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

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. Ex-tensive 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.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This article presents a case study of an 80-year-old man who underwent aortic valve replacement 12 years ago and subsequently required re-replacement due to calcification. The surgically explanted valve tissue showed amyloid deposits with specific protein composition. The amyloid was classified as Mu heavy chain, which is uncommon in bioprosthetic valves. The article also provides a literature review on isolated amyloid deposition in aortic valves.