Early efforts to simply transplant stem cells and let them do their work continue to show promise. First generation cell transplants are not a miracle cure, but they are an improvement over any other options available for some patients: "researchers are [utilizing] patients' own stem cells to regenerate heart and vascular tissue [in] a study examining stem cell transplantation as treatment for critical limb ischemia. ... Traditionally, cardiovascular medicine has focused on repairing damaged tissues with medication or surgery. For some patients, their cardiovascular disease is advanced to the point that standard treatment options are not effective. Regenerative cardiovascular medicine strives to redevelop cardiac and vascular tissue and stimulate new blood supply to areas like the heart and legs by using stem cells already present in the patient's body. ... [the] study examined the effectiveness of stem cell therapy in limb preservation for patients with critical limb ischemia (CLI). CLI develops in patients with severe obstruction of the arteries which limits blood flow to the extremities. CLI results in more than 100,000 amputations annually in the United States. The trial tested the ability of CD34+ cells to stimulate new blood vessel formation in ischemic limbs, which can improve perfusion and salvage function. ... The patients enrolled in this study were [in] the later stages of peripheral artery disease and at heightened risk for amputation. Patients in the randomized group had CD34 injected at eight locations in the ischemic limb and were followed for 12 months. ... Stem cell treatment was associated with a significant reduction in amputation rate. Treatment was associated with a 50 percent reduction in the total amputation rate compared to control."