CAndesartan vs LIsinopril Effects on the BRain

* Hypertension is associated with cognitive impairment even in the absence of clinical dementia. To date, no specific treatment is available for this pattern of mild cognitive impairment related to hypertension. * Objectives or purpose: The aims of this study are to investigate the effects of candesartan on executive function decline and on changes in cerebral perfusion, cerebrovascular reserve and microvascular brain injury. The study also intends to identify potential underlying mechanisms related to vascular structure and function, including atherosclerosis, vascular inflammation, vascular stiffness, and endothelial progenitor cells, by which candesartan may affect the cognitive and cerebrovascular outcomes. * Study methodology:This is a double blind randomized clinical trial that will be conducted in 140 individuals (70 in the candesartan group, 70 in the lisinopril group). Our target population is subjects: 55 years or older with hypertension and Executive Mild Cognitive Impairment. * Endpoints to be measured:Our measures include cognitive function, cerebral perfusion and reserve, markers of vascular brain damage, atherosclerosis, stiffness, vascular inflammation and endothelial function. * Description of intervention, follow-up, and duration of study: Eligible participants will undergo randomization into 2 groups and will be seen frequently until their blood pressure is controlled (\<140/90 mmHg). Participants will be seen at 3, 6 and 12 months afterwards.