The present study was designed to assess the 3-year safety and clinical outcomes of this angiogenic cell therapy by investigating the mortality and leg amputation-free interval as primary end points. The median follow-up time for surviving patients was 25.3 months (range, 0.8-69.0 months), and 3-year overall survival rates were 80 % (95 % CI 68-91) in patients with atherosclerotic peripheral arterial disease (11 died in 74 patients) and 100 % (no death) in 41 patients with thromboangiitis obliterans (TAO; Buerger's disease). Three-year amputation-free rate was 60 % (95 % CI 46-74) in PAD and 91 % (95 % CI 82-100) in patients with TAO. The multivariate analysis revealed that the severity of rest pain and repeated experience of bypass surgery were the prognostic factors negatively affecting amputation-free interval. The significant improvement in the leg pain scale, ulcer size, and pain-free walking distance was maintained during at least 2 years after the therapy, although the ankle brachial index and transcutaneous oxygen pressure value did not significantly change.
The angiogenic cell therapy using bone marrow mononuclear cells can induce a long-term improvement in limb ischemia, leading to extension of amputation-free interval. The safety and efficacy are not inferior to the conventional revascularization therapies.