Treatment for VaD involves controlling the vascular risk factors such as blood pressure, cholesterol levels, diabetes etc.
the strongest evidence available to date involves the use of anti-hypertensive agents - randomized placebo controlled trials (PROGRESS, HOPE trials) have found that anti-hypertensive agents reduce the incidence of dementia in elderly patients 
each 1 mmHg decrease in BP in mid-life is equal to a 1% less chance of developing dementia in later years 
a recent meta-analysis found that ChEis are associated with differential risks for death in VaD, from no risk to substantially increased risk - this is likely due to the heterogeneity of risk factors in VaD and further studies are required to know the overall effectiveness and safety of these drugs and what patient benefits the most 
4. Schneider, LS, Loy C, Birks J, Hermans D, Insel P, McShane R. Cholinesterase inhibitors are associated with differential risks for death in vascular dementia and in severe Alzheimer's Disease. Alzheimer Association's International Conference on Alzheimer's Disease and Related Disorders; 2006 July 15-20; Madrid, Spain.