Intramyocardial delivery of CD133+ bone marrow cells and coronary artery bypass grafting for chronic ischemic heart disease: Safety and efficacy studies

Abstract

Cellular therapy for ischemic heart disease has attracted tremendous attention, especially since initial experimental studies have suggested that somatic stem cells can regenerate both blood vessels and cardiomyocytes after myocardial infarction. Recently, the capacity of bone marrow–derived stem cells to form new heart muscle cells has been questioned, but clinical pilot trials have been initiated nevertheless.^E1,E2 In the setting of acute myocardial infarction, several studies have shown a functional benefit of intracoronary infusion of bone marrow cells relative to the standard treatment alone,^E3-E5 but patients with chronic ischemic heart disease and impaired heart function may require a different approach. Our group therefore developed a protocol for injection of purified CD133⁺ bone marrow stem cells directly into the diseased myocardium at the time of coronary artery bypass grafting (CABG). Because of the encouraging results in the first 6 patients,^E6 we completed a dose-escalation safety trial and then conducted an efficacy study to compare the outcome with that of standard CABG. Results of both trials are presented here.