Evaluation of syncardia total artificial heart using device thrombogenicity emulator

The thrombogenicity of the left ventricle of the temporary Total Artificial Heart (TAH-t) (SynCardia Systems, Inc. Tucson, AZ) was evaluated using our device thrombogenicity emulator (DTE) methodology [1] that integrates advanced numerical modeling of the whole device combined with experimental measurements of platelet activity. The ejection phase of the cardiac cycle, including diaphragm motion, was modeled with fully-coupled fluid structure interaction (FSI) simulation. Stress loading histories of several thousand platelet trajectories were extracted from these simulations and collapsed into quantitative probability density function (PDF) distributions that represent the TAH-t thrombogenic footprint. Representative stress-loading waveforms with substantially higher stress accumulation (high propensity to cause platelet activation) were replicated in computer controlled hemodynamic shearing device (HSD), where the effect on platelet activation was measured with a modified prothrombinase assay. By determining the platelet stress accumulation distribution, the thrombogenic signature unique to specific TAH design from the results, this methodology facilitates virtual evaluation and optimization of various designs.