Time to Positivity of Rapid Bedside Assay for Cardiac-Specific Troponin T Predicts Prognosis in Acute Coronary Syndromes: Thrombolysis in Myocardial Infarction (TIMI) 11 Substudy

Objectives. We sought to determine whether the rapid bedside assay for troponin T identified patients at risk for more complicated hospital stay and higher rate of adverse clinical events. Background. In patients with an acute coronary syndrome, the amount of cardiac-specific troponin T released bears stoichiometric relation to the extent of myocardial damage. Methods. In 597 patients with unstable angin or non–Q wave myocardial infarction participating in the Thrombolysis in Myocardial Infarction (TIMI) 11 substudy, rapid bedside assay and simultaneous quantitative serum measurement for troponin T were obtained at enrollment. Results. The composite end point of the sum of death, nonfatal myocardial infarction or recurrent ischemi through day 14 occurred in 33.6% of patients with positive assay compared with only 22.5% of patients with negative assay (p = 0.01). Those patients in whom the rapid assay became positive in ≤10 min had the highest mortality rate of 4.2% through day 14 compared with 1.1% in those patients who had either late-appearing positive assay (>10 min) or negative assay. The duration of hospital stay in the 116 patients (19%) with positive rapid assay at enrollment was median of 5 days compared with only 3 days in the 481 patients (81%) with negative rapid assay at enrollment (p = 0.002). Conclusions. positive rapid assay for troponin T at presentation identifies those patients at risk for higher rates of adverse clinical events and longer, more complicated hospital stays. Stratification of patients by time to development of positive rapid assay identifies those patients at highest mortality risk.