Survival in Subcortical Vascular Dementia: Predictors and Comparison to Probable Alzheimer's Disease in a Tertiary Memory Clinic Population

Background: Subcortical vascular dementia (SVaD) is one of the most common dementias, after Alzheimer's disease (AD) dementia. Few survival analyses in SVaD patients have been reported. Methods: The dates and causes of death of 146 SVaD and 725 AD patients were included. We used the Cox proportional hazards model to compare survival between SVaD and AD patients and to explore possible factors related to survival of SVaD patients. Results: The median survival time after the onset of SVaD (109 months) was shorter than that recorded for AD (152 months). The most common cause of death in SVaD was stroke (47.1%). Factors associated with shorter survival in SVaD were late onset, male sex, worse baseline cognition, absence of hypertension and a family history of stroke. Conclusions: Stroke prevention may be important in SVaD treatment because 47.1% of SVaD patients died of stroke. A family history of stroke and absence of hypertension were associated with a shorter survival in SVaD, suggesting the existence of genetic or unknown risk factors.