心肌肌钙蛋白检测诊断急性心肌梗死临床应用评价

目的　比较研究心肌肌钙蛋白I和T对急性心肌梗塞（AMI）的临床诊断应用价值。方法　采用前瞻性双盲随机及平行对照试验方法，将研究对象分为AMI组和非AMI组。AMI组共有按WHO标准诊断的AMI病人121例，随机分二组分别作肌钙蛋白I(cTnI)和肌钙蛋白T(cTnT)检查。作cTnI的共62例，作cTnT的59例。非AMI组包括健康人80例及陈旧心肌梗死、心绞痛、肾衰等患者。本法采用单克隆抗体酶联免疫法检测。cTnI和cTnT的正常值均为0.2mg/L。CK-MB正常为25U/L。结果　在AMI早期cTnI诊断敏感性较cTnT为高，胸痛2h阳性率分别为41.7%和0.0%(P<0.01)。在AMI中晚期则cTnI较cTnT为低，AMI第10d阳性率分别为38.7%和62.7%(P<0.05)。连续检测两者敏感性均可达100%(AMI8～12h)。各期敏感性均优于CK-MB。在非AMI组cTnT可出现在肾衰病人。cTnI、cTnT和CK-MB诊断AMI特异性无明显差异（P>0.05）。cTnI和cTnT有较高的阴性预测值，它们均可达100%。血管再通和梗塞部位及有无Q波影响它们在AMI早期的敏感性。结论　cTnI和cTnT是诊断AMI的敏感指标。在AMI早期检测cTnI而中晚期检测cTnT可提高AMI的诊断阳性率。

Comparison between cardiac troponin I and T for detection of acute m-yocardial infarction

Objective　To compare the value be tween cardiac troponin I (cTnI) and T (cTnT) for detection of acute myocardial infarction(AMI). Methods　In this prospective, double-blind, randomized, parallel controlled study, the subjects were divided into two: AMI g roup and non-AMI group. There were 121 patients with AMI(WHO Criteria). Serum cTnI and cTnT were measured randomly in the two groups. cTnI in 62 patients with AMI and cTnI in 59 patients with AMI were measured. Non-AMI group included 80 normal subjects, patients w ith old myocardial infarction, angina pectoris, renal failure and so on. The monoclonal enzyme immunoassay test was us ed. The normal range for both cTnI and cTnT was 0.2 mg/L and for c reatine kinase isoenzyme MB(CK-MB) was 25 U/L. Results　The sensitivity of cTnI was higher in early period and that of cTnT was better in late period. Sen sitivity of cTnI and cTnT was 41.7% and 0.0% (P<0.01) respectively at h 2 af ter chest pain. It was 38.7% and 62.7% (P<0.05) at d 10 of AMI. Sensitivity of cTnI and cTnT could reach 100% after serial assays (at h 8～10 a fter AMI) and both were better than CK-MB. In a few patients with angina pec toris in n on-AMI group， cTnI and cTnT were positive and these were positive in pati ents with renal failure. There was no significant difference of the specificity among cTnI, cTnT and CK-MB for detection of AMI. Both cTnI and cTnT had high er negative prospective values (to 100%). There were effects of reperfu sion and side of infarction and non-Q infarction on their sensitivit y in early period of AMI. Conclusion　Test of both cTnI and cTnT were t he sensitive methods. The results indicate that sensitivity for diagnosis of AMI can be increased if cTnI is tested in early AMI and cTnT in middle and late AMI .