Introduction: The current situation of international studies is an important medical field of cardiac surgery with respect to the usage of bone marrow stem cells (BMSC). But it also provides an example of the susceptibility of studies to errors concerning execution and evaluation - which may lead to considerable misinterpretations of study results.
Material and Methods: This review is founded on the critical meta-analysis `Discrepancies in autologous bone marrow stem cell trials and enhancement of ejection fraction` (`DAMASCENE`) of the cardiovascular scientist Alexandra Nowbar of the London Imperial College published in 2014 in the British Medical Journal (BMJ) and the study `Stem cell therapy for chronic ischaemic heart disease and congestive heart failure` of the Cochrane Heart Group published in 2016 in the Cochrane-database of systematic reviews. Several studies were analysed by the teams and showed discrepancies in important parts of the study designs. These discrepancies also affect the ongoing phase-3-study „Bone-marrow-derived mononuclear cell on all-cause mortality in Acute Myocardial Infarction`(BAMI).
Results: The two studies revealed complementary results: Nowbar`s team found alarming discrepancies in 49 of the investigated studies. As a characteristic: Studies with the most promising results on the cardiac ejection fraction tend to show the highest number of discrepancies. The Cochrane-study additionally discovered evidence of low quality in their observed stem cell studies and suggested a careful use of them for further investigations.
Conclusion: The benefits of research on and utilisation of stem cells in cardiology are unquestionable. Unfortunately many studies need to be more focused on actual facts. Open questions are, if studies should be controlled more consequently and if physicians should be taught a more critical way of thinking on trials, if consequent critical check-ups of data will be a guarantee for an efficient validation.
