Comparative study of CKMB and cardiac troponin in patients with suspected acute coronary syndrome without st elevation

Introduction: many medical centers in Argentina still measure CK-MB activity instead of cardiac troponin (cTn) to assess patients with acute coronary syndromes (ACS). Objective: to evaluate whether an abnormal CK-MB (> 25 U/L) and/or an abnormal cTn (> 99th percentile) are associated with cardiac events or ischemia in patients with acute chest pain. Material and method: a database from two urban centers was analyzed. The levels of CK-MB and cTn (cTnI or cTnT) were measured > 6 hours after the onset of chest pain. All patients were classified according to whether or not they had undergone cardiac events (myocardial infarction, coronary angioplasty, CABG or death) or had positive cardiac tests by images during hospitalization or thirty days follow-up. The odds ratios (OR) were estimated for association with cardiac events/ischemia through multiple logistic regression, by using version 12.1 Stata software. Results: 254 patients were analyzed (169 men, 66.5%), median age 59.8 +/- 1.7 years. The regression analysis showed: male sex OR 2.4, P 0.004 (CI95% 1.34 to 4.61), abnormal cTn OR 3.7, P 0.000 (CI95% 1.85 to 7.49) and abnormal CK-MB OR 1.3, P 0.278 (CI95% 0.77 to 2.40). Other variables were not significant. In regression models with abnormal cTn only or with abnormal CK-MB only, event/ischemia association was maintained with abnormal cTn OR 3.9, P 0.000 (CI95% 1.99 to 7.93) but not so with abnormal CK-MB, OR 1.6, P 0.06 (CI95% 0.96 to 2.89). Conclusions: male sex and abnormal cTn showed significant association with cardiac events/ischemia, but abnormal CK-MB activity did not.