Heck - I wouldn't shoot a 3" 12 gauge again, even if I was a healthy 25 Y.O.
JMO, But EVERY doctor would recommend reduced shooting, if they were asked. Most equate "guns" with atomic bombs, from what I've heard some say.
My best bud (of 45 years) and I both had heart attacks - me in 2002, and him w/open heart surgery in 2003.
Both attacks occurred around the Christmas holidays, so both of us had some time to recuperate before hunting season in those respective years - but we both shot the rifles/shotguns we have all along, with no ill effects. (YMMV, of course)
Heck, three weeks after I got out of the ICU, I was scheduled to fly to Florida for some R&R (this was before my retirement) & told my Cardiologist about it, and he said OK, but just don't go pushing any airplanes around for awhile.
I still don't drag any deer out, by myself - and neither should you.
If I were you, at this time of year, I'd use a .30-30 rifle and a low-base 20ga (light loads) for this year.