I work with 2 people who have had; quad at age 62 and triple at age 42 by-passes.
They both said they didn't realise how bad they had been till they felt the improvement afterwards.
They both had very quick diagnosis and ops.
Both on daily tablets, but generally in good health.
They couldn't do heavy lifting for 6 months, gets a bit messy when your chest opens up apparently..

Good that it was spotted in time in your father.