In addition, we are performing a cardiac stress MRI for research purposes to look at the blood flow in the small vessels in your heart. During the stress cardiac MRI, we will give you a medication called Regadenoson (Lexiscan) which "stresses" your heart by dilating the blood vessels to your heart. This drug is approved by the U.S. Food and Drug Administration (FDA) for this purpose. We will then be able to measure the myocardial perfusion reserve (MPR) which is a measure of blood flow through the small blood vessels to see if an abnormal MPR and small blood vessel disease is associated with an increased risk of cardiovascular events, such as heart attack. At this point, there is no specific therapy for small vessel disease. In addition we have phase II of this study which is to determine if exercise and intensive medical therapy together compared to intensive medical therapy alone improves pain from the heart and improves overall quality of life.