Vascular dementia

My FIL has vascular dementia. Doc originally said Alzheimer’s but changed it recently to vascular which makes far more sense to the experiences we had and have with him.

I’m looking for others experience with this type of dementia particularly in relation to length of time of decline etc

He’s only 68 but I reckon he has it 8 years and he’s fully mobile etc but getting worse and worse.

Is the end for vascular patients more likely to be a heart attack or a stroke. Or even more sudden than with Alzheimer’s?

I’ve had people in the past pass with Alzheimer’s and it was a long long long drawn out affair.

Looking for others experience with vascular.