A 3D Window on the Achilles' Heel of Transcatheter Aortic Valve Replacement.

SEE PAGE 114 A lthough transcatheter aortic valve replacement (TAVR) is now an established procedure that is starting to compete with conventional surgical aortic valve replacement in selected patient groups, the presence of post-implantation aortic regurgitation (AR) is higher than in comparative surgical groups and is associated with worse outcomes (1). There have been significant technical advances in valve design to try and mitigate against postimplantation AR, and there is a greater appreciation of the importance of accurate valve sizing and aortic root morphology (2). However, paravalvular and, to a lesser extent, transvalvular AR remain important Achilles’ heels of the TAVR procedure. Echocardiography plays a pivotal role postimplantation in documenting the presence and extent of AR and in helping to decide if further procedures, such as post-dilation, are required to reduce any significant leaks. Pre-procedure planning needs to take into account factors that may make AR more likely, especially as TAVR moves toward lower-risk patient groups where surgery is an alternative. A number of factors such as the relationship between annulus dimension and valve size, eccentricity of the annulus, extensive and irregular annular calcification, underor overexpansion of the valve, and incorrect valve positioning have all been shown to predict the presence of postprocedural AR (3). Most of these factors can be evaluated bymulti-slice computed tomography (MSCT) and 3-dimensional (3D) transesophageal echocardiography TEE, provided that an experienced operator analyzes the images. The paper by Shibayama et al. (4) in this issue of iJACC examines