Exaggerated Postural Blood Pressure Rise Is Related to a Favorable Outcome in Patients With Acute Ischemic Stroke

Orthostatic Hypertension: A Newcomer Among the Hypertension Phenotypes

The prognostic role and the clinical significance of orthostatic hypertension (OHT) remained undefined for long because data were sparse and often inconsistent. In recent years, evidence has been accumulating that OHT is associated with an increased risk of masked and sustained hypertension, hypertension-mediated organ damage, cardiovascular disease, and mortality. Most evidence came from studies in which OHT was defined using systolic blood pressure (BP) whereas the clinical relevance of diastolic OHT is still unclear. Recently, the American Autonomic Society and the Japanese Society of Hypertension defined OHT as an orthostatic systolic BP increase ≥20 mm Hg associated with a systolic BP of at least 140 mm Hg while standing. However, also smaller orthostatic BP increases have shown clinical relevance especially in people ≤45 years of age. A possible limitation of the BP response to standing is poor reproducibility. OHT concordance is better when the between-assessment interval is shorter, when OHT is evaluated using a larger number of BP readings, and if home BP measurement is used. The pathogenetic mechanisms leading to OHT are still controversial and may vary according to age. Excessive neurohumoral activation seems to be the main determinant in younger adults whereas vascular stiffness plays a more important role in older individuals. Conditions associated with higher activity of the sympathetic nervous system and/or baroreflex dysregulation, such as diabetes, essential hypertension, and aging have been found to be often associated with OHT. Measurement of orthostatic BP should be included in routine clinical practice especially in people with high-normal BP.

Early mobilisation is associated with lower subacute blood pressure and variability in ICH: A retrospective cohort study✰

BACKGROUND

Very early rehabilitation after stroke appears to worsen outcome, particularly in intracerebral haemorrhage (ICH). Plausible mechanisms include increased mean blood pressure (BP) and BP variability.

AIMS

To test associations between early mobilisation, subacute BP and survival, in observational data of ICH patients during routine clinical care.

METHODS

We collected demographic, clinical and imaging data from 1372 consecutive spontaneous ICH patients admitted between 2 June 2013 and 28 September 2018. Time to first mobilisation (defined as walking, standing, or sitting out-of-bed) was extracted from electronic records. We evaluated associations between early mobilisation (within 24 h of onset) and both subacute BP and death by 30 days using multifactorial linear and logistic regression analyses respectively.

RESULTS

Mobilisation at 24 h was not associated with increased odds of death by 30 days when adjusting for key prognostic factors (OR 0.4, 95% CI 0.2 to 1.1, p = 0.07). Mobilisation at 24 h was independently associated with both lower mean systolic BP (-4.5 mmHg, 95% CI -7.5 to -1.5 mmHg, p = 0.003) and lower diastolic BP variability (-1.3 mmHg, 95% CI -2.4 to -0.2 mg, p = 0.02) during the first 72 h after admission.

CONCLUSIONS

Adjusted analysis in this observational dataset did not find an association between early mobilisation and death by 30 days. We found early mobilisation at 24 h to be independently associated with lower mean systolic BP and lower diastolic BP variability over 72 h. Further work is needed to establish mechanisms for the possible detrimental effect of early mobilisation in ICH.

Blood pressure reduction cut-points for orthostatic hypotension in stroke survivors using a sit-up test: a multicentre cross-sectional study

OBJECTIVE

The sit-up test is used to assess orthostatic hypotension in stroke survivors who cannot stand independently without using a tilt table. However, no study has identified the optimal cut-points for orthostatic hypotension using the test. Therefore, this study aimed to examine the decrease in SBP and DBP during the sit-up test to detect orthostatic hypotension in individuals with stroke.

METHODS

Thirty-eight individuals with stroke, recruited from three convalescent rehabilitation hospitals, underwent the sit-up and head-up tilt tests. Systolic and diastolic orthostatic hypotension was defined as a decrease of at least 20 and 10 mmHg in the SBP and DBP, respectively, during the head-up tilt test. The receiver operator characteristic curve with the Youden Index was used to identify the optimal cut-points.

RESULTS

Eight and three participants showed systolic and diastolic orthostatic hypotension, respectively. The optimal cut-points for orthostatic hypotension using the sit-up test were a decrease of 10 mmHg in SBP [sensitivity = 87.5% (95% confidence interval: 47.4-99.7), specificity = 96.7% (82.8-99.9)] and 5 mmHg in DBP [sensitivity = 100.0% (29.2-100.0), specificity = 88.6% (73.3-96.8)].

CONCLUSION

Compared with the conventional cut-points, smaller cut-points of a decrease in SBP and DBP may be better to identify orthostatic hypotension in individuals with stroke using the sit-up test. The findings of this study may provide valuable information for the clinical application of the sit-up test.

International beliefs and head positioning practices in patients with spontaneous hyperacute intracerebral hemorrhage

Background

Prior to the conduct of the Head Position in Stroke Trial (HeadPoST), an international survey (n = 128) revealed equipoise for selection of head position in acute ischemic stroke.

Objectives

We aimed to determine whether equipoise exists for head position in spontaneous hyperacute intracerebral hemorrhage (ICH) patients following HeadPoST.

Design

This is an international, web-distributed survey focused on head positioning in hyperacute ICH patients.

Methods

A survey was constructed to examine clinicians' beliefs and practices associated with head positioning of hyperacute ICH patients. Survey items were developed with content experts, piloted, and then refined before distributing through stroke listservs, social media, and purposive snowball sampling. Data were analyzed using descriptive statistics and χ² test.

Results

We received 181 responses representing 13 countries on four continents: 38% advanced practice providers, 32% bedside nurses, and 30% physicians; overall, participants had median 7 [interquartile range (IQR) = 3-12] years stroke experience with a median of 100 (IQR = 37.5-200) ICH admissions managed annually. Participants disagreed that HeadPoST provided 'definitive evidence' for head position in ICH and agreed that their 'written admission orders include 30-degree head positioning', with 54% citing hospital policies for this head position in hyperacute ICH. Participants were unsure whether head positioning alone could influence ICH longitudinal outcomes. Use of serial proximal clinical and technology measures during the head positioning intervention were identified by 82% as the most appropriate endpoints for future ICH head positioning trials.

Conclusion

Interdisciplinary providers remain unconvinced by HeadPoST results that head position does not matter in hyperacute ICH. Future trials examining the proximal effects of head positioning on clinical stability in hyperacute ICH are warranted.

Acquired loss of cardiac vagal activity is associated with myocardial injury in patients undergoing noncardiac surgery: prospective observational mechanistic cohort study

BACKGROUND

Myocardial injury is more frequent after noncardiac surgery in patients with preoperative cardiac vagal dysfunction, as quantified by delayed heart rate (HR) recovery after cessation of cardiopulmonary exercise testing. We hypothesised that serial and dynamic measures of cardiac vagal activity are also associated with myocardial injury after noncardiac surgery.

METHODS

Serial autonomic measurements were made before and after surgery in patients undergoing elective noncardiac surgery. Cardiac vagal activity was quantified by HR variability and HR recovery after orthostatic challenge (supine to sitting). Revised cardiac risk index (RCRI) was calculated for each patient. The primary outcome was myocardial injury (high-sensitivity troponin ≥15 ng L^-1) within 48 h of surgery, masked to investigators. The exposure of interest was cardiac vagal activity (high-frequency power spectral analysis [HF_Ln]) and HR recovery 90 s from peak HR after the orthostatic challenge.

RESULTS

Myocardial injury occurred in 48/189 (25%) patients, in whom 41/48 (85%) RCRI was <2. In patients with myocardial injury, vagal activity (HF_Ln) declined from 5.15 (95% confidence interval [CI]: 4.58-5.72) before surgery to 4.33 (95% CI: 3.76-4.90; P<0.001) 24 h after surgery. In patients who remained free of myocardial injury, HF_Ln did not change (4.95 [95% CI: 4.64-5.26] before surgery vs 4.76 [95% CI: 4.44-5.08] after surgery). Before and after surgery, the orthostatic HR recovery was slower in patients with myocardial injury (5 beats min^-1 [95% CI: 3-7]), compared with HR recovery in patients who remained free of myocardial injury (10 beats min^-1 [95% CI: 7-12]; P=0.02).

CONCLUSIONS

Serial HR measures indicating loss of cardiac vagal activity are associated with perioperative myocardial injury in lower-risk patients undergoing noncardiac surgery.

The association between orthostatic blood pressure changes and subclinical target organ damage in subjects over 60 years old

Background

Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension independently predict cardiovascular events, the underlying mechanisms are still controversial. The aim of the study was to investigate the relationships between orthostatic changes and organ damage in subjects over 60 years old.

Methods

This is a prospective observational cohort study. One thousand nine hundred and ninety-seven subjects over 60 years old were enrolled. Participants were grouped according to whether they had a drop ≥ 20 mmHg in systolic or ≥ 10 mmHg in diastolic BP (orthostatic hypotension), an increase in mean orthostatic systolic blood pressure ≥ 20 mm Hg (orthostatic hypertension), or normal changes within 3 min of orthostatism. Multiple regression modeling was used to investigate the relationship between orthostatic hypotension, orthostatic hypertension and subclinical organ damage with adjustment for confounders.

Results

Orthostatic hypotension and orthostatic hypertension were found in 461 (23.1%) and 189 (9.5%) participants, respectively. Measurement of carotid intima-media thickness (IMT), brachial-ankle pulse wave velocity (baPWV), clearance of creatinine, and microalbuminuria were associated with orthostatic hypotension; measurement of IMT and baPWV were associated with orthostatic hypertension in a cruse model. After adjustment, IMT [odds ratio (OR), 95% confidence interval (CI) per one-SD increment: 1.385, 1.052–1.823; P = 0.02], baPWV (OR = 1.627, 95% CI: 1.041–2.544; P = 0.033) and microalbuminuria (OR = 1.401, 95% CI: 1.002–1.958; P = 0.049) were still associated with orthostatic hypotension, while orthostatic hypertension was only associated with IMT (OR = 1.730, 95% CI: 1.143–2.618; P = 0.009).

Conclusions

Orthostatic hypotension seems to be independently correlated with increased carotid atherosclerosis, arterial stiffness and renal damage in subjects over 60 years old. Orthostatic hypertension correlates with carotid atherosclerosis only.

Orthostatic hypotension and physical functioning in older adults: A systematic review and meta-analysis

BACKGROUND

Orthostatic hypotension (OH) may negatively affect physical functioning and aggravate morbidities, but existing evidence is contradictory.

METHODS

MEDLINE (from 1946), PubMed (from 1966) and EMBASE databases (from 1947) were systematically searched for studies on the association of OH and physical functioning in older adults, categorized as: balance, gait characteristics, walking speed, Timed Up and Go time, handgrip strength (HGS), physical frailty, exercise tolerance, physical activity, activities of daily living (ADL), and performance on the Hoehn and Yahr scale (HY) and Unified Parkinson's Disease Rating Scale (UPDRS). Study quality was assessed using the Newcastle Ottawa Scale.

RESULTS

Forty-two studies were included in the systematic review (29,421 individuals) and 29 studies in the meta-analyses (23,879 individuals). Sixteen out of 42 studies reported a significant association of OH with worse physical functioning. Meta-analysis showed a significant association of OH with impaired balance, ADL performance and HY/UPDRS III performance, but not with gait characteristics, mobility, walking speed, TUG, HGS, physical frailty, exercise tolerance, physical activity and UPDRS II performance.

CONCLUSIONS

OH was associated with impaired balance, ADL performance and HY/UPDRS III performance, but not with other physical functioning categories. The results suggest that OH interventions could potentially improve some aspects of physical functioning.

The association between orthostatic hypertension and all-cause mortality in hospitalized elderly persons

Background

Little is known about the prevalence of orthostatic hypertension (OHT) and its effect on long-term mortality in the elderly. We evaluated the prevalence of OHT and its effect on mortality in hospitalized elderly patients.

Methods

Out of 1852 patients admitted between 31/12/1999 and 31/12/2000 to an acute geriatric ward, 474 patients (48% males) with a mean age of 81.5 ± 6.8 years were enrolled in this study. Blood pressure (BP) was measured three times during the day in a supine and standing position. Patients with at least one increase in systolic or diastolic BP levels upon standing were diagnosed with OHT. Medical history, physical examination and laboratory parameters were retrieved from the medical records. Mortality data until 18^th June 2014 were retrieved from the computerized system of the Ministry of the Interior.

Results

Four hundred and seven patients (86%) were diagnosed with OHT. Those without OHT had a lower body mass index and were more likely males, smokers, had a higher rate of Parkinson's disease and less congestive heart failure compared with those with OHT. Patients with OHT had a better survival rate than those without OHT (P = 0.024). Hazard ratios (HRs) for mortality in those with OHT adjusted to age and multiple risk factors were: 0.67 [95% confidence interval (CI): 0.51−0.87] and 0.73 (95% CI: 0.55−0.97), respectively; a similar tendency was noticed in a sensitivity analysis by gender.

Conclusion

Hospitalized elderly patients with OHT had a better survival rate than those without OHT.

Very early mobilization in stroke patients treated with intravenous recombinant tissue plasminogen activator

BACKGROUND

There are limited prospective data on the relative safety of very early mobilization of stroke patients after intravenous recombinant tissue plasminogen activator (IV rtPA) in stroke patients. We hypothesized that very early patient mobilization within 24 hours after IV rtPA administration for acute ischemic stroke would be safe and feasible.

METHODS

The study was a prospective observational safety and feasibility study involving very early mobilization of stroke patients by physical therapy/occupational therapy within 24 hours after IV rtPA administration for treatment of ischemic stroke. A premobilization safety checklist was completed before mobilization to ensure hemodynamic stability. We assessed adverse safety events, including changes in patient symptoms, changes in vital signs, and bleeding complications.

RESULTS

Eighteen patients were enrolled in the study, and informed consent was obtained. One hundred percent of patients were evaluated with a premobilization safety checklist; 72.2% (13 of 18) were mobilized without any adverse event. Eighty-nine percent (42 of 47) of mobilization activities were tolerated without an adverse response. One patient was orthostatic, and 1 patient had transient worsening of hemiparesis. No patient had intracranial bleeding or permanent worsening of neurologic deficits.

CONCLUSIONS

Very early mobilization within 24 hours of ischemic stroke for patients who receive IV rtPA appears to be relatively safe and feasible in most patients. Patients who are mobilized within 24 hours of IV rtPA require detailed neurologic and vital sign monitoring.