Transposition of a pericardial-derived vascular adipose flap for myocardial salvage after infarct

Abstract

Aims: Coronary artery occlusion is associated with the risk of ventricular remodelling, heart failure, and cardiogenic shock. Novel strategies are sought to treat these ominous complications. We examined the effect of a pericardial-derived fat flap secured over an acute infarct caused by coronary occlusion.

Methods and results: A novel intervention consisting of the pericardial isolation of a vascularized adipose flap and its transposition fully covering acute infarcted myocardium was developed in the swine model of coronary artery ligation (n= 52). Left ventricular (LV) ejection fraction and LV end-diastolic and end-systolic volumes were assessed using magnetic resonance imaging (MRI). Infarct size and gene expression analysis were performed on Day 6 and 1 month. Histological changes, collagen volume fraction (CVF), and vascular density were also evaluated on postmortem sections. One month after the intervention, a 18.8% increase in LV ejection fraction (P= 0.007), and significant reductions in LV end-systolic (P= 0.009) and LV end-diastolic volumes (P= 0.03) were found in treated animals compared with the control-MI group. At Day 6, histopathology confirmed a significant infarct size reduction (P= 0.018), the presence of vascular connections at the flap-myocardium interface, and less apoptosis in the infarct border zone compared with control animals (P< 0.001). Up-regulation of genes involved in cell cycle progression, cellular growth and proliferation, and angiogenesis were identified within the flap.

Conclusions: Our results indicate that a vascular fat flap exerts beneficial effects on LV function and limits myocardial remodelling. Future studies must confirm whether these findings provide an alternative therapeutic approach for myocardial salvage after infarction.