Influência prognóstica da elevação de CK e CKMB nas síndromas coronárias agudas sem supradesnivelamento do segmento ST Implication of different CK and CKMB levels for clinical outcomes and prognosis in patients presenting with acute coronary syndromes without ST- segment elevation

The new definition of acute myocardial infarction includes acute coronary syndrome (ACS) with elevated troponin levels in patients without ST - segment elevation (NSTEMI). The world of patients with myocardial necrosis now diagnosed is much larger and we need to study the evo- lution of this new entity. Objectives: The present study aimed to determine the influence of elevated CK and CKMB levels in acute coronary syndromes with elevated troponin levels in patients presenting without ST-segment elevation, in terms of clinical characteristics, evolution and prognosis. Methods: For 8 months, we studied sequentially all new admissions of patients with ACS - NSTEMI with elevated troponin levels in our Intensive Care Unit. We compared the population with a CK and CK-MB pathologically elevated level (both: CK level more then twice its normal maximal level and a CKMB level greater than10% of CK level) with the group of patients with no elevation of these markers. Patients with elevation of only one parameter (CK or CK-MB) were included in the second group. The two groups were compared in terms of risk factors, previous history, clinical and angiographical characteristics and evolution at 30 days and 6 months. Results: From the 75 patients with ACS-NSTEMI (52 men), with the mean age of 68.4 +-10.4 years, 43 (57%) had elevated CK and CKMB levels and the other 32 had elevated troponin levels without elevation of CK and CKMB levels. Comparing the two groups, they were similar in terms of age, gender, cardiovascular risk factors, but those without CK elevation levels had more frequently a previous myocardial infarction (31 versus 19, p<0.05). The coronary morphology was not different, and the clinical evolution was similar, at 30 days and after 6 months. There was no significant difference in terms of re-infarction, need for revascularization and co- ronary mortality. However, there was a significantly positive correlation between previous myocardial infarction and the total cardiovascular mortality (0.43, p<0.01). Conclusions: ACS-NSTE with elevated troponin level is a new entity with a similar evolution to the previously described non-Q wave infarction. The prognosis is the same whether or not there is an elevation of CK and CKMB levels. In our study, we verified that ACS - NSTEMI without elevated CK and CKMB levels presented more frequently in patients with previous infarction (p<0.05), and there was a positive correlation with total car- diovascular mortality at 6 months (p<0.01) in this group of patients.