Effects of Intracoronary CD34 + Stem Cell Transplantation in Nonischemic Dilated Cardiomyopathy Patients

Abstract

Rationale: CD34 + transplantation in dilated cardiomyopathy was associated with short-term improvement in left ventricular ejection fraction and exercise tolerance. Objective: We investigated long-term effects of intracoronary CD34 + cell transplantation in dilated cardiomyopathy and the relationship between intramyocardial cell homing and clinical response. Methods and Results: Of 110 dilated cardiomyopathy patients, 55 were randomized to receive CD34 + stem cell transplantation (SC group) and 55 received no cell therapy (controls). In the SC group, CD34 + cells were mobilized by granulocyte colony-stimulating factor and collected via apheresis. Patients underwent myocardial scintigraphy and cells were injected in the artery supplying segments with the greatest perfusion defect. At baseline, 2 groups did not differ in age, sex, left ventricular ejection fraction, or N-terminal B-type natriuretic peptide levels. At 5 years, stem cell therapy was associated with increased left ventricular ejection fraction (from 24.3 ± 6.5% to 30.0 ± 5.1%; P =0.02), increased 6-minute walk distance (from 344 ± 90 m to 477 ± 130 m; P <0.001), and decreased N-terminal B-type natriuretic peptide (from 2322 ± 1234 pg/mL to 1011 ± 893 pg/mL; P <0.01). Left ventricular ejection fraction improvement was more significant in patients with higher myocardial homing of injected cells. During follow-up, 27 (25%) patients died and 9 (8%) underwent heart transplantation. Of the 27 deaths, 13 were attributed to pump failure and 14 were attributed to sudden cardiac death. Total mortality was lower in the SC group (14%) than in controls (35%; P =0.01). The same was true of pump failure (5% vs 18%; P =0.03), but not of sudden cardiac death (9% vs 16%; P =0.39). Conclusions: Intracoronary stem cell transplantation may be associated with improved ventricular function, exercise tolerance, and long-term survival in patients with dilated cardiomyopathy. Higher intramyocardial homing is associated with better stem cell therapy response.