Cardiac Computed Tomography Angiography Anatomical Characterization of Patients Screened for a Dedicated Transfemoral Transcatheter Valve System for Primary Aortic Regurgitation

Background

Cardiac computed tomography angiography was used to identify anatomical characteristics of the aortic root in patients with severe aortic regurgitation (AR) as compared to those with aortic stenosis (AS) to judge feasibility of transcatheter aortic valve replacement (TAVR) with the JenaValve Trilogy system.

Methods

Cardiac computed tomography angiography was performed prior to planned TAVR for 107 patients with severe AR and 92 patients with severe AS. Measurements related to aortic root and coronary artery anatomy were obtained and compared between groups. Perimeter >90 mm and aortic annulus angle ​>70 degrees were defined as the theoretical exclusion criteria for TAVR. A combination of sinus of Valsalva diameter <30 mm and coronary height <12 mm was defined as high risk for coronary occlusion.

Results

The mean age of patients in the AR group was 74.9 ± 11.2 years, 46% were women, and the mean Society of Thoracic Surgeons risk score for mortality was 3.6 ± 2.1. Comparatively, the mean age of patients in the AS group was 82.3 ± 5.53 years, 65% were women, and the mean Society of Thoracic Surgeonsrisk score was 5.5 ± 3.3. Annulus area, perimeter, diameter, and angle were larger in patients with severe AR. Sinus of Valsalva diameters and heights were larger in patients with severe AR. More AR patients were excluded based on perimeter (14 vs. 2%) and annulus angle (6 vs. 1%). More AS patients exhibited high-risk anatomy for left main coronary occlusion (21 vs. 7%) and right coronary occlusion (14 vs. 3%). The maximum dimension of the ascending aorta was larger in patients with severe AR (39 vs. 35 mm). The percentage of referred AR patients with significant aortopathy requiring surgical intervention was very low (only 1 AR patient with ascending aorta diameter >5.5 cm).

Conclusions

A significantly larger proportion of patients with severe AR are excluded from TAVR as compared to AS due to large aortic annulus size and steep annulus angulation. By far the most prevalent excluding factor is aortic annulus size, with fewer patients excluded due to angulation. AR patients have lower-risk anatomy for coronary occlusion. Larger transcatheter valve sizes and further delivery system modifications are required to treat a larger proportion of AR patients.