BACKGROUND: The aim of this study was to evaluate the cardioprotective effects of bone marrow-derived stem cells on myocardial compliance in a chronic ischemia model regarding strain rate (SR) parameters during dobutamine stress echocardiography (DSE). METHODS: Ameroid constrictors were placed around the circumflex arteries of 23 domestic pigs to induce chronic vessel occlusions. Fifteen pigs received transendocardially bone marrow derived stem cells, and 8 received placebo injections (a 0.9% solution of NaCl) into the ischemic region. At week 6, the animals were evaluated regarding myocardial fibrosis, neovascularization, apoptosis, and diastolic function during DSE. RESULTS: Stem cell-injected hearts showed significantly less fibrosis, higher ejection fractions, significant neovascularization, and less ventricular dilatation than controls (P <.05). Strain rate imaging revealed improved diastolic function, with higher early diastolic SR values and lower E/Ea ratios compared with controls (P <.05). Early diastolic SR during DSE identifies viable myocardium (extent of fibrosis, r = 0.86, P = .0001). CONCLUSION: The endocardial injection of stem cells improves diastolic function in chronic ischemic myocardium and helps attenuate postinfarction remodeling.
