Animal Model of Cardiac Reperfusion Injury to Evaluate the Effects of Electrical Microcurrent Application: Preliminary Results

Purpose Reperfusion injury (RI) occurs after cardiac surgery, myocardial infarction or heart transplantation, however effective treatment strategies are still lacking. Cardiac micro intensity electrical current (C-MIC) modulates inflammation, myocardial remodeling and recovery in failing hearts in vivo and in vitro. This study aimed to establish a large animal model of RI to test C-MIC application on RI after cardiopulmonary bypass (CPB). Methods Seven swines underwent CPB with 120 mins crossclamp time, and were assigned to a control (n=3) or treatment group (n=4). The treatment group received a C-MIC device consisting of an epicardial patch electrode placed on the left ventricular lateral free wall, a transvenous right ventricular counter electrode, and a current generator. C-MIC treatment was continued until CPB weaning. Reperfusion on full CPB flow lasted 20 mins, followed by a stepwise weaning process. Inotropes or pacing were not allowed. Noradrenaline was used to maintain arterial pressure and xylocaine for arrhythmia treatment. Defibrillation was performed as needed. Primary end-point was survival at 20 mins after CPB weaning. Results Baseline characteristics and pre-CPB hemodynamics were comparable between groups. All C-MIC devices were successfully implanted, without observed malfunction. A microcurrent in the upper µA range was delivered. In the C-MIC group, CPB weaning was successful in all animals, and survival with stable hemodynamics was observed in 50% of cases (Table 1). Weaning and survival rates were lower in the control group. Noradrenaline was required in 50% of the C-MIC animals and in 100% of control animals to maintain arterial pressure after CPB. Conclusion Our study presents an animal model which allows evaluation of RI treatment strategies. In this pilot trial, the C-MIC device was safely and successfully implanted. Our data suggest a potential benefit of C-MIC treatment for RI and further studies are needed to test this promising therapy.