I'm late to the comment column on this post, but as a family physician I felt compelled to put in my thoughts. This is indeed a very interesting experimental device. Although the surgery to implant the device will almost certainly be an open thoracotomy, requiring a cardiothoracic surgeon to open the chest as with other open heart surgeries, the potential advantage of a durable device that can improve ventricular pumping function without implanting a pump inside the vasculature and requiring blood thinners and risking stroke is a major step forward.
The animal studies that are sure to follow should help determine how much irritation these devices cause on the outside of the heart, how durable the devices are and whether there unexpected complications with time of use.
I don't want to sound like a skeptic, but this device is far from ready for prime time, and has huge challenges to meet before being ready for use at scale in humans.
Still a cool hunt, allowing us to dream big.