Effect of catheter-based transendocardial delivery of stromal cell-derived factor 1α on left ventricular function and perfusion in a porcine model of myocardial infarction

Background Myocardial regeneration after myocardial infarction can occur via stem cell recruitment. Stromal cell-derived factor 1 alpha (SDF-1 alpha) has been shown to be critical for stem cell homing to injured tissue. Methods Myocardial infarction was induced in pigs via microembolization of the distal left anterior descending artery. Two weeks after myocardial infarction animals underwent catheter-based transendocardial injection of SDF-1 alpha into the periinfarct myocardium (18 injections, 5 mu g per injection) (n = 12) or sham-intervention (n = 8). Tc99m sestamibi single-photon emission computed tomography (SPECT) and electromechanical mapping (EMM) of the left ventricle were performed two and seven weeks after myocardial infarction. Results Infarct size by tetrazolium staining was similar in both groups (8.9 +/- 1.2% of left ventricle vs. 8.9 +/- 2.6%). Vessel density in the periinfarct area was significantly higher in SDF-1 alpha treated animals than in controls (349 +/- 17/mm(2) vs. 276 +/- 21/mm(2), p < 0.05). Myocardial perfusion (SPECT) did not change in either group. Ejection fraction and stroke volume (EMM) decreased in SDF-1 alpha animals and increased in controls (difference between groups p = 0.05 for ejection fraction and p < 0.05 for stroke volume). Linear local shortening (EMM) did not change in controls (11.4 +/- 1.3% to 11.5 +/- 0.5%) but decreased significantly in SDF-1 alpha treated animals (12.1 +/- 0.9% to 8.4 +/- 0.9%, p < 0.05, p < 0.05 for difference between groups). SDF-1 delivery was associated with a substantial loss of collagen in the periinfarct area (32 +/- 5% vs. 61 +/- 6% in control animals, p < 0.005). Conclusion A strategy to augment stem cell homing by catheter-based transendocardial delivery of SDF-1 alpha in experimental myocardial infarction increases periinfarct vessel density, fails to improve myocardial perfusion, is associated with loss of collagen in the periinfarct area and impairs left ventricular function.