Delayed Transplantation of Autologous Mitochondria for Cardioprotection in a Porcine Model.

Background. We have previously demonstrated the efficacy of mitochondrial transplantation (MT) for the treatment of ischemia-reperfusion injury (IRI). We now investigate the efficacy of delayed MT by intracoronary administration in a model of regional IRI as a strategy for cardioprotection. Methods. Female Yorkshire pigs (40-50 kg; n = 16) underwent 30 minutes of ischemia by snaring of the left anterior descending artery, and the hearts were then reperfused for 120 minutes. At that point, vehicle only or autologous mitochondria (1 x 10(9) in 5 mL of vehicle) were delivered as a bolus to the left coronary ostium, followed by a further 120-minute reperfusion. Results. Echocardiographic analysis demonstrated that hearts receiving delayed MT after regional IRI had enhanced ejection fraction (P = .019), fractional shortening (P = .022), and fractional area change (P = .011) at 240 minutes of reperfusion compared with the untreated pigs. At the end of reperfusion there was a difference between the groups in measures of global left ventricular (LV) function such as LV end-diastolic pressure (P = .015) and rate of rise of LV pressure (P = .021). No significant differences were found between the groups in the area at risk (P = .48). Infarct size (% area at risk) was significantly decreased in hearts receiving MT compared with hearts receiving vehicle only (P < .001). Conclusions. Delayed MT by intracoronary injection appreciably decreases myocardial infarct size, increasing regional and global myocardial function. These results suggest that this can be a viable treatment modality in IRI, thus reducing long-term morbidity and mortality in cardiac surgical patients. (C) 2020 by The Society of Thoracic Surgeons