Penetapan Nilai Cutoff Cardiac Troponin I (cTnI) Pada Infark Miokard Akut

Dian Ariningrurn, Setyawati, Osman Sianipar, Determination cutoff Valli& of cardiac troponin f for diagnosis for acute myocardial infarction Background: Recent advances in fibrinolytic and angioplasty require an earlier, more rapid and specific diagnosis of acute myocardial infarction VI,MII. Lack of diagnostic sensitivity and specificity of conventional marker (CKMB activity) can give rise to delayed treatment. Cardiac Troponin I (cTnl ) as a component of the contractile apparatus in Cordiornyocites is thought to tiu a more sensitive and specific marker of myocardial necrosis. Objective: The objective of this study is to determine the cutoff value of cTnI for diagnosis for acute myocardial infarction. Methods: The cardiac troponin I is validated independently and blindly with the WHO criteria of AMI. The diagnosis AMI is determined by presenting of al least any 2 out of 3 following sign and symptom namely: typical history of chest pain, unequivocal electrocardiographic changes and unequivocal cardiac enzymes (CKMB activity) changes. The earliest blood sample sent to the laboratory for CKMB activity determination is retrieved and stored at -20)C for later determination of cTnl. The interval between the onset of the symptoms and admission Is noted, The diagnosis of AMI is obtained from inspection of medical records for each patients. The clinical sensitivity, specificity, positive and negative predictive values, accuracy and likelihood ratios are calculated by 2x2 tables. Receiver Operating Characteristics 1ROC) analysis is used to determine the cutoff point of cTnl, Result: Fifty four of seventy five specimens were from AMI patients. At 3,25 ng!mL as a cutoff point, regardless the interval between the onset of the symptoms and taking of blood samples, the sensitivity, specificity, positive and negative predictive values and diagnostic accuracy are 85%, 9U%, 96%, 70%, 87%, respectively. Likelihood ratios for positive and negative results respectively are 8,9 and 0,2. Conclusion: The level of cardiact troponin 13.25 ngirriL is the cutoff point for diagnosis for acute myocardial infarction, Kay words: acute myocardial infarction- cTnl- cutof