Abstract 4433: Transcatheter Aortic Valve Implantation: Role of Multi-slice Computed Tomography to Evaluate Prosthesis Positioning and Deployment in Relation to Valve Function
Background: Aortic regurgitation after transcatheter aortic valve implantation is one of the most frequent complications. However, the underlying mechanisms of this complication remain unclear.
Objectives: To study the anatomic and morphologic features of the aortic valve annulus that may predict aortic regurgitation after transcatheter aortic valve implantation.
Methods and results: In 49 patients with severe aortic stenosis undergoing transcatheter aortic valve implantation, multi-slice computed tomography assessment of the aortic valve apparatus was performed. For aortic valve annulus sizing, 2 orthogonal diameters were measured (coronal and sagittal). In addition, the extent of valve calcifications was quantified. At 1-month follow-up after procedure, multi-slice computed tomography was repeated to evaluate and correlate the prosthesis deployment to the presence of aortic regurgitation. Successful procedure was achieved in 44 (90%) patients. At baseline, multi-slice computed tomography demonstrated an ellipsoid shape of the aortic valve annulus with significantly larger coronal diameter as compared to sagittal diameter (25.3±2.4 mm vs. 23.1±2.2 mm, p<0.001). At follow-up, multi-slice computed tomography showed a non-circular deployment of the prosthesis in 8 (19%) patients. Moderate postprocedural aortic regurgitation was observed in 5 (12%) patients. These patients showed significantly larger aortic valve annulus (28.2±1.8 mm vs. 24.8±2.3 mm, p=0.003) and more calcified native valves (4172±2071 HU vs. 2470±1264 HU, p=0.037) at baseline and less favourable deployment of the prosthesis after transcatheter aortic valve implantation.
Conclusions: Multi-slice computed tomography enables an accurate sizing of the aortic valve annulus and constitutes a valuable imaging tool to evaluate prosthesis location and deployment after transcatheter aortic valve implantation. In addition, multi-slice computed tomography helps to understand the underlying mechanisms of post-procedural aortic regurgitation.