CASE REPORT: SELF–EXPANDING TRANSCATHETER VALVE IMPLANTATION (ACURATE NEO 2) IN A VERY SMALL NATIVE AORTIC ANNULUS

Abstract

Abstract We present the case of a 74–year–old female, symptomatic for dyspnea on exertion, evaluated by our Cardiac Team for severe aortic valve (AV) stenosis. The transesophageal echocardiography showed a stenotic tricuspid AV (valve area of 0.51 cm2, peak and mean gradients of 75 mmHg and 43 mmHg respectively), normal left ventricle (LV) ejection fraction without significant intraventricular gradient. Pre–operative thoraco–abdominal computed tomography angiography showed an AV without significant calcifications, an aortic annulus perimeter of 51.7 mm (area of 207,8 mm2) and a left ventricular outflow tract (LVOT) perimeter of 45.3 mm with elliptical shape (area of 149,9 mm2). The TAVR procedure was performed with an ‘off–label’ implantation of a SE THV with supra–annular location of leaflets (Acurate Neo 2 23 mm), without any predilation. The post–procedural transthoracic echocardiographic study highlighted the correct positioning of the bioprosthesis without significant protrusion in the LVOT and without any interference with the mitral valve apparatus. The main clinical, technical and procedural considerations have been: According to recommendations, the minimum perimeter of 56.5 mm and the minimum area of 254 mm2 represent the lower limits of the sizing guidelines for THV currently available. We used a SE valve with supra–annular location of the leaflets that offers a potential advantage over BE valves and intra annular SE valves, ensuring a larger effective orifice area. We avoided pre– and post–dilatation to reduce the risk of annular damage and/or rupture The precision of THV implantation (with minimal protrusion in LVOT) was maximized when the rapid pacing during phase 2 of the valve deployment was utilized. A short period of DAPT can be considered in order to prevent a potential increase of thromboembolic events secondary to small aortic valve area. In our opinion the main goal is to prevent high implantation and commissural misalignment in order to facilitate the subsequent coronary percutaneous interventions if needed. Even prophylactic coronary stenting (‘chimney fashion‘) should be avoided unless absolutely necessary. These technical considerations applies also to allow a subsequent valve–in–valve (VIV) procedure, if indicated. To our knowledge, this is among the smallest native aortic annulus so far described and treated percutaneously in a tricuspid stenotic aortic valve with a self–expanding (SE) THV Acurate Neo 2.