Strength training with aortic dissection?

My father had an aortic dissection last year. The tear was quite long so in the end they needed to use a very long stent. More or less all the way from the liver to the heart, 30cm.
He needs to start to loose weight but also so strengthen his chest and back muclse that haven’t recovered from the surgery.
Is barbell training and Hiit suitable with that kind of injury? He is taking his meds and the blood presuar is under control but he still gets out of breath very quickly just by walking 4-500meters.

I heard Jordan talk a little bit about aorta aneurysm on a lecture online, but as I understod that, it was more as a preventiv measure.

He is 73yr, 196cm, 125+kg and a complete novice when it comes to this type of training.

/Jonas

This is not something either of us is going to be comfortable giving recommendations on, sorry.