That is a lot of progression in a short period of time, so I would get a second opinion from someone who sees a high number of patients with aortic valve disease. It's not the absolute size of the root that is concerning, as some people can have a 4.7cm root and go for many years before anything has to be done about it. It's the rate at which it is enlarging, especially in view of your family history, that is the issue. Measurement error is possible, so maybe it's really not enlarging that fast, but if those measurements are accurate, then it's concerning. It will be important to find a cardiologist who has special expertise in aortic valve disease and aortic root aneurysms. When you see the new doctor, I would try to take him the actual pictures of all three scans and not just the written reports. That way the doctor can look at all three sets of pictures with his or her own eyes and compare "apples to apples." Good luck.