Stem cells harvested from heart attack victims' own hearts can be used to repair the injured organ, US doctors have shown for the first time.
Los Angeles-based Cedars-Sinai researcher Raj Makkar and his colleagues recruited 31 patients with a history of a recent heart attack. The patients were randomly assigned to either an intervention arm, destined to undergo cell therapy, or a control group who received standard supportive care and rehabilitation.
About 2 weeks after their cardiac events, the intervention group of patients underwent a biopsy procedure during which a small catheter was threaded into the right sides of their hearts and a small lentil-sized specimen of healthy heart tissue was recovered.
The cells in the sample were then separated and grown in a culture dish where they produced proliferating balls of cells called cardiospheres. From these, muscle cells called CDCs - cardiosphere derived cells - were prepared.
Five weeks after their heart attack, up to 25 million of these CDCs were then squirted down the coronary artery that had caused the heart attack and the patients were then followed up using a range of cardiac tests and imaging investigations at 6 and 12 months.
Incredibly, the volume of scar tissue visible on scans of the treated patients' hearts had fallen by 12% at the one year time point compared with the control patients in which there was virtually no change. The cell recipients also showed an increase in viable heart muscle tissue and better function of the affected region of the heart, although the patients' "ejection fractions", a measure of the overall pumping efficiency of the heart, did not differ between the two groups and for the moment it's not clear why.
But as the researchers point out, these encouraging results based on this small group of patients nonetheless show that the approach is safe and moving to a much larger, more powerful study is warranted in order to explore the full potential of this technique.