Amyloid deposition in an explanted bioprosthetic aortic valve: case report and review of the literature

• Published in: Cardiovascular pathology Vol. 61; p. 107469
• Main Authors: Weerasekare, Jonika M., Zhou, Fang, Skolnick, Adam H., Jilaihawi, Hasan, Williams, Mathew R., Dasari, Surendra, McPhail, Ellen D., Theis, Jason D., Dao, Linda N., Bois, John P., Maleszewski, Joseph J., Bois, Melanie C.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.11.2022
• Subjects: Amyloid; Aortic valve; Bioprosthetic Valve; Liquid Chromatography-tandem mass spectrometry-based proteomics; Bioprosthetic Valve; Amyloid; Liquid Chromatography-tandem mass spectrometry-based proteomics; Aortic valve
• ISSN: 1054-8807; 1879-1336
• DOI: 10.1016/j.carpath.2022.107469

•Degenerated bioprosthetic aortic valves may show amyloid deposition, which appears to be human (rather than bovine or porcine) in origin.•Proteomic characterization provides additional insights into the origin and possible significance of amyloid deposits in bioprosthetic aortic valves.•Bioprosthetic valve amyloid appears to be a localized (non-systemic) phenomenon thus far; however, its contribution to valve degradation and disfunction remains unknown. Herein we present a case of an 80-year-old gentleman who presented with exertional dyspnea status post aortic valve replacement with #23 Trifecta pericardial St. Jude aortic bioprosthetic valve (BV) 12 years prior. He subsequently underwent valve re-replacement due cusp calcification. Histologically, the surgically explanted BV revealed Congophilic deposits with birefringence under cross-polarized light. Extensive work-up identified no systemic source of amyloid in this patient. Liquid chromatography-tandem mass spectrometry-based (LC-MS/MS) proteomics showed the amyloid was composed of human-origin amyloid signature proteins (apolipoprotein A4, apolipoprotein E, serum amyloid P) and human-origin mu heavy chains. Background bovine collagen was also present. Transmission electron microscopy (TEM) showed collections of 7.5-10 nm nonbranching fibrils, consistent with amyloid. Using these techniques, we classified the amyloid as Mu heavy chain, deposition of which is highly unusual in BV. Finally, we provide a review of the literature regarding isolated amyloid deposition in BV.