Preclinical Evaluation of the EVAHEART 2 Centrifugal Left Ventricular Assist Device in Bovines

The EVAHEART 1 left ventricular assist device was miniaturized to the EVAHEART 2, with a new inflow cannula designed to mitigate the risks of malposition. To evaluate the safety of the new double-cuff tipless inflow cannula, in vivo studies were performed in healthy bovines. Eight consecutive studies were done: five short-term studies of hematological adaptation and three long-term studies of tissue adaptation. Each inflow cannula was purposefully implanted in the worst-case setting with marked malposition. Two studies terminated early: one because of an animal-specific ancillary component and one because of an accidental radial fracture. Six studies reached the study endpoint without major adverse events. One animal could not achieve proper anticoagulation because of warfarin resistance. Pump speed and power were maintained within stable, normal ranges. There were no major organ dysfunction or suction events. Necropsy results showed two cases of pannus formation around the inflow ostium because of warfarin resistance and hyperinflammation at the inflow cuff suture line. There was one case of trivial pannus; four cases were pannus-free, with no evidence of ventricular wall suction. No wedge thrombus formation occurred. The EVAHEART 2 tipless inflow cannula may reduce adverse events attributable to the inflow cannula, such as stroke.