Photoacoustic mapping of tissue hypoxia after myocardial infarction in mice

Introduction Early alterations of microvascular blood flow after myocardial infarction (MI) may participate in the development of multiple organ failure. The aim of this study was to assess the contribution of photoacoustic imaging, a hybrid technology based on laser and ultrasound energy coupling, to detect early oxygen saturation (sO2) impairment in peripheral organs (kidney, liver) after MI in mice. Methods An experimental preclinical study was carried out on two groups of six week BALB/c mice: Sham (n=22) versus MI (n=40). MI was obtained by permanent ligation of the left anterior descending artery within 7 days of follow-up. High resolution ultrasound was used to assess left ventricular (LV) function (ejection fraction (EF), Cardiac Output (CO) and longitudinal strain). Photoacoustic imaging (VevoLAZR, ViualSonics®) was used to measure kinetics of the heart, kidney and liver sO2 after MI. Plasma biomarkers (ASAT, ALAT, creatinine, lactate) were assessed. Results LV function was altered 4h post-MI (LVEF: Sham 61.7% n=16, MI 25.7% n=32, p Discussion Post-MI heart failure generates moderate hypoxia of the peripheral organs in mice. Photoacoustic imaging enables early detection of sO2 multi-organ desaturation. The mapping of sO2 organs in real time seems to be an accurate marker to identify microcirculation alteration. This emerging imaging technology could be used to improve and evaluate early microvascular therapeutics.