PROGNOSTIC-SIGNIFICANCE OF ADMISSION TROPONIN-T CONCENTRATIONS IN PATIENTS WITH MYOCARDIAL-INFARCTION

Background New, highly specific cardiac structural proteins can now be measured. The early presence of one of these proteins, troponin T, ha s been found to have important prognostic significance in patients wit h unstable angina pectoris. The prognostic significance of its presenc e on admission was assessed in patients with myocardial infarction. Me thods and Results Two hundred forty patients admitted with myocardial infarction were studied and followed prospectively for a median of 3 y ears. The prognostic significance of an admission troponin T concentra tion greater than or equal to 0.2 ng/mL for subsequent cardiac death a nd/or reinfarction was assessed and compared with other variables in a regression model. Any detectable troponin T on admission was associat ed with a worse prognosis on followup. An admission concentration of g reater than or equal to 0.2 ng/mL was associated with a higher risk of subsequent cardiac death (chi(2), 13.3; P=.0002) and death or nonfata l reinfarction (chi(2), 16; P=.00006). The excess risk was seen primar ily in patients with admission ECG ST-segment elevation (cardiac death chi(2), 9.7; P=.001; death or nonfatal reinfarction chi(2), 10.3; P=. 001). In a stepwise regression mode for cardiac death or nonfatal rein farction, troponin T was superior to most of the other variables enter ed in both myocardial infarction subgroups. Conclusions The presence o f admission troponin T in patients with myocardial infarction defines a subgroup, particularly those with ST-segment elevation, at increased risk of subsequent cardiac events and identifies a group that may ben efit from alternative early management strategies.