Stem Cells Reduce Angina Frequency in Refractory Angina
Autologous CD34+ cell injections tied to decreased angina, improved exercise tolerance
FRIDAY, July 8 (HealthDay News) -- Patients with refractory angina who receive injections of CD34+ cells experience a significant decrease in weekly angina frequency and improvement in exercise tolerance, according to a study published online July 7 in Circulation Research.
Douglas W. Losordo, M.D., from Northwestern University in Chicago, and colleagues assessed the safety and efficacy of intramyocardial injections of autologous CD34+ cells in 167 patients with refractory angina at 26 U.S. medical centers who had exhausted all other available treatment options. Patients were randomly allocated to receive injections into 10 sites of ischemic, viable myocardium of either mobilized autologous CD34+ cells (low or high dose) or an equal volume of placebo. Outcome measures included weekly angina frequency six and 12 months after treatment, as well as exercise tolerance.
The investigators found that weekly angina frequency was significantly lower and exercise tolerance was significantly greater in the low-dose injection group compared to the control group at both six- and 12- month follow-up. The high-dose group reported lower angina frequency and improved exercise tolerance, but these results were not significant. A total of 4.6 percent of the patients had cardiac enzyme elevations indicative of non-ST segment elevation myocardial infarction during cell mobilization and collection. At 12 months, mortality was 5.4 percent in the control group and 0 percent in the group receiving cell injections.
"Intramyocardial injection of autologous CD34+ cells was associated with a significant decrease in angina frequency and a significant improvement in exercise tolerance in patients with optimally managed but refractory angina," the authors write.
Several of the study authors disclosed financial ties to Baxter Healthcare, which also funded the study.