Admission creatine kinase as a prognostic marker in acute myocardial infarction.

Objectives: To investigate the prognostic significance of creatine kinase (CK) in Pakistani patients suffering from acute myocardial infarction (AMI) and to find out if CK combined with troponin T (TnT) could be a better predictor for long-term adverse cardiac event.

Methods: One hundred and eighty six consecutive patients with AMI who were eligible for streptokinase (SK) treatment were included in this prospective cohort study. The relationship between their serum/plasma CK and TnT levels at the time of admission and clinical outcome was investigated over a mean follow up of 24.12 +/- 3.75 months.

Results: Admission CK was found to be associated with subsequent cardiac event and mortality (P < 0.01 and P < 0.04 respectively). Admission CK was also mildly associated with time interval between onset of symptoms to SK treatment (correlation coefficient 'r' = 0.23). Odds of encountering a cardiac event in AMI patients with above-normal CK levels (adjusted for gender) were 3.46 times higher than the odds in patients with normal CK levels. Similarly, odds of mortality in patients with positive TnT were 4.6 times the odds in patients with negative TnT. The two biochemical markers, CK and TnT, together did not provide any further information about prognosis of the disease.

Conclusion: Admission CK is a better prognostic marker for a subsequent cardiac event, while TnT is a better predictor of mortality over a mean follow up of nearly 2 years. Together, they do not improve predictability of an adverse cardiac event.