Efficacy of CD34+ Stem Cell Therapy in Nonischemic Dilated Cardiomyopathy Is Absent in Patients With Diabetes but Preserved in Patients With Insulin Resistance

The association of diabetes and insulin resistance (IR) with the cell therapy response in patients with nonischemic dilated cardiomyopathy (DCM) was evaluated. Outpatients with DCM received granulocyte colony‐stimulating factor for 5 days. CD34+ cells were collected by apheresis and injected transendocardially. However, transendocardial CD34+ cell therapy appeared ineffective in DCM patients with diabetes. IR was associated with improved CD34+ stem cell mobilization and a preserved clinical response to cell therapy. We evaluated the association of diabetes and insulin resistance with the response to cell therapy in patients with nonischemic dilated cardiomyopathy (DCM). A total of 45 outpatients with DCM received granulocyte colony‐stimulating factor for 5 days. CD34+ cells were then collected by apheresis and injected transendocardially. Twelve patients had diabetes mellitus (DM group), 17 had insulin resistance (IR group), and 16 displayed normal glucose metabolism (no‐IR group). After stimulation, we found higher numbers of CD34+ cells in the IR group (94 ± 73 × 106 cells per liter) than in the no‐IR group (54 ± 35 × 106 cells per liter) or DM group (31 ± 20 × 106 cells per liter; p = .005). Similarly, apheresis yielded the highest numbers of CD34+ cells in the IR group (IR group, 216 ± 110 × 106 cells; no‐IR group, 127 ± 82 × 106 cells; DM group, 77 ± 83 × 106 cells; p = .002). Six months after cell therapy, we found an increase in left ventricular ejection fraction in the IR group (+5.6% ± 6.9%) and the no‐IR group (+4.4% ± 7.2%) but not in the DM group (−0.9% ± 5.4%; p = .035). The N‐terminal pro‐brain natriuretic peptide levels decreased in the IR and no‐IR groups, but not in the DM group (−606 ± 850 pg/ml; −698 ± 1,105 pg/ml; and +238 ± 963 pg/ml, respectively; p = .034). Transendocardial CD34+ cell therapy appears to be ineffective in DCM patients with diabetes. IR was associated with improved CD34+ stem cell mobilization and a preserved clinical response to cell therapy. Significance The present study is the first clinical study directly evaluating the effects of altered glucose metabolism on the efficacy of CD34+ stem cell therapy in patients with nonischemic dilated cardiomyopathy. The results offer critical insights into the physiology of stem cell mobilization in heart failure and possibly an explanation for the often conflicting results obtained with stem cell therapy for heart failure. These results demonstrate that patients with dilated ca