Cardiac replacement
From Memory Alpha, the free Star Trek reference.
A cardiac replacement is a medical procedure which replaces the heart with a parthenogenetic implant. The mortality rate for this procedure is less than 2.4%.
In 2365, Doctor Pulaski ordered Captain Picard to undergo a cardiac replacement at Starbase 515 in order to fix a prior faulty replacement. (TNG: "Samaritan Snare")
