Yasunari Hayashi ^1,2 Seungil Kim ^1,3 Taro Fujii ^1,2* Drake Dalton Pedersen ^1,3* Hongbin Jiang ^1* Antonio D'Amore ^1,4 William R Wagner ^1,2,3*

• ¹ McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
• ² Department of Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
• ³ Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States
• ⁴ Fondazione RiMED, Palermo, Palermo, Italy

In a model of right heart failure secondary to pulmonary artery banding, a mechanical approach, using an elastic, biodegradable epicardial patch with integrated extracellular matrix digest was evaluated for its potential to inhibit disease progression. Adult male syngeneic Lewis rats 6-7 weeks old were used. Biohybrid cardiac patches were generated by coprocessing biodegradable poly(ester carbonate urethane) urea and a digest of porcine cardiac extracellular matrix. Three weeks after pulmonary artery banding (PAB), the cardiac patch was attached to the epicardium of the right ventricle (RV). Cardiac function was evaluated using echocardiography and catheterization for 9 weeks after PAB, comparing patch (n = 7) and sham (n = 10) groups. Nine weeks after PAB, the RV wall was thickened, the RV cavity was enlarged with a reduced left ventricular cavity, and the RV wall interstitial fibrosis was increased, but these effects were diminished in the patch group. Left ventricular ejection fraction in the patch group was higher than sham (P < 0.001), right end-systolic pressure was lower (P = 0.045), and tricuspid annular plane systolic excursion improved in the patch group (P = 0.007). In addition, von Willebrand Factor expression was significantly greater in the patch group (P = 0.007). Placement of a degradable, biohybrid patch onto the RV in a right ventricular failure model with fixed afterload improved myocardial output and moderated pressure stress, and was associated with reduced right ventricular fibrosis.