Computed tomography anatomical characteristics based on transcatheter aortic valve replacement in aortic regurgitation

Abstract

This study analyzed computed tomography (CT) measurement characteristics and anatomical classifications based on transcatheter aortic valve replacement (TAVR) in patients with aortic regurgitation (AR) to establish a preliminary summary of CT anatomical characteristics and to design a novel self-expanding transcatheter heart valve (THV). This single-center retrospective cohort study included 136 patients diagnosed with moderate-to-severe AR at Fuwai Hospital from July 2017 to April 2022. Patients were classified into four anatomical classifications according to dual-anchoring multiplanar measurement of where THV anchoring took place. Types 1-3 were considered candidates for TAVR, whereas type 4 was not. Among 136 patients with AR, there were 117 (86.0%) tricuspid, 14 bicuspid, and five quadricuspid valves. Dual-anchoring multiplanar measurement showed that the annulus was smaller than left ventricular outflow tract (LVOT) at 2, 4, 6, 8, and 10 mm on the annulus. The ascending aorta (AA) 40 mm was wider than AA 30 mm and AA 35 mm, but narrower than AA 45 mm and AA 50 mm. For 10% oversize of the THV, the proportions of the annulus, LVOT, and AA unable to meet the diameter were 22.8%, 37.5%, and 50.0%, respectively, and the proportions of anatomical classification types 1-4 were 32.4%, 5.9%, 30.1%, and 31.6%, respectively. The novel THV could significantly improve the type 1 proportion (88.2%). Existing THVs cannot meet the anatomical characteristics of patients with AR. Conversely, based on anatomical characteristics, the novel THV could theoretically facilitate TAVR.

Keywords: Anatomical classifications; Aortic regurgitation; Computed tomography; Multiplanar measurement; Transcatheter aortic valve replacement; Transcatheter heart valve.