V. Bhayana et al., COMBINATION (MULTIPLE) TESTING FOR MYOCARDIAL-INFARCTION USING MYOGLOBIN, CREATINE KINASE-2 (MASS), AND TROPONIN-T, Clinical biochemistry, 27(5), 1994, pp. 395-406
We retrospectively determined the mass concentrations of myoglobin, cr
eatine kinase-2 (CK-2), and troponin T in serial samples from 80 patie
nts with confirmed myocardial infarction (MI) and 60 non-MI patients.
Results from receiver operating characteristic curve analyses show tha
t all three tests are comparable in their diagnostic utility within th
e first 12 h of infarction. Decision thresholds were selected at a con
stant rule-in specificity of 95% and rule-out sensitivities of 95% at,
respectively, 3-6, 6-9, and 9-12 h intervals after the onset of sympt
oms. Test sensitivities and specificities were compared for each, used
as: a single test; two-test parallel combination; three-test parallel
combination; two-test series combination; and three-test series combi
nation. Our results from combination testing indicate that for the ear
ly diagnosis of MI, a single serum myoglobin measurement has diagnosti
c utility at 3 h after the onset of symptoms, and myoglobin and CK-2 (
mass) in combination later than 3 h following the onset of symptoms. S
erum troponin T is diagnostically similar to CK-2 (mass), although it
has superior cardiac-tissue specificity, but it is not as yet commerci
ally available as a ''stat'' test. Therefore, we recommend using tropo
nin T as a confirmatory test 9 h after the onset of MI. Based on our f
indings, we suggest a testing algorithm for the early biochemical diag
nosis of MI.