Measurement of resistance-area product by transcranial Doppler: An alternative tool for cognitive screening in hypertensive on drug treatment?

Introduction

Arterial hypertrophy and remodeling are adaptive responses present in systemic arterial hypertension that can result in silent ischemia and neurodegeneration, compromising brain connections and cognitive performance (CP). However, CP is affected differently over time, so traditional screening methods may become less sensitive in assessing certain cognitive domains. The study aimed to evaluate whether cerebrovascular hemodynamic parameters can serve as a tool for cognitive screening in hypertensive without clinically manifest cognitive decline.

Methods

Participants were allocated into groups: non-hypertensive (n = 30) [group 1], hypertensive with systolic blood pressure (SBP) < 140 and diastolic blood pressure (DBP) < 90 mmHg (n = 54) [group 2] and hypertensive with SBP ≥ 140 or DBP ≥ 90 (n = 31) [group 3]. Measurements of blood pressure and middle cerebral artery 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.

Results

Patients in groups 2 and 3 show no significant differences in most of the clinical-epidemiological variables or pulsatility index (p = 0.361), however compared to group 1 and 2, patients in group 3 had greater resistance-area product [RAP] (1.7 [±0.7] vs. 1.2 [±0.2], p < 0.001). 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).

Conclusion

RAP reflects the real cerebrovascular resistance, regardless of the direct action of antihypertensive on the microcirculation, and seems to be a potential alternative tool for cognitive screening in hypertensive.

Evaluation of cerebral autoregulation performance in patients with arterial hypertension on drug treatment

Cerebral autoregulation (AR) keeps cerebral blood flow constant despite fluctuations in systemic arterial pressure. The final common AR pathway is made up of vasomotor adjustments of cerebrovascular resistance mediated by arterioles. Structural and functional changes in the arteriolar wall arise with age and systemic arterial hypertension. This study evaluated whether AR is impaired in hypertensive patients and whether this impairment differs with disease control. Three groups of patients were prospectively compared: hypertensive patients under treatment with systolic blood pressure (SBP) <140 and diastolic blood pressure (DBP) <90 mm Hg (n = 54), hypertensive patients under treatment with SBP > 140 or DBP > 90 mm Hg (n = 31), and normotensive volunteers (n = 30). Simultaneous measurements of cerebral blood flow velocity (CBFV) and BP were obtained by digital plethysmography and transcranial Doppler, and the AR index (ARI) was defined according to the step response to spontaneous fluctuations in BP. Compared to the uncontrolled hypertension, the normotensive individuals were younger (age 43.42 ± 11.14, P < .05) and had a lower resistance-area product (1.17 ± 0.24, P < .05), although age and greater arteriolar stiffness did not affect the CBFV mean of hypertensive patients, whether controlled or uncontrolled (62.85 × 58.49 × 58.30 cm/s, P = .29), most likely because their ARIs were not compromised (5.54 × 5.91 × 5.88, P = .6). Hypertensive patients under treatment, regardless of their BP control, have intact AR capacity.

Systemic arterial hypertension and cognition in adults: effects on executive functioning

BACKGROUND

Central nervous system changes associated to systemic arterial hypertension (SAH) are progressive and may cause negative effects on cognitive performance. The objective of this study was to investigate the relation between SAH and the components of executive functions (EF), inhibitory control (IC), updating and shifting, comparing a control group (without SAH) to patients with SAH, in two levels of severity.

METHODS

The protocol included the following tests to evaluate EF components: T.O.V.A. Test (IC), Backward Digit Span from Wechsler Adults Intelligence Scale (WAIS-III), Phonemic and Semantic Verbal Fluency (updating), and Trail Making Test Part B (shifting).

RESULTS

A total of 204 participants was included: 56 from the Control Group (CG), 87 SAH stage 1, and 61 SAH stage 2. The groups were not different for age (52.37±12.29) and education (10.98±4.06). As to controlled blood pressure (BP), duration of hypertension treatment and number of drugs, the SAH 2 group had a worse BP control, longer duration of hypertension treatment and use of more drugs when compared to the SAH 1. The findings revealed that patients with more severe hypertension presented worse performance in updating (Backward Digit Span, phonemic and semantics VF) and shifting (Trail Making Test Part B).

CONCLUSION

The results suggest that patients with SAH have a significant impairment in EF, more specifically in updating and shifting. Besides that, such damage may be directly proportional to the severity of SAH. It is suggested that future studies include neuroimaging exams to exclude possible cerebrovascular diseases.

Gender differences of aortic wave reflection and influence of menopause on central blood pressure in patients with arterial hypertension

Background

Evidences suggest that central hemodynamics indexes are independent predictors of future cardiovascular events and all-cause mortality. Multiple factors have been pointed to have potential influence on central aortic function: height, heart rate, left ventricular ejection duration and blood pressure level. Data related to the influence of gender and postmenopausal status on aortic waveform reflection is scarce. We aim to evaluate the impact of gender and menopause on central blood pressure of hypertensive patients.

Methods

In a cross sectional study 122 hypertensive patients (52 men and 70 women) were studied. Hypertension was defined as blood pressure (BP) levels ≥140/90 mmHg or use of antihypertensive drugs. Central arterial pressure, augmentation index (AIx) and augmentation index normalized to 75 bpm (AIx75) were obtained using applanation tonometry. Menopause and postmenopause history were accessed by a direct series of questions. Postmenopause was defined as at least one year since last menstruation. Patients were paired by age, gender and menopausal status, and the data were compared considering gender and menopausal status.

Results

Height and weight were significantly lower in women than in men at the same age. Conversely, AIx (32.7 ± 9.8% vs. 20.1 ± 11.7%, p < 0.01), AIx75 (29.6 ± 6.7% vs. 18.3 ± 9.4%, p < 0.01) and central systolic blood pressure (136 ± 30 vs. 125 ± 23 mmHg, p = 0.03) were higher in women than men. The menopausal women (mean age of menopause = 48 years) had the worst indexes of aortic wave reflection, compared to men at the same age and younger women.

Conclusion

Hypertensive women had both higher reflected aortic pressure waveform and central blood pressure indexes than hypertensive men, and these findings were worsened by the menopausal status.

Impact of hypertension severity on arterial stiffness, cerebral vasoreactivity, and cognitive performance

Aging, hypertension (HTN), and other cardiovascular risk factors contribute to structural and functional changes of the arterial wall.

Intermittent claudication and severe renal artery stenosis are independently associated in hypertensive patients referred for renal arteriography

OBJECTIVE:

The purpose of this study was to evaluate the association between the presence of clinical symptoms of peripheral artery disease and severe renal artery stenosis in patients referred for renal angiography.

METHOD:

We included 82 patients with clinical suspicion of renovascular hypertension and performed an imaging investigation (renal Doppler ultrasound and/or renal scintigraphy) for possible renal artery stenosis. All patients underwent renal arteriography and were examined for peripheral artery disease based on the presence of intermittent claudication and ankle-brachial index test results. Severe renal artery stenosis was defined as a lesion causing 70% obstruction.

RESULTS:

Severe renal artery stenosis was present in 32 of 82 (39%) patients. Patients with severe renal artery stenosis were older (63±12 vs 56±12 years, p=0.006), had more intermittent claudication (55 vs 45%, p=0.027), and had a greater prevalence of an ankle-brachial index <0.9 (44% vs 20%, p=0.021) than patients without severe renal artery stenosis. Multivariate logistic regression analysis showed that the presence of intermittent claudication was independently associated with renal artery stenosis ≥70% (OR: 3.33; 95% CI 1.03-10.82, p=0.04), unlike the ankle-brachial index, which showed no association (OR: 1.44; 95% CI 0.37-5.66, p=0.60).

CONCLUSION:

Intermittent claudication is independently associated with severe renal artery stenosis (≥70%) in patients clinically suspected of having renovascular hypertension.