Abstract 3546: Cardiac Rehabilitation Improves Blood Flow in the Scarred Myocardium and Decreases Angiogenic Cytokines

Abstract

Background Cardiac rehabilitation improves myocardial blood flow (MBF) in the patients with myocardial infarction (MI), but the mechanism is unclear. Angiogenic cytokines such as stromal-derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF) and stem cell factor (SCF) could recruit circulating stem cells to improve tissue perfusion. We tested the hypothesis that plasma SDF-1, VEGF or SCF levels were association with MBF in the scarred myocardium in the post-MI patients undergoing cardiac rehabilitation. Methods and Results Thirty-nine patients were recruited, and 20 were randomly assigned to undergo a training program. Nineteen age- and sex- matched healthy subjects without any cardiovascular risk factors constituted the normal group. MBF, quantified with cardiac magnetic resonance by model-independent deconvolution methods, was assessed in the scarred myocardium at rest and at stress. Compared to the healthy subjects, peak oxygen uptake (VO 2 ) and MBF at stress, but not that at rest were lower; while SDF-1 and VEGF, but not SCF were higher in the post-MI patients. After 3 months, an increased MBF at stress (+30%, P <0.01) and peak VO 2 (+15%, P =0.01) and decreased SDF-1 (−11%, P =0.01) and VEGF (−9%, P <0.01) were seen in the training group, but not the MI control or normal group. The change in peak VO 2 correlated with the changes in MBF at stress and SDF-1 and VEGF ( r =0.48, −0.38, −0.40, respectively; all P <0.05). Conclusions Cardiac rehabilitation improves myocardial blood flow in the scarred myocardium with a concomitant decrease in plasma angiogenic cytokines.