Deformation of Surgically Implanted Aortic Valves: CT Findings Prior to Valve-in-Valve Implantation and Association With Mechanism of Failure

Background: Degeneration of surgically implanted bioprosthetic valves (BPVs) has been linked to risk factors including BPV construct and patient comorbidities. However, the role of the intrinsic structural configuration and potential structural changes of the surgical BPV itself on valve failure is unclear. Methods: Patients who underwent cardiac computed tomography prior to aortic valve-in-valve due to surgical BPV failure were enrolled. Assessment included BPV ring dimensions, strut angles, strut-to-strut distance, and projected geometric orifice area (PGOA), defined as the area of the circle connecting the distal aspects of the struts. These measurements were compared with those of nonimplanted surgical BPVs matched for valve type and size. Echocardiograms were obtained before the valve-in-valve procedure, and valve structure and function were assessed. Mechanism of BPV failure was classified as aortic stenosis, aortic regurgitation, or mixed. Results: A total of 222 patients were included. Aortic stenosis occurred in 111 (50%), aortic regurgitation in 55 (24.8%), and mixed in 56 (25.2%). Moderate/severe ring deformation (eccentricity index >10%) was present in 17% of cases. Strut angles, strut-to-strut distance, and PGOA were all significantly smaller in implanted than in reference valves (all P < .0001). The greatest average strut angle decrease was seen in Mitroflow valves (10°, P < .0001). The Mitroflow valve had the highest reduction in PGOA (27.7%), followed by Hancock (15.1%) and Perimount (11.6%; P < .0001). Smaller ring dimensions, smaller PGOA, and smaller strut-to-strut distance were associated with failure by stenosis (all P < 0.05) in univariable but not multivariable analysis. Conclusions: Potential intrinsic changes (frame deformation) affect stented surgical BPVs implanted in aortic position. Whether these changes are associated with early valve degeneration and failure remains unknown.