Objective: The aim of this study was to investigate the effectiveness of copeptin in the early diagnosis of acute myocardial infarction (AMI), and to compare the diagnostic efficacy of copeptin with other cardiac markers.
Patients and methods: A total of 160 cases were enrolled in the study. All were over 18 years of age, and consisted of 54 non-ST elevation MI (NSTEMI), 54 ST segment elevation MI (STEMI), and 52 healthy subjects (controls). Serum troponin-I, CK-MB mass, copeptin and CRP levels were measured in each of the cases, and were compared between the three groups for statistical differences.
Results: The copeptin levels in the STEMI (p < 0.001) and NSTEMI (p = 0.042) groups were found to be significantly higher than the control group. Spearman's correlation analysis showed a significant positive correlation between the level of copeptin and the presence of AMI (r = 0.285, p < 0.001), CK-MB mass (r = 0.246, p = 0.002), and troponin-I (r = 0.199, p = 0.012). Sensitivity, specificity, and AUC values of the tests, according to ROC analysis performed for the diagnosis of AMI were; troponin-I > 0.1 ng/mL (71.0%, 100.0%, and 0.855); CK-MB mass > 3.59 ng/mL (77.8%, 92.3%, and 0.911); CRP > 6.37 mg/L (53.7%, 88.5%, and 0.769); and copeptin > 2.47 ng/mL (66.7%, 75.0%, and 0.676), respectively (p < 0.001).
Conclusions: Cardiac troponin remains the gold standard biomarker for the diagnostic evaluation of AMI. Copeptin can be used as a diagnostic marker in patients with suspected AMI in combination with other biomarkers, but, copeptin alone should not be considered as a single diagnostic marker in patients with suspected AMI.