Cardiac CT for Guiding Mitral Valve Interventions

Preprocedural planning of transcatheter mitral valve interventions by multidetector CT: What the radiologist needs to know

“…As its name suggests, it consists of a clip that allows capturing both the anterior and posterior mitral leaflets with its two arms, resulting in shrinking of the regurgitant mitral valve orifice. TMVRep with Mitraclip ® is performed using a trans-septal approach with 3D-transesophageal echocardiography as the gold standard for preprocedural planning and intraoperative guidance, although MDCT can provide incremental anatomical data such as for the severity assessment of mitral valve calcifications (which may interfere with or contraindicate device implantation) [ 6 , 11 , 12 ]. Among current percutaneous treatment options, Mitraclip ® -based edge-to-edge TMVRep is the most commonly performed transcatheter mitral valve procedure, has gained both CE and FDA approval, and although the rate of residual MR up to 5 years is higher than with surgical repair, it is generally safe and can improve symptoms while inducing reverse left ventricular remodelling [ 13 ].…”

“…In fact, the majority of percutaneous mitral valve prostheses are positioned via a transapical approach (i.e. through puncture of the left ventricular apex), whereas others are deployed through a trans-septal (venous) approach, which would be ideal in highest risk patients [ 11 , 12 , 14 , 15 ]. Encouraging data have recently been provided by a feasibility study ( NCT02321514 ) about the effectiveness and safety of transapical TMVR using a self-expanding device in patients with native MR at high risk for cardiac surgery, resulting in NYHA functional class improvement with mild or no symptoms in 75% of patients and successful device implantation without cardiovascular mortality, stroke, and device malfunction in 86.6% of patients at 30-day follow-up [ 16 ].…”

“…While cardiac ultrasound is the gold standard for diagnosing, grading and monitoring mitral valve disease before and after treatment and (in combination with fluoroscopy and angiography) for intraoperative guidance, MDCT has gained widespread acceptance for interventional planning in patients candidate to transcatheter mitral valve procedures. Cardiac MDCT has several strengths, including: fast imaging time (<10 s) and widespread availability excellent spatial resolution (≃0.5 mm) with voxel isotropy, allowing for high quality 2D and 3D reconstructions of the mitral valve and subvalvular apparatus at any time point of the cardiac cycle high reproducibility and relative operator-independence direct visualisation and quantification of mitral calcifications panoramic view of the whole heart (including the coronary arteries, the aortic root and the left ventricular outflow tract) and the chest wall [ 5 , 6 , 11 , 12 , [17] , [18] , [19] , [20] ]. …”

“…panoramic view of the whole heart (including the coronary arteries, the aortic root and the left ventricular outflow tract) and the chest wall [ 5 , 6 , 11 , 12 , [17] , [18] , [19] , [20] ].…”

“…A direct approach to mitral valve segmentation consists of drawing the contours of the saddle-shaped mitral annulus on conventional four-, three-, two-chamber and short axis views by placing 16 seeding points along the posterior mitral leaflet insertion and the fibrous continuity. However, segmentation using this approach can be time consuming and challenging due to the non-planar shape of the mitral annulus, and the inclusion of the anterior horn of the mitral annulus for device sizing carries the risk of left ventricular outflow tract (LVOT) obstruction [ 11 , 12 ]. A simpler method devised by Blanke et al (simplified D-shape model) consists of assimilating the mitral annulus to a planar D-shape by connecting the two fibrous trigones along a virtual straight line, thereby excluding the anterior horn [ 11 , 12 , 24 , 25 ] ( Fig.…”