Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States.
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States.
Clin Biochem. 2020 Sep;83:28-36. doi: 10.1016/j.clinbiochem.2020.05.014. Epub 2020 May 30.
Cardiac troponin (cTn) is the keystone for diagnosis of acute myocardial infarction (AMI). We examined the analytical and clinical diagnostic characteristics of the ACCESS hsTnI assay in a United States (US) population.
All measurements and studies were conducted using a lithium heparin matrix. Sex-specific 99th percentile upper reference limits (URLs) were determined for 1089 healthy women (54.6%) and men using non-parametric statistics. High-sensitivity (hs) performance was assessed to determine if the total CV was ≤10% at sex-specific URLs, and if ≥50% of cTnI values for each sex exceeded the assay's limit of detection (LoD). Precision, analytical measurement range, high-dose hook effect, and endogenous/exogenous interferences were examined with CLSI guidance. Clinical characterization included serial sampling of 1854 suspected AMI subjects presenting to 14 US Emergency Departments. AMI was adjudicated by a panel of expert cardiologists. The study's only exclusion was end stage renal disease.
99th percentile URLs were 11.6-, 19.8- and 17.5-ng/L for respective female, male and all-subject populations. Total %CV was <8% from 6.8 to 19,000 ng/L, and <6% at sex-specific 99th percentiles; ≥99% of ACCESS hsTnI values for each sex exceeded the LoD. No high-dose hook effect or endogenous/exogenous interferences were identified. A comparison of Baseline samples collected at ≤1 h and any-time after presentation, found 4% lower sensitivity for AMI than with earlier sampling. For 1-9 h post presentation, the sensitivity was >90%, specificity >85%; and negative and positive predictive value were ≥99% and >60%, respectively.
Analytical and clinical performance of the ACCESS hsTnI assay meets the definition of a hs cTn method. The ACCESS hsTnI assay has good precision over a wide range, no significant interferences, and sensitivity >90% and NPV ≥99%. Performance is appropriate for aiding in AMI diagnosis.
心肌肌钙蛋白（cTn）是诊断急性心肌梗死（AMI）的关键。我们在美国（US）人群中研究了 ACCESS hsTnI 检测的分析和临床诊断特征。
所有测量和研究均使用锂肝素基质进行。使用非参数统计方法确定了 1089 名健康女性（54.6%）和男性的性别特异性 99%上限参考限值（URL）。评估高灵敏度（hs）性能，以确定在性别特异性 URL 处总变异系数（CV）是否≤10%，以及每个性别是否有≥50%的 cTnI 值超过检测限（LoD）。根据 CLSI 指南检查精密度、分析测量范围、高剂量钩状效应和内源性/外源性干扰。临床特征包括对 1854 名疑似 AMI 患者进行连续采样，这些患者就诊于 14 家美国急诊室。AMI 通过专家组的专家心脏病学家进行裁决。该研究的唯一排除标准是终末期肾病。
女性、男性和所有受试者人群的 99% URL 分别为 11.6、19.8 和 17.5ng/L。从 6.8 到 19000ng/L，总 CV%<8%，在性别特异性 99% URL 处<6%；每个性别≥99%的 ACCESS hsTnI 值均超过 LoD。未发现高剂量钩状效应或内源性/外源性干扰。对≤1 小时和就诊后任何时间采集的基线样本进行比较，发现 AMI 的敏感性比早期采样低 4%。在就诊后 1-9 小时，敏感性>90%，特异性>85%；阴性和阳性预测值分别≥99%和>60%。
ACCESS hsTnI 检测的分析和临床性能符合 hs cTn 方法的定义。ACCESS hsTnI 检测具有良好的宽范围精密度，无明显干扰，敏感性>90%，NPV≥99%。性能适合辅助 AMI 诊断。
