Methodological exploration of bone marrow stem cell therapy in acute myocardial infarction - how to achieve greater benefit on cardiac outcomes: A systematic review and meta-analysis.

BACKGROUND: Clinical trials of intracoronary injection of bone marrow-derived stem cells (BMCs) in patients with acute myocardial infarction (AMI) have revealed promising but variable and modest results. One of the reasons underlying this situation may be the unstandardized preparation of BMCs.

OBJECTIVES: The aim of this study was to explore whether methodological differences affect the prognosis of acute myocardial infarction patients who received BMCs transplantation.

MATERIAL AND METHODS: MEDLINE was searched for randomized controlled trials providing AMI patients with intracoronary BMCs injection or a standard therapy. Changes in cardiac parameters and clinical outcomes were analyzed. Subgroup analyses were conducted according to different methodologies for cell preparation, including supplement for serum or plasma, use of heparin and cell washout.

RESULTS: Non-use of serum or plasma in the cell suspension is associated with more reduction in infarct size (IS) and a lower risk of all-cause mortality. Heparin usage could diminish the benefit in reducing IS. All-cause mortality rose significantly without the cell washout procedure when heparin was used.

CONCLUSIONS: Methodological differences in BMCs preparation as well as the use of heparin and serum/ plasma impact on the prognosis of AMI patients.