AAV9.I-1c Delivered via Direct Coronary Infusion in a Porcine Model of Heart Failure Improves Contractility and Mitigates Adverse Remodeling

Background-Heart failure is characterized by impaired function and disturbed Ca2+ homeostasis. Transgenic increases in inhibitor-1 activity have been shown to improve Ca-2 cycling and preserve cardiac performance in the failing heart. The aim of this study was to evaluate the effect of activating the inhibitor (I-1c) of protein phosphatase 1 (I-1) through gene transfer on cardiac function in a porcine model of heart failure induced by myocardial infarction. Methods and Results-Myocardial infarction was created by a percutaneous, permanent left anterior descending artery occlusion in Yorkshire Landrace swine (n=16). One month after myocardial infarction, pigs underwent intracoronary delivery of either recombinant adeno-associated virus type 9 carrying I-1c (n=8) or saline (n=6) as control. One month after myocardial infarction was created, animals exhibited severe heart failure demonstrated by decreased ejection fraction (46.4 +/- 7.0% versus sham 69.7 +/- 8.5%) and impaired (dP/dt)(max) and (dP/dt)(min). Intracoronary injection of AAV9.I-1c prevented further deterioration of cardiac function and led to a decrease in scar size. Conclusions-In this preclinical model of heart failure, overexpression of I-1c by intracoronary in vivo gene transfer preserved cardiac function and reduced the scar size.