The use of stem cells for regenerating damaged heart tissue offers great potential, but many technical questions remain. Understanding which cell types are most beneficial and how they should be employed is a central issue. Several clinical trials involving stem cells were presented at AHA. Two were of particular interest. SCIPIO, a phase I clinical trial, is the first to assess the effectiveness of cardiac stem cells (CSCs) for treating ischemic heart failure. Dr. Roberto Bolli of the University of Louisville reported second-year findings in which patients given CSC injections showed improvement. The cells originated from percutaneous biopsies of the patients’ hearts. Results indicated that the therapy reduced the scope of damage to heart tissue, increased heart function and improved quality of life. A phase II trial is planned.
Another phase I/II trial, call POSEIDON, looked at the use of connective tissue stem cells called mesenchymal stem cells (MSCs). Though the data are preliminary, the researchers found that MSCs from either the patient or a donor are equally effective and safe. Successful results would mean an important advance in CSC therapy. The ability to use off-the-shelf cells offers big advantages over preparing cells from patients while they are under treatment.
At the preclinical level, the Heart Institute’s Dr. Darryl Davis presented research comparing the effect of CSCs and another cell type, blood-derived circulatory angiogenic cells (CACs), in a mouse model of myocardial infarction. His lab found that both cell types had equally beneficial but unique effects. When given together, they had a synergistic effect that offered even greater improvement in cardiac function than either cell type alone, likely due to their complementary properties. These results suggest that therapies using multiple cell types may have greater regenerative impact than single-cell approaches.