Hi and welcome to HCM.
It doesnt have to be related t ohis previous surgery. MAny people develop high blood pressure
,most common it is called esential. The same is with proteins
in urine. It can be found in healthy people too. But I suggest to do kidney ultrasound
and creatinin and urea blood levels. If this is normal then he has nothing to worry about. Just regulate blood pressure by standard medicines.
Wish you good health.