The investigators expect to see that : 1) Patients with ASA will have a decreased ability for their arteries to dilate due to nitric oxide deficiency, 2) Treatment of ASA with the nitric oxide supplement will improve the ability of their arteries to dilate, and 3) Through the testing of subjects' fibroblasts (cells in connective tissue that produce collagen and other fibers), the investigators hope to predict which patients may respond NO supplementation.