Can eating a high fiber diet reduce symptoms of vascular conditions?

Not really: A diet high in fiber gives you great roughage and results in good bowel function. Good bowel function means you are able to absorb food more efficiently and effectively, which may mean you could get higher levels of triglycerides or cholesterol -- which can affect heart and vascular function. However, that is mot really likely as a real life scenario.

Not related: However a healthy diet is recommended for patients with vascular disease. Ideal body weight, lower blood sugar, increased lean muscle are helpful in risk reduction for cardiovascular events. High fiber is the beginning of better diet.