365 Combining mechanisms of prosthetic valve dysfunction

Abstract

Abstract A 32-year-old female was referred to our outpatient clinic for exertional dyspnoea that had worsened in the preceding months. She had a history of mitral and aortic valve replacement with bileaflet mechanical prosthesis (St. Jude Master n. 25 and Medtronic Open Pivot n. 16, respectively) for rheumatic heart disease. A recent echocardiography showed borderline-high trans-aortic gradients (mean 26 mmHg, peak 42 mmHg). Transthoracic echocardiography revealed abnormal aortic transprosthetic flow (peak velocity 442 cm/s, mean gradient 48 mmHg). Continuous Wave Doppler signal was rounded with a long acceleration time (108 ms). Effective orifice area (EOA) was 0.8 cmq (index EOA 0.48 cmq/mq) and Doppler Velocity Index 0.28. Further investigations revealed no signs of infections but suboptimal anticoagulation (INR 2.5). Transesophageal 3D echocardiography was suggestive for hypomobility of the prosthetic leaflets and the presence of an isoechoic mass encircling the ventricular side of the aortic prosthesis compatible with pannus overgrowth. Cardiac CT confirmed the presence of a symmetrical reduction in the systolic opening of both leaflets. The patient underwent a redo of aortic valve replacement that confirmed the presence of an asymmetric subprosthetic pannus overgrowing on the previously implanted surgical pledgets. After pannus debritment a St. Jude Regent n. 21 was implanted. The patient experienced complete symptomatic resolution. We presented the case of a prosthetic aortic valve dysfunction due to a combination of patient-prosthesis mismatch and pannus overgrowth. In our patient, as assessed in the old echocardiographic examinations, the presence of mildly elevated transprosthetic gradients was suggestive for prosthesis undersizing related to body surface area. In this scenario, subvalvular pannus formation caused significant changes in prosthetic valve transvalvular flow dynamic leading to prosthesis dysfunction. This case emphasises the crucial role of echocardiographic follow up in detection of causes of prosthetic heart valve dysfunction and how optimal valve sizing is paramount in aortic valve replacement.