Intramyocardial autologous CD34+ cell therapy for refractory angina: A meta-analysis of randomized controlled trials

Background: Previous studies have demonstrated that intramyocardial human CD34+ cells may relieve symptoms and improve clinical outcomes in chronic refractory angina unresponsive to optimal medical therapy or not amenable to revascularization. Methods: We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the impact of human CD34+ cells compared with placebo in chronic refractory angina. Primary efficacy outcomes in our analysis were angina frequency and exercise time. Primary safety outcomes included major adverse cardiovascular events such as myocardial infarction (MI), stroke and death. Results: Three eligible randomized trials including 269 patients (placebo = 90, CD34+ = 179) were included. Dose of auto-CD34+ cells ranged from 5 x 10(4) to 5 x 10(5) cells/kg. Follow-up ranged from 6 to 24 months. In a pooled analysis, administration of CD34+ cells decreased the risk of all-cause mortality [OR 0.24, 95% CI (0.08-0.73), p = 0.01], reduced angina frequency [mean difference -2.91, 95% CI (-4.57 to -1.25), p = 0.0006] and improved exercise time [mean difference 58.62 s, 95% CI (21.19 to 96.06), p = 0.02] compared with control group. However, there was no significant difference in the risk of myocardial infarction (MI) and stroke between groups. Conclusion: In a meta-analysis, intra-myocardial CD34+ cell therapy was superior to placebo in improving risk of all - cause mortality, angina frequency with an increase in exercise time, without a significant increase in adverse events. This analysis supports further trials of CD34+ cell therapy for ischemic heart disease. (C) 2018 Elsevier Inc. All rights reserved.