Dimethyl Sulfoxide Reduces Microvascular Obstruction and Intramyocardial Hemorrhage in a Porcine Ischemia-Reperfusion Model

Background: Microvascular obstruction (MVO) and Intramyocardial hemorrhage (IMH) are associated with myocardial reperfusion injury and recognized as predictors of adverse left ventricular remodeling in acute myocardial infarction. The pathophysiology of reperfusion injury is characterized by release of reactive oxygen species and inflammation. We investigated whether post-ischemic reperfusion with Dimethyl sulfoxide (DMSO), an organic solvent with therapeutic anti-inflammatory and antioxidant capabilities, could diminish or even abrogate the development of MVO and IMH in a porcine myocardial ischemia/reperfusion model. Methods and Results: Myocardial ischemia was induced in 20 pigs by balloon occlusion of the Left anterior descending artery (LAD) for 65 minutes. The pigs were allocated to one-hour reperfusion with DMSO or placebo. Eight days post-injury, IMH, MVO, left ventricular function, and myocardial salvage were assessed by Cardiovascular Magnetic Resonance (CMR) imaging; and IMH and myocardial salvage were also assessed by gross pathology. All pigs in the placebo group (100%) but only 10% of the pigs in the DMSO group had IMH. CMR imaging showed presence of MVO in all placebo-treated pigs (100%) and 88% of the DMSO-treated pig and the MVO size was 45% (p=0.03) smaller in DSMO treated pigs. No difference in myocardial salvage between the placebo and the DMSO group was found by CMR, and pathological investigation and global left ventricular function examination showed no difference between the two study groups. Conclusion: Reperfusion with a DMSO-containing solvent applied during ischemic reperfusion protected against IMH and MVO in a porcine myocardial ischemic/reperfusion model.