Purpose: It is uncertain whether patients with elevated troponin and non-classical presentation of acute coronary syndrome (ACS) should receive coronary CT angiography (CCTA). A proportion of these patients will have no coronary artery disease (CAD) and would benefit from non-invasive investigations and expedited discharge. Objectives were to determine most common diagnoses and rate of ACS among patients with positive troponin and low clinical suspicion of ACS who received CCTA.
Methods: IRB approved retrospective analysis of 491 consecutive patients in a level I trauma center ED referred for CCTA between April 4, 2015 to April 2, 2017. Patients were included if there was an elevated troponin (TnI > 0.045 μg/L) and atypical chest pain within 24 h prior to imaging. One hundred one patients met inclusion criteria; 17 excluded due to technical factors or history. Scans performed on dual-source CT.
Results: Eighty-four patients (47 men, 37 women) with median TnI of 0.11 ± 0.21 μg/L underwent CCTA 8.20 ± 6.41 h after first elevated Tn. Mean age was 53.2 ± 14.6 years. CCTA demonstrated absence of CAD in 39 patients (46.4%; 20 M, 19 F). CAD < 25% stenosis was observed in 24 (28.6%; 9 M, 15 F). CAD with 25-50% stenosis was observed in seven (8.3%; six M, one F). CAD > 50% stenosis was observed in 11 (13.1%; 9 M, 2 F), and non-diagnostic in three (3.6%, 3 M, 0 F). Forty-six (56.8%) were discharged directly from ED with median stay 15.82 ± 6.41 h.
Conclusions: Use of CCTA in ED patients with elevated troponin and low clinical suspicion for ACS allowed obstructive CAD to be excluded in 83%.
Keywords: Acute coronary syndrome; Coronary artery disease; Coronary computed tomography angiography; Troponin.