Aortic valve calcification is a condition in which calcium deposits form on the aortic valve in the heart. These deposits can cause narrowing at the opening of the aortic valve. This narrowing can become severe enough to reduce blood flow through the aortic valve, a condition called aortic valve stenosis. Aortic valve calcification may be an early sign that you have heart disease, even if you don't have any other heart disease symptoms. Calcification and stenosis generally affect people older than age 65. When it occurs in younger people, it's often caused by: 1  A heart defect that's present at birth.