Numerous human cardiac stem cell studies have been published, including relatively small number of patients. Meta-analysis of randomized trials have reported safety and a 3-6% increase in global left ventricular performance after intracoronary stem cell therapy in patients with acute myocardial infarction. Since most of the studies used different type of stem cells, delivery modes, and patient population, the results are heterogenous, therefore the comparison of the results is biased regarding generalizable conclusions about the effect of treatment. The present comparative meta-analysis is based on individual patient data, and gathers and pools the raw data, and analyzes the clinical outcome, safety and efficacy of the cardiac stem cell therapy.

• 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.
• Study design: individual patient data meta-analysis
• Data sources: European Centre performing human cardiac stem cell therapy have been contacted calling for participation.
• Methods: Individual data gathering and entering into the database for a pooled analysis. The meta-analysis will be done in line with recommendation from the Cochrane Collaboration and the Quality of Reporting of Meta-analyses guidelines with Review Manager 5.0. Fixed-effect model will be used.

Inclusion Criteria:

• patient included in one of the registered cell-based cardiac therapy of the participating center

Exclusion Criteria:

• none

Patients treated with cell-based cardiac therapy at one of the participating centers