An Elastic, Biodegradable Cardiac Patch Induces Contractile Smooth Muscle and Improves Cardiac Remodeling and Function in Subacute Myocardial Infarction
Our objective in this study was to apply an elastic, biodegradable polyester urethane urea (PEUU) cardiac patch onto subacute infarcts and to examine the resulting cardiac ventricular remodeling and performance.
Background
Myocardial infarction induces loss of contractile mass and scar formation resulting in adverse left ventricular (LV) remodeling and subsequent severe dysfunction.
Methods
Lewis rats underwent proximal left coronary ligation. Two weeks after coronary ligation, a 6-mm diameter microporous PEUU patch was implanted directly on the infarcted LV wall surface (PEUU patch group, n = 14). Sham surgery was performed as an infarction control (n = 12). The LV contractile function, regional myocardial wall compliance, and tissue histology were assessed 8 weeks after patch implantation.
Results
The end-diastolic LV cavity area (EDA) did not change, and the fractional area change (FAC) increased in the PEUU patch group (p < 0.05 vs. week 0), while EDA increased and FAC decreased in the infarction control group (p < 0.05). The PEUU patch was largely resorbed 8 weeks after implantation and the LV wall was thicker than infarction control (p < 0.05 vs. control group). Abundant smooth muscle bundles with mature contractile phenotype were found in the infarcted myocardium of the PEUU group. The myocardial compliance of the PEUU group was distributed between normal myocardium and infarction control (p < 0.001).
Conclusions
Implantation of a novel biodegradable PEUU patch onto a subacute myocardial infarction promoted contractile phenotype smooth muscle tissue formation and improved cardiac remodeling and contractile function at the chronic stage. Our findings suggest a new therapeutic option against post-infarct cardiac failure.
Abbreviations and Acronyms
bFGF
basic fibroblast growth factor
CHF
congestive heart failure
EDA
end-diastolic left ventricular cavity area
ESA
end-systolic left ventricular cavity area
FAC
fractional area change
LV
left ventricular
PEUU
polyester urethane urea
P-E
pressure-strain
SMA
smooth muscle actin
SMMHC-2
smooth muscle myosin heavy chain 2
VEGF
vascular endothelial growth factor
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This work was supported by the National Heart, Lung, and Blood Institute, grant HL069368.