973-112 Prognostic Value of TroponinT, Myoglobin and CK-MB Mass in Patients with Chest Pain without Acute Myocardial Infarction

Abstract

We investigated the prognostic value of Minimal Myocardial Damage (MMD) as indicated by minor elevations of TroponinT (TnT), Myoglobin (Myo) and CK-MB Mass (CK-MB) in 128 patients (pts) presented with chest pain at the emergency room (ER) in whom an acute myocardial infarction (AMI) was excluded. Blood was drawn 3, 4, 5, 6, 7, 8, 12, 16, 20, 24 hours after the onset of symptoms. Gold standard for AMI was a typical rise and fall of the CK-MB curve with a peak> 14 ng/ml. A minor elevation of CK-MB was considered present if the marker showed a typical rise and fall but with a peak below 14 ng/ml. TnT was considered abnormal if it showed a gradual rise with a highest value >0.01 ng/ml, Myo was considered abnormal if tie curve showed a typical rise and fall with highest value at least tvvice the lowest value. Only CK-MB results were reported to the attending physician. A documented history of Coronary Artery Disease (CAD) was defined as either previous AMI, PTCA, CABG or a previous positive exercise test. Pts with unstable angina were admitted to the CCU and stabilized with intravenous nitrates, aspirin, heparin, β-blockers and Calcium-antagonists. PTCA or CABG was performed for recurrent refractory angina. Follow up was completed after six months. Major events were cardiac death and AMI, minor events were PTCA and CABG. Diagnosis was unstable angina in 54 pts, stable angina in 59 pts, atypical chest pain in 13 pts and arrhythmia in 2 pts. 75 Pts had a documented history of CAD. MMD was indicated by abnormal TnT in 24 pts, by CK-MB in 13 pts and by Myo in 20 pts. There were 24 events (3 major and 21 minor). 20 events occurred in pts with a history of CAD (Relative Risk: RR, 95% Confidence Limits CL: 3.53, 1.28–9.74). Events rate for TnT was 8/24 (RR: 2.17, 95% CL: 1.05–4.47), CK-MB 4/13 (RR: 1.77, 95% CL: 0.71–4.38) and Myo 5/20 (RR: 1.42, 95%CL: 0.60–3.361 Minor elevations of CK-MB or Myoglobin have limited prognostic value in pts presented at the ER with chest pain in whom an AMI has been excluded. Minor elevation of TnT has some prognostic value but the best predictor of future events in this group is a history of CAD.