EVOLUTION OF IMPLANTABLE, MAGNETICALLY LEVITATED HEARTQUEST??? VAD FOR DESTINATION THERAPY

Abstract

AIM: Develop the magnetically levitated HeartQuest™ VAD to support late-stage CHF patients for 10+ years. METHODS: Lessons learned from clinical VAD experience and knowledge of clinical needs for Destination Therapy were applied to configure the HeartQuest VAD. A clinically viable system utilized advances in key components (centrifugal pump, magnetic levitation, brushless motor, and control schemes) that were innovatively integrated. The system's design optimization process relied on a unique computer-based tool that integrated analytical equations and heuristic knowledge for each key component and its behavior under static and dynamic loads. Biocompatibility and hemo-dynamic capacity were evaluated in 22 in vivo studies in calves (2 years cumulative implant time, longest duration 5 months). Anatomic fit and placement were evaluated intra-operatively in twenty consenting adults. RESULTS: The compact HeartQuest LVAD is 75mm in diameter, 35mm thick, and has 22 ml priming volume. The efficacy of completely suspending and rotating the impeller with only a single actively-powered axis of levitation control has been demonstrated. Performance highlights include: - Insignificant hemolysis (110 mg/dl PFH), thrombosis, and minimal pump-related complications in calves - Wide range of operation: from low (0-1.7 L/m) to high (15 Urn) flow rates in calves -Excellent anatomic fit in 1.0–2.9 m2, BSA patients Such results provide the basis to complete and verify the system design for initial clinical trials in the near future.