BACKGROUND: There is uncertainty as to the comparative prognostic value between cardiac troponin I (cTnI) and CK-MB in acute coronary syndrome (ACS). OBJECTIVE: To compare the prognostic value between cTnI and CK-MB mass in patients with ACS without ST-segment elevation. METHODS: 1,027 patients were analyzed in a prospective way in a tertiary cardiology center. Combinations of biomarkers were examined: normal cTnI, normal CK-MB mass (65.5%), normal cTnI, elevated CK-MB mass (3.9%), elevated cTnI, normal CK-MB mass (8.8%), elevated cTnI, elevated CK-MB mass (20.7%). A multivariate analysis of clinical, electrocardiographic and laboratory variables determined the independent prognostic value of biomarkers for the event of death or (re)infarction within 30 days. RESULTS: Patients with at least one elevated biomarker were older (p = 0.02) and males (p < 0.001). The previous use of aspirin (p = 0.001), beta-blockers (p = 0.003) or statin (p = 0.013) was most frequent among those without elevated cTnI. Patients with both biomarkers elevated had more ST-segment depression (p < 0.001) or elevated creatinine (p < 0.001). In a multivariate analysis with the inclusion of cTnI, the CK-MB mass was not an independent variable for the event of death or (re) infarction within 30 days (odds ratio [OR] 1.16, p = 0.71). When cTnI was not included, we had the following values: age (OR 1.07; p < 0.001); male (OR 1.09; p = 0.77); diabetes mellitus (OR 1.95; p = 0.02); previous stroke (OR 3.21; p = 0.008); creatinine level (OR 1.63; p = 0.002); CK-MB mass (OR 1.96; p = 0.03). C-statistic 0.77 (p < 0.001). CONCLUSION: With a dose of cTnI, CK-MB mass may be dispensable for prognostic evaluation. If cTnI is unavailable, CK-MB mass is acceptable for making a decision on treatment options.
Acute coronary syndrome; troponin I; creatine kinase; myocardial infarction; prognostic
