Study on the Efficacy and Mechanism of Cardiac Rehabilitation for Stem Cell Mobilization and Heart Failure Improvement
Condition: Myocardial Infarction
MeSH terms: Myocardial Infarction; Infarction
Study type: Interventional

Summary: 
      One emerging concept is that some form of injury or inflammation is a prerequisite for the
      success of circulating-cell participation in differentiated tissue structure and function.
      Once reperfusion is achieved in acute myocardial infarction, an intense inflammatory cascade
      is unleashed.

      The architecture of the left ventricle rearranges, leading to ventricular remodeling. The
      "homing process"involves stem cell migration to the sites of injury or ischemia, which
      provides an environment that is favorable to growth and function. This microenvironment is a
      stimulus for homing and differentiation of stem cells of the appropriate lineage. It
      increases vascular permeability and expression of adhesion proteins like integrin, along with
      homing receptors that facilitate the attachment, which is mediated by cell-to-cell contact
      and chemoattractant release from local tissue injury.The migratory capacity of stem cells
      might be dependent on natural growth factors such as vascular endothelial growth factor
      (VEGF) , stromal cell-derived factor-1 (SDF-1)and stem cell factor (SCF).The expression of
      VEGF ,SDF-1 and SCF is highly up-regulated in hypoxic tissue, supporting the hypothesis that
      these factors may represent homing signals crucial to the recruitment of circulating
      progenitor cells to assist the endogenous repair mechanisms in the infarcted tissue. This
      study will examine whether cardiac rehabilitation increases the concentration of stem cell
      factors released into the bloodstream and if these factors are correlated with the
      improvement of heart function.
    

Detailed description: 
      Exercise training has beneficial hemodynamic effects in patients with congestive heart
      failure.A similar benefit may be seen after MI, with an improvement in functional capacity
      averaging 20 percent. More important, however, is the possible effect on survival. In a
      meta-analysis of 24 trials examining the effect of cardiac rehabilitation after MI, there was
      a significant reduction in mortality with rehabilitation (odds ratio 0.81).

      Previous studies focused on the effect of rehabilitation comes from the improvement of oxygen
      utilization in skeletal muscle. The effects on cardiac morphology and perfusion status were
      rather little to be addressed.

      In this study, we will collect the questionaires, blood sampling for assay of stem cell
      factors, maximal O2 consumption, and cardiac MRI before and after cardiac
      rehabilitation.SDF-1 (stromal cell derived factor-1), SCF(stem cell factor), and VEGF
      (vasculoendothelial growth factor) will be measured by ELISA. Cardiac MRI will provide the
      information about (1) LV function, (2) scar size, and (3) perfusion status (dipyridamole
      stress MRI).
    

Intervention name(s): cardiac rehabilitation
Intervention type(s): Behavioral
Intervention description(s): Those in the training group participated in a 3-month rehabilitation training program at an exercise intensity of 55% to 70% of peak oxygen uptake (VO2); those in the nontraining group continued their usual lifestyle.
Other intervention name(s): exercise training
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Myocardial infarction, stem cell, cardiac rehabilitation