Bone marrow stem cell therapy in heart failure patients with low ejection fraction: a systematic review

The association of bone marrow stem cells (BMSCs) with cardiac function outcomes and treatment outcomes in heart failure (HF) patients with low ejection fraction (EF) has been heterogeneous across studies. This systematic review aimed to investigate the effect of BMSCs on functional, clinical, quality of life, and major adverse cardiovascular events (MACE) outcomes in HF patients with low EF. PubMed, Scopus, Clinicaltrial.gov, Cochrane Library, Google Scholar, and Web and reference databases were searched for articles that examined the effect of BMSCs therapy on improving cardiac outcomes in patients with low EF, from 2000 to 2024. Differences in left ventricular ejection fraction (LVEF), MACE, echocardiographic indices (left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV)), 6-min walk test (6-MWT), New York Heart Association (NYHA) class and immunologic responses were defined as outcomes. Low EF was defined as an EF <45%. Finally, 14 RCTs involving 710 HF patients with low EF were included. BMSCs transplantation was associated with improvements in echocardiographic parameters, EF rate, and NYHA class in most studies (9 of 14) compared to the control group, regardless of the time of outcome assessment (3 or 6 months). It also significantly improved the 6-MWT in most studies. Improvements in parameters and functional outcomes were similar at both evaluation periods, 6 and 12 months. The BMSCs transplantation was not significantly associated with the incidence of MACE and immunological responses. The results of this systematic review supported the positive role of BMSCs transplantation in improving echocardiographic parameters, EF rate, NYHA class, and 6-MWT in HF patients with low EF. BMSCs transplantation was not significantly associated with the incidence of MACE and immunological responses.