Too many assunptions are being made in the defence of such a thing for this to be morally or scientifically justifiable.
First, the assumption that these injections/treatments work against corona to a fitting degree. Second, that they don't introduce their own drawbacks/side effects which can inhibit the success of the new heart if not be as bad as corona. Third, that the aforementioned are true and will remain true in the long term. Fourth, that the aforementioned are true and currently gathered data and those working with it are sufficient to draw such a conclusion with enough certainty to effectively kill people over it. Fifth, that the previous point should ever apply in any sort of democratic or life-respecting society. Sixth, that such assumptions can be made and used thusly without incurring long term social consequences.
Finally, there is the assumption by society at large that such decisions, with their associated details, can be allowed to happen without at least losing the favour if not outright incurring the wrath of any higher power(s) that may be watching and judging.