Introduction: Despite recent technological advances, use of current mechanical circulatory support (MCS) devices often results in thromboembolic complications. Other approaches for therapy of end-stage left heart failure (LHF) such as direct cardiac compression or passive restraint devices have limitations.
Hypothesis: We developed an implantable soft robotic device that is anchored to the ventricular septum. When the device actuators contract precisely timed to the native cardiac cycle, the LV free wall is approximated toward the septum, which augments the LV ejection.
Methods: The device was tested in adult Yorkshire swine (N=12). LHF was induced by coronary artery ligation and/or Esmolol injection (Group 1, N=6) or by intracoronary injection of 50-100μm microbeads (Group 2, N=6). Aortic and pulmonary flow rate, aortic and left atrial pressures were measured. LV function was assessed using pressure volume catheter and echocardiography. The measurements were taken at healthy baseline, LHF, 5 and 30 min after device actuation.
Results: The device was deployed in 9 animals. Two animals in Group 1 developed untreatable ventricular fibrillation, before (N=1) or during the deployment. The first animal from Group 2 was used solely for characterization of the LHF. After 5 minutes of the device operation, the aortic flow rate improved by 52%, pulmonary by 64.8%, aortic pressure by 24%, and LV ejection fraction by 48.3% from the LHF. LVEDP, LVESP, LAP and dP/dt continued to improve at 30 min. The device operation resulted in elimination of the mitral regurgitation and restoring the leaflets coaptation height.
Conclusions: Implantable soft robotic device provides pulsatile augmentation of the LV blood ejection and dynamically improves the mitral valve function. This approach would reduce thromboembolic complications of MCS and unlike extracardiac direct compression and restraint devices, targets only the diseased LV, while preserving the right ventricular function.