One of the promises of stem cell therapy lies on its potentials to treat heart disease. A new research, however, suggests that the potentials and benefits of cardiac stem cell therapy may have been overstated.
In a new study published in the British Medical Journal (BMJ) April 29, researchers sought to determine if the discrepancies in the trials that evaluate the effects of stem cell treatment in patients who have heart disease is associated with the size of reported improvements in heart function.
Study researcher Darrel Francis, a cardiologist from the Imperial College London and his colleagues reviewed 133 reports from 49 randomized trials that involve treatment of patients who suffered from heart attack and were published up to April 2013, for discrepancies.
The researchers found over 600 discrepancies that range from minor mistakes to apparent deception but observed that the number of discrepancies is strongly correlated to the reported improvements in heart function.
Studies with more errors notably tend to report large effects of treatment. The five trials that did not have discrepancies, for instance, reported there was no improvement in heart function while the five trials that have the most number of discrepancies reported of large improvements in heart function.
"There was a significant association between the number of discrepancies and the reported increment in EF with bone marrow stem cell therapy," the researchers reported. "Trials with no discrepancies were a small minority (five trials) and showed a mean EF effect size of -0.4%. The high discrepancy group, comprising five trials with over 30 discrepancies each, showed a mean effect size of 7.7%."
Stem cell researcher Steven Epstein from the MedStar Heart Institute said that the findings of the study are shocking and disappointing albeit he was not surprised with the result.
"The findings and conclusions are not at all surprising to me, as for many years I've been aware of investigators presenting results as more positive than they actually were," Epstein said.
The release of the study incidentally coincides with the publication of a new study on treating chronic ischaemic heart disease and heart failure with stem cells which was published in the Cochrane Library. The findings of the study, which involved 1,255 subjects from 23 trials, suggest that stem cell treatment is more effective than drugs in treating people with chronic ischemic heart disease and heart failure.