Stem cell therapy improves myocardial perfusion and cardiac synchronicity: new application for echocardiography

Intravenous delivery of mesenchymal stem cell (MSC) is a noninvasive approach for myocardial tissue repair. We aimed to test this strategy in a pig model of myocardial infarction and to examine the usefulness of new echocardiographic applications to monitor cardioprotective effects of stem cell therapy.

Pigs (n = 8) received autologous or allogeneic MSCs (1 x 10(6)/kg body weight) labeled with fluorescent dye 48 hours after proximal left anterior descending coronary artery occlusion. Infarct size, myocardial function, and perfusion (A x beta) were assessed by myocardial contrast echocardiography and standard histologic methods after 1 month.

Morphologic analysis revealed that labeled MSCs migrated in the peri-infarct region resulting in smaller infarct size by myocardial contrast echocardiography (control vs autologous and allogeneic MSC: 38 +/- 10% vs 25 +/- 5% and 28 +/- 6%, P < .01), higher fractional area shortening (23 +/- 3% vs 34.0 +/- 7% and 28 +/- 2%, P < .01), higher cardiac synchrony (167 +/- 36 vs 68 +/- 17 and 85 +/- 26 milliseconds, P < .003), and improved microvascular flow A x beta in the ischemic border zone (0.18 +/- 0.2 vs 0.56 +/- 0.3 and 0.49 +/- 0.2, P < .03).

Systemic delivery of autologous and allogeneic MSCs preserves myocardial viability even in large animals and is, therefore, an attractive approach for tissue repair. Myocardial contrast echocardiography is useful to evaluate microvascular perfusion, which was enhanced by MSCs.