The Clinical Application Of Four Cardiac Marker Combinations In Diagnosing AMI

ObjectiveTo study and compare the diagnostic efficiency of four different cardiac markers（troponin TCTnT, myoglobin Myo, heart-type fatty acid-binding protein H-FABP, N-terminal pro-brainnatriuretic peptide NT-ProBNP） and their combinations in diagnosing acute myocardialinfarction（AMI）, and to discuss the clinical application value of cardiac marker combinations.MethodsPatients with acute onset of chest pain were selected randomly. Plasma concentrations offour cardiac markers for myocardial infarction （CTnT, Myo, H-FABP, NT-ProBNP）were testedimmediately.The patients were divided into AMI group and NON-AMI group according to theWHO criteria. Then ROC curves were established for four cardiac markers respectively Then thecutoff value of these markers were determined and then four cardiac marker combinations weredesigned （CTnT+NT-proBNP，CTnT+Myo，CTnT+H-FABP），CTnT+Myo+NT-proBNP). Thesensitivity,the specificity and the diagnostic efficacy of the four cardiac markers and thecombinations were calculated and compared respectively.ResultsThe plasma concentrations of CTnT,Myo, H-FABP,NT-proBNP in AMI group were0.497±0.023μg/L,89.48±12.49μg/L,18.5±1.973ng/ml and4793±398.49pg/ml respectively,which were higher than those in NON-AMI group（0.016±0.019,40.36±16.85,1.46±1.366,1243±292.43）.The difference of the four cardiac marker plasma concentrations betweenAMI and NON-AMI group was extremely significant. The AUCs for the four cardiac markerswere: AUC_CTnT=0.945（95%CI0.895-0.995）,AUC_Myo=0.745（95%CI0.653-.838）,AUC_H-FABP=0.917（95%CI0.871-0.962）,AUC_NT-proBNP=0.763（95%CI0.689-0.831）.The diagnosis ability of CTnT and H-FABP were better than the other cardiacmarkers. The sensitivity of the four markers were Sen_CTnT=0.755,Sen_Myo=0.600,Sen_H-FABP=0.736,Sen_NT-proBNP=0.755respectively; The specifity of the four markers wereSpe_CTnT=0.936, Spe_Myo=0.755,Spe_H-FABP=0.909,Spe_NT-proBNP=0.809respectively; The diagnostic efficacy of the four markers were Eff_CTnT=0.877, Eff_Myo=0.724, Eff_H-FABP=0.853, Eff_NT-proBNP=0.791respectively.By analysis of statistics，CTnT and H-FABP had higher diagnostic efficaciesthan the other markers. The sensitivity of the four combinationswere:Sen_CTnT+Myo=0.962,Sen_CTnT+H-FABP=0.962,Sen_{CTnT+NT-proBNP}=0.943,Sen_{CTnT+Myo+NT-proBNP}=0.981respectively; The specifity of the four combinations were Spe_CTnT+Myo=0.727,Spe_CTnT+H-FABP=0.918,Spe_{CTnT+NT-proBNP}=0.809,Spe_{CTnT+Myo+NT-proBNP}=0.890respectively; The diagnosticefficacies of the four combinations were: Eff_CTnT+Myo=0.804, Eff_CTnT+H-FABP=0.933, Eff_{CTnT+NT-proBNP}=0.863, Eff_{CTnT+Myo+NT-proBNP}=0.920respectively.The combination of “CTnT+H-FABP)”had a higher sensitivity， specifity and diagnostic efficacy than other combinations. Thedifference of the sensitivity，specifity and diagnostic efficacy between “CTnT+H-FABP)” and“CTnT+Myo+NT-proBNP” were not significant statistically.ConclutionThe study shows that the four cardiac markers （CTnT, H-FABP,Myo and NT-proBNP）) havediagnostic value for AMI.Among the four cardiac markers, CTnT and H-FABP have higher diagnostic efficaciesthan other cardiac markers in diagnosing AMI.The combinations of “CTnT+H-FABP”and”CTnT+Myo+NT-proBNP” have higherdiagnostic efficacies than other combinations in diagnosing AMI.