Imaging and 1-day kinetics of intracoronary stem cell transplantation in patients with idiopathic dilated cardiomyopathy

Background: Stem cell transplantation is an emerging method of treatment for patients with cardiovascular disease. There are few studies completed or ongoing on stem cell therapy in patients with idiopathic dilated cardiomyopathy (IDCM). Information on stem cell homing and distribution in the myocardium after transplantation might provide important insight into effectiveness of transplantation procedure.

Aim: To assess early engraftment, retention and migration of intracoronarily transplanted stem cells in the myocardium of patients with advanced dilated cardiomyopathy of non-ischaemic origin using stem cell labeling with (99m)Tc-exametazime (HMPAO).

Materials, methods: Thirty-five patients with IDCM and advanced heart failure were included in the study. Autologous hematopoietic (CD34+) stem cells were harvested by peripheral blood apheresis after bone marrow stimulation, labeled with (99m)Tc-HMPAO, tested for viability and injected into coronary vessel supplying areas of myocardium selected by myocardial perfusion scintigraphy as dysfunctional yet viable. Imaging was performed 1h and 18h after transplantation.

Results: Myocardial stem cell retention ranged from 0 to 1.44% on early and 0-0.97% on delayed imaging. Significant efflux of stem cells occurred from site of delivery in this time period (p<0.001). Stem cell viability was not affected by labeling.

Conclusion: Stem cell labeling with (99m)Tc-HMPAO is a feasible method for stem cell tracking after transplantation in patients with IDCM.