Comparative Analysis Between Coronary Angiotomography and Sensitive Troponin in Chest Pain With Intermediate Risk of Acute Coronary Syndrome: Conecttin Trial

Introduction: Various questions about methods of diagnosis still remain obscure and there is no effective comparison between them in patients with intermediate risk. Hypothesis: Coronary computed tomography angiopraphy (CCTA) is better than troponins in the detection of coronary artery disease in patients with chest pain and the intermediate probability of acute coronary syndromes (ACS). Methods: Were included prospectively 100 patients with chest pain and TIMI risk score 3 or 4. All patients were submitted to troponin measurements and CCTA. If CCTA showed coronary stenosis ≥ 50%, patient was initiate the ACS treatment and was hospitalized to have coronary cineangiography. If CCTA shows lesions < 50%, the patient was discharged and monitored for 30 days. A second sampling of the troponin was obtained (blinded) from all patients three hours after the first collection. Significant coronary lesion was considered when ≥ 70%. The kit of troponin ADVIA Centaur® TnI-Ultra (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) was used. The CCTA used was the 320-channel Toshiba Aquilium machine. The comparison between methods was performed through the Kappa agreement analysis. Were calculated sensitivity, specificity, and negative and positive predictive values between the sensitivity troponin versus CCTA in the detection of an ACS. Complementary analysis was made by ROC curve calculating the area under the curve (AUC) and the cut-off score of troponin and coronary lesions on angiography/events. Combined events after 30 days were: hospitalization, death and myocardial infarction. Results: The Kappa agreement analysis between troponin and CCTA in the detection of coronary lesions showed low correlation (kappa = 0.022, p = 0.78). Thirty eight (38%) patients were subjected to angiography and significant coronary injury was confirmed at 81.6%. In 62 patients with CCTA lesions < 50%, 2 (3.2%) events were observed in 30 days. Area under the troponin curve related to the presence of significant coronary lesions was 0.401 (IC 95%: 0.156 - 0.646), related to events was 0.808 (IC 95%: 0.695 - 0.922) and related to coronary lesions or events was 0.547 (IC 95%: 0.428 - 0.667). The best percentage variation cutting points of troponin were 20% (sensitivity = 32.3% and specificity = 71%) and 27.5% (sensitivity = 50% and specificity = 75%), respectively related to significant coronary lesions and events. Conclusion: The use of CCTA in patients with intermediate risk for ACS proved to be safe and superior to the sensitive troponin in the detection of coronary heart disease.