Evaluation of the Appropriate Use of Coronary Computed Tomography Angiography: A Retrospective, Single-Center Analysis

Purpose: We assessed the application of appropriate use criteria of coronary computed tomography angiography (CCTA) in comparison to invasive coronary angiography results and revascularization rates in patients with coronary artery disease (CAD). Methods: 1305 patients referred to invasive coronary angiography (ICA) after CCTA were evaluated retrospectively. The primary indication for CCTA was assessed according to the consensus for intermediate-risk (15-85% pre-test probability) into appropriate (A), inappropriate (I), and uncertain while referring to published guidelines. Patients' risk factors, angina, and heart failure symptoms (Canadian Cardiovascular Society classification (CCSC), New York Heart Association (NYHA); clinical data; and ICA results were gathered. Results: Of 1305 patients referred to CCTA prior to ICA, 496 (38.0%) were appropriate, 766 (56.9%) inappropriate, and 43 (3.3%) uncertain. Of 766 patients with inappropriate CCTA referrals, 370 (48.3%) were classified as "inappropriately low" (<15% pre-test probability) and 396 (51.7%) as "inappropriately high" (>85%) in regard to the recommended CCTA utilization. Sub-analysis of the adherence to the appropriate use criteria did not differ between the source of the referring physicians (intramural tertiary, private practice primary care, or external secondary care hospitals). Obstructive CAD with subsequent revascularization rates (total of 39.2%) did not differ significantly between the appropriate (38.3%), inappropriate (41.0%), or uncertain (23.3%) groups (p = 0.068). Conclusion: The total coronary revascularization rate after CCTA was 39.2% and not different among low, intermediate, and pre-test probability groups. These findings support the role of CCTA as an excellent gatekeeper in patients with suspected obstructive CAD even beyond pre-test probability calculation models.