Abstract: Objective To detect the circulating CPNE3 mRNA in the patients with acute myocardial infarction for evaluation of its diagnostic potential. Methods A total of 154 patients who were suffering from chest pain were admitted to the hospital. The patients were divided into AMI group （48 cases） and non-AMI group （106 cases） according to the diagnostic criteria. Sixty healthy persons were taken as control. Vein blood of AMI patients was collected immediately on admission and 4h,6h,12h,24h after admission. The level of serum cTnI was detected by Latex particle-enhanced turbidimetric immunoassay and serum cTnI,by electrochemiluminescence. The circulating CPNE3 mRNAs were examined by qRT-PCR. Results Compared to the non-AMI or the control,AMI mostly occurred in the individuals of smoking,hypertension and diabetes with a high level of TC,TG,LDL-C,CK-MB,and cTnI and a low level of HDL-C （P﹤0.05）. The CPNE3 mRNA in the AMI patients was significantly elevated （P﹤0.05） on immediate admission but greatly reduced at 4h after admission and no significant difference was noted between the non-AMI group and the control （P﹥0.05）. The level of cTnI reached peak value at 6h after admission and CK-MB,at 12h after admission. The cTnI and CK-MB increased and CPNE3 mRNA remarkably decreased in AMI patients at different stages of admission （P﹤0.05）. ROC curve analysis showed that the area under ROC curve （AUC） for the diagnostic value of CPNE3 mRNA on AMI was 0.910,with the sensitivity and specificity of 97.9% and 75.0%,respectively. The AUC for cTnI was 0.801,with the sensitivity and specificity of 68.7% and 89.6%. The AUC for CK-MB was 0.912,with the sensitivity and specificity of 75.0% and 95.8%. Conclusion The circulating CPNE3 mRNA has the potential in early diagnosis of AMI,which may be superior or equal to cTnI or CK-MB.

Key words: CPNE3 mRNA, Cardiactroponin I, Creatine kinase isoenzyme, Acute myocardial infarction, Diagnosis