Efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy: An umbrella review of systematic reviews

Background: Stem cell therapy (SCT) has emerged as a potential therapeutic avenue, with various cell types being explored for their efficacy in treating DCM. However, the safety and efficacy of these therapies have been the subject of numerous systematic reviews. This umbrella review aims to consolidate the existing evidence on stem cell interventions for DCM, providing a comprehensive overview of the current research landscape. Methods: This review was conducted following the JBI and PRISMA guidelines. Systematic reviews and meta-analyses of randomized controlled trials (RCTs) evaluating the safety and efficacy of SCT for DCM were included. Outcomes such as 6MWT, LVEDD, LVEF, MACE, NYHA, and QoL, among others, were considered. A literature search was executed across databases like PubMed, Embase, Web of Science, and Cochrane Database up to October 07, 2023. The quality of the included reviews was assessed using the JBI Checklist for Systematic Reviews and Research Syntheses. Data synthesis was carried out in both narrative and tabular formats, with the GRADE criteria guiding the determination of evidence certainty. Results: Nine systematic reviews met the inclusion criteria. LVEF found to be significantly improved with SCT. LVEDD and LVEDV assessments yielded mixed results, with some reviews observing significant changes. LVESV showed consistent reductions across multiple studies. BNP concentrations post-interventions were explored in several studies, with mixed findings. Health-related quality of life (HRQL) showed varied results, with some studies noting improvements and others finding no significant differences. NYHA classifications and 6-MWT results indicated potential benefits from stem cell treatments. SCT was observed to be generally safe. The certainty of evidence was low or very low for most of outcomes. Conclusion: SCT showed has shown promise in treating DCM, with many studies highlighting its safety and potential benefits. Nonetheless, the existing data has its limitations due to biases in the RCTs studies. To truly establish the benefits of SCT for DCM, future high quality RCTS, are crucial.