I had triple bypass surgery in Nov, 2020. I'm now 67, and started martial arts training (again) at 64 with my granddaughters. Was at Red belt/Black stripe level (one step shy of my black belt) when I had the surgery. Miracle of miracles: they caught the blockage before I had a heart attack! I had to take basically a year off from full participation in martial arts. Waited about 4 months before I started working out lightly in class. It was a year before I chanced letting anyone throw me. My instructor was completely behind my ideas about a slow return. Got my black belt in April of this year. I still lack the "air" to participate at full steam for long periods of time. The martial arts federation I learn under allowed me to do the forms part of the test at a different time than the others. With just the judge, my instructor and myself present, I could take short breaks between each one (there were 12!) I made it through. Later, with the group, was able to demonstrate the various kicks, punches, throws, etc. CABG surgery usually has COPD attached to it so your "air supply" for strenuous exercise may limit your participation for a bit. As someone suggested already . . . check with your cardiologist and personal care physician before "getting back to it." They'll be happy for you to have the desire since exercise will be key to your keeping healthy for a few more years.