequently biphasic, with the initial S-TNT peak closely paralleling that of the mass concentrations of S-CK-MB. With a biological half-life for S-TNT of 2 h, the prolonged increases in S-TNT indicate a continuous release of S-TNT from necrotizing cells. Clinical specificities of S-TNT and S-CK-MB (mass) were greater than that of S-CK-MB (catalytic), even in the presence of 30% to 40% severe skeletal muscle injuries. The combination of S-TNT and S-CK-MB (mass) is excellent for detection of acute IMI, including minor myocardial damage.
Gerhardt
W
W
Department of Clinical Chemistry, Helsingborg, Sweden.
Katus
H
H
Ravkilde
J
J
Hamm
C
C
Jørgensen
P J
PJ
Peheim
E
E
Ljungdahl
L
L
Löfdahl
P
P
D002384:Catalysis; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D003402:Creatine Kinase / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007527:Isoenzymes; D009203:Myocardial Infarction / Q000378:metabolism* / Q000503:physiopathology; D014336:Troponin / Q000032:analysis*; D020107:Troponin T
D007527:Isoenzymes; D014336:Troponin; D020107:Troponin T; D003402:Creatine Kinase