Marfan syndrome (MFS) is an inherited disorder of connective tissue with morbidity and mortality from aortic dilatation and dissection. The current standard of care is beta-blocker (BB) treatment and therapeutic target is heart rate. The degree of aortic dilatation and response to BB vary in adults with MFS. However, aortic stiffness is often present, and can be a predictor of aortic dilatation and cardiovascular complications. Aortic stiffness is a logical therapeutic target in adults with MFS.