A 78-year-old woman with symptomatic severe aortic stenosis was referred for transcatheter aortic valve implantation. A 26-mm CoreValve revalving system (Medtronic, Minneapolis, Minnesota) was implanted, but the valve migrated to the ascending aorta (Online Video 1). Afterward, a second 26-mm CoreValve was implanted, but the valve was placed low into the left ventricle outflow tract (A, arrow; Online Videos 2 and 3).

The patient rapidly developed heart failure. An intraprocedural transesophageal echocardiogram revealed a seriously restricted diastolic opening of the anterior mitral leaflet caused by the low-placed CoreValve, leading to severe mitral stenosis with a mean gradient of 13 mm Hg (B to D, prosthesis marked with an asterisk;Online Videos 4, 5, 6, and 7).

The patient underwent urgent aortic valve replacement surgery in which both CoreValves were extracted and a 23-mm Mitroflow bioprosthesis (Sorin Group, Milan, Italy) was implanted, with satisfactory post-operative outcome. AML = anterior mitral leaflet; AO = aorta; GP = pressure gradient; IVT = time-velocity integral; LA = left auricle; LV = left ventricle.