COMPARISON OF TROPONIN-T WITH OTHER CARDIAC MARKERS IN A VA HOSPITAL

Measuring protein markers of cardiac damage is important for the diagn osis of myocardial infarction (MI). This study accessed the positive a nd negative predictive values of cardiac markers for detecting MI and perioperative MI in cardiac surgery by evaluating: creatine kinase (CK ); creatine kinase MB isoenzyme mass assay (CR-MB); lactate dehydrogen ase (LDH); lactate dehydrogenase isoenzyme-1 (LDH-1); myoglobin; and c ardiac troponin T (cTnT) in a Veterans Affairs Medical Center. Inclusi on criterion was any patient who had a CK ordered over a 6-month perio d. Patient history and diagnosis were obtained from discharge summarie s. The two groups of patients studied either presented with symptoms o f MI (n = 370), or underwent open heart surgery (n = 63). In the patie nts evaluated for MI, there were 433 suspected cardiac events with 48 MIs diagnosed. Cardiac marker sensitivities and specificities were cTn T (98% and 73%), CK-MB mass (81% and 97%), CK (73% and 78%), LDH (67% and 80%), LDH-1 (33% and 95%), and myoglobin (79% and 65%). For detect ing MI, the marker that provided the optimum specificity was CK-MB mas s, but cTnT had the highest negative predictive value. There was one p erioperative MI in the 63 cardiac surgery patients. Surgical duration and aortic cross clamp time correlated with peak cTnT and CK-MB mass c oncentrations, but there was a wide degree of variability for any give n time period.