COMPARISON OF LionHeart??? LVAD-IMPLANTED CALVES BASED ON RENAL INFARCTIONS

Abstract

Background: Early implantations of the LionHeart™ (Arrow International) left ventricular assist device (LVAD) in calves may have had fewer renal infarctions, an indicator of favorable outcome, during FDA Investigational Device Exemption (IDE), pre-clinical trials than in later implantations. We compared these results. Methods: From 1998–1999, 9 calves were implanted with the First Generation LionHeart™ without clinical or mechanical errors. From 1999–2005, 18 similar, anticoagulated animals were implanted with First and later generation LionHearts™. Renal infarct severity was graded (0–4) based on photographs, necropsy reports, and histopathology. Calves were compared for differences in device flow, device percent fill, plasma hemoglobin level, outlet graft-to-graft anastamosis technique, and anticoagulation (corrected prothrombin time ratio, similar to international normalized ratio). Results: Pre-clinical, IDE calves had significantly lower renal infarction scores compared to later implantations: 2 +/-1 vs. 3 +/-1 (mean, SD), p=0.021. They also had lower device percent fill: 88.5 +/-1.8 vs. 94.3 +/-2.2, p=0.0000003. Also, all pre-clinical implants had factory-sewn outlet graft-to-graft anastamoses while later anastamoses were hand-sewn. There were no significant differences in anticoagulation, device flow, or plasma hemoglobin level. Discussion: Pre-clinical, IDE LionHeart™ LVAD-implanted calves had significantly less renal infarctions. Two factors that may explain this difference are decreased device percent fill and factory-sewn graft-to-graft anastamoses.