I know you're hearing alot of testimonials, but my dad was almost 70 when he had his quad bypass surgery. He always tells us that his "first heart" lasted him almost 70 years, and he expects that his "second refurbished heart" will last him at least another 70!! He has reason to believe it works b/c HIS father lived to be 94 and had also had heart bypasses. So here's to lots of long Disney-filled years together and the memories that make them last. Our prayers are with you and your family.
What insight you have to bring us all back to the reality of what's really important in our lives and to be especially thankful for our health and loved ones. We will all be wishing your DH and family the very best during these trying times.
Good luck! Our DD had open-heart surgery at 4 1/2 months and it was stressful and scary BUT they have made so many advances in the areas of heart surgery-I'm sure he will be fine and you will have many, many more years of Disney magic together.
My mom had a double bypass six years ago at 69, and she was on kidney dialysis to boot. She's frail now for a combination of reasons: she can't see very well, she fell this past spring and fractured her pelvis in 5 places and shattered her shoulder, and dialysis is hard on the body. However, I take to the cardiologist every three months, and he says that despite all these other ailments, her heart is doing great.
Best of luck and keep the faith. These things can turn around.