三种心肌标志物在急性心肌梗死早期诊断中的临床意义

Three cardiac markers in the early diagnosis of acute myocardial infarction

目的探讨心肌损伤标志物[血清肌钙蛋白I（cTnI）、肌红蛋白（Mb）、肌酸激酶同工酶（CK—MB）]单项及联合检测在急性心肌梗死（AMI）患者早期诊断中的意义。方法检测AMI患者（AMI组）发病后2、4、8h血液中Mb、CK—MB、cTnI浓度，与非AMI心胸疾病（UA）患者（UA组）进行比较，并分析Mb、CK—MB、cTnI单项及多项联合指标对诊断AMI的敏感性和特异性。结果AMI组在2、4、8h各项指标与UA组比较，经统计学分析，差异具有显著性（P〈0．05）.发病2h，Mb敏感性和特异性与其他单项指标和联合指标相比，经统计学分析，差异具有显著性（P〈0．05）。发病4h，Mb、CK—MB、cTnI的敏感性为87．5％、53．13％、43．75％，特异性为70．97％、74．19％、80．65％，经统计学分析，差异具有显著性（P〈0．05）；联合指标Mb＋cTnI、Mb＋CK—MB和cTnI＋CK—MB敏感性和特异性较高。发病8h，Mb、cTnI和CK—MB敏感性均达到100％，特异性分别为87．09％、90．32％、96．77％；联合指标以Mb＋cTnI＋CK—MB敏感性及特异性最高。结论对AMI患者早期进行cTnI、Mb和CK—MB的联合检测，既可尽早确诊，又可避免误诊，对提高AMI诊断的敏感性和特异性，提高确诊的速度和确诊率，具有重要的临床意义。

Objective To investigate the significance of single or combined detection of cardiac markers-serum troponin I （ cTnI ）, myoglobin （ Mb ）, and creatine kinase isoenzyme （ CK-MB ） in the early diagnosis of acute myocardial infarction （ AMI ）. Methods Blood levels of Mb, CK-MB, and cTnI were detected in patients at hours2, 4, and 8 hours after onset of AMI and were compared with those from patients with cardiothoracic diseases （ UA ）but non-AMI. The sensitivity and specificity of Mb, CK-MB and cTnI alone or combined detection for diagnosis of AMI were analyzed. Results Levels of Mb, CK-MB, anti cTnI differed significantly between AMI group and UA group at hours 2, 4, and 8 （ P〈 0.05 ）; The sensitivity and specificity of Mb differed sigificantly from those of other markers alone or combined detection at hour 2 （ P〈 0.05 ）. The sensitivity was 87.5% for Mb, 53.13% for CK-MB, and 43.75% for cTnI; and the specificity was 70.97%, 74.19%, and 80.65%, respectively; with a significant difference （ P 〈 0.05 ）. Combined detection of Mb and cTnI, Mb and CK-MB, or cTnI and CK-MB has a higher sensitivity and specificity. The sensitivity was up to 100% for the three markers at hour 8; and the specificity was 87.09%, 90.32%, and 96.77%, respectively. Combined detection of Mb plus cTnI and CK-MB has the highest sensitivity and specificity. Conclusions Early comhined detection of cTnI, Mb, and CK-MB in AMI patients not only establishes the dignosis earlier but also avoids misdiagnosis. It has important clinical significance in the improvement of the sensitivity and specificity, the diagnosis of AMI diagnosis, and the accurate rate of diagnosis.