Transplantation of blood-derived progenitor cells after recanalization of chronic coronary artery occlusion - First randomized and placebo-controlled study

Transplantation of blood-derived circulating progenitor cells ( CPC) has been shown to improve myocardial regeneration after myocardial infarction. It remains unclear whether CPC transplantation exerts beneficial effects also in patients with chronic myocardial ischemia. We initiated a randomized, double-blind, placebo-controlled study evaluating the impact of intracoronary infusion of CPCs on coronary vasomotion and left ventricular ( LV) function in patients after recanalization of chronic coronary total occlusion ( CTO). After recanalization of CTO, 26 patients ( age, 63 +/- 2 years; LV ejection fraction, 53 +/- 2%) were randomly assigned to the treatment ( intracoronary transplantation of CPCs) or control group. Coronary flow reserve in response to adenosine ( 2.4 mg/min) was measured in the target vessel at the beginning of the study and after 3 months. LV function and infarct size were assessed by MRI and metabolism by F-18 deoxyglucose positron emission tomography. CPC application resulted in an increase in coronary flow reserve by 43% from 2.3 +/- 0.3 to 3.3 +/- 0.5 ( P < 0.05 versus beginning and control). At 3 months, the number of hibernating segments in the target region ( from 2.9 +/- 0.6 to 2.0 +/- 0.6 segments, P < 0.05 versus beginning and control) had declined in the treatment group, whereas no significant changes were observed in the control group. MRI revealed a reduction in infarct size by 16% and an increase in LV ejection fraction by 14% in the treatment group ( from 51.7 +/- 3.7 to 58.9 +/- 3.2%; P < 0.05 versus beginning and control) because of an augmented wall motion in the target region. Hence, intracoronary transplantation of CPCs after recanalization of CTO results in an improvement of macro- and microvascular function and contributes to the recruitment of hibernating myocardium.