Aortic Arch Morphology Influences Procedural Complexity During Diagnostic Coronary Angiography: Development of a...

Procedural complexity during diagnostic coronary angiography varies considerably and may result in prolonged fluoroscopy exposure and increased contrast utilization. Although vascular access route and operator experience are recognized contributors, the influence of proximal vascular anatomy remains less clearly defined. This study evaluated the association between aortic arch branching morphology and procedural complexity and explored the development of a CTA-informed procedural complexity index.

To assess the procedural impact of aortic arch branching morphology during diagnostic coronary angiography.

This retrospective observational study included 250 consecutive adult patients undergoing diagnostic coronary angiography who had preprocedural computed tomography angiography (CTA) of the thoracic aorta available for evaluation. Aortic arch branching patterns were classified into four configurations (Types A-D) using axial images, multiplanar reconstructions, and three-dimensional CTA analysis. Procedural measures included fluoroscopy time, contrast volume, procedure duration, vascular access route, and access-site crossover. Multivariable linear regression was used to assess predictors of fluoroscopy time, while a separate multivariable logistic regression model for prolonged fluoroscopy was used to derive a weighted CTA-informed procedural complexity index. Discrimination was assessed using receiver operating characteristic analysis, with internal validation by 10-fold cross-validation.

Variant aortic arch morphology was identified in 55 patients (22.0%). Patients with variant configurations had longer fluoroscopy times than those with classical Type A anatomy (7.4 ± 2.6 vs 5.9 ± 2.1 minutes; P = 0.002), greater contrast utilization (88 ± 25 vs 78 ± 21 mL; P = 0.01), and longer procedure duration (26 ± 10 vs 22 ± 8 minutes; P = 0.02). Variant arch morphology remained independently associated with longer fluoroscopy time (β = +1.3 minutes; P = 0.003). The derived procedural complexity index demonstrated an apparent area under the curve of 0.72 (95% CI, 0.64-0.80), with a 10-fold cross-validated AUC of 0.68.

CTA-defined aortic arch morphology was associated with procedural complexity during diagnostic coronary angiography. The proposed CTA-informed procedural complexity index demonstrated modest discriminatory performance and may provide additional information regarding anticipated procedural difficulty. The index should be considered exploratory and requires prospective external validation before clinical implementation.