The role of cardiac troponin-I (cTnI) in risk stratification of patients with unstable coronary artery disease

In patients with chest pain at rest but no ST-segment elevation on the elec trocardiogram, the diagnoses of unstable angina and non-Q-wave myocardial i nfarction (MI) are usually considered together because they cannot be diffe rentiated clinically or angiographically. Since the extent of myocardial ne crosis is an important determinant of the risk of death, it is important to identify serum markers with which to predict prognosis, in order to initia te appropriate medical treatment and/or invasive procedures in these patien ts. Cardiac troponin-I (cTnI), one of the subunits of the troponin regulato ry complex, binds to actin and inhibits interactions between actin and myos in. The presence of elevated cTnI in serum is a significant prognostic indi cator in patients with unstable angina and non-Q wave MI. Its independent p rognostic potential persists even after adjustment for independent baseline variables known to be significantly associated with an increased risk of c ardiac events. The use of cTnI in the triage of patients with unstable coro nary disease may identify those at greater risk for adverse cardiac events.