I am personally against the idea of raising pigs for the sole purpose of being organ reserves for humans, regardless of circumstances, although yes the idea is particularly aggravating in light of nutritionally-induced heart disease.

This said, there is one scenario that I would find possibly acceptable: kidney transplant from a healthy pig to a needy human, assuming that 1) pigs can live with a single kidney as humans can and 2) the organ recipient adopts the pig as a lifelong companion, provides them with the care and love due to a family member, and adopts a fully plant-based diet. I'd say that's a reasonable trade-off.