Applicability of Cardiac Troponin T and I for Early Risk Stratification in Unstable Coronary Artery Disease

Abstract

Background Studies have demonstrated that troponin T is a strong independent indicator of a poor prognosis in patients with unstable coronary artery disease. Up to the present, no study has compared the prognostic value of troponin T with that of troponin I in the same cohort of patients. Methods and Results Patients (n=516) suspected of having unstable coronary artery disease were investigated. Follow-up was done after 30 days, and the occurrences of cardiac death, acute myocardial infarction, refractory angina pectoris, and recurrent angina pectoris were registered. Elevated levels of troponin T (≥0.10 μg/L) were associated with an increased risk of cardiac death at 30 days compared with patients with normal levels, 3.2% versus 0.4% ( P =.014). Troponin I values above the chosen cutoff (2.0 μg/L) were similarly found to be an indicator of increased risk of cardiac death, 3.2% versus 0.7% ( P =.026). With regard to the composite end point of cardiac death/acute myocardial infarction, the troponins were strong independent indicators of adverse outcome. Conclusions In patients suspected of having unstable coronary artery disease, both troponin T and troponin I provide independent prognostic information with regard to cardiac death and acute myocardial infarction.