Cardiac Computed Tomography: Application in Valvular Heart Disease

Abstract

The incidence and prevalence of valvular heart disease (VHD) is increasing and has been described as the next cardiac epidemic. Advances in imaging and therapeutics have revolutionized how we assess and treat patients with VHD. Although echocardiography continues to be the first-line imaging modality to assess the severity and the effects of VHD, advances in cardiac computed tomography (CT) now provide novel insights into VHD. Transcatheter valvular interventions rely heavily on CT guidance for procedural planning, predicting and detecting complications, and monitoring prosthesis. This review focuses on the current role and future prospects of CT in the assessment of aortic and mitral valves for transcatheter interventions, prosthetic valve complications such as thrombosis and endocarditis, and assessment of the myocardium.

Keywords: TAVR; TMVR; aortic stenosis; cardiac computed tomography; valvular heart disease.

FIGURE 1

Peripheral access planning for TAVR, requires assessment of the size, tortuosity, calcification (both severity and distribution) and any prosthetic material such as stents or pathologies such as aneurysms. (A) Multiplanar reconstruction of the vascular tree, (B) Sagittal view, (C) Axial view.

FIGURE 2

Measurements of the aortic root and ascending aorta. (A) aortic valve (AV) annulus, (B) sinus of Valsalva, (C) sino-tubular junction, (D) ascending aorta, (E) left coronary ostial height from AV annulus, (F) right coronary ostial height.

FIGURE 3

Steps in planning for mitral intervention in a patient with a heavily calcified mitral annulus. (A) 2D ECG-gated CT scan. Pre-existing TAVR valve in aortic position, with dense calcification of the mitral annulus. (B) Coronal view. 3D volume-rendered image of pre-existing TAVR valve in situ in aortic position. Cylindrical valve simulated in mitral position, thereby allowing for anatomical and geometrical calculations to be made prior to implantation. (C) 2D CT- En-face view of calcification surrounding mitral annulus. Also visible is the TAVR valve in the aortic position. (D) 3D volume-rendered en-face image of mitral annulus down through the left atrium. MAC highlighted in yellow. Panels (B,D) created courtesy of post-acquisition processing with Mimics Enlight TMVR planner, Beta version, Materialise NV Inc.

FIGURE 4

Hypo-attenuated leaflet thickening seen in three views of the same patient (A) at the level of the sinus of Valsalva, (B) left ventricular outflow tract view, (C) three chamber view.

FIGURE 5

Aortic root abscess seen in a patient with a previous metallic surgical aortic valve implanted in 2010. An axial slice from 2013 without an abscess (A), and a similar slice from 2017 showing a root abscess indicated by a white arrow (B). A coronal view (C) and 3D reconstructions (D,E) illustrate the abscess indicated by the white arrow.

FIGURE 6

Extracellular volume quantification in two patients: (A) severe AS and (B) severe AS and cardiac transthyretin amyloidosis. Each panel illustrates a short-axis, 4 and 2 chamber views and a bull’s eye plot. High extracellular volume seen in panel (B) is identified by the yellow/orange coloration compared to lower extracellular volume in panel (A) identified by the green/blue areas.