Rj. Dewinter et al., CRITICAL DIFFERENCE BETWEEN SERIAL MEASUREMENTS OF CK-MB MASS TO DETECT MYOCARDIAL DAMAGE, Clinical chemistry, 43(2), 1997, pp. 338-343
To assess the critical difference in serial measurements of CK-MB(mass
) and the ability of this critical difference to detect myocardial dam
age, we studied 110 patients in whom an acute myocardial infarction (A
MI) had been ruled out. Blood samples were drawn at 3, 4, 5, 6, 7, 8,
12, 16, 20, and 24 h after onset of symptoms. With a critical differen
ce of 72.6%, an increase of > 2.0 mu g/L between two CK-MB(mass) measu
rements was determined to be significant. Twenty-three of the non-AMI
patients had an increase in CK-MB(mass) > 2.0 mu g/L, but five of thes
e did not have an abnormal concentration of troponin T (i.e., not > 0.
1 mu g/L). Also among the 110 non-AMI patients, 22 did have an abnorma
l troponin T value, 18 of whom (82%) also had CK-MB(mass) increased by
> 2.0 mu g/L. In 20 of the 23 patients with an increase in CK-MB(mass
) > 2.0 mu g/L, this increase was detected from the values for two sam
ples collected at 5 and 12 h after onset of symptoms. In conclusion, u
sing the critical difference for CK-MB(mass) defined as an increase >
2.0 mu g/L detected myocardial damage in patients without AMI.