Yes. you can have atherosclerosis
(hardening of the arteries) without ateriosclerosis (blockage of the arteries). you can have a weakness in the vessels that may lead them to "balloon" or rupture. Both are causes of stroke
and other serious health issues.
Here is a question, why is he worried about living long enough to retire when he should be worried about living after he retires? - believe me, thats when most people feel they have the opprotunity for the first time in thier lives to do what they want - so tell him to make some changes in his diet, and go for a half hour walk every day.
That way he will be around long enough to enjoy his retirement, not just earn it.