Objective: The goal of this study was to investigate the efficacy of VPASS with physiological measurements, magnetic resonance imaging (MRI), and histology in a porcine model of myocardial infarction. Background: A catheter-based ventricle-to-coronary vein bypass (VPASStrade mark) has been proposed as a potential treatment strategy for refractory coronary artery disease patients. Methods: In an acute setting, the VPASS implant was deployed percutaneously in three swine. The partial pressure of oxygen (PO(2)) in the anterior interventricular vein (AIV) and left ventricle (LV) were measured before and after VPASS implant with various combinations of balloon occlusion in the AIV and left anterior descending artery (LAD). In a separate chronic study, the VPASS procedure was completed on three swine with a mid-LAD occlusion. Thirty days post-VPASS procedure, angiography, contrast-enhanced MRI, and histology were performed to assess myocardial viability. Perfusion was analyzed using the average percent signal intensity change (APSIC) in the anterior walls (AW) and inferior walls (IW). Results: The VPASS implant was performed without complication. Post-VPASS implantation, the distal AIV PO(2) increased up to the LV PO(2) level during simultaneous AIV and LAD blockage (432 +/- 24 mmHg). At day 30, quantitative perfusion analysis demonstrated no difference in APSIC between AW and IW (125 +/- 26% vs. 137 +/- 38%, P = 0.46). Delayed enhancement and histology showed focal subendomyocardial infarction. Conclusions: VPASS implant with simultaneous AIV and LAD occlusion allows perfusion of oxygenated blood to the distal AIV, which in the setting of an acute myocardial infarction model was capable of rescuing most of the myocardium at risk.
Tags: Magnetic Resonance Imaging, Massachusetts, methods, model, MRI, myocardial infarction, myocardium, NO, patients, Perfusion, physiology, pressure