373 Optimal Stem Cell Transplantation Strategy in Ischemic Stroke: A Systematic Review, Meta-Analysis and Meta-Regression

INTRODUCTION: Stem cell therapy presents a promising therapy for ischemic stroke recovery, its clinical application is hindered by variable outcomes, attributed to differences in stem cell types, dosages, delivery methods, and timing of administration. METHODS: We conducted a systematic review and meta-analysis including randomized and non-randomized clinical trials on stem cell therapy for ischemic stroke. The outcomes assessed were good clinical outcomes (mRS 0–2), mortality, and serious adverse events (SAE) in double-arm studies. Barthel index (BI) and mRS improvement and SAE in single-arm studies. Subgroup analyses were performed to evaluate the efficacy and safety of stem cell therapy based on cell type, dosage, administration route, and timing post-stroke. RESULTS: Eighteen studies were included comprising a total of 948 patients, 539 were treated with stem cell therapy (56.86%). Autologous mesenchymal stem cells (MSCs) administered at doses less than 108 cells showed a significant reduction in mortality (OR 0.24, 95% CI 0.08 to 0.73, p=0.01) without impact on SAE incidence. Functional recovery, measured by improvements in the BI and mRS varied across cell types and dosages without significant differences, indicating a broadly comparable efficacy profile for different stem cell therapies. Meta-regression analysis found a statistically significant association between patient age with BI improvement (p=0.03) and between NIHSS scores with good clinical outcomes (mRS 0-2) (p=0.04). CONCLUSIONS: The optimal stem cell transplantation strategy for ischemic stroke recovery may involve early administration of lower doses of autologous MSCs, balancing efficacy and safety. This approach shows promise in reducing mortality, with an acceptable safety profile.