https://orcid.org/0000-0002-2617-0513
A 26-year-old obese female was referred for severe dyspnoea. She had received St. Jude 21-mm aortic valve (AV) and St. Jude 27-mm mitral valve (MV) mechanical replacements for rheumatic heart disease 15 years prior. Transthoracic echocardiogram (TTE) demonstrated severe AV prosthetic obstruction [Panel A, mean gradient (MG): 45 mmHg; acceleration time (AccT): 111 ms; dimensionless index: 0.23]. The occluders were impossible to visualize (Supplementary data online, Video S1—parasternal long-axis). However, parasternal long-axis colour Doppler showed turbulent flow beginning underneath (Panel B, arrow) the valve plane (Panel B, dashed line, Supplementary data online, Video S2) suggesting sub-valvular pathology. Outside fluoroscopy was inconclusive. Contrast-enhanced electrocardiogram-gated multi-detector computed tomography (MDCT) with dynamic three-dimensional cine-imaging revealed slightly abnormal MV opening-angle (17°) (Panel C, blue bracket, Supplementary data online, Video S3), and asymmetrically restricted systolic AV occluder opening-angle (39°) (Panel D, blue bracket, Supplementary data online, Video S3). Additionally, hypo-attenuating material was identified on the ventricular side of the prosthetic AV, suggestive of pannus versus thrombus formation, as visualized in cross-sectional (Panel E, arrows) and coronal (Panel F, arrows) reconstruction.
Intra-operatively, a 5-mm thick circumferential membrane was visualized underneath AV, confirming sub-valvular pannus [Panel G, valve in situ (asterisks), Panel H, explanted valve (asterisks)]. Panel I shows the ventricular side of the explanted AV surrounded by pannus and Panel J shows the excised pannus. Pathology showed obstructive fibrous ingrowth consistent with pure pannus. The patient underwent posterior-root patch-enlargement and 23-mm bileaflet mechanical valve replacement. Post-operative TTE showed AV MG of 10 mmHg with no regurgitation. Pannus is seen in <2% of patients and diagnosis by echocardiography is challenging, particularly if overweight as our patient. This case is a striking example of the importance of a multi-modality imaging in assessment of prosthetic valve dysfunction, where TTE confirmed obstruction and MDCT demonstrated dysfunctional prosthetic valve anatomy requiring surgical intervention. Ant, anterior; Ao, aorta; LV, left ventricle; Post, posterior; RV, right ventricle.
Supplementary data are available at European Heart Journal - Cardiovascular Imaging online.
