Wild-type mice (n聽=聽25) were studied 7 and 28聽days after permanent ligation of the left anterior descending coronary artery. Animals were randomized to receive closed-chest ultrasound-guided intramyocardial delivery of saline (n聽=聽13) or 5聽脳聽105 multipotential adult progenitor cells (MAPCs; n聽=聽12) on day 7. LV end-diastolic and end-systolic volumes, LV ejection fraction, and stroke volume were measured using high-frequency echocardiography. Multiplanar assessments of perfusion and defect area size were made using myocardial contrast echocardiography.
Between days 7 and 28, MAPC-treated animals had 40% to 50% reductions in defect size (P聽<聽.001) and 20% to 30% increases in total perfusion (P聽<聽.01). Perfusion did not change in nontreated controls. Both LV end-diastolic and end-systolic volumes increased between days 7 and 28 in both groups, but LV end-systolic volume increased to a lesser degree in MAPC-treated compared with control mice (+4.2聽卤聽7.9 vs +19.2聽卤聽22.0聽渭L, P聽<聽.05). LV ejection fraction increased in the MAPC-treated mice and decreased in control mice (+3.0聽卤聽4.3% vs 鈭?.6聽卤聽5.9%, P聽<聽.01). There was a significant linear relation between the change in LV ejection fraction and the change in either defect area size or total perfusion.
High-frequency echocardiography and myocardial contrast echocardiography in murine models of ischemic LV dysfunction can be used to assess the response to stem cell therapy and to characterize the relationship among spatial flow, ventricular function, and ventricular remodeling.