Clinical Durability of the CARMEDA BioActive Surface in EXCOR Ventricular Assist Device Pumps

The durability of CBAS Heparin Surface on EXCOR pumps retrieved after clinical use for varying periods of time was studied by analyzing samples for surface heparin density and bioactivity. The mean time of clinical use of the investigated 14 EXCOR pumps was 178 days (range, 15-461 days). Mean heparin density was 3.1 ± 0.6 μg/cm² (range, 2.2-4.8 μg/cm²), and the measured mean heparin bioactivity was 14 ± 5 ρmol/cm² (range: 7-27 ρmol/cm²). There was no detectable degradation or loss of function of CBAS Heparin Surface over time. Samples from the housing and the membrane of the EXCOR pump showed no significant difference in heparin bioactivity or density. The CBAS Heparin Surface stays on the surface and remains bioactive on the EXCOR pump at least up until 1 year. This is an important demonstration of coating durability and supports the mid-term and long-term clinical use as bridge-to-heart transplantation or to myocardial recovery.