Troponin T (TnT) elevations (> or =0.1 ng/mL) indicate an increased risk of adverse outcomes in patients with acute coronary syndromes (ACS). There is little data on the prognostic significance of TnT in elders with ACS. We sought to define the ability of TnT to predict adverse outcomes in elders with suspected ACS compared with the younger cohort. This is a nested cohort study of patients aged <65 and > or =65 years with suspected ACS. Serial ECGs, CKMB and TnT assays were obtained at presentation and 4, 8, and 16 hours later. Adverse outcomes at hospital discharge included death, nonfatal myocardial infarction, coronary artery bypass grafting, and positive cardiac catheterization. A total of 695 patients were enrolled. A total of 301 (48%) were aged 65 or older. Although there was no difference in TnT sensitivity between the younger and older cohorts, there was a difference in specificity, 94% versus 83% (P <.01), respectively. In both cohorts, renal insufficiency was associated with a significantly lower TnT specificity. In both elders and younger patients with abnormal renal function, low TnT specificity warrants careful consideration of this marker as the sole criterion for aggressive medical management.