Enhanced External Counterpulsation: From Vascular Repair Concept to CD34+ Cell Therapy in Angina-A Scalable Solution to Refractory Angina in the Global Health Era

Background: Refractory angina represents a growing clinical challenge characterized by persistent ischemic symptoms despite optimal medical therapy and lack of revascularization options. Increasing evidence implicates impaired microvascular function and defective endogenous vascular repair, including dysfunction of CD34+ endothelial progenitor cells (EPCs), in its pathophysiology. Objectives: To review the mechanistic and clinical evidence supporting CD34+ cell therapy and enhanced external counterpulsation (EECP), and to propose an integrated regenerative framework for their application. Key Findings: Autologous CD34+ cell therapy improves angina burden, exercise capacity, and myocardial perfusion, largely through paracrine signaling that enhances angiogenesis and endothelial function. However, its clinical application is limited by procedural complexity and variability in cell function. EECP, a noninvasive therapy, improves symptoms and functional capacity while also enhancing endothelial function and mobilizing endogenous progenitor cells. Conclusions: EECP and CD34+ cell therapy converge on shared pathways of vascular repair but differ in their mode of action. EECP may serve as a scalable regenerative platform by activating endogenous repair mechanisms, particularly when combined with strategies that enhance progenitor cell mobilization. This integrated approach may provide a practical alternative to exogenous cell therapy in refractory angina.