I just saw this and I am 52 and on 24 Oct 23 I have CABG x3 (Triple Bypass). I started a 12 week Cardiac Rehab program through the hospital that I had surgery at on 4 December. Since they had stationary bikes there they allowed me to ride at home on my trainer (Zwift) on 14 December with a strict heart rate limit. On 3 Jan I was allowed outside but just rode my mountain bike for 5 miles through the neighborhood nice and easy. I was so paranoid of wrecking and cracking my chest as well. I have since progressed nicely and this last weekend did a 75 mile route with a friend on the road. I am registered for a ride this weekend and I will either do the 85 or 100 mile option. Really all depends but I am cleared to do it.
I hope that answered your question but more importantly how is your recovery going?