DETECTION OF THE HYPERTENSION-MEDIATED COGNITIVE BRAIN DAMAGE. CLOCK DRAWING TEST UTILITY

Abstract

Objective: Hypertension (HTN) is the main modifiable vascular risk factor for developing cognitive impairment and dementia. ‘Cognitive status’ could be a “surrogate” or ‘potential biomarker’ of HTN-mediated brain damage. Thirty percent of the hypertensive patients have cognitive impairment and/or silent brain damage (white matter hyperintensities) without cardio-renal damage. However, the involvement of the brain as a HTN-related target-organ damage (TOD) is not systematically evaluated. Then our objective were : 1) to know the prevalence of cerebral, cardiac, and renal TOD in a sample of hypertensive patients, and 2) to demonstrate the usefulness of the clock drawing test (CDT) as a cognitive screening tool to assess brain TOD HTN-mediated. Design and method: Multicentre study (4 centres in Argentina, 1 centre in Uruguay), 441 hypertensive patients were included. Age, gender, weight, height and other variables were recorded. Hypertension was defined according to ESH guidelines. TOD were defined as: renal compromise when, creatinine >1.2 mg/dl and/or creatinine clearance < 60 mL/min (Cockcroft-Gault equation), cardiac compromise when: left ventricular mass index > 95 gr/m2 in female and > 115 gr/m2 in male (transthoracic cardiac ultrasound) and cerebral impairment when: the score of the CDT </ = 5 points. Results: Average age 63.2±11.8 years, 53.4% female. The 60.5% of the sample presented some TO damage. The heart was affected in 32.8% and the kidney in 20.4% while the brain damage (abnormal CDT) was observed in 38% of the total sample, in 47.2% of the hypertensive patients with cardiac and/or renal damage, and in 30.7% of hypertensive patients without cardiac and/or renal damage. Conclusions: The CDT turned out to be a useful, fast and simple tool to be used in routine clinical practice to detect cerebral TOD (cognitive impairment) in hypertensive patients. The clinical expression of the cerebral TOD was more prevalent than pre-clinical cardiac and/or renal TOD.