Refractory Coronary Artery Disease is a significant cause of mortality and decreased quality of life. Intracoronary infusion of CD133+ progenitor cells is a viable treatment option for patients with this condition. After clinical and laboratory evaluation, 50-100 ml of bone marrow will be obtained by bone marrow aspiration from the posterior iliac crest under local anesthesia. From this sample, CD133+ endothelial progenitor cells will be isolated, purified and packed within the next 12 hours of extraction, and resuspended in 30 ml saline solution. The patient will undergo coronary catheterization for selection of the target obstructed artery for cell infusion, which will be performed using a balloon catheter under hemodynamic monitoring. Once concluded, the patient will be transferred to intermediate care unit for post-interventional observation for approximately 24 hours before being released. Ambulatory follow-up will be performed at specific intervals to determine efficacy and safety of this intervention by clinical and laboratory examination, including imaging and cardiac function studies.