With a proper treatment, the Cleveland Clinic Foundation, 93% of the patients achieved a remission of the disease.
The 5-year survival is 90-95% and the 15 years of the 85%, but in more severe cases low to 65%. The concurrence of major complications (retinopathy, hypertension, aortic insufficiency, aneurysms, cerebral ischemia, ischemic heart disease, etc...) and a progressive course, predict a generally poor prognosis. In any case, the survival is variable of some geographic areas to others, probably due to genetic variations and to differences in the health care dispensed. The main causes of death are heart failure, acute myocardial infarction, pulmonary hypertension, stroke, intestinal ischemia, rupture of aneurysms, kidney failure, and postoperative complications.