Effect of older age on diagnostic and prognostic performance of high-sensitivity troponin T in patients presenting to an emergency department

Background The effect of age on diagnostic and prognostic performance of high-sensitivity cardiac troponin T (hs-cTnT) has not been addressed adequately, so far. Methods High-sensitivity cardiac troponin T was measured serially in patients with acute symptoms presenting to our emergency department. We tested the diagnostic and prognostic performance of baseline and serial hs-cTnT concentrations related to age in all consecutive patients with acute coronary syndrome (ACS) (n = 342) or hs-cTnT increases not due to ACS (n = 442). Results Prevalence of elevated hs-cTnT in the study population was higher among patients = 75 years compared with younger patients (89.1 % vs 73.3 %, hazard ratio [HR] 1.2, P < .0001). Elevated hs-cTnT was more likely due to ACS in the younger patients (HR 1.4, P = .001) and conversely more frequently due to non-ACS conditions in the elderly patients (HR 1.3, P = .0001). Diagnostic performance of hs-cTnT using the 99th percentile was significantly superior in younger than in elderly patients (P < .0001). For receiver operating characteristic-optimized cutoffs, a trend to significance was found between younger and older patients (area under the curve 0.87 vs 0.79, P = .074), with higher sensitivities (98.2 % vs 72.6%) and negative predictive values (97.3% vs. 78.5%) for patients <75 years. Moreover, receiver operating characteristic-optimized cutoff values for diagnosis of non-ST-segment elevation myocardial infarction were significantly higher in elderly patients (32.9 ng/L) compared with younger patients (12.9 ng/L). The prognostic information of single and serial hs-cTnT measurements was comparably poor in both age groups, showing no better prognostic information to hs-cTnT measurement on presentation. Conclusions Elevated hs-cTnT is more common in the elderly due to higher prevalence of non-ACS conditions and significantly impairs diagnostic performance in discriminating non-ST-segment elevation myocardial infarction. (Am Heart J 2012;164:698-705.e4.)