Hawkins R C, Tan H L
Department of Pathology and Laboratory Medicine, Tan Tock Seng Hospital, Singapore.
Singapore Med J. 1999 Nov;40(11):680-4.
The aim of the study was to investigate the clinical performance of serum creatine kinase (CK), CKMB (mass and activity), Troponin T (TnT) and Troponin I (TnI) in the diagnosis of acute myocardial infarction (AMI) in patients admitted to the Coronary Care Unit at Tan Tock Seng Hospital between June and July 1998.
Routine blood samples sent to the laboratory for cardiac enzyme determination (CK, CKMB activity) were stored at -20 degrees C for later determination of CKMB mass (Abbott Axsym, Ortho Clinical Diagnostics (OCD) ECi and Roche Elecsys), Troponin I (Abbott Axsym) and Troponin T (Roche Elecsys). For CKMB mass measurements, the relative index (RI = CKMB mass/CK) was calculated. The diagnosis of acute myocardial infarction was obtained from inspection of clinical notes and/or discharge diagnosis for each patient.
Forty-four of fifty-nine specimens were from AMI patients. Area under Receiver Operating Curve values were: CK 0.56, CKMB activity 0.72, percentage of CKMB activity 0.73, CKMB mass (Abbott) 0.76, CKMB mass (Roche) 0.77, CKMB mass (OCD) 0.78, RI (Roche) 0.83, RI (Abbott) 0.86, RI (OCD) 0.87, TnT 0.94, TnI 0.95. Sensitivity: TnI 88%, TnT 93%; specificity TnI 100%, TnT 92%. There was no significant difference in performance between Troponin T and Troponin I assays or between any of the CKMB mass measurements.
Troponin T and I are superior to CKMB (mass or activity) and CK in the identification of patients with AMI. Combining multiple sampling of the percentage of CKMB with single confirmatory troponin testing may provide a cost-effective testing protocol for suspected AMI patients.
本研究旨在调查1998年6月至7月间在新加坡陈笃生医院冠心病监护病房收治的患者中，血清肌酸激酶（CK）、肌酸激酶同工酶（CKMB，质量法和活性法）、肌钙蛋白T（TnT）和肌钙蛋白I（TnI）在急性心肌梗死（AMI）诊断中的临床性能。
送往实验室进行心肌酶测定（CK、CKMB活性）的常规血样保存在-20℃，以备后续测定CKMB质量（雅培Axsym、奥森多临床诊断公司（OCD）ECi和罗氏Elecsys）、肌钙蛋白I（雅培Axsym）和肌钙蛋白T（罗氏Elecsys）。对于CKMB质量测定，计算相对指数（RI = CKMB质量/CK）。通过检查每位患者的临床记录和/或出院诊断来确诊急性心肌梗死。
59份标本中有44份来自AMI患者。受试者工作特征曲线下面积值分别为：CK为0.56，CKMB活性为0.72，CKMB活性百分比为0.73，CKMB质量（雅培）为0.76，CKMB质量（罗氏）为0.77，CKMB质量（OCD）为0.78，RI（罗氏）为0.83，RI（雅培）为0.86，RI（OCD）为0.87，TnT为0.94，TnI为0.95。敏感性：TnI为88%，TnT为93%；特异性：TnI为100%，TnT为92%。肌钙蛋白T和肌钙蛋白I检测之间或任何CKMB质量测定之间的性能无显著差异。
肌钙蛋白T和I在识别AMI患者方面优于CKMB（质量法或活性法）和CK。将CKMB活性百分比的多次采样与单次肌钙蛋白确证检测相结合，可能为疑似AMI患者提供一种经济有效的检测方案。
