(957) Implantable Direct Cardiac Compression Devices Do Not Cause Cardiac Injury or Induce Thrombus Formation

PurposeImplantable direct cardiac compression (DCC) devices are under development for mechanical cardiac support. They provide cardiac compression in synchrony with the cardiac cycle, compressing the ventricles during systole and relaxing during diastole. Concern has been expressed about the possibility of coronary artery damage, thrombus, and direct cardiac damage. As part of a study examining DCC in an ovine model of heart failure (HF), the effect of DCC on the coronary arteries, cardiac muscle, and promotion of intraventricular thrombus was assessed.MethodsThree control animals and 3 experimental animals had HF induced with microsphere embolization over 6-8 weeks. All had EF<30% after embolization. 3 experimental animals had a DCC device implanted for 14 days. At 14 days, hemodynamics were assessed and animals were sacrificed. Coronary arteries and ventricular wall were assessed at necropsy. Gross and histologic examination were used to assess for thrombus.ResultsNo coronary artery damage was identified in any animal. Representative H&E stain is seen in Fig 1. Cardiac ventricular wall was free of hematoma or myocardial damage (Fig 2). No thrombus was identified in the cardiac cavities, brain, liver, kidneys or lung of any animal.ConclusionDCC for 14 days using a mechanical device does not result in damage to the coronary arteries or ventricular wall. Intracardiac ventricular thrombus formation did not occur in our series. DCC may provide effective mechanical cardiac support without damaging the coronary arteries and avoiding problems with intraventricular thrombus seen with other types of mechanical cardiac assist. Implantable direct cardiac compression (DCC) devices are under development for mechanical cardiac support. They provide cardiac compression in synchrony with the cardiac cycle, compressing the ventricles during systole and relaxing during diastole. Concern has been expressed about the possibility of coronary artery damage, thrombus, and direct cardiac damage. As part of a study examining DCC in an ovine model of heart failure (HF), the effect of DCC on the coronary arteries, cardiac muscle, and promotion of intraventricular thrombus was assessed. Three control animals and 3 experimental animals had HF induced with microsphere embolization over 6-8 weeks. All had EF<30% after embolization. 3 experimental animals had a DCC device implanted for 14 days. At 14 days, hemodynamics were assessed and animals were sacrificed. Coronary arteries and ventricular wall were assessed at necropsy. Gross and histologic examination were used to assess for thrombus. No coronary artery damage was identified in any animal. Representative H&E stain is seen in Fig 1. Cardiac ventricular wall was free of hematoma or myocardial damage (Fig 2). No thrombus was identified in the cardiac cavities, brain, liver, kidneys or lung of any animal. DCC for 14 days using a mechanical device does not result in damage to the coronary arteries or ventricular wall. Intracardiac ventricular thrombus formation did not occur in our series. DCC may provide effective mechanical cardiac support without damaging the coronary arteries and avoiding problems with intraventricular thrombus seen with other types of mechanical cardiac assist.