Beginning in 2001, a phase-1 equivalent feasibility and safety evaluation of intramyocardial injection of autologous CD133+ bone marrow cells during elective CABG surgery was conducted at Rostock University. No procedure-related adverse events were observed and there was some improvement of myocardial contractility and perfusion. It was decided to proceed with a controlled efficacy testing, comparing the outcome of standard CABG surgery with that after CABG and CD133+ cell injection. The results of that study indicate that the additional cell injection yields a better left ventricular contractility than CABG alone (LVEF = 47.1±8% vs. 41.3±9% at 6 months). Although this result is encouraging, the trial had several limitations that hamper interpretation of the data. Most notably, no sham-injection of placebo material was performed in the control group, and standard 2D echocardiography served as the only measurement of global LV contractility.