Adult Emergency Department, Auckland City Hospital, Auckland, New Zealand.
Emerg Med Australas. 2011 Aug;23(4):490-501. doi: 10.1111/j.1742-6723.2011.01446.x. Epub 2011 Jun 23.
High sensitivity troponin T (hsTnT) detects lower levels of troponin T with greater precision than the 4th generation (cTnT) assay. However, the clinical implications of this are uncertain.
Primary: Describe the proportion of patients who test 'positive' with hsTnT but negative with cTnT. Secondary: Determine proportion in each group with an adverse event (representation, AMI or died) within 90 days of the index test.
161 patients samples were tested with cTnT and hsTNT assays. McNemar's test was used to compare paired samples. Electronic medical records were reviewed, with discharge diagnosis and 90 day outcomes determined blind to hsTnT results. Patients were then classified as 'TnT negative' (hsTnT was <0.014 mcg/mL), 'new positive' (hsTnT was ≥ 0.014 mcg/mL and cTnT <0.03 mcg/mL) and 'TnT positive' (cTNT was ≥ 0.03 mcg/mL).
Positive results more than doubled with the hsTnT assay (50% vs 22%, P < 0.001). 81 patients were 'TnT negative', 44 were 'new positive' and 36 'cTnT positive'. The discharge diagnosis for 'new positives' was AMI in 4 (9%), other cardiac in 13 (30%) and non-cardiac in 27 (61%). At 90 days adverse events occurred in 30%, 54% and 50% of the groups respectively. There were no late cases of AMI or cardiovascular death in 'new positive' patients.
Many patients with diagnoses other than AMI will have hsTNT above the reference level. Indiscriminate testing with hsTnT might lead to more patients requiring serial troponin testing and/or invasive further tests, which will have process and resource implications for EDs and health services.
高敏肌钙蛋白 T（hsTnT）比第 4 代（cTnT）检测法更精确地检测到更低水平的肌钙蛋白 T。然而，其临床意义尚不确定。
主要描述 hsTnT 检测结果为阳性但 cTnT 检测结果为阴性的患者比例。次要目的：确定每组中在索引测试后 90 天内发生不良事件（表现、AMI 或死亡）的比例。
对 161 例患者样本进行 cTnT 和 hsTNT 检测。采用 McNemar 检验比较配对样本。电子病历进行了回顾，根据 hsTnT 结果盲法确定出院诊断和 90 天结局。然后将患者分为“TnT 阴性”（hsTnT<0.014 mcg/mL）、“新阳性”（hsTnT≥0.014 mcg/mL 且 cTnT<0.03 mcg/mL）和“TnT 阳性”（cTnT≥0.03 mcg/mL）。
hsTnT 检测的阳性结果增加了一倍以上（50%比 22%，P<0.001）。81 例患者为“TnT 阴性”，44 例为“新阳性”，36 例为“cTnT 阳性”。“新阳性”患者的出院诊断为 AMI 4 例（9%）、其他心脏疾病 13 例（30%）和非心脏疾病 27 例（61%）。90 天时，各组分别有 30%、54%和 50%的患者发生不良事件。“新阳性”患者无迟发性 AMI 或心血管死亡病例。
许多诊断为非 AMI 的患者 hsTNT 水平将高于参考值。hsTnT 的无差别检测可能导致更多的患者需要进行连续的肌钙蛋白检测和/或侵入性进一步检查，这将对 ED 和卫生服务产生流程和资源方面的影响。
