Effects of coronary venous retroinfusion of lipo-prostaglandin E₁ on myocardial infarct size in pigs

Abstract

The coronary venous system is an alternate route for drug delivery to the acutely ischemic myocardium when the coronary arterial blood flow is impeded. This study was designed to determine the effect of retrograde infusion of lipid microsphere containing prostaglandin E₁ (lipo-PGE₁), which is believed to prevent rapid destruction of PGE₁, on myocardial infarct size after acute myocardial ischemia and reperfusion. Twenty-one open-chest porcine models were subjected to 45 minutes of left anterior descending coronary artery (LAD) occlusion followed by 4 hours of reperfusion. Group A (n = 7), the control group, was given, into the great cardiac vein, 4 ml of vehicle dissolved in 36 ml of saline for 5 minutes starting before the onset of reperfusion. In group B (n = 7), 20 μg/4ml of lipo-PGE₁ was administered into the great cardiac vein in the same manner as in group A. Group C (n = 7) was treated the same as group B, but lipo-PGE₁ was injected into the inferior vena caval vein. Infarct size, expressed as a percentage of area at risk, was significantly smaller in group B (56.1±12.6%) than groups A (79.4 ± 11.4%) and C (83.0 ± 11.1%) (p< 0.05). The results of this study indicate that retrograde infusion of lipo-PGE₁ is an effective treatment for the prevention of myocardial reperfusion injury in the experimental model.