Thrombosed epic mitral bioprosthesis in the late postoperative period: A case report

Bioprosthetic valve thrombosis (BVT) is a rare complication following surgical valve replacement, with a particularly low incidence of 0.3% reported for the Epic bioprosthesis (St. Jude Medical, Inc., St. Paul, MN, USA) in the mitral position. We report a case of late-onset BVT of the Epic mitral bioprosthesis, resulting in significant prosthetic valve dysfunction. A 74-year-old man was admitted with acute heart failure 5.5 years after undergoing mitral valve replacement with a 29-mm Epic bioprosthetic valve. Although he had been taking edoxaban for paroxysmal atrial fibrillation, it was discontinued one year prior to admission. Moreover, daprodustat was initiated for renal anemia six months before admission. Transthoracic echocardiography on admission revealed severe mitral stenosis, with a mitral valve area of 0.8 cm² and a mean transvalvular pressure gradient of 25.5 mmHg, indicating prosthetic valve dysfunction. Redo mitral valve replacement was performed, during which the Epic valve was explanted and replaced with a 25-mm St. Jude Medical prosthesis. The explanted valve was markedly thrombosed, with severely restricted leaflet mobility. Postoperatively, anticoagulation therapy with warfarin was initiated. Over the two-year follow-up period, no evidence of valve thrombosis or hemorrhagic events has been observed, and the clinical course has remained favorable.

We report a case of late-onset bioprosthetic valve thrombosis (BVT) of the Epic mitral bioprosthesis. In this case, discontinuation of edoxaban combined with initiation of daprodustat likely contributed to BVT. These findings underscore the importance of maintaining long-term anticoagulation in patients with risk factors for BVT and of carefully monitoring for thrombotic events in patients receiving hypoxia-inducible factor prolyl hydroxylase inhibitors.