Prospective study of the role of cardiac troponin T in patients admitted with unstable angina.

OBJECTIVE--To examine the prognostic significance and role in risk stratification of the biochemical marker troponin T in patients admitted with unstable angina. DESIGN--Single centre, blinded, prospective study of patients admitted with chest pain. SETTING--Coronary care unit of a district general hospital. SUBJECTS--460 patients admitted with chest pain and followed up for a median of three years. 183 patients had a final diagnosis of unstable angina. MAIN OUTCOME MEASURES--Cardiac death, need for coronary revascularisation, or readmission with non-fatal myocardial infarction as first events. RESULTS--62 (34%) unstable angina patients were troponin T positive. This group had significantly increased incidence rates of subsequent cardiac death (12 cases (19%) v 14 (12%)), coronary revascularisation (22 (35%) v 26 (21%)), death or revascularisation (33 (53%) v 40 (33%)), and death or non-fatal myocardial infarction (18 (29%) v 21 (17%)) compared with the troponin T negative group. In multiple logistic regression troponin T status was a highly significant predictor for the end points coronary revascularisation and cardiac death or revascularisation as first events. CONCLUSION--Troponin T in the serum of patients with unstable angina identifies a subgroup at higher risk of subsequent cardiac events and its measurement aids in risk factor stratification. The increased risk extends to two years after admission. Prospective randomised trials are required to identify optimum therapeutic strategies for this subgroup.