Subacute Transcatheter CoreValve Thrombotic Obstruction

An 86-year-old man with severe symptomatic aortic stenosis (additive Euroscore 7) underwent a transcatheter aortic valve implantation with a CoreValve bioprosthesis (26 mm, CoreValve Revalving Technology, Medtronic, Inc., Minneapolis, MN). The patient was discharged on aspirin and clopidogrel and advised to stop the clopidogrel after 3 months. This first 6-month follow-up was uneventful. Repeated echocardiograms obtained during this period revealed a slight increase in mean transprosthetic aortic pressure gradient without significant concomitant aortic regurgitation. At the last visit, 1 year later, the patient became symptomatic (New York Heart Association class II–III). He had no fever. Between the 6th and 12th month of follow-up, there was a documented increase in transprosthetic aortic peak velocity (4.11 m/s) and mean gradient (41 mm Hg) and a significant reduction in aortic effective orifice area (0.69 cm2), which indicated severe prosthetic valve stenosis. To evaluate the shape of the CoreValve, both transesophageal echocardiogram and cardiac computed tomography were performed. Although computed tomography revealed no change in prosthesis position (when compared with pre–transcatheter aortic valve implantation computed tomography) and the absence of significant deformation of the stent by any calcifications (Figure 1A–1D), transesophageal echocardiogram evidenced thickened …