Late-Onset Prosthetic Valve Dysfunction Associated With Hypoattenuated Leaflet Thickening Detected After a New Heart Murmur: A Case Report

Hypoattenuated leaflet thickening (HALT) is increasingly recognized after bioprosthetic aortic valve replacement; however, its clinical significance and optimal detection strategy in routine practice remain uncertain.We report the case of a 79-year-old woman who underwent minimally invasive aortic valve replacement using a Perceval S sutureless bioprosthesis for severe aortic stenosis.Early postoperative transthoracic echocardiography and cardiac computed tomography demonstrated normal prosthetic valve function without evidence of HALT.Oral anticoagulation was discontinued three months after surgery, and the patient remained asymptomatic.At the one-year follow-up visit, a newly detected systolic heart murmur prompted further evaluation despite stable N-terminal pro-B-type natriuretic peptide levels.Echocardiography revealed increased transvalvular gradients and mild-to-moderate transvalvular regurgitation, while cardiac computed tomography demonstrated HALT involving the right and noncoronary cusps.The combination of hemodynamically significant prosthetic valve dysfunction and CT-confirmed HALT was considered consistent with clinically overt bioprosthetic valve thrombosis.Oral anticoagulation was restarted, followed by complete resolution of HALT and improvement in prosthetic valve hemodynamics.This case demonstrates that clinically overt bioprosthetic valve thrombosis associated with HALT may develop in an asymptomatic patient and that a newly detected cardiac murmur may serve as a clinical trigger for further echocardiographic and CT evaluation.Careful routine clinical follow-up may facilitate recognition of hemodynamically relevant prosthetic valve dysfunction and appropriate therapeutic intervention.