I'm a nurse, hopefully I can help with this one. So Vader is 61, most of his wrestling/football career hes always been big, maybe he hasnt been acquiring to a healthy lifestyle all these years which attributed to his diagnosis. He's weighed over 300lbs for such a long time that in reality he should be between 168-210lbs. Maybe he was a drinker or a smoker or did other drugs after all these years, (which disqualifies you for a transplant btw) that lead to his CHF. Im sure he was diagnosed with an early CAD (chronic arterial disease) years ago but probably was non-compliant with his medication regimen which lead to his heart failure. I think because of his age, prior diagnosis(s), and possible risks he may not receive a transplant. If he does get the transplant, you have to worry about the risk (M.I., cardiac arrest, dysrhythmia) especially because of his weight and past/current lifestyle. Imagine the aorta and SVC being all messed up all these years, that even if they did the transplant, theres a chance that the new heart will not last--blood flow will not be flowing properly leading to other cardiovascular issues.
The only way for him to have prevented this was adhering to a healthy lifestyle and being compliant to medication regimen.
If he were to request a transplant he would have to go through a series of test and factors (which takes a long time) to prove does this individual need a new heart, how would the interdisciplinary team know if he'll take care of the new one, what is his past medical/social/history of present illness? We also have to think about his kidneys as well because thats the organ that filters everything in our bodies and an individual with CAD is also at risk for CKD (chronic kidney disease--end stage renal failure)...Once the kidneys go, then thats it (not to mention that it is extremely difficult for most people to receive a kidney transplant or a liver transplant for that matter, and if he were to consider getting you have to out-weigh the risks.) Also I wanted to mention he stated "Congestive Heart Failure," which is the heart not pumping well and blood could be backing up into other organs, lets say the lungs for example which leads to shortness of breath. If he does get the transplant theres a risk that he can develop ARF (Acute Resp. Failure) in which he would either get a tracheostomy (a hole in his throat that will be used for him to breathe in) or be sedated on a ventilator. From there, his quality of life will just be going downhill. We also have to think if his body can even handle cardiothoracic surgery. CHF medications involve in reducing fluid (need to keep a close eye on the kidneys because if they arent filtering then fluid will accumulate leading to shortness of breath which leads to many problems), meds to lower BP, vasodilators to widen the blood vessels allowing blood to flow, heart meds to reduce blockage of the arteries.
In terms of other surgery he could probably get is CAB coronary artery bypass surgery in which a device is inserted in the femoral artery all the way to the blocked artery near his heart and clears the blockage (stent). Other than that its hard to say if his body can handle the stress. Either way I truly don't know him nor his actual history, im just stating the possibilities and risks he can face based on looking him up and reading that tweet he posted. His doctors probably told him that if he doesn't acquire to medication regimen, proper diet, and exercise at this point he will only have 2 years left to live. He can extend those years (Vader Time) if were to be compliant, but hey who knows, Im probably wrong about that too, maybe he was acquiring to medication regimen. In order for any of us to know how to treat this guy, we need to know more of his history and current present illness, lab tests, etc. I'll pray for him regardless and hopefully this health lesson was helpful to some of you lol