Evaluation of the Navitor Transcatheter Heart Valve in Low and Intermediate Risk Patients who have Severe, Symptomatic, Aortic Stenosis Requiring Aortic Valve Replacement

Aortic stenosis is a type of heart valve disease where the valve located between the lower left heart chamber and the body’s main artery (aorta) becomes narrowed and cannot open completely. This narrowing of the valve reduces or blocks the blood flow from the heart to the rest of the body. The treatment for severe aortic stenosis is aortic valve replacement. While aortic valve replacement has traditionally been done through open heart surgery, a less invasive technique called transcatheter aortic valve implantation (TAVI) has become an alternative option for patients. The Navitor TAVI System has been FDA approved for patients with symptomatic, severe aortic stenosis who are at high or extreme risk for open heart surgery. The purpose of this research study is to study the safety and efficacy of the device in people with similar valve disease at lower risk from open heart surgery, and possibly expand the indication of the Navitor TAVI System to patients at intermediate and low risk for open heart surgery. The safety and effectiveness of the Navitor TAVI System will be compared to that of any commercially available transcatheter aortic valve system approved by FDA for treating patients considered intermediate or low risk.