Background: Preclinical and clinical evidence suggests that mesenchymal stem cells (MSCs) may be beneficial in treating Heart Failure (HF). However, the effects of stem cell therapy in patients with heart failure is an ongoing debate and the safety and efficacy of MSCs therapy are not well-known. We conducted a systematic review of clinical trials that evaluated the safety and efficacy of MSCs for HF. This study aimed to assess the safety and efficacy of MSCs therapy compared to the placebo in heart failure patients.
Methods: We searched PubMed, Embase, Cochrane library systematically, with no language restrictions. Randomized Controlled Trials (RCTs) assessing the influence of MSCs treatment function controlled with placebo in heart failure were included in this analysis. We included RCTs with data on safety and efficacy in patients with heart failure after mesenchymal stem cell transplantation. Two investigators independently searched the articles, extracted data, and assessed the quality of the included studies. Pooled data was performed using the fixed-effect model or random-effect model by the use of Review Manager 5.3. The Cochrane risk of bias tool was used to assess the bias of included studies. The primary outcome was safely assessed by death and rehospitalization and the secondary outcome was efficacy, which was assessed by six-minute walk distance and Left Ventricular Ejection Fraction (LVEF), Left Ventricular End-systolic Volume (LVESV), Left Ventricular End-diastolic Volume (LVEDV) and Brain Natriuretic Peptide (BNP).
Results: A total of twelve studies were included, involving 823 patients who underwent MSCs or placebo treatment. The overall rate of death showed a trend of reduction of 27% (RR [CI]=0.73 [0.49, 1.09], p=0.12) in the MSCs treatment group. The incidence of rehospitalization was reduced by 47% (RR [CI]=0.53[0.38, 0.75], p=0.0004). The patients in the MSCs treatment group realised an average of 117.01m (MD [95% CI]=117.01m [94.87, 139.14], p<0.00001) improvement in 6MWT. MSCs transplantation significantly improved Left Ventricular Ejection Fraction (LVEF) by 5.66 % (MD [95% CI]=5.66 [4.39, 6.92], p<0.00001), decreased Left Ventricular End-Systolic Volume (LVESV) by 14.75 ml (MD [95% CI]=-14.75 [-16.18, - 12.83], p<0.00001) and Left Ventricular End-Diastolic Volume (LVEDV) by 5.78 ml (MD [95% CI]=- 5.78[-12.00, 0.43], p=0.07), in the MSCs group, BNP was decreased by 133.51 pg/ml MD [95% CI]= - 133.51 [-228.17,-38.85], p=0.54, I2= 0.0%) than did in the placebo group.
Conclusion: Our results suggested that mesenchymal stem cells as a regenerative therapeutic approach for heart failure are safe and effective by virtue of their self-renewal potential, vast differentiation capacity and immune modulating properties. Allogenic MSCs have superior therapeutic effects and intracoronary injection is the optimum delivery approach. In the tissue origin, patients who received treatment with umbilical cord MSCs seem more effective than bone marrow MSCs. As to dosage injected, (1-10)*10^8 cells were of better effect.