Represents the results of a clinical trial implantation xenopericardial prosthesis mounted on a frame of variable stiffness "Tiara" in the aortic position. Prosthesis implanted in a single-row suture cubcoronary supraannulary position. Implantation performed two patients 71 and 75 years with a good clinical outcome. According to the control echocardiography peak gradients at rest were 9-15 mm Hg. According to the results of a clinical trial prosthesis can be recommended for implementation in everyday clinical practice.