- Background: Many clinical trials and meta-analyses presented moderate but significant improvement of the left ventricular ejection fraction (LVEF) after intracoronary autologous bone-marrow (BM) or peripheral blood origin stem cells transfer. However, it remains controversial, whether this beneficial effects is comparable with the intramyocardial delivery of the stem cells, or could be maintained during moderate and long term follow-up. The BOOST trial suggested that cardiac stem cell therapy did not improve LVEF at 5-year follow-up. By contrast, BALANCE study showed a long sustained benefit of BM-stem cells treatment. Due to these divergent outcomes of the presented trials, the aim of the present meta-analysis is to compare the safety and effectiveness of the cardiac stem cell therapy in different patient population, delivery mode and cell type, to find out, which patients with which therapy mode can have the greatest benefit from cardiac stem cell therapy.