Dysfunction following myocardial infarction is attenuated by implantation of myoblast-based polyurethane patches

Objectives: Myocardial cell transplantation has recently demonstrated great potential for the management of patients with severe heart failure (HF). We previously reported on the potential of myoblast-based bio-artificial constructs for increasing the density of cells after implantation as compared to direct injection. We present now the functional analysis of post-infarction hearts treated by implantation of such a patch.

Material and Methods: Adult Lewis rats with echo confirmed post-infarction reduced ejection fraction (EF) were randomized to a) implantation of myoblasts seeded polyurethane patches at the site of infarction (group A, n=11), b) implantation of naked polyurethane patches (group B, n=11), c) sham operation (group C, n=12). Echo was repeated 4 weeks later as well as the analyses of left ventricular contractile parameters (dP/dtmax). Histological and immunostaining analysis were later carried out.

Results: Pre-randomization EF was similar in all groups (47.9±2.1%; 48.3±2.2%; 48.2±2.7% for groups A, B and C respectively). Four weeks post-intervention, it significantly decreased in groups B (39.1±2.3%; p=0.02) and C (39.9±3.5%; p=0.04) whereas it remained stable in group A (48.4±3.1%). Similarly, dP/dtmax remained significantly higher in group A (4960±266mmHg/s) as compared to groups B (3909±248mmHg/s, p=0.01) and C (4028±199mmHg/s, p=0.01). Immunohistology identified a high density of myoblasts within the seeded scaffold.

Conclusions: Myoblast-seeded bio-artificial patches prevent the progression toward HF after myocardial infarction. Since a high number of myoblasts can be delivered, this technique may allow long term benefit as compared to direct injection. A long term study has been initiated.