If the rate of available organs isn't high enough to cover the rate of those in need. How does extending the life of those in need change that? Is that not just putting newer additions to the need list further behind while complicating the recovery of those with pig hearts?
I mean, its neat. I just don't see how it will help unless there are times where a viable heart is waiting for a patient, not the other way around. At lest then you might hope that an oversupply of donated hearts occurs and you could get one. Otherwise it seems kind of pointless.