Effects of repetitive transendocardial CD34+ cell transplantation in patients with nonischemic dilated cardiomyopathy

Abstract

Rationale: Preclinical data in heart failure models suggest that repetitive stem cell therapy may be superior to single-dose cell administration. Objective:We investigated whether repetitive administration of CD34+ cells is superior to single-dose administration in patients with nonischemic dilated cardiomyopathy. Methods and Results: Of 66 patients with dilated cardiomyopathy, New York Heart Association functional class III, and left ventricular ejection fraction (LVEF) <40% enrolled in the study, 60 were randomly allocated to repetitive cell therapy (group A, n=30) or single-cell therapy (group B, n=30). Patients received G-CSF (granulocyte colony-stimulating factor) for 5 days, and 80 million CD34+ cells were collected by apheresis and injected transendocardially. In group A, cell therapy was repeated at 6 months. All patients were followed for 1 year, and the primary end point was the difference in change in LVEF between the groups. At baseline, the groups did not differ in age, sex, LVEF, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or 6-minute walk test distance. When directly comparing groups A and B at 1 year, there was no significant difference in change in LVEF (from 32.2±9.3% to 41.2±6.5% in group A and from 30.0±7.0% to 37.9±5.3% in group B, P=0.40). From baseline to 6 months, both groups improved in LVEF (+6.9±3.3% in group A, P=0.001 and +7.1±3.5% in group B, P=0.001), NT-proBNP (−578±211 pg/mL, P=0.02 and −633±305 pg/mL, P=0.01), and 6-minute walk test (+87±21 m, P=0.03 and +92±25 m, P=0.02). In contrast, we observed no significant changes between 6 months and 1 year (LVEF: +2.1±2.3% in group A, P=0.19 and +0.8±3.1% in group B, P=0.56; NT-proBNP: −215±125 pg/mL, P=0.26 and −33±205 pg/mL, P=0.77; 6-minute walk test: +27±11 m, P=0.2 and +12±18 m, P=0.42). Conclusions: In patients with dilated cardiomyopathy, repetitive CD34+ cell administration does not seem to be associated with superior improvements in LVEF, NT-proBNP, or 6-minute walk test when compared with single-dose cell therapy.