Progenitor Cells Produce Positive Outcomes
Although small, REPAIR-AMI LATE trial found significant differences vs. placebo at one year.
Treatment with enriched bone-marrow-derived progenitor cells was associated with a significant improvement in the combined outcome of death, MI or rehospitalization for heart failure.
At one year, there were 12 events in the placebo group and two in the treatment group (P = .006) (Figure).
“Our study was not powered to detect clinical differences, but it appears that intracoronary infusion of bone marrow, in addition to improving left ventricular ejection fraction, may also reduce cardiovascular events at one year,” Andreas Zeiher, MD, Professor of Cardiology at Johann Wolfgang Goethe University Hospitals, said during his presentation on the REPAIR-AMI LATE trial.
Treatment with progenitor cells was not associated with a decrease in mortality; there were two deaths in the treatment group vs. six in the placebo group (P=.28). Rehospitalization for heart failure was also not significantly different: none in the treatment group vs. three in the placebo group (P = .25).
Long-term follow-up
The REPAIR-AMI LATE trial is the long-term follow-up of the original REPAIR-AMI trial, which enrolled 204 patients with AMI.
Patients were randomized to treatment with autologous bone marrow progenitor cells or placebo.
Clinicians aspirated 50 mL of bone marrow cells three to five days after AMI from a patient’s hip using local anesthesia; a sham procedure was performed on patients in the placebo group.
Cells were then sent to a central processing center before being infused into the infarct artery.
Patients were originally evaluated three to seven days after AMI to assess the primary outcome of recovery of LV function. Treated patients had a 5.5% relative improvement in ejection fraction compared with 3% for those treated with placebo (P = .014).
The mean age of the patients was about 56 years. Although there were more patients with diabetes in the placebo group (n = 21) than in the treatment group (n = 12), the difference was not statistically significant (P = .069). Approximately 60% of the patients had hypertension; 55%, hyperlipidemia.
Nearly all patients were receiving aspirin, ACE inhibitors, beta-blockers, and statins.
Larger trials needed
Zeiher said larger clinical trials are needed to confirm these clinical benefits.
In a comment period following the presentation, Bernard Gersh, MD, Professor of Medicine at the Mayo Clinic, agreed. “Clinical questions are still unresolved, but the mechanisms of any therapy depend upon our current perceptions of the state of the science,” Gersh said.
“It took us 100 years to figure out aspirin and a decade to figure out the pleotropic effects of statins.”