Contemporary Multi-modality Imaging of Prosthetic Aortic Valves

Abstract

With the aging of the general population and the rise in surgical and transcatheter aortic valve replacement, there will be an increase in the prevalence of prosthetic aortic valves. Patients with prosthetic aortic valves can develop a wide range of unique pathologies compared to the general population. Accurate diagnosis is necessary in this population to generate a comprehensive treatment plan. Transthoracic echocardiography is often insufficient alone to diagnose many prosthetic valve pathologies. The integration of many imaging modalities, including transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography, cardiac magnetic resonance imaging, and nuclear imaging, is necessary to care for patients with prosthetic valves. The purpose of this review is to describe the strengths, limitations, and contemporary use of the different imaging modalities necessary to diagnose prosthetic valve dysfunction.

Keywords: cardiac computed tomography; echocardiography; multimodality imaging; prosthetic valve dysfunction.

Fig. 1.

Algorithm for differentiating prosthetic valve aortic stenosis versus mimickers in the setting of elevated gradients.

Fig. 2.

Prosthetic aortic stenosis on transthoracic echocardiography. Patient with #23 Carpentier Edwards bioprosthetic aortic valve with severe stenosis (peak/mean gradient 50/31 mmHg). (A) Doppler profile shows late-peaking signal (acceleration time (AT) 115 ms) with abnormal acceleration time to ejection time (ET) ratio (0.38). The aortic valve time-velocity integral (AV VTI) was 82 cm and the left ventricular outflow tract time-velocity integral (LVOT VTI) 20 cm (B), resulting in a dimensionless index (DI) of 0.24. These findings are concerning for true aortic stenosis.

Fig. 3.

Common clinical indications for multimodality imaging for the assessment of prosthetic aortic stenosis. TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; CT, computed tomography; HALT, hypoattenuating leaflet thickening; IE, infective endocarditis.

Fig. 4.

Transesophageal echo with paravalvular leak. Patient with #27 Inspiris surgical bioprosthetic aortic valve who presents with moderate aortic regurgitation of unclear mechanism on transthoracic echocardiography. Transesophageal echocardiography, using multiplanar reconstruction, demonstrates a paravalvular leak at the 5 o’clock position.

Fig. 5.

Common clinical indications for multimodality imaging for the assessment of prosthetic aortic regurgitation. TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; CT, computed tomography; CMR, magnetic resonance imaging; IE, infective endocarditis.

Fig. 6.

Endocarditis with paravalvular abscess and pseudoaneurysm. Patient with severe aortic regurgitation due to endocarditis (A). There is evidence of thickening around the aortic root on transesophageal echocardiography (TEE) concerning for root abscess (B). Cardiac computed tomography (CT) confirms aortic root abscess and partially thrombosed pseudoaneurysm (C,D). CT better demonstrates the extent of annular complication than TEE. PAT, patient temperature.

Fig. 7.

Hypoattenuating leaflet thickening with restricted leaflet motion. Patient with a 29 mm Edwards Sapien S3 transcatheter aortic valve developed increased gradients from baseline (A). Cardiac 4D computed tomography shows severe hypoattenuating leaflet thickening and restriction of the right coronary cusp equivalent leaflet and mild hypoattenuating leaflet thickening of the left coronary cusp equivalent leaflet (B–D). 4D, 4-dimensional.

Fig. 8.

Planning valve-in-valve transcatheter aortic valve replacement. Patient presented with severe aortic stenosis in a #25 Carpentier Edwards bioprosthetic aortic valve and underwent valve-in-valve transcatheter aortic valve replacement. (A,B) demonstrate embedded virtual prosthesis. The virtual prosthesis is used to measure virtual transcatheter heart valve to coronary distance (VTC) (C) and virtual transcatheter heart valve to sinotubular junction distance (VTSTJ) (D). A VTC $>$4 mm and a VTSTJ $>$2 mm is considered low risk of coronary obstruction.

Fig. 9.

Assessment of prosthetic valve endocarditis with fluorodeoxyglucose positron emission tomography/computed tomography. Fluorodeoxyglucose positron emission tomography/computed tomography can aid in the diagnosis of prosthetic aortic valve and aortic graft endocarditis. (A) Patient with streptococcal bacteremia with intense tracer uptake in their bioprosthetic aortic valve. (B–D) Patient with prior Type A dissection, aortic valve repair, ascending aorta and total arch repair with persistent enterococcus faecalis bacteremia. There is intense tracer uptake in the graft.

Fig. 10.

Common clinical indications for multimodality imaging for the assessment of prosthetic valve endocarditis. TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; CT, computed tomography; FDG PET/CT, F-18 fluorodeoxyglucose positron emission tomography/computed tomography.