Acute coronary syndromes (ACS) account for an increasing level of healthcare expense although patient morbidity and mortality remain relatively high. Current methods for assessing the extent of cardiac ischemic injury in an acute setting offer limited sensitivity and specificity, which leads to both under- and over-treatment of patients with suspected ACS. In the current project, we propose to develop a novel molecular imaging probe for visualization of recent myocardial ischemia using echocardiography. Specifically, we aim to develop a microbubble contrast agent targeted to a molecular marker of recent ischemia. We have identified a novel targeting ligand, and developed a biocompatible coupling chemistry suitable for translation to human use. We will validate ligand conjugation and microbubble stability, and assess the targeting efficacy of the resultant microbubble formulations in vitro and in a mouse model of ischemic memory. Successful completion of these aims will result in a molecular imaging probe that may be used to accurately and rapidly identify patients with recent myocardial ischemia. PUBLIC HEALTH RELEVANCE: Imaging of recent ischemia is a critical unmet need in cardiac care. In the current project, we aim to develop a diagnostic imaging test for detecting recent myocardial ischemia using ultrasound imaging. Success in this project will enable rapid identification of patients who would benefit from myocardium-sparing treatments, and eliminate unnecessary hospitalizations for patients who have not experienced an ischemic event.