P27: Initial Fitting Study of Left Atrial Assist Device in Heart Failure with Preserved Ejection Fraction: Virtual Assessment with 3-D Computed Tomography Images

Abstract

Study: We are developing the left atrial assist device (LAAD) with specific features: 1) it is implantable in the mitral plane, and 2) it delivers blood from the left atrium to the left ventricle to mitigate high left atrial pressure of heart failure with preserved ejection fraction (HFpEF). Here we report the first results of a virtual fitting study using 3D heart images of patients with HFpEF. Methods: Virtual fitting using five computed tomography (CT) scan images of adult HFpEF patients was performed. 3D CT images of the chest in five cases of HFpEF (60.4 ± 9.8 years old, 107.6 ± 20.4 kg, two cases were male) were obtained and combined with a virtual LAAD in stereolithographic (STL) file format. Anatomical fit of the pump was evaluated by size and alignment per each case. For each of the five patients, the LAAD 3D-reconstructed image was virtually inserted into the mitral plane of the patients’ heart, and the pump position was finely adjusted. Scales of the pump and the hearts were calibrated to match each other. Results: All five patients’ chests were able to accommodate the LAAD (Fig. 1). With several cross sectional and multi-directional views per each case, feasibility in size and alignment were confirmed. The five patients’ hearts had typical HFpEF features, such as, expanded left atrium and narrow left ventricle, and there was enough space around the LAAD’s inlet in the left atrium, indicating that there was a low risk of wall suction. Also, the LAAD pump does not cause any obstruction of the left ventricular outflow tract. Conclusions: This initial study revealed the suitable range of LAAD implantation in various sizes of the HFpEF population. Further studies including more heart anatomies of HFpEF patients are required and planned.Figure 1. Combined 3-dimentional images of the left atrial assist device and a patient heart with heart failure with preserved ejection fraction. A: top view, B: backside view, C: side view, D: cross sectional view.