Whole Blood And Plasma For Point-of-Caretesting Myocardial Injury Markers Differential Analysis In STEMI Applications

BackgroundIn order to improve the prognosis of myocardial infarction,chest pain centers were set up in each hospital,and point-of-care testing（POCT）was required to detect myocardial injury markers,and the Turn around Time（TAT）was within 20min,especially troponin.However,POCT platforms are numerous,and the mixed use of multiple specimen types（serum,plasma and whole blood）often occurs.Different types of specimens have different matrix effects.Many people believe that all specimen types are applicable,so the selection is relatively random,ignoring the matrix effect of different specimens,bringing the difference.Therefore,it is necessary to compare and evaluate the test results of different types of specimens used in the same POCT platform,in order to find the optimal specimen type.ObjectiveThree types of heparin sodium plasma,EDTA-K₂plasma and EDTA-K₂whole blood samples were used to detect myocardial injury markers hs-c Tn I,CK-MBmass and Myo in STEMI patients using the same POCT analyzer.The consistency and bias of the three types of samples were evaluated.MethodsThis study refers to the CLSI EP9-A3 document,the Guide for Measurement System Comparison and Biase Evaluation with Clinical Samples version 3.When clinical laboratories are used to compare experimental results between different methods,at least 40specimens covered high,medium and low concentrations.Medical records of STEMI patients admitted to the emergency Department of Luanchhuan County People’s Hospital from May2021 to October 2021 who met the diagnostic criteria of STEMI and received thrombolytic therapy were collected.Blood samples were collected and divided into three groups:heparin sodium plasma group,EDTA-K₂plasma group and EDTA-K₂whole blood group.hs-c Tn I,CK-MBmass and Myo were detected simultaneously.The results of heparin sodium plasma group were used as reference ratio to compare and evaluate the detection results of EDTA-K₂plasma group and EDTA-K₂whole blood group.SPSS25.0 and Med Calc19.0software were used for statistical analysis.Results1.Paired T test of the three groups of specimens:hs-c Tn I results of EDTA-K₂plasma and EDTA-K₂whole blood group were significantly different from those of the reference group（p<0.05）,which was statistically significant;However,the pairing results of Myo and CK-MBmass showed no significant difference（p>0.05）.2.When the preliminary analysis of relative bias by Bland-Altman mapping method,Myo,hs-c Tn I and CK-MBmass in EDTA-K₂whole blood group were decreased by about1.7%,increased by about 15.1%and 5.0%,respectively,compared with the control group,and hs-c Tn I deviation was greater than the acceptable standard by 15%.The results of Myo,hs-c Tn I and CK-MBmass in the EDTA-K₂plasma group were about 2.0%higher and 14.8%higher,and about 0.1%lower than those in the control group,with acceptable differences.3.Further assess the bias at the level of medical decision,hs-c Tn I in the EDTA-K₂plasma group and the EDTA-K₂whole blood group was more biased than that in the reference group and was not acceptable,while Myo and CK-MBmass were completely acceptable.ConclusionsHypersensitive POCT analyzer Super Flex was used to detect myocardial injury markers hs-c Tn I,CK-MBmass and Myo in STEMI patients.Results showed differences among different types of specimens:1.In the detection of hs-c Tn I,the detection results of EDTA-K₂plasma and EDTA-K₂whole blood samples had a large bias with the results of the reference group,and were not suitable as the replacement specimens of heparin sodium plasma.2.When CK-MBmass and Myo were detected,EDTA-K₂plasma and EDTA-K₂whole blood samples showed good correlation and high consistency with the results of the reference group.The three samples had the same efficacy and could be substituted for each other.