**2. Background**

Aortic stenosis is the most prevalent form of native valvular disease. Significant stenosis, as determined by the gradients across the valve and estimated orifice areas, are encountered in up to 2% of the population over 65 years old, 3% in those over 75 years old and 4% over 85 years old. Furthermore, over 100,000 people in the United States alone are diagnosed with severe aortic stenosis each year. Historically, the management of severe and critical aortic stenosis, especially in the context of symptoms such as chest pain, syncope, and shortness of breath, has focused on surgical intervention. However, the risks increase substantially with patients age and comorbidities [1].

Typically, severe or critical stenosis is manifested with the onset of symptoms such as shortness of breath. However, when patients start developing heart failure, chest pain, or syncope, their prognosis becomes worse than many cancers, including breast and colon. In fact, without intervention, the estimated survival in this population is less than 50% at two years [2].
