Geriatric hypotensive syndromes are not explained by cardiovascular autonomic dysfunction alone

Autonomic responses in young females with typical vasovagal syncope

To determine whether young women who have experienced typical vasovagal syncope (tVVS) have altered autonomic response parameters, based on a battery of autonomic tests and maneuvers. Notably, previous studies including small cohorts and a partial list of tests yielded conflicting results. A total of 91 otherwise healthy women were included and divided according to those who had experienced tVVS (39 patients) or not (52 patients). Heart rate variability was evaluated at rest, under strict conditions, during 5 min of standing and during a deep breathing test. Response to Valsalva maneuver and Ewing maneuver were also quantified and compared. Both groups had similar clinical characteristics at baseline. No significant differences were found between the two groups in any of the autonomic parameters evaluated. Autonomic responses in young women who experienced typical vasovagal syncope at baseline were indistinguishable from those who did not. Thus, using non-tilt test autonomic screening tests does not seem to provide diagnostic benefits, and may not be useful in predicting recurrence in this patient population.

Assessment of autonomic symptoms may assist with early identification of mild cognitive impairment with Lewy bodies

OBJECTIVES

Autonomic symptoms are a common feature of the synucleinopathies, and may be a distinguishing feature of prodromal Lewy body disease. We aimed to assess whether the cognitive prodrome of dementia with Lewy bodies, mild cognitive impairment (MCI) with Lewy bodies (MCI-LB), would have more severe reported autonomic symptoms than cognitively healthy older adults, with MCI due to Alzheimer's disease (MCI-AD) also included for comparison. We also aimed to assess the utility of an autonomic symptom scale in differentiating MCI-LB from MCI-AD.

METHODS

Ninety-three individuals with MCI and 33 healthy controls were assessed with the Composite Autonomic Symptom Score 31-item scale (COMPASS). Mild cognitive impairment patients also underwent detailed clinical assessment and differential classification of MCI-AD or MCI-LB according to current consensus criteria. Differences in overall COMPASS score and individual symptom sub-scales were assessed, controlling for age.

RESULTS

Age-adjusted severity of overall autonomic symptomatology was greater in MCI-LB (Ratio = 2.01, 95% CI: 1.37-2.96), with higher orthostatic intolerance and urinary symptom severity than controls, and greater risk of gastrointestinal and secretomotor symptoms. MCI-AD did not have significantly higher autonomic symptom severity than controls overall. A cut-off of 4/5 on the COMPASS was sensitive to MCI-LB (92%) but not specific to this (42% specificity vs. MCI-AD and 52% vs. healthy controls).

CONCLUSIONS

Mild cognitive impairment with Lewy bodies had greater autonomic symptom severity than normal ageing and MCI-AD, but such autonomic symptoms are not a specific finding. The COMPASS-31 may therefore have value as a sensitive screening test for early-stage Lewy body disease.

Determinants of orthostatic cerebral oxygenation assessed using near-infrared spectroscopy

BACKGROUND

To understand the relationship between blood pressure changes during standing up and clinical outcome, cerebral oxygenation needs to be measured, which may be performed using near-infrared spectroscopy (NIRS). However, the role of potential determinants of NIRS-derived orthostatic cerebral oxygenation, i.e., age, sex, type of postural change (i.e., standing up from sitting versus supine position), blood pressure (BP) and baroreflex sensitivity (BRS) is still unknown and needed to better interpret findings from studies using orthostatic NIRS measurements.

METHODS

34 younger (median age 25 years, inter quartile range (IQR) 22-45) and 31 older adults (median age 77 years, IQR 72-81) underwent BP, BRS and NIRS measurements during standing up from sitting and supine position. Linear regression models were used to assess the potential determinant role of age, sex, type of postural change, BP and BRS in orthostatic cerebral oxygenation drop and recovery. Orthostatic cerebral oxygenation test-retest reliability was assessed using intra class correlations.

RESULTS

Younger age, male sex and standing up from supine compared to sitting position were positively associated with cerebral oxygenation drop; older age and standing up from sitting compared to supine position were associated with higher cerebral oxygenation recovery. Test-retest reliability was highest (ICC > 0.83) during standing up from supine position.

CONCLUSION

Based on the findings of this study, age, sex and type of postural change are significant determinants of NIRS-derived orthostatic cerebral oxygenation and should be taken into account in the interpretation of NIRS measurements. In the design of new studies, standing up from supine position is preferable (higher reliability) over standing up from sitting position.

Study on the Relationship Between Orthostatic Hypotension and Heart Rate Variability, Pulse Wave Velocity Index, and Frailty Index in the Elderly: A Retrospective Observational Study

Background: Orthostatic hypotension (OH) is a common disease of the elderly. It is generally believed that the pathogenesis of OH is related to the impairment of autonomic nerve function and the decreased vascular capacity regulation. This study aims to explore the relationship between OH and heart rate variability (HRV) parameters, which reflects autonomic nerve function; ankle-brachial pressure index (ABI), which reflects the degree of vascular stenosis; pulse wave velocity (PWV) index, which reflects vascular stiffness; and frailty index (FI), which reflects the overall health status of the elderly. Methods: From January to September 2018, 24-h HOLTER monitoring, PWV, and ABI were performed in 108 elderly patients with OH and 64 elderly patients who underwent physical examination in our hospital. Analysis software was used to record the subject's standard deviation of the cardiac cycle (SDNN), the standard deviation of the 5-min average cardiac cycle (SDANN), the square root of the average square sum of consecutive n-interval differences (rMSSD), the percentage of the number of adjacent cardiac interval differences >50 ms (pNN50), low frequency (LF), high frequency (HF), very low frequency (VLF), and low frequency/high frequency ratio (LF/HF). Then, FI was evaluated qualitatively and quantitatively in the form of a scale. Results: There was no statistical difference between the two groups on the basis of age, sex, body mass index (BMI), low-density lipoprotein (LDL), resting heart rate, blood pressure, fasting blood glucose, long-term medication, etc. There were significant differences in PWV, SDNN, LF, VLF, and LF/HF between the two groups (P < 0.05). The risk factor of OH in the qualitative (P = 0.04) and quantitative (P = 0.007) index FI was higher in the OH group than in the control group. The risk factors of OH were PWV, SDNN, VLF, LF/HF, and FI, where FI was positively correlated and LF/HF was negatively correlated. Conclusions: The pathogenesis of OH is related to vascular stiffness, imbalance of autonomic nerve regulation, and its comprehensive health status in the elderly. However, arteriosclerosis has not been confirmed as an independent risk factor. Clinical Trial Registration: Retrospectively registered, http://www.chictr.org.cn.

Orthostatic blood pressure recovery associates with physical performance, frailty and number of falls in geriatric outpatients

Blood pressure (BP) recovery after orthostatic hypotension might be important to prevent cerebral hypoperfusion episodes in older adults, and be related to better clinical outcome. The objective was to study the relationship between BP recovery and clinical outcome, that is physical and cognitive performance, frailty and falls, in geriatric outpatients.

Blood Pressure Drop Rate After Standing Up Is Associated With Frailty and Number of Falls in Geriatric Outpatients

Background

The relationship between orthostatic hypotension and clinical outcome in older adults is poorly understood. Blood pressure drop rate (ie, speed of blood pressure drop) may particularly reflect the imposed challenge to the baroreflex and the associated clinical outcome (ie, frailty and number of falls). This study aimed to compare orthostatic blood pressure drop rate and drop magnitude with regard to their association with frailty and number of falls.

Methods and Results

Blood pressure was measured continuously during a standardized active stand task in 168 patients (mean age 81.4±7.0; 55.4% female) who visited a geriatric outpatient clinic for cognitive or mobility problems. The association of orthostatic blood pressure drop rate, blood pressure drop magnitude, and baroreflex sensitivity (ie, increase in heart rate divided by systolic blood pressure drop magnitude) with frailty (Fried criteria and 4 frailty markers) and self‐reported number of falls was assessed using linear regression models, adjusting for age and sex. Systolic blood pressure drop rate had the strongest association with frailty according to the 4 frailty markers (β 0.30; 95% CI, 0.11–0.49; P=0.003) and number of falls (β 1.09; 95% CI, 0.19–1.20; P=0.018); diastolic blood pressure drop magnitude was most strongly associated with frailty according to the Fried criteria (β 0.37; 95% CI, 0.15–0.60; P<0.001). Baroreflex sensitivity was associated with neither frailty nor number of falls.

Conclusions

Orthostatic blood pressure drop rate was associated with frailty and falls and may reflect the challenge to the baroreflex rather than drop magnitude.

Baroreflex function and postprandial hypotension in older adults

PURPOSE

Postprandial hypotension (PPH) is a common but poorly understood etiology for fainting in older adults. One potential mechanism is age-related baroreflex dysfunction. We examined baroreflex function in older adults with PPH and without PPH (noPPH) during a standardized meal test.

METHODS

57 adults (age ≥ 65; 24 PPH, 33 noPPH, mean age 77.9 ± 0.9 years, 54% female) were recruited and had meal tests performed. The baroreflex effectiveness index (BEI, %) and baroreflex sensitivity (BRS, ms/mm Hg) were calculated using the sequence method.

RESULTS

Baseline BEI (22 ± 2 versus 23 ± 2 percent, t = - 0.411, p = 0.682) and BRS (14.1 ± 2.4 versus 13.8 ± 2.5 ms/mm of Hg, t = - 0.084, p = 0.933) were similar in PPH and noPPH subjects. During the meal test PPH subjects showed significantly lower BEI as compared to noPPH subjects (time × PPH, F = 2.791, p = 0.042), while there was no difference in the postprandial change in BRS (time, F = 0.618, p = 0.605).

CONCLUSION

Patients with PPH demonstrated an acute postprandial decrease in baroreflex effectiveness during meal testing as compared with normal subjects, suggesting a potential contributing mechanism for this condition.

Blood pressure management in older people: balancing the risks

Guidelines of arterial hypertension treatment based on individualised expected outcomes are not available for frail older persons. In this paper, we review the evidence, concerning management of arterial blood pressure (BP) in frail older patients. We focused on the best affordable methods for BP measurement; the age-related optimum BP; specific BP goals in agreement with the patients' general heath, frailty status, orthostatic and postprandial hypotension; balancing the benefits against risks of antihypertensive treatment. Lenient BP goals are generally recommended for older persons with moderate or severe frailty, multimorbidity and limited life expectancy. To this aim, there may be a need for deintensification of antihypertensive treatment.

New Horizons in orthostatic hypotension

Background

orthostatic hypotension (OH) is a common disabling condition associated with increased morbidity and mortality. Much of the evidence available is derived from younger populations with chronic neurological disease leading to uncertainty for the diagnosis and management of older people.

Objective

to provide an overview of recent and emerging evidence for the diagnosis, management and prognosis of OH in older persons.

Methods

a narrative review of recent studies, emerging therapies and relevant regulatory updates.

Findings

revisions to the diagnostic criteria for OH include the duration of the blood pressure drop, specific criteria for initial and delayed OH and OH with hypertension. Non-drug therapies remain the first-line treatment option and Comprehensive Geriatric Assessment appears to result in lower rates of OH. Recent evidence concerning withdrawal of causative medication is inconsistent. Midodrine has recently become the only licenced medication for OH in the UK. Other emerging treatments include atomoxetine and droxidopa but these require further evaluation. Many other agents may be used but are not supported by high-quality evidence. The increase in mortality associated with OH is less apparent in older people.

Summary

OH remains common in older people, the new diagnostic criteria address some of the previous uncertainty but evidence concerning withdrawal of antihypertensives is conflicting. Midodrine is now the only licenced medication for OH in the UK, but non-drug therapies remain first line and fludrocortisone may be considered before midodrine. We may see other agents such as droxidopa becoming increasingly used over the coming years.

Nutrient stimulation of mesenteric blood flow - implications for older critically ill patients

Nutrient ingestion induces a substantial increase in mesenteric blood flow. In older persons (aged ≥ 65 years), particularly those with chronic medical conditions, the cardiovascular compensatory response may be inadequate to maintain systemic blood pressure during mesenteric blood pooling, leading to postprandial hypotension. In older ambulatory persons, postprandial hypotension is an important pathophysiological condition associated with an increased propensity for syncope, falls, coronary vascular events, stroke and death. In older critically ill patients, the administration of enteral nutrition acutely increases mesenteric blood flow, but whether this pathophysiological response is protective, or precipitates mesenteric ischaemia, is unknown. There are an increasing number of older patients surviving admission to intensive care units, who are likely to be at increased risk of postprandial hypotension, both during, and after, their stay in hospital. In this review, we describe the prevalence, impact and mechanisms of postprandial hypotension in older people and provide an overview of the impact of postprandial hypotension on feeding prescriptions in older critically ill patients. Finally, we provide evidence that postprandial hypotension is likely to be an unrecognised problem in older survivors of critical illness and discuss potential options for management.

Postprandial hypotension: a systematic review

BACKGROUND

Postprandial hypotension (PPH) is an important clinical problem, which has received inappropriately little attention.

METHODS

A systematic search of the databases PubMed, Embase, Cochrane Library, and Web of Knowledge, from their inception to the present time, was conducted to identify studies relevant to the epidemiology, pathophysiology, and/or management of PPH.

RESULTS

A total of 417 full-text papers were retrieved from database searching and, following screening, 248 were retained. Of these, 167 papers were considered eligible for inclusion.

CONCLUSIONS

PPH occurs commonly in older people and represents a major cause of morbidity. Although the pathophysiology of PPH remains poorly defined, diverse factors, including impairments in sympathetic and baroreflex function, release of vasodilatory peptides, the rate of small intestinal nutrient delivery, gastric distension, and splanchnic blood pooling, appear important. Current pharmacologic and nonpharmacologic management is suboptimal. Research into the pathophysiology of PPH represents a priority so that management can be targeted more effectively.

Impaired systolic blood pressure recovery directly after standing predicts mortality in older falls clinic patients

BACKGROUND

Normally, standing up causes a blood pressure (BP) drop within 15 seconds, followed by recovery to baseline driven by BP control mechanisms. The prognostic value of this initial BP drop, but also of the recovery hereafter, is unknown. The aim of this study was to examine the prognostic value of these BP characteristics in response to standing.

METHODS

In a retrospective cohort study of 238 consecutive patients visiting our falls outpatient clinic, we examined the relation between all-cause mortality and BP decline and recovery directly after active standing up with Cox proportional hazards analyses.

RESULTS

Of 238 patients (mean age 78.4 ± 7.8 years), during a median follow-up of 21.0 months, 36 (15%) patients died. Neither absolute nor relative (%) initial BP drop after standing predicted mortality. In contrast, the magnitude of BP recovery 40-60 seconds after standing was associated with mortality, even after adjustment for age, comorbidity, and other baseline characteristics. When systolic BP had recovered to less than 80% of prestanding baseline after 60 seconds of standing, this was a powerful independent predictor of mortality (hazard ratio: 3.00; 95% confidence interval 1.17-7.68).

CONCLUSIONS

Failure to recover from BP decline in the first minute after active standing up is associated with excess mortality in falls clinic patients. A recovery of systolic BP to less than 80% of baseline after 60 seconds may be used as an easily available cardiovascular marker for increased mortality risk in older falls clinic patients.