Sub-Acute Animal Implantation of a Novel Bioprosthethic Artificial Heart

Purpose The Carmat total artificial heart (TAH) is a recently developed electro-hydraulically driven biventricular system. It is designed as an alternative to heart transplant and placed in orthotopic position. The TAH has bioprosthetic blood-contacting surfaces and provides 3-9 l/min pulsatile flow in response to preload changes detected by the device. The purpose of this pre-clinical study was to monitor device performance and physiologic response during 48 hours functioning in an animal model. Methods and Materials Five female calves of the Charolais race, 2-4 months old, weighing 100-110kg, were selected. The TAH was implanted via mid-sternotomy and powered by an external console through a percutaneous driveline. Animals were maintained under anesthesia during the study. The procedure was managed by a team of veterinarians, cardiac surgeons and clinical anesthesiologists/intensivists. Hemodynamic measurements, diuresis and blood samples to assess venous oxygen saturation and serum lactate were taken before implantation and during device functioning. Results Baseline cardiac output of the native heart was 13.0±2.2 l/min. The TAH maintained a pulsatile flow between 7 and 9 l/min in all animals. The mean arterial pressure was 119±8 mmHg at baseline, 75±4 mmHg at 24 and 82±10 mmHg at 48 hours, with pulse pressure (systolic-diastolic) 42±9 mmHg at baseline 36±11 mmHg at 24 hours and 41±12 mmHg at 48 hours. Serum lactate decreased from 9.8±4.5 mmol/l post-CPB to 1.6±0.2 mmol/l at 24 hours and 1.2±0.6 mmol/l at 48 hours. Venous oxygen saturation at baseline was 73±18%, and remained stable at 78±7.5% at 24 hours and 83±0% at 48 hours. Diuresis averaged 321±172 ml/hour. It was decided to stop the procedures at 3.5 and 16 hours for technical reasons and at 36, 49 and 51 hours per protocol. Conclusions The implantation technique for the Carmat TAH is similar to heart transplantation. In a Charolais calf model under anesthetized conditions, the TAH is capable to produce pulsatile flow up to 9 l/min and restore tissue perfusion.