Early Differentiation of Stress Cardiomyopathy from Acute Anterior Wall Myocardial Using Changing Cardiac Enzyme Patterns

BACKGROUND: Most patients with acute anterior wall ST elevation myocardial infarction (STEMI) or stress cardiomyopathy (SCMP) show elevations in cardiac enzymes that peak within 24 hours. The changing pattern of cardiac enzymes can be an early clue to the differentiation of anterior STEMI and SCMP. METHODS: This study was a retrospective analysis (matching cases and respective control subjects) performed at a single center. We compared 27 patients with SCMP and 30 patients with anterior STEMI. We used laboratory data included cardiac marker, such as the initial creatine kinase MB (CK-MB) fraction and troponin T (Tn-T), at admission and peak CK-MB and Tn-T at follow up. RESULTS: The mean age was 69.3 ± 14.1 years, and 38.6% of patients were female. The SCMP patients were older, more often female, and had lower left ventricular ejection fractions than the anterior STEMI patients. The initial CK-MB was higher in the anterior STEMI group than in the SCMP group. In contrast, the initial Tn-T level was not significantly different between the 2 groups. Peak CK-MB and Tn-T levels and change from initial levels were significantly greater in the anterior STEMI group than they were in the SCMP group. SCMP could be differentiated from anterior STEMI based on peak CK-MB > 46.65 ng/mL or Tn-T > 1.56 ng/mL. CONCLUSIONS: Follow-up changes in cardiac enzymes can be an effective early tool for differentiating SCMP from anterior STEMI.