Hypoxia-inducible factor prolyl hydroxylase inhibitor-induced thrombosis leading to transcatheter aortic valve dysfunction: a case report.

Background: Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for patients with severe aortic valve stenosis; however, clinical valve thrombosis is a major challenge.

Case summary: A 92-year-old woman underwent TAVR for severe aortic stenosis. One month later, the patient developed acute heart failure. As the progression of anaemia due to renal anaemia seemed to cause acute heart failure exacerbation, we started an oral hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor. After 2 weeks, the patient redeveloped shortness of breath. Transthoracic echocardiography revealed that the mean aortic valve pressure gradient (ΔP) increased from 9 to 54 mmHg, and the aortic valve area decreased from 1.93 to 0.86 cm². Blood work revealed a markedly elevated haemoglobin level from 8.0 to 13.2 g/dL, and transoesophageal echocardiography revealed markedly decreased left coronary and non-coronary cusp mobility. We diagnosed that the rapid increase in the haemoglobin level caused by the HIF-PH inhibitor was related to valve thrombosis and bioprosthetic dysfunction of the transcatheter aortic valve. The HIF-PH inhibitor was discontinued, and anticoagulation therapy was started. Transthoracic echocardiography at 16 days later revealed that the mean aortic valve ΔP improved by 15 mmHg, and the subjective symptoms resolved.

Discussion: This is the first report on a successful treatment of TAVR thrombosis formation associated with HIF-PH inhibitor use. When treating renal anaemia in patients undergoing TAVR, care should be taken to avoid rapid anaemia resolution and valve thrombosis development.