Troponin T in patients with low grade or atypical angina - Identification of a high risk group for short- and long-term cardiovascular events

Aims Cardiac troponin T is an established marker of cardiovascular risk in patients with severe angina pectoris. Data are scarce on patients admitted to a coronary care unit with low grade or atypical angina pectoris to rule out myocardial infarction. Methods and Results We investigated 106 patients (57.4 SD 11.6 years) with low grade (Braunwald class I) or atypical symptoms out of 702 patients admi tted to the coronary care unit with suspected acute myocardial infarction. Serum concentrations of troponin T were measured at admission and 4 h later . In hospital cardiovascular events including acute myocardial infarction, life threatening cardiac arrhythmias, congestive heart failure, and death w ere recorded. Patients were additionally observed after 3 and 6 months post -discharge regarding acute myocardial infarction, unstable angina, rehospit alization for cardiac causes and death. The patients were divided into a tr oponin T positive (greater than or equal to 0.2 mu g.l(-1) at admission or 4 h later; n = 11) and a troponin T negative group. The mean value of tropo nin T 4 h after admission in the positive group was 0.58 mu g.l(-1). Of the troponin T positive patients, 0.82 (0.95 CI: 0.48- 0.98) had a cardi ovascular event during their stay in hospital vs 0.41 (0.95 CI: 0.31-0.52) of troponin T negative patients (P < 0.05). In the troponin T positive grou p 0.64 (0.95 CI: 0.31-0.89) developed myocardial infarction in hospital vs 0.07 (0.95 CI: 0.03-0.15) in the troponin T negative group (P < 0.001). Tro ponin T predicts outcome after 3 and 6 months significantly (P < 0.05). Conclusion Troponin T identifies patients with low grade or atypical angina at risk of severe short- and long-term cardiovascular events. Therefore, t roponin T adds substantial information in patients with ruled out acute myo cardial infarction. Troponin T positive patients have to be observed carefu lly regardless of their symptom intensity and may have to receive early car diac catheterization; troponin T negative patients could be released safely from the coronary care unit early.