Time-dependent effects on coronary remodeling and epicardial conductance after intracoronary injection of enriched hematopoietic bone marrow stem cells in patients with previous myocardial infarction

Bone marrow (BM) cells may interact with coronary endothelium and modulate coronary atherosclerosis. We investigated the time course of coronary luminal loss and changes in conductance after intracoronary injection of enriched hematopoietic BM stem cells in patients with previous myocardial infarction (MI). Among 24 patients with acute MI, 13 were randomized to early (<7 days) and 11 to late (4 months) intracoronary injection of CD133(+) cells after the infarction. Segmental quantitative coronary angiography and fractional flow reserve (FFR) measurements of the infarct-related (IR) artery (A) and contralateral artery (control) were performed. In the early group, at 4 months, cumulative luminal loss (LL) of the minimal luminal diameter (MLD) of the IRA distal to the stented segment was -0.39 (-0.51-0.10) mm (p < 0.05 vs. control). There was no further change in LL between 4 and 8 months [-0.09 (-0.26-0.15) mm]. In parallel, FFR decreased at 4 months [-0.16 (-0.26-0.001), p < 0.05 vs. control] but slightly increased from 4 to 8 months follow-up [+0.05 (-0.10-0.09)]. In the late group, LL of the MLD of the IRA distal to the stented segments was -0.12 (-0.47-0.07) mm (NS vs. control) at 4 months and further -0.07 (-0.25-0.05) mm (NS) between 4 and 8 months. At 8 months, the total LL of the MLD in the early and late group was only slightly higher compared to control [-0.34 (-0.48--0.16), -0.36 (-0.69--0.09), and -0.12 (-0.39-0.05) mm, respectively, NS]. Early intracoronary administration of hematopoietic BM stem cells in patients with previous MI is associated with accelerated luminal loss and reduced conductance of the infarct-related artery.