Usually the main predictors of aortic dissection are family history, aortic size, and aortic
flexibility. For someone of your aortic size, I would take it easy. Try the ARB approach with a max or ultra-max high dosage (as long as your doctor lets you) and see if that reduces aortic size and aortic flexibility (the "pulse pressure" is one way to estimate the flexibility - Google it). If so, then perhaps you can talk to your doctor about athletics.