A Comparative Study on the Diagnostic Utility of Creatine Kinase-MB (Myocardial Band) Mass Estimation Over Its Activity Measurement in Patients with Acute Myocardial Infarction in a Tertiary Care Hospital in Puducherry

Author(s): Nikhila Suresh Kumar1, Sivaa Rajendran2, Sunil Kumar Nanda3, Mark Christopher4, Ravichandran Kandasamy5

Cardiovascular diseases (CVDs) are one of the major health problems and leading
cause of death worldwide. Acute myocardial infarction (AMI) is one of the
cardiovascular diseases which has high mortality in early hours of presentation
and hence early and accurate diagnosis is important to reduce the morbidity and
mortality. Troponin I and CKMB (Creatine Kinase-Myocardial Band) activity are the
routine biomarkers used for early diagnosis of AMI. Since there is a high degree
of instability in the measurement of CKMB activity and also there are frequent noncorrelation
with the Troponin I levels, we aimed to estimate and compare the
levels of CKMB mass and CKMB activity in patients with and without AMI.
This comparative study included 40 cases and 40 controls. Cases were adult
patients between the age group of 30 -70 years diagnosed with AMI by
electrocardiogram (ECG) and positive troponin I, and controls were who presented
with non myocardial infection (MI) chest pain. Blood samples were collected to
estimate CKMB activity and CKMB mass.
The median value of CKMB activity in controls was 21 IU/L (IQR 13.25-27.75) and
that in cases was 40 IU/L (IQR 30.25-94.25) and this difference is statistically
significant. The median value of CKMB mass in controls was 5 ngmL (IQ 4-6) and
that in cases was 19.50 ng/mL (IQR 6-61.50) which is also statistically significant
in differentiating both. In Spearman correlation test, both showed a better
statistical significance and correlation in cases (r = 0.787). It was evident that the
median value of CKMB activity in controls was higher than that of the normal range
for CKMB activity which is 8-16 IU/L, but the median value of CKMB mass in
controls was well within the normal range of 5- 10 ng/mL, considering it to be a
better marker for eliminating false positive results.
CKMB mass can be considered as a better marker than CKMB activity for accurate
diagnosis of AMI along with troponin I.