One reason for the limited efficacy observed thus far with therapeutic angiogenesis may rest in that factors produced by the lining of the coronary arteries themselves are essential for angiogenic substances to take effect in the heart muscle of patients with severe coronary artery disease. These same patients, however, virtually all have, as a result of their disease, marked dysfunction of their coronaries and therefore fail to produce these factors in adequate quantities. This hypothesis has been verified with extensive animal data by the investigators of this research, where a swine model of coronary disease was shown to severely inhibit the action of angiogenic growth factors. If one wants angiogenesis to work, a means of improving the function of the coronary lining of patients with severe ischemic heart disease must be identified and its effects evaluated in order to allow for angiogenic substances to exert their action towards successful revascularization of the heart muscle.