Intracoronary Transplantation of CD34+ Cells Is Associated With Improved Myocardial Perfusion in Patients With Nonischemic Dilated Cardiomyopathy

Background: We investigated the effects of intracoronary transplantation of CD34(+) cells on myocardial perfusion in patients with nonischemic dilated cardiomyopathy (DCM). Methods and Results: We enrolled 21 patients with DCM (left ventricular ejection fraction [LVEF] <40%, New York Heart Association functional class III) who underwent peripheral stem cell mobilization with granulocyte-colony stimulating factor (G-CSF). CD34(+) cells were collected by means of apheresis. Patients underwent myocardial perfusion imaging, and CD34(+) cells were injected in the coronary artery supplying viable segments with reduced myocardial perfusion and regional dysfunction. Myocardial perfusion imaging was repeated 6 months later. Clinical response to stem cell therapy was predefined as a change in LVEF >5%. The majority of patients were men (81%) with an overall mean age 53 +/- 9 years, LVEF 25 +/- 5%, and 6-minute walking distance 354 71 m. Myocardial perfusion defects at rest were observed in 86% of patients and were more common in the left anterior descending territory (50%). At 6 months' follow-up, there was a significant improvement in rest myocardial perfusion scores (6.3 +/- 5.8 vs 3.1 +/- 4.3; P < .001), LVEF (25 +/- 7% vs 29 +/- 8%; P = .005), and 6-minute walking distance (354 +/- 71 m vs 404 +/- 91 m; P <.001). Responders to stem cell therapy had lower summed rest perfusion score at both baseline (3.2 +/- 3.0 vs 9.1 +/- 6.3; P = .015) and follow-up (1.0 +/- 1.5 vs 5:0 +/- 5.1; P = .028). Conclusions: CD34(+) cell transplantation may lead to improved myocardial perfusion in patients with nonischemic DCM. Patients with less severe myocardial perfusion defects at baseline may have an increased likelihood to respond to intracoronary CD34(+) cell transplantation.