CD34 and angina pectoris: A meta-analysis of these three randomized double-blinded trials revealed that autologous CD34+ cell therapy significantly improved change in TET at 3 and 6 months and tended to improve change in TET at 12 months, and the relative frequency of angina was significantly lower at 3, 6, and 12 months in the CD34+ cell therapy group than in the placebo group.