Retrospective analysis of adverse events in preclinical ventricular assist device experiments

Ventricular assist devices (VADs) are a widely acceptable therapeutic option for patients with end-stage heart failure. Data from preclinical animal trials provide important information about the efficacy, biocompatibility, and functioning of these devices. However, animal experiments have several limitations that may significantly affect outcomes even after implanting a properly functioning device. This retrospective analysis was performed to analyze, at explant, adverse events associated with VADs during the animal phase of testing. Data were collected from 141 VAD experiments performed in cattle that had received 11 different types of devices. A total of 294 adverse events were documented. Inflow cannula problems were cited in 79 implants (56%) and pump-related issues in 55 cases (39%). Adverse events associated with connectors were found in 53 implants (38%). Adverse events directly having to do with the animals represented only 17 implants (12%) in this series. These findings suggest that preclinical testing needs to place greater emphasis on the entire VAD system. In support of these results, human clinical data seem to indicate that actual VAD failure is rarely a cause for premature device removal.