Multi-slice CT (MSCT) imaging in pretrans-catheter aortic valve implantation (TAVI) screening. How to perform and how to interpret

Abstract

Aortic valve stenosis (AS) is the most common valvular heart disease among elderly. Trans-catheter aortic valve implantation (TAVI) has become an established and effective alternative therapeutical procedure for inoperable and high-risk patients with symptomatic AS. The procedural success is greatly dependent on a thorough pre-TAVI imaging screening. This requires a comprehensive and multi-modality approach, in which multi-slice computed tomography (MSCT) is the cornerstone in the selection of eligible patients, in choosing the appropriate prosthesis and size, and in mapping the safest access route for the intervention. From our experience of more than 400 TAVI procedures and many more MSCTs for screening purposes, we provide clinical and technical details on the use of MSCT pre-TAVI and brief review of the knowledge so far.

Cardiac Computed Tomography – More Than Coronary Arteries? A Clinical Update

“…With the introduction of catheter-based minimally invasive methods to treat valvular disorders, this procedure has gained increasing interest throughout Europe in the past years. Transcatheter aortic valve implantation (TAVI), as well as transcatheter mitral valve implantation (TMVI), have become established alternatives to open heart surgery specifically for high-risk patients with symptomatic valve disease [6,7]. For instance, in Germany the number of TAVI procedures has increased 20-fold from 2008 (with 637 procedures) to 2013 (with 13 264 procedures), thus outnumbering surgical aortic valve replacements and becoming the most commonly performed procedure in the treatment of aortic valve stenosis in patients of age [68].…”

“…4). Especially measuring the effective diameter of the aortic annulus (formed by the lowest points of each of the three aortic cusps and their connection to the wall of the left ventricular outflow tract) in an appropriate cardiac phase (late systole) is of importance, as the prosthesis is fitted to this ring-like structure [6,69]. One advantage over the traditional measurements performed with 3D echocardiography (which only delivers a single diameter) is the possibility to assess the minimal as well as the maximal diameter and the area of the aortic annulus, which oftentimes resembles an oval shape.…”

“…As this shape is likelier understood with multiple measurements, CT assessment may be beneficial in prosthesis sizing [13]. Furthermore, the distance from the aortic annulus to the ostia of the coronary arteries as well as the diameter of the ascending aorta are required for planning the intervention to avoid injury or occlusion [6]. Additionally, pre-procedural CT has been proven beneficial in determining optimal fluoroscopic angulations for an orthogonal view of the aortic valve leading to a significant reduction of contrast use during intervention [70].…”

“…5). Furthermore, the aortic valve and vessel wall calcifications can be quantified, which may present contraindications for the implementation of certain devices [6,7,73,74].…”

“…Innovations and advanced post-processing tools have generated increasing potential for applications beyond the anatomical imaging of coronary arteries including functional and structural assessment [5]. Furthermore, there has been an increasing demand to use cardiac CT for pre-interventional planning in minimally invasive procedures such as transcatheter valve implantation, mitral valve repair, and pulmonary vein ablation [6][7][8]. As all of these applications are expected to gain increasing importance in the clinical routine, this review intends to give an overview of the current use of cardiac CT as well as emerging techniques with a specific focus on applications beyond coronary arteries and their potential for future clinical application.…”