I've seen my husband through 4 thoracic surgeries, two valve surgeries, and two lung surgeries, all about the same as far as risk and recovery. He had one other valve surgery before we were married.
The only way I was able to get through those surgeries was to have confidence in the surgeon, learn as much as I could about his medical problems and the surgery itself. It was very difficult to read at first, but I forged ahead with my "education" online until I was as comfortable as possible with what was going to happen. I learned how he was going to act and look first thing out of surgery, how he would very slowly recover, and what I would be seeing. I learned that he would be weak and not himself for a while, and could not drive or lift heavy things. I learned that he would be on an emotional rollercoaster from the meds and anesthesia, and that would last for a while and that I would have to ignore the emotionality. I learned that he wouldn't be sleeping well at night, and probably would want to sleep sitting up or in a recliner. I learned that he would not be eating well at all. I learned that he would be having appointments to check his progress, and that I would be with him for these. I learned that he would need close care for the first two weeks 24/7. I learned that I would have to get rest when I could during this time. I learned that I would not want to be away from him for any time at all during the first two weeks. I learned that this surgery is like no other, and that it is NOT like an appendectomy. I learned that the initial healing would take 6-8 weeks, and then there would be gradual healing that would take a year or longer.
And I learned that this was all to be expected and most others go through the exact same thing. That gave me comfort.
Then I sailed over the actual event in my mind into the near future when I would be doing what I could to help Joe, and make his recovery as easy as I could at home. That kept me very busy physically and emotionally.
The secret to it all is to educate yourself, both of you. Do not go into this without knowledge. It will help you tremendously, to get over the rough spots, if you know what to expect.
The mortality rate is very low, considering the seriousness of the operation, and that is because the surgeons who do this are in and out of hearts a couple of times per day in most cases. They and their teams really know their stuff and know how to handle any issues that could come up.
You will be in very good hands and will have the best of care the hospital can give.