The Importance of Serial Time Point Quantitative Assessment of Cardiac Troponin I in the Diagnosis of Acute Myocardial Damage.

Objective: The present study was aimed to establish a threshold value for cardiac troponin I (cTnI) for nonacute coronary syndrome (ACS) participants from the local population and also to determine the importance of serial time point estimation of cTnI in acute myocardial infarction (AMI), non-ST-elevated MI (NSTEMI), and unstable angina cases.

Methods: The present study included 194 cases, admitted in ICCU with the complaint of anginal pain; 31 were diagnosed with AMI with typical electrocardiography (ECG) changes; whereas, 48 cases were diagnosed with NSTEMI. The latter group of cases was selected for the time point study of cTnI release at 0-4 h, 6-12 h, 72 h, and 144 h of admission. cTnI levels were assessed using the Abbott ARCHITECT i1000SR system.

Results: ACS was clinically ruled out in 98 cases, and cTnI level for them was used to decide cTnI threshold for the non-ACS group. cTnI level was checked in 17 cases of unstable angina. The threshold value of cTnI for non-ACS participants was 0.1 ng/ml and can be considered as cut-off value for the regional population. The data suggested that the peak of cTnI levels in most of the AMI cases reached during 6-12 h. The cTnI levels were lower than 0.1 ng/ml, and no significant change in ECG was noticed in 17 cases of unstable angina.

Conclusion: The present study suggested that the repeat of cTnI assay after 4-6 h of admission is required if the initial value is <3 ng/ml.