Ultrasound Targeted Microbubble Cavitation (UTMC) for the treatment of Myocardial Microvascular Obstruction (MVO)

Abstract

Congestive heart failure following acute myocardial infarction is increasing due to microvascular obstruction (MVO), for which there is no effective therapy. We have been developing ultrasound-targeted microbubble cavitation (UTMC) as a potential treatment. Rapacz familial hypercholesterolemic (RFH) pigs were used in this study. MVO was created in the left anterior descending (LAD) microcirculation. UTMC therapy was applied during infusion of Definity®. Left ventricular (LV) segmental wall motion and microvascular perfusion were assessed with ultrasound. Cardiac MRI was obtained to measure infarct size and area of MVO; ultrasound imaging and coronary angiography were performed at 48h. LAD angiographic flow was improved at 48 h post-treatment in comparison to control. UTMC treatment significantly improved echo-based LV systolic performance. UTMC was also found to significantly enhance LAD blood volume at 48h versus control. MRI-derived LV segmental wall motion and ejection fraction also improved post-treatment. Infarct size was reduced as assessed by both Evans Blue/TTC staining and MRI. In conclusion, we demonstrated that UTMC significantly reduced infarct size, enhanced LAD microvascular perfusion and improved LV systolic performance.