my mate's hubby had his done in the summer. He got a bit breathless during the Bath Half Marathon and thought he'd picked up a bit of a virus,popped to the doc's on the Monday for a check-up and got blue-lighted straight into the local cardiac unit!
Anyhow, he had his op and is monstering his way to recovery. Its been slow but steady. His main problem was rib cage pain, which panicked him a bit, but when you think they open you up like a book its understandable that your muscles are going to ache a bit!
He's finished his cardio-rehab and is back out slowly building his running up again, so tell your missus to keep her chin up, do as she's told TO THE LETTER and take it slow.
PS The old chap in the next bed to him had his op 4 days later (he's in his late 70's) and while his recovery has been slower,due to age and initial fitness, he's also doing really well and regularly walking 3-4 miles
My daughter had open heart surgery a few years back. A good source of information was the British Heart Foundation and from them we were directed to Heartline. Heartline have offices and workers all over the country who are availble for visits or just a chat over the phone. I think they have a forum (similar to ARSSE) as well.