OBJECTIVE: To compare the diagnostic accuracy of different myocardial injury markers and their combinations in diagnosing acute myocardial infarction (AMI). METHODS: The myocardial injury markers: AST, CK, CK-MB, LDH, HBDH, cTnI, CK-MB mass were detected in patients with acute chest pain-onset who were hospitalized in Sichuan University West China Hospital from July 2005 to October 2006. The accuracy of those markers in diagnosing AMI were evaluated by their sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio. Student t-test and one-way ANOVA were performed to compare the diagnostic accuracy of the markers. RESULTS: cTnI had the highest diagnostic accuracy, with 85% of sensitivity and 92.5% of specificity (P < 0.05). cTnI in parallel with myocardial enzymes produced the highest combined diagnostic accuracy, with 100% of sensitivity and 37.29% of specificity (P < 0.05). Myocardial enzymes in sequence with cTnI produced the highest sequential diagnostic accuracy, with 50% of sensitivity and 100% of specificity (P < 0.05). CONCLUSION: cTnI is the best indicator for diagnosis and differential diagnosis of AMI. Myocardiozymogram is poor in sensitivity and specificity, which should be used only in combination with cTnI or CK-MB mass. Parallel testing can increase sensitivity, while sequential testing can improve specificity.
OBJECTIVE: To compare the diagnostic accuracy of different myocardial injury markers and their combinations in diagnosing acute myocardial infarction (AMI). METHODS: The myocardial injury markers: AST, CK, CK-MB, LDH, HBDH, cTnI, CK-MB mass were detected in patients with acute chest pain-onset who were hospitalized in Sichuan University West China Hospital from July 2005 to October 2006. The accuracy of those markers in diagnosing AMI were evaluated by their sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio. Student t-test and one-way ANOVA were performed to compare the diagnostic accuracy of the markers. RESULTS:cTnI had the highest diagnostic accuracy, with 85% of sensitivity and 92.5% of specificity (P < 0.05). cTnI in parallel with myocardial enzymes produced the highest combined diagnostic accuracy, with 100% of sensitivity and 37.29% of specificity (P < 0.05). Myocardial enzymes in sequence with cTnI produced the highest sequential diagnostic accuracy, with 50% of sensitivity and 100% of specificity (P < 0.05). CONCLUSION:cTnI is the best indicator for diagnosis and differential diagnosis of AMI. Myocardiozymogram is poor in sensitivity and specificity, which should be used only in combination with cTnI or CK-MB mass. Parallel testing can increase sensitivity, while sequential testing can improve specificity.