Diagnostic Accuracy of High-Sensitivity Cardiac Troponin I for Predicting Acute Total Coronary Occlusion in Patients with Non-ST-Elevation Myocardial Infarction

Abstract

Objective: To determine the diagnostic accuracy of high-sensitivity cardiac troponin I (hs-cTnI) for predicting acute total coronary occlusion (ATCO) in patients with non-ST-elevation myocardial infarction (NSTEMI), using coronary angiography as the reference standard. Methodology: This prospective diagnostic accuracy study was conducted in the Department of Cardiology, Choudhary Pervaiz Elahi Institute of Cardiology (CPEIC), Multan, Pakistan, over a six-month period. A total of 300 consecutive patients diagnosed with NSTEMI were enrolled. Baseline hs-cTnI levels were measured at presentation using a standardized high-sensitivity assay. All participants subsequently underwent coronary angiography during index hospitalization. ATCO was defined as Thrombolysis in Myocardial Infarction (TIMI) flow grade 0–1 on coronary angiography. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal hs-cTnI cut-off value and evaluate diagnostic performance. Results: The mean age of the participants was 44.18 ± 8.89 years, and 69.0% were male. Cardiovascular risk factors included smoking in 34.3%, diabetes mellitus in 37.0%, and hypertension in 46.3% of patients. Acute total coronary occlusion was identified in 97 patients (32.3%). Patients with ATCO had significantly higher hs-cTnI concentrations than those without ATCO (1185.50 ± 165.94 ng/L vs. 602.31 ± 184.70 ng/L, p<0.001). ROC analysis demonstrated excellent diagnostic performance, with an area under the curve (AUC) of 0.984 (95% CI: 0.971–0.996; p<0.001). The optimal hs-cTnI cut-off value was 988 ng/L, yielding a sensitivity of 91.8% (95% CI: 86.4–95.1) and specificity of 98.5% (95% CI: 94.2–99.6). Positive and negative predictive values were 96.5% and 96.1%, respectively, with an overall diagnostic accuracy of 96.2%. Conclusion: High-sensitivity cardiac troponin I demonstrated excellent diagnostic performance for identifying acute total coronary occlusion among patients presenting with NSTEMI. Elevated hs-cTnI levels may assist in early risk stratification and identification of high-risk patients; however, external validation in larger multicenter populations is required before routine clinical implementation.