Introduction:
Transcatheter aortic valve replacement has revolutionized the treatment of severe aortic stenosis, but post implantation perivalvular aortic regurgitation may result in increased mortality.
Hypothesis:
The purpose of this study was to identify structural abnormalities in the frame of self-expanding aortic valve prostheses (CoreValve®, Medtronic, Minneapolis, MN) immediately following implantation and evaluate their relationship to subsequent perivalvular aortic regurgitation severity.
Methods/Results:
After implantation of CoreValve, 14 patients with evidence of frame deformation by fluoroscopy underwent intraprocedural C-arm CT imaging (syngo DynaCT®, Siemens Medical Solutions, USA) acquired using 5-s, 200° rotation under breath-hold and rapid right ventricular pacing (120-140bpm). CT-like multi-planar reconstructions (Figure) were performed; perimeter (P), maximum (Dmax) and minimum (Dmin) diameters of the CoreValve frame were measured at multiple levels (0mm, 8mm, 16mm) orthogonal to the longitudinal axis. Ellipticity index (EI) was measured as Dmax divided by Dmin. Color Doppler transthoracic echo was performed the day following valve implantation to assess perivalvular regurgitation. One-way ANOVA demonstrated that degree of perivalvular aortic regurgitation was significantly related to valve frame perimeter underexpansion at the inferior margin of the frame (20.8% [17.2-25.7%], p=0.011) and increased ellipticity index both at the 8mm above the edge of the frame (1.4, [1.3-1.5], p=0.012) and 16mm above the edge of the frame (1.4, [1.3-1.5], p=0.038).
Conclusions:
Intraprocedural DynaCT effective at determining aortic valve frame deformations in 3D, which was associated with increased perivalvular aortic regurgitation, and may provide a method for risk stratifying post-implantation aortic regurgitation and need for additional procedural maneuvers such as post-stent dilation or additional revalving.