Can CAD Lead To Mild Cerebral Atrophy?

Dear Doctor,
My father has a coronary artery disease and he is gonna to make an open heart surgery but his left hand is continuously shaky so that he has made MRI on his brain and appeared in the result of Mild Cerebral Atrophy so I would like to ask you, Has the CAD affected the brain cause of his left hand started off the shakes with CAD?
what is the right diagnosis? and what is the treatment?

Thanks a lot.
Best regards,

Majed