The Antihypertensives and Vascular, Endothelial and Cognitive Function Trial (AVEC)

The purpose of this study is to examine the effects of blood pressure medications on cognition and blood flow in hypertensive elderly patients with cognitive impairment. The hypothesis is that treatment with an angiotensin receptor blocker (ARB) or an angiotensin-converting enzyme inhibitor (ACEI) will be associated with a slower rate of further cognitive decline, improved cerebral blood flow and its regulation, and preserved physical function as compared to treatment with a diuretic (HCTZ), independent of blood pressure level.

There is mounting evidence that hypertension, which affects more than 65% of the US elderly population, accelerates cognitive decline and increases the risk of functional disability among older individuals. Hypertension is also associated with cerebral blood flow reduction and dysregulation which contribute to further cognitive and functional impairment. Drugs that inhibit angiotensin II (ACEI and ARB) are commonly used antihypertensives and may have a protective effect on cognitive function, cerebral blood flow and physical function compared to other antihypertensives such as hydrochlorothiazide (HCTZ). A total of 100 individuals will be recruited for this pilot 3-arm randomized study to investigate the effects of: (i) 12 months treatment with candesartan (ARB) compared to hydrochlorothiazide (HCTZ) and (ii) 12 months treatment with lisinopril (ACEI) compared to HCTZ and (iii) to estimate the effect size difference between lisinopril and losartan on cognition, cerebral blood flow regulation, and functional measures in a sample of elderly hypertensive individuals with objective evidence of cognitive impairment.

orally 8 mg increased to 16 mg then 32 mg to achieve target blood pressure of 140/90, then daily for 12 months

orally 10 mg increased to 20 mg then 40 mg to achieve target blood pressure of 140/90, then daily for 12 months

orally 12.5 mg increased to 25 mg to achieve target blood pressure of 140/90, then daily for 12 months

If needed to achieve target blood pressure of 140/90, added to ARB or ACEI at 30 mg increased to 60 mg and 90 mg in 2 week increments

If needed to achieve target blood pressure of 140/90, added to ARB or ACEI at 12.5 mg increased to 25 mg and 50 mg

This test requires the connection of sequentially numbered circles (A), and the connection of circles marked by numbers and letters in alternating sequence (B). This test is considered a benchmark of executive function. The test score is the time required to complete the task in seconds.

This is a 12-item list learning test in which individuals are presented three learning and recall trials followed by a delayed recall and 24 item recognition test. The HVLT-R has been identified as an ideal memory measure for elderly patients, and appropriate reliability and validity have been shown in older individuals. The test score is the number of correct answers in the delayed recall ( score range 0-12)

This test consists of series of digits of increasing length, some of which are recited as presented, and some of which are to be recited in reversed order. The forward digit span score ranges from 0 (ie cannot repeat two digits) to 8 ( participant can repeat up to 8 digits)

Blood pressure was measured as follows: the participant was in the sitting position, rested for 5 minutes, no caffeine or smoking 2 hours prior to measurement, using appropriate cuff size (covering 60% of upper arm length and 80% of arm circumference), correct cuff placement (1-2 inches above brachial pulse on bare arm), and the bell of the stethoscope. The systolic blood pressure was defined as the pressure corresponding to the first korotkoff sounds (K1) and the diastolic as the pressure corresponding to the last korotkoff sound (K5). Blood pressure was measured in both arms and recorded

Inclusion Criteria: 60 years or older Hypertension Cognitive criteria: score either 10 or less out of 15 for the executive clock draw test 1 (CLOX1) or less than or equal to 1 standard deviation from the corresponding age specific mean on the immediate memory subtest Exclusion Criteria: Intolerance to ACEI or ARB History of congestive heart failure History of diabetes mellitus History of stroke (less than 6 months)

Lipsitz LA, Gagnon M, Vyas M, Iloputaife I, Kiely DK, Sorond F, Serrador J, Cheng DM, Babikian V, Cupples LA. Antihypertensive therapy increases cerebral blood flow and carotid distensibility in hypertensive elderly subjects. Hypertension. 2005 Feb;45(2):216-21. doi: 10.1161/01.HYP.0000153094.09615.11. Epub 2005 Jan 17.

Hajjar I, Hart M, Milberg W, Novak V, Lipsitz L. The rationale and design of the antihypertensives and vascular, endothelial, and cognitive function (AVEC) trial in elderly hypertensives with early cognitive impairment: role of the renin angiotensin system inhibition. BMC Geriatr. 2009 Nov 18;9:48. doi: 10.1186/1471-2318-9-48.

Hajjar I, Hart M, Chen YL, Mack W, Milberg W, Chui H, Lipsitz L. Effect of antihypertensive therapy on cognitive function in early executive cognitive impairment: a double-blind randomized clinical trial. Arch Intern Med. 2012 Mar 12;172(5):442-4. doi: 10.1001/archinternmed.2011.1391. No abstract available.

Hajjar I, Hart M, Chen YL, Mack W, Novak V, C Chui H, Lipsitz L. Antihypertensive therapy and cerebral hemodynamics in executive mild cognitive impairment: results of a pilot randomized clinical trial. J Am Geriatr Soc. 2013 Feb;61(2):194-201. doi: 10.1111/jgs.12100. Epub 2013 Jan 25.