The most common heart valve disease in humans is aortic stenosis which is a critical narrowing of the valve through which the heart has to pump blood to the rest of the body. This condition occurs in 2-3% of adults over 65 years of age and when it progresses to a severe stage leads to heart failure and need for valve replacement procedures (including surgery and catheter-based replacement). Aortic stenosis has a strong male predominance. The purpose of this study is to evaluate whether loss of Y-chromosome from circulating blood cells in males, which has been associated with TGF-beta-related fibrosis of other organs, is associated with the development of aortic stenosis.