Abstract
Computed tomography coronary angiography (CTCA) is under-utilised in detecting coronary artery disease (CAD) in obese patients due to concerns about non-evaluable testing. We hypothesise that these concerns are predominantly related to smaller and branch coronary vessels, and CTCA remains adequate for proximal segment stenosis interpretation, which has significant clinical implications. This retrospective cohort study, on consecutive patients referred for CTCA for suspected CAD, grouped patients by body mass index. A 4-point Likert scale assessed image quality, with any poorly visualised segment at the per-patient level resulting in the CTCA being subsequently analysed for proximal coronary artery segment evaluability. Of the 703 patients, 93.5% of the studies were fully evaluable. Patients with a BMI ≥ 40, diabetic patients, and patients with an elevated acquisition heart rate were associated with suboptimal studies. Of the 46 suboptimal studies, 163/182 (90%) of proximal segments were fully evaluable. Non-evaluable segments were derived from seven patients (one with a BMI ≥ 40). Reasons for proximal segment non-evaluability were predominantly due to calcific blooming (12/19 segments). While CTCA may be less reliable for distal and side-branch artery evaluation in obese patients, it remains highly evaluable for stenosis severity of the proximal main coronary segments, which carries prognostic significance. It may therefore be considered a suitable non-invasive anatomic test for patients, regardless of BMI.