Project Summary Minimally invasive cardio-thoracic approaches, such as transcatheter aortic valve replacement (TAVR), have recently overtaken traditional surgical methods due to significant reductions in procedural mortality, morbidity, and improved time to recovery. Transfemoral access of the heart via the femoral artery is the most common approach for delivery of large bore devices such as heart valves and left ventricular assist devices (LVAD). Despite improvements in health outcomes through transfemoral percutaneous approaches, large bore catheter sheaths are used that cannot be inserted safely in approximately 20% of patients because of small vessel diam- eter, diffuse atherosclerotic disease, or extensive tortuosity. Transcaval access to the heart has emerged as a new approach to introducing large bore devices into the abdominal aorta, with the donor catheter entering from the femoral vein and the receiver catheter entering from the radial artery, aligning in the inferior vena cava, and crossing over to the aorta. It is vastly superior to transfemoral access due to lower pressure and increased controllability that results from the reduced tortuosity of the venous system, reduced propensity for obstruction, and large size of the veins. However, transcaval access is technically challenging, requiring multiple fluoroscopic viewing angles and operators, which limits its use to specialized medical centers. MagPAD is developing the MagPAD (Magnetic Puncture, Access, and Delivery) device, a cardiac catheter de- livery system that uses magnets to simplify transcaval access to the heart, for large bore access through the venous system. The system employs magnets that are embedded in the leading ends of catheters that automat- ically aligns the catheters and brings the inferior vena cava and aorta closer in 3-dimensional space to simplify crossover to the aorta. This has potential to substantially reduce the difficulty of the process, as it removes the variability in time and difficulty in each procedure by eliminating the need for multiple fluoroscopic viewing angles and potentially multiple operators that are necessary to accurately traverse the guidewire through the snare in three-dimensions. Prior to this Phase I proposal, MagPAD has developed an early prototype catheter and demonstrated magnetic auto-alignment in a porcine cadaveric model. The goal of this project will be to develop a functional prototype and demonstrate feasibility for magnetic alignment, tissue approximation, and guidewire crossover into the aorta in a live porcine model. Success with these goals will substantially lower the barrier to adoption for transcaval procedures, expand access to more patients that are unsuitable for transfemoral TAVR, and improve health outcomes by accessing the heart through the venous system which may reduce vascular complications and risks of ischemia and stroke across all patients