High-sensitivity cardiac troponin T for diagnosis of NSTEMI in the elderly emergency department patient: a clinical cohort study

<b>Purpose:</b> The aim of this study is to evaluate the impact of age on the diagnostic performance of high-sensitivity troponin T (hsTnT) under routine conditions. <b>Materials and methods:</b> Data of 4118 consecutive emergency department (ED) patients who underwent a routine TnT measurement between 11 October 2012 and 30 November 2013 were analysed. Diagnostic accuracy of hsTnT was compared in four age categories (&lt;50, 50–64, 65–74, ≥75 years of age) for different cut-off values. Primary endpoint was a main hospital diagnosis of NSTEMI. <b>Results:</b> The median age of the study population (<i>n</i> = 4118) was 61 years (IQR: 45–75 years). NSTEMI was diagnosed in 3.3% (<i>n</i> = 136) of all patients. There were significant differences in hsTnT concentrations between age-groups (<i>p</i> p = 0.297). 72.2% of all patients ≥75 years of age (583/808) without NSTEMI had hsTnT concentrations above the 99th percentile of a healthy reference population. Specificity at 14 ng/L was 93.6% (95% CI: 92.12–94.87) in patients below 50 years of age and 27.9% (95% CI: 24.78–31.08) in patients 75 years of age and older. <b>Conclusions:</b> Patients’ age needs to be considered at least one influencing factor on hsTnT concentrations at admission and should be included in the clinical interpretation of hsTnT concentrations for further clinical workup beneath other influencing factors like comorbidities and symptom onset time. The implementation of age-specific cut-off values could be considered for single troponin testing at admission but is associated with an increased risk of underdiagnosis of NSTEMI.

**研究目的**：本研究旨在评估常规临床实践场景下，年龄对高敏肌钙蛋白T（high-sensitivity troponin T, hsTnT）诊断效能的影响。
**材料与方法**：本研究分析了2012年10月11日至2013年11月30日期间，4118例连续纳入的急诊科室（emergency department, ED）患者的常规肌钙蛋白T检测数据。针对不同临界值，将hsTnT的诊断准确度按四个年龄组（<50岁、50~64岁、65~74岁、≥75岁）进行比较。本研究的主要终点为非ST段抬高型心肌梗死（non-ST elevation myocardial infarction, NSTEMI）的院内主要诊断。
**结果**：本研究队列（n=4118）的年龄中位数为61岁（四分位间距（interquartile range, IQR）：45~75岁）。所有患者中3.3%（n=136）被诊断为NSTEMI。不同年龄组的hsTnT浓度存在显著差异（p=0.297，原文本存在重复标注p值的笔误）。72.2%的≥75岁且未发生NSTEMI的患者（583/808），其hsTnT浓度高于健康参考人群的99百分位数。在<50岁人群中，14ng/L临界值下的特异度为93.6%（95%置信区间（confidence interval, CI）：92.12~94.87）；在≥75岁人群中，该临界值下的特异度仅为27.9%（95%置信区间：24.78~31.08）。
**结论**：患者年龄至少可作为入院时hsTnT浓度的影响因素之一，在结合合并症、症状发作时间等其他影响因素进行hsTnT浓度的临床解读以指导后续临床诊疗时，应将年龄纳入考量范畴。对于入院时的单次肌钙蛋白检测，可考虑采用年龄特异性临界值，但该方案会增加NSTEMI漏诊的风险。