Mitral valve prolapse doesn't cause the aorta to thicken. The aorta is the large blood vessel that branches off the heart to deliver oxygen-rich blood to the body. In some cases, however, people who have mitral valve prolapse may have problems with their aorta. This is especially likely if a person has Marfan syndrome or another connective tissue disorder.
Mitral valve prolapse is a heart disorder that occurs when the valve between the heart's left upper chamber (left atrium) and the left lower chamber (left ventricle) doesn't close properly. Mitral valve prolapse is often harmless. Most people who have mitral valve prolapse don't require treatment. If leakage is severe, however, the mitral valve may need to be repaired or replaced.