After a decade of research, the safety and efficacy of intravenous infusion of bone-marrow-derived stem cells for therapeutic treatment in individuals with heart failure have been well established; however, until Bartolucci et al’s phase 1 / 2 randomized controlled trial of intravenous infusion umbilical cord mesenchymal stem cells (UC-MSCs) on heart disease, no clinical studies have examined the safety and efficacy of similar intravenous infusion of UC-MSCs in patients with chronic systolic heart failure (HFrEF).
Specifically, therapeutic treatment of heart failure with stem cells harvested from bone marrow has demonstrated improved cardiac function and regeneration of damaged heart tissue resulting in moderate clinical benefits in survival, left ventricular function, and improved quality of life in patients with HFrEF.
While MSCs isolated from adult bone marrow have demonstrated benefits, the invasive harvesting procedure and differentiation potential related to donor age and comorbidity associated with BM-MSC present several disadvantages when evaluating for clinical application.
On the other hand, when compared to BM-MSCs, umbilical cord-derived MSCs, or UC-MSCs, are easily attainable, demonstrate less cellular aging, and are not obstructed by potential ethical concerns.
With preclinical research demonstrating UC-MSC supporting enhanced vascular regeneration and cardiomyocyte protection, Bartolucci et al’s study aimed to evaluate the safety and efficacy of intravenous infusion of UC-derived stem cells for therapeutic treatment in individuals with heart failure.
This RIMECARD trial was the first randomized, double-blind, placebo-controlled study of intravenous infusion of allogeneic UC-MSCs in patients with chronic HFrEF. Although there has been limited experience on intravenous administration of MSCs in patients with cardiovascular diseases, it has been well established that MSC-based therapies are considered safe for therapeutic use in this application; further review of prospective clinical trials also did not detect a risk of infusion toxicity, organ system complications, infection, death, or malignancy in treated patients.
The results of the RIMECARD trial demonstrated that delivery of UC-MSCs seems safe for use in the HFrEF population with observable improvements in LVEF in patients receiving intravenous UC-MSC treatments. Researchers have proposed many potential reasons for the clinical benefits of the application of UC-MSCs among patients with heart failure including reduction in myocardial cell apoptosis, less myocardial inflammation and myocardial fibrosis, the formation of new cardiac-related blood vessels, and increased cell differentiation.
One notable observation of this study was the notable cardiomyogenic differentiation potential between UC-MSCs and BM-MSCs. It appeared that BM-MSCs presented a more favorable profile of transcription factors related to cardiac differentiation; however, findings demonstrating poor retention rates after intramyocardial injections of BM-MSCs render them potentially insufficient for what is required to be deemed clinically beneficial.
By comparison, the paracrine factors observed demonstrate a significant advantage of UC-MSCs over BM-MSCs with the most prominent difference being the expression of hepatocyte growth factor in UC-MSCs from all tested donors (BM-MSCs showed low to undetectable levels).
While further analysis and outcomes were considered limited based on small patient sample groups, IV infusion of UC-MSCs was found to be feasible and safe among patients with HFrEF, inducing no humoral immune response among test subjects. While findings suggest significant improvements in left ventricular function, functional status, and quality of life, the impact of UC-MCSs in patients with heart failure would be further supported through larger clinical trials.
Reference: (2017, September 26). Safety and Efficacy of the Intravenous Infusion of Umbilical …. Retrieved December 28, 2020, from https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.117.310712