Combined assessment of aortic root anatomy and aortoiliac vasculature with dual-source CT as a screening tool in patients evaluated for transcatheter aortic valve implantation

Abstract

Objective: The objective of our study was to investigate the feasibility, image quality, and clinical implications of a combined dual-source CT angiography (CTA) protocol to assess aortic root anatomy and aortoiliac vasculature in patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation.

Subjects and methods: Eighty consecutive patients (47 women and 33 men; mean age, 82.3 ± 7.8 [SD] years) with severe aortic stenosis evaluated for transcatheter aortic valve implantation underwent a combined single-dose contrast-enhanced dual-source CTA protocol (body weight < 70 kg, 110 mL of contrast medium; ≥ 70 kg, 130 mL) consisting of ECG-gated dual-source CTA of the chest with integrated cardiac CT and ungated CTA of the abdomen and pelvis. Two independent observers measured the dimensions of the aortic root and the aortoiliac vasculature and rated image quality semiquantitatively. Vessel attenuation was assessed. Amenability to transfemoral access was evaluated on the basis of vessel diameter (> 7 mm), anatomy, and the presence of vascular disease.

Results: Image quality of the aortic root was diagnostic in all 80 patients, and image quality of the aortoiliac vasculature was diagnostic in 79 patients. Vascular attenuation was greater than 200 HU at any vessel level. The mean diameter of the aortic annulus was 24.1 ± 2.9 (SD) mm. Inter- and intraobserver correlations for aortic root and aortoiliac measurements were high (r = 0.93-0.99). Aortic root dimensions were suitable for transcatheter aortic valve implantation in 65 patients (81%). Thirty-eight patients (48%) were deemed amenable to instant transfemoral access without another vasculature intervention.

Conclusion: The dimensions of the aortic root and the aortoiliac vasculature can be assessed with a combined single-dose contrast-enhanced dual-source CTA protocol, thereby allowing determination of patient eligibility for transcatheter aortic valve implantation, prosthesis sizing, and evaluation of the access route in one examination.