Measurement of resistance-area product by transcranial Doppler: a reliable marker of preclinical cognitive decline in hypertensive patients on drug treatment

Arterial hypertrophy and remodeling are adaptive responses present in SAH that can result in silent ischemia and neurodegeneration, compromising brain connections and cognitive abilities. However, antihypertensives can minimize these histological changes. We try to assess whether cerebrovascular hemodynamic parameters, representative of these histological adaptations, can identify cognitive impairment in a preclinical stage in chronic hypertensive on drug treatment. Three groups of patients without cognitive complaints were prospectively compared: hypertensive under treatment with systolic blood pressure (SBP) < 140 and diastolic blood pressure (DBP) < 90 mmHg (n=54), hypertensive under treatment with SBP > 140 or DBP >90 mmHg (n=31) and volunteers normotensive (n=30). Simultaneous measurements of systemic BP and middle cerebral artery (MCA) blood flow velocity were obtained from digital plethysmography and Transcranial Doppler. For the cognitive assessment, the Mini Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) and a broad neuropsychological battery were applied. In relation to normotensive, uncontrolled hypertensive were older (51 ± 12 years), had greater resistance-area product (RAP 1.7 [±0.7] vs. 1.2 [±0.2], p< 0.001), but did not differ in relation to the pulsatility indices (p=0.361). There was a negative correlation between RAP, episodic memory (r = -0.277, p=0.004) and cognitive processing speed (r = -0.319, p=0.001). In chronic hypertensive using antihypertensive, the RAP is a reliable marker of preclinical cognitive decline in specific domains, as it is less influenced by the direct action of these drugs, and should be further explored as an alternative tool for screening for cognitive impairment in these individuals.