We had a much older guy, have multiple bypass(open-heart) surgery. He successfully returned to work. In his mid to late 50's.
Maybe 6 months total recovery. He was never really the same(dynamically). But was fully certified.....at least from all appearances.....he had a bid feeder run(afterwards).
I would think....a better resource than a BA would be YOUR DOCTOR! If he thinks your surgery was successful and you are cleared for "normal" activities that can include long hours, lifting to 150 lbs, stress and all that goes with UPS....
I think as far as CDL goes.....there are standards and thresholds to be met. This from our guy in related conversations. That there was a mandatory period of time for evaluation, recertification etc. I don't think you can just show back up for work.
In other words, open-heart is a pretty big deal. Heart attacks, strokes are a big deal. Cancer too. Our guy failed a stress test which led to his surgery. He DID Not have a heart attack. BTW, our guy fancied himself "in shape" and "worked out a lot".
I will say, most of us were surprised of his surgery. Usually hear of that kind of thing after retirement....when all that hard living, smoking and drinking catches up with you. Congenital defects(or the like) are a different matter....
You didn't say what your job was/is.....some of the above applies to pkg/feeder. If you are a pt whatever....some of that may or may not apply. Either way, you are subject to UPS doctors and your doctor.
Recovery will take time and personal discipline.......(sorry for the inside joke). I know our guy was pretty shaky for awhile when first back. My Dad had several open heart surgeries...he was never the same. Most folks I know(several).....it's a pretty life-changing event. You are relatively young. Lastly, I would imagine the question is: Can hard work(like we do) make it fail again?
Good luck.