Abnormal Blood Pressure Circadian Rhythm in Acute Ischaemic Stroke: are Lacunar Strokes Really Different?

Association of reverse dipping blood pressure with mortality among critically ill patients with ischemic stroke

Reverse dipping blood pressure, generally regarded as a pathological condition, is frequently observed in patients with acute stroke. We aimed to assess the association of reverse dipping blood pressure with in-hospital mortality among critically ill patients with ischemic stroke. This is a retrospective study of patients in the Medical Information Mart for Intensive Care IV database with ischemic stroke requiring intensive care unit admission. Diurnal (9:00-21:00) and nocturnal (1:00-6:00) mean arterial pressures (MAPs) were collected. Reverse dipping was defined as having an average nocturnal MAP higher than the average diurnal MAP. Multivariable binary logistic regression analysis was used to assess the association of reverse dipping with in-hospital mortality. A total of 2080 patients (median age, 73 years; 50.3% female) were enrolled, among which 681 patients (32.7%) had reverse dipping. Patients with reverse dipping blood pressure had a higher in-hospital mortality compared to those without (19.8% vs. 11.4%, p < 0.001). After adjusting for potential confounders, reverse dipping was associated with a higher likelihood of in-hospital mortality (adjusted OR, 1.59; 95% CI 1.21-2.11; p = 0.001). Reverse dipping blood pressure was associated with a higher mortality rate among critically ill patients with ischemic stroke. The circadian rhythm of blood pressure should warrant more attention in cerebrovascular neurocritical care.

Characteristic of 24-Hour Blood Pressure Dipping Patterns in Hypertensive Stroke Patients

Objective

We conducted a study titled for Investigation on the characteristics of 24-hour blood pressure (BP) dipping patterns in hypertensive stroke patients.

Methods

Descriptive research, analysis, and comparison, the research was conducted from July 2019 to September 2020 at the Vietnam Heart Institute - Bach Mai Hospital. There are 100 patients diagnosed with idiopathic hypertension who were divided into two groups (without stroke complications and another group with chronic stroke complications > 6 weeks), both groups were similar in age (45-64 years old).

Results

The daytime systolic BP (SBP) indices, 24-hour BP including SBP, diastolic BP (DBP), and mean arterial pressure (MAP), and particularly night-time BP indices were elevated in the stroke group compared with those without stroke complications (p < 0.05); there were no significant differences observed in daytime DBP and MAP between the two groups. SBP indices were higher in those with hemorrhage stroke compared with those with ischemic stroke, albeit without statistical significance. The prevalence of non-dipper was significantly higher in the stroke group compared with the non-stroke group (p < 0.001).

Conclusion

The daytime SBP indices, 24-hour BP (SBP, DBP, MAP), and particularly night-time BP indices were elevated in the stroke group compared with those without stroke complications. The prevalence of non-dipper was significantly higher in the stroke group compared with the non-stroke group.

Importance of blood pressure monitoring in the acute phase of stroke. An update

INTRODUCTION

The evaluation of blood pressure (BP) is essential in the acute phase of stroke. Although ambulatory blood pressure monitoring (ABPM) is a validated method for BP control, there are few studies assessing the usefulness of ABPM in the acute phase of stroke.

DEVELOPMENT

A systematic review was carried out according to the PRISMA criteria in the PubMed/Medline and Scopus databases. Those articles that analysed the use of ABPM in the first days after suffering a stroke from 1992 to 2022 were selected. Those articles focused on the post-acute or sequelae phase of the stroke, with a sample size of less than 20 and those where the primary objective was different from the defined one. A total of 28 articles were included.

CONCLUSIONS

The use of ABPM in patients with recent stroke demonstrates that the normal circadian profile of BP is altered in more than two-thirds of patients and that this will be fundamentally conditioned by the haemodynamic changes that occur on autoregulation of cerebral blood flow, the type of stroke or the response to treatment. Furthermore, these changes in BP have prognostic implications and are correlated with functional status, stroke recurrence and mortality, among others. However, although they continue to be a growing area of research, new studies are needed to clarify the real role of this technique in patients with acute stroke.

Stroke in the Time of Circadian Medicine

Time-of-day significantly influences the severity and incidence of stroke. Evidence has emerged not only for circadian governance over stroke risk factors, but also for important determinants of clinical outcome. In this review, we provide a comprehensive overview of the interplay between chronobiology and cerebrovascular disease. We discuss circadian regulation of pathophysiological mechanisms underlying stroke onset or tolerance as well as in vascular dementia. This includes cell death mechanisms, metabolism, mitochondrial function, and inflammation/immunity. Furthermore, we present clinical evidence supporting the link between disrupted circadian rhythms and increased susceptibility to stroke and dementia. We propose that circadian regulation of biochemical and physiological pathways in the brain increase susceptibility to damage after stroke in sleep and attenuate treatment effectiveness during the active phase. This review underscores the importance of considering circadian biology for understanding the pathology and treatment choice for stroke and vascular dementia and speculates that considering a patient's chronotype may be an important factor in developing precision treatment following stroke.

Association between non-dipping blood pressure pattern and different glucometabolic profile during oral glucose tolerance test

It is known that, a not physiological blood pressure (BP) circadian pattern has been associated with increased risk of organ damage and cardiovascular (CV) event. The aim of this study was to assess the association between circadian BP pattern and glucometabolic phenotypes occurring after oral glucose tolerance test (OGTT). We recruited 810 hypertensive Caucasian patients. All participants underwent to OGTT, laboratory test and 24-h ambulatory BP monitoring (ABPM). The analysis of collected data allowed classifying patients based on nocturnal BP profiles into four categories: dippers, non-dippers, extreme dippers, and reverse dippers. Considering the dipping pattern, the proportion of non-dippers in normal glucose tolerance patients with 1-h glucose ≥ 155 mg/dL (NGT ≥ 155) (36.4%) was higher than NGT < 155 (29.6%) and impaired glucose tolerance (IGT) (34.8%), but lower than type 2 diabetes group (T2DM) (52.6%) (p = 0.001). The proportion of dippers was lower in NGT ≥ 155 (47%) and T2DM (34.6%), when compared with NGT < 155 (53.8%) and IGT (51.2%) (p = 0.017). From logistic regression analysis, 1-h glucose ≥ 155 increased the risk of a pathological nocturnal drop in BP by 74%, (OR = 1.740, 95% CI 1.254-2.415, p < 0.0001). In addition, the improvement in 1 unit of Matsuda was responsible for a 3.5% risk decrease (OR = 0.965, 95% CI 0.958-0.971, p < 0.0001), while e-GFR determined a 0.9% risk reduction of nocturnal BP drop (OR = 0.991, 95% CI 0.984-0.999, p = 0.020). Our data demonstrated the existence, in newly diagnosed hypertensive patients, of an association between circadian BP profile and altered glycemic response during OGTT, in particular NGT ≥ 155 subjects are associated with a non-dipper BP pattern, this is clinically relevant because may explain, at least in part, the increased CV risk in this setting of patients.

Circadian Factors in Stroke: A Clinician's Perspective

Stroke remains one of the leading causes of mortality and long-term and permanent disability worldwide despite technological innovations and developments in pharmacotherapy. In the last few decades, the growing data have evidenced the role of the circadian system in brain vulnerability to damage, the development and evolution of stroke, and short-term and long-term recovery. On the other hand, the stroke itself can affect the circadian system via direct injury of specific brain structures involved in circadian regulation (i.e., hypothalamus, retinohypothalamic tracts, etc.) and impairment of endogenous regulatory mechanisms, metabolic derangement, and a neurogenic inflammatory response in acute stroke. Moreover, the disruption of circadian rhythms can occur or exacerbate as a result of exogenous factors related to hospitalization itself, the conditions in the intensive care unit and the ward (light, noise, etc.), medication (sedatives and hypnotics), and loss of external factors entraining the circadian rhythms. In the acute phase of stroke, patients demonstrate abnormal circadian variations in circadian biomarkers (melatonin, cortisol), core body temperature, and rest-activity patterns. The approaches aimed at the restoration of disrupted circadian patterns include pharmacological (melatonin supplementation) and non-medication (bright light therapy, shifting feeding schedules, etc.) interventions; however, their effects on short- and long-term recovery after stroke are not well understood.

Time point of nocturnal trough systolic blood pressure as an independent predictor of cardiovascular events

Nocturnal trough systolic blood pressure (NTSBP) and Time Point of Nocturnal Trough Systolic Blood Pressure (T‐NTSBP) were important parameters of nocturnal blood pressure, the predictive values of which are unclear for stroke outcome. This study aimed to examine the relationship between NTSBP/T‐NTSBP and stroke outcome. The authors used data from a nationwide ambulatory blood pressure monitoring cohort study conducted in China, which recruited 2348 ischemic stroke and transient ischemic attack (TIA) patients. NTSBP was defined as the lowest SBP during nighttime (22:00–6:00), and T‐NTSBP was defined as the corresponding time point of NTSBP. The associations between NTSBP/T‐NTSBP and stroke outcome (stroke recurrence and combined vascular event [CVE]) at 90 days or 1 year were analyzed using cox regression models. According to NTSBP classified by quartile, hazard ratio (HR) with 95% confidence interval (CI) for NTSBP quartile 4 (>129 mm Hg) was 2.727 (1.148–6.478) for CVE at 90‐day, compared with quartile 1 (≤102 mm Hg). However, an attenuated association between NTSBP and CVE was observed at 1 year. In addition, we observed the group of T‐NTSBP at 4:00–6:00 had a lowest CVE incidence at 90 days among four groups (22:00–23:59, 00:00–1:59 2:00–3:59, 4:00–6:00). After multivariable adjustment, T‐NTSBP was significantly associated with CVE incidence at 90 days (T‐NTSBP at the 4:00–6:00 versus the 22:00–23:59 group: HR, 0.433; 95%CI, 0.190–0.986), independent of NTSBP and average nocturnal SBP. Both of NTSBP and T‐NTSBP were important predictors for short‐term cardiovascular risk in ischemic stroke and TIA patients.

Implications of Circadian Rhythm in Stroke Occurrence: Certainties and Possibilities

Stroke occurrence is not randomly distributed over time but has circadian rhythmicity with the highest frequency of onset in the morning hours. This specific temporal pattern is valid for all subtypes of cerebral infarction and intracerebral hemorrhage. It also correlates with the circadian variation of some exogenous factors such as orthostatic changes, physical activity, sleep-awake cycle, as well as with endogenous factors including dipping patterns of blood pressure, or morning prothrombotic and hypofibrinolytic states with underlying cyclic changes in the autonomous system and humoral activity. Since the internal clock is responsible for these circadian biological changes, its disruption may increase the risk of stroke occurrence and influence neuronal susceptibility to injury and neurorehabilitation. This review aims to summarize the literature data on the circadian variation of cerebrovascular events according to physiological, cellular, and molecular circadian changes, to survey the available information on the chronotherapy and chronoprophylaxis of stroke and its risk factors, as well as to discuss the less reviewed impact of the circadian rhythm in stroke onset on patient outcome and functional status after stroke.

Exposure to the Chinese famine in early life and self-reported arthritis risk in adulthood

Evidence shows that undernutrition during early life is associated with an increased risk of chronic diseases in adulthood. We aimed to investigate whether exposure to the Chinese famine in the fetal or infant stage was associated with self-reported arthritis risk in adulthood. A total of 3,622 participants were included in the final analysis. Participants were classified into non-, fetal-, and infant-exposed group. Arthritis was self-reported doctor-diagnosed arthritis. A multivariate logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of arthritis. The prevalence of arthritis was 27.07%, 27.74%, and 34.09% among individuals in non-, fetal-, infant-exposed group, respectively. Infant-exposed group (OR: 1.32; 95% CI: 1.12-1.56) had a higher arthritis risk then non-exposed group after adjustment for gender, age, area, education level, smoking status, drinking status, and physical activity. Participants who experienced severe famine during infant and fetal period had higher (41.46%, OR=1.71 and 32.94%, OR=1.36) arthritis risk than those exposed to less severe famine. Exposure to the Chinese famine in early life was associated with an increased risk of arthritis in adulthood, which was partially influenced by some factors (e.g., gender, area, body mass index, and born in severely affected area or not).

miR‑126a‑5p‑Dbp and miR‑31a‑Crot/Mrpl4 interaction pairs crucial for the development of hypertension and stroke

The present study aimed to integrate the mRNA and microRNA (miRNA) expression profiles of spontaneously hypertensive rats (SHR rats) and stroke-prone spontaneously hypertensive rats (SHRSP rats) to screen for potential therapeutic targets for hypertension and stroke. The datasets GSE41452, GSE31457, GSE41453 and GSE53363 were collected from the Gene Expression Omnibus (GEO) database to screen differentially expressed genes (DEGs). The GSE53361 dataset was obtained to analyze differentially expressed miRNAs (DEMs). The DEGs and DEMs were identified between SHR (or SHRSP) rats and normotensive Wistar-Kyoto (WKY) rats using the Linear Models for Microarray (limma) data method. Venn diagrams were used to show the SHR-specific, SHRSP-specific and SHR-SHRSP shared DEGs and DEMs, and these were utilized to construct the protein-protein interaction (PPI) and miRNA-mRNA regulatory networks. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to explore the function of the genes. Subsequently, the connectivity Map (CMAP) database was searched to identify small-molecule drugs. Comparisons between the GSE41452-GSE31457-GSE41453 merged and GSE53363 datasets identified 2 SHR-specific, 8 SHRSP-specific and 15 SHR-SHRSP shared DEGs. Function enrichment analysis showed that SHRSP-specific D-box binding PAR bZIP transcription factor (Dbp) was associated with circadian rhythm, and SHR-SHRSP shared carnitine O-octanoyltransferase (Crot) was involved in fatty acid metabolic processes or the inflammatory response via interacting with epoxide hydrolase 2 (EPHX2). SHR-SHRSP shared mitochondrial ribosomal protein L4 (Mrpl4) may exert roles by interacting with the threonine-tRNA ligase, TARS2. The miRNA regulatory network predicted that upregulated Dbp could be regulated by rno-miR-126a-5p, whereas downregulated Crot and Mrpl4 could be modulated by rno-miR-31a. The CMAP database predicted that small-molecule drugs, including botulin, Gly-His-Lys, and podophyllotoxin, may possess therapeutic potential. In conclusion, the present study has identified Dbp, Crot and Mrpl4 as potential targets for the treatment of hypertension and stroke. Furthermore, the expression of these genes may be reversed by the above miRNAs or drugs.

Ambulatory blood pressure monitoring on admission in survivors of recent stroke entering inpatient rehabilitation

Arterial hypertension (AHT) is a major risk factor for stroke, yet blood pressure (BP) goals thereafter remain uncertain. Although additional prognostic value of 24-hour ambulant BP monitoring (ABPM) is acknowledged, its clinical impacts remain limited. We suspected that routine ABPM could identify characteristic circadian BP patterns in different brain lesion types, the knowledge of which might, in turn, be helpful in improving overall BP management in patients after stroke. In our study, we compared cardiovascular parameters derived from ABPM and traditional blood pressure measurements (TBPM) among 105 stroke survivors who entered our inpatient neuro-rehabilitation program. The mean age of mostly male (64.8%) patients was 71 ± 12 years. Ischemic strokes were predominant (75.2%). Despite normotensive systolic BP means in TBPM (133.5 ± 18.2 mmHg) and ABPM (24 h: 122.8 ± 14.7 mmHg), AHT persisted in up to 67.6% of all patients, with ABPM uncovering nocturnal systolic non- or reversed dipping in 89.5% and 53.3%, respectively. The latter was predominant (85.7%) in the hemorrhagic subgroup which also displayed lower daytime SBP than the ischemic one (ABPM: 117.1 ± 11.8 vs 124.7 ± 14.7 mmHg, p = 0.033). Further differences were present among distinct brain lesion types. Sufficient dippers were younger (58 ± 12 vs 75 ± 11 years, p < 0.001), but adjusting for age yielded no independent correlations. In spite of normotensive daytime BP measurements, ABPM detects latent AHT and insufficient nocturnal BP dipping after the acute phase of stroke. Further studies are needed to elucidate the role of increased nocturnal BP in patients after stroke.

Carbon Monoxide Preserves Circadian Rhythm to Reduce the Severity of Subarachnoid Hemorrhage in Mice

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) is associated with a temporal pattern of stroke incidence. We hypothesized that natural oscillations in gene expression controlling circadian rhythm affect the severity of neuronal injury. We moreover predict that heme oxygenase-1 (HO-1/Hmox1) and its product carbon monoxide (CO) contribute to the restoration of rhythm and neuroprotection.

METHODS

Murine SAH model was used where blood was injected at various time points of the circadian cycle. Readouts included circadian clock gene expression, locomotor activity, vasospasm, neuroinflammatory markers, and apoptosis. In addition, cerebrospinal fluid and peripheral blood leukocytes from SAH patients and controls were analyzed for clock gene expression.

RESULTS

Significant elevations in the clock genes Per-1, Per-2, and NPAS-2 were observed in the hippocampus, cortex, and suprachiasmatic nucleus in mice subjected to SAH at zeitgeber time (ZT) 12 when compared with ZT2. Clock gene expression amplitude correlated with basal expression of HO-1, which was also significantly greater at ZT12. SAH animals showed a significant reduction in cerebral vasospasm, neuronal apoptosis, and microglial activation at ZT12 compared with ZT2. In animals with myeloid-specific HO-1 deletion (Lyz-Cre-Hmox1fl/fl ), Per-1, Per-2, and NPAS-2 expression was reduced in the suprachiasmatic nucleus, which correlated with increased injury. Treatment with low-dose CO rescued Lyz-Cre-Hmox1fl/fl mice, restored Per-1, Per-2, and NPAS-2 expression, and reduced neuronal apoptosis.

CONCLUSIONS

Clock gene expression regulates, in part, the severity of SAH and requires myeloid HO-1 activity to clear the erythrocyte burden and inhibit neuronal apoptosis. Exposure to CO rescues the loss of HO-1 and thus merits further investigation in patients with SAH.

Clinical and prognostic significance of a reverse dipping pattern on ambulatory monitoring: An updated review

Reverse or inverted dipping (ie, the phenomenon characterized by higher nighttime compared with daytime blood pressure values) is an alteration of circadian blood pressure rhythm frequently documented in hypertension, type 2 diabetes mellitus, chronic kidney disease, and sleep apnea syndrome, and generally regarded as a harmful condition. Available literature on the clinical and prognostic implications of reverse dipping is scanty. The present article will review a number of relevant issues concerning reverse dipping, in particular: (1) its possible mechanisms; (2) prevalence and clinical correlates, (3) concomitant cardiac and extracardiac subclinical organ damage; (4) association with acute and chronic cardiovascular diseases; (5) prognostic value in predicting cardiovascular events and mortality; and (6) therapeutic interventions aimed at reverting this abnormal circadian blood pressure rhythm.

Cerebral microbleeds are associated with nocturnal reverse dipping in hypertensive patients with ischemic stroke

Background

Abnormalities in nocturnal blood pressure dipping are well known for its relationship to cardiovascular diseases. Cerebral microbleeds are frequently observed in patients with hypertension and are known to be potent risk factors for stroke. However, there are scanty reports about the relationship between nocturnal dipping and cerebral microbleeds.

Methods

We recruited consecutive patients with both hypertension and ischemic stroke within 7 days after symptom onset, and those with cardioembolism were excluded. We applied 24-hour ambulatory blood pressure monitoring two weeks after stroke onset, and we used brain MRI to detect cerebral microbleeds. Various blood pressure parameters such as mean 24-hour blood pressure, awake/sleep blood pressure, and morning surge were compared between cerebral microbleeds (+) vs. (-) groups. Subjects were further classified according to nocturnal dipping status and were analyzed by logistic regression to determine its association with cerebral microbleeds with adjustment for age, gender, and cardiovascular risk factors.

Results

A total of 162 patients (100 males, age 65.33 ± 10.32 years) were included. Cerebral microbleeds were detected in 65 patients (40.1%). Most ambulatory blood pressure parameters except morning surge were significantly higher in those who had cerebral microbleeds. After adjusting for the confounding factors, the reverse dippers were prone to have cerebral microbleeds (odds ratio, 3.81; 95% confidential interval, 1.36-10.65; p-value = 0.01).

Conclusion

Cerebral microbleeds are independently associated with reverse dipping on ambulatory blood pressure monitoring in hypertensive stroke patients.

Systolic Blood Pressure During Acute Stroke Is Associated With Functional Status and Long-term Mortality in the Elderly

Background and Purpose—

The prognostic value of blood pressure (BP) levels during acute stroke has not been adequately studied. Most studies do not use continuous BP measurements, and patients are followed only for a short period. We designed a study to assess, with 24-hour BP monitoring (24H BPM), the impact of BP levels during the first day of stroke, on the short-term functional status and long-term mortality in elderly patients.

Methods—

We studied 177 patients with acute stroke (89 men), mean age 84±6 years. BP was measured on admission and 24H BPM was recorded within 24 hours of admission. After 7 days, patients were assessed for functional status according to the modified Rankin Scale and were subsequently followed up for mortality ≤5 years (mean, 2.07±1.48).

Results—

After 7 days, functional status improved and modified Rankin Scale decreased from 4.2 to 3.7. Follow-up analysis disclosed that 71 patients (27 men and 44 women) had died. Mortality rate was higher in women (50% versus 30%; P <0.01) and in patients with a history of congestive heart failure. Only average systolic BP, recorded by 24H BPM, predicted short-term functional status and long-term mortality. Cox proportional hazards model analysis demonstrated that age, sex, congestive heart failure, and average systolic BP >160 mm Hg, recorded by 24H BPM, were associated with increased mortality.

Conclusions—

High systolic BP recorded by 24H BPM on the first day of stroke was found to be associated with unfavorable short-term functional status and long-term mortality in elderly patients.

Blood Pressure Monitoring in the Assessment of Old Patients with Acute Stroke

Background

Most patients have elevated blood pressure in the early phase of acute stroke that it often returns to normal within approximately seven-days. Most available data on the pattern of blood pressure in acute stroke are based on manual blood pressure measurements.

Aims

The aims of the present study were to assess with 24 h blood pressure monitoring the pattern of blood pressure in acute stroke, and the change in blood pressure during the first week of event in very old patients.

Methods

We studied 99 patients with acute stroke (58 males), mean age 83 ± 6 years (range 70–97). Casual blood pressure and 24 h blood pressure monitoring were recorded within 24 h of admission, and then after six- to seven-days.

Results

Casual blood pressure before beginning the 24 h blood pressure monitoring was 154 ± 23/80 ± 15 mmHg and the average 24 h blood pressure was 147 ± 20/74 ± 11 mmHg. One-week after stroke, casual blood pressure decreased by 15/7 mmHg, whereas 24 h blood pressure decreased by only 7/2 mmHg ( P<0·01). Blood pressure decreased remarkably only in those with admission elevated systolic blood pressure. The change in 24 h systolic blood pressure after one-week correlated to the 24 h admission systolic blood pressure ( R=0·47; P<0·01).

Conclusions

Casual blood pressure may overestimate blood pressure in stroke patients. Very old patients with stroke exhibit a mild increase in blood pressure during the acute phase, and blood pressure decreases spontaneously only in those with elevated blood pressure levels. Use of 24 h blood pressure monitoring may be helpful in elderly patients with acute stroke.

Postural changes in blood pressure and incidence of ischemic stroke subtypes: the ARIC study

The relation of orthostatic blood pressure decrease, or increase, with occurrence of ischemic stroke subtypes has not been examined. We investigated the association of orthostatic blood pressure change (within 2 minutes after supine to standing) obtained at baseline (1987 to 1989) in the Atherosclerosis Risk in Communities Study with incidence of ischemic stroke subtypes through 2007. Among 12 817 black and white individuals without a history of stroke at baseline, 680 ischemic strokes (153 lacunar, 383 nonlacunar thrombotic, and 144 cardioembolic strokes) occurred during a median follow-up of 18.7 years. There was a U-shaped association between orthostatic systolic blood pressure change and lacunar stroke incidence (quadratic P=0.004). In contrast, orthostatic systolic blood pressure decrease of 20 mm Hg or more was associated with increased occurrence of nonlacunar thrombotic and cardioembolic strokes independent of sitting systolic blood pressure, antihypertensive medication use, diabetes, and other lifestyle, physiological, biochemical, and medical conditions at baseline (for nonlacunar thrombotic: hazard ratio, 2.02; 95% CI, 1.43 to 2.84; for cardioembolic: hazard ratio, 1.85, 95% CI, 1.01 to 3.39). Orthostatic diastolic blood pressure decrease was associated with increased risk of nonlacunar thrombotic and cardioembolic strokes; the hazard ratios (95% CI) associated with 10 mm Hg lower orthostatic diastolic blood pressure (continuous) were 1.26 (1.06 to 1.50) and 1.41 (1.06 to 1.88), respectively, in fully adjusted models. In conclusion, the present study found that nonlacunar ischemic stroke incidence was positively associated with an orthostatic decrease of systolic and diastolic blood pressure, whereas greater lacunar stroke incidence was associated with both orthostatic increases and decreases in systolic blood pressure.

Retinal microvascular abnormalities and risk of lacunar stroke: Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

The retinal microvasculature reflects cumulative small-vessel damage from hypertension and other vascular processes. No study has prospectively examined retinal findings in relation to the incidence of clinical lacunar stroke in comparison with other ischemic stroke subtypes.

METHODS

In 10 496 adults initially free of stroke, we related retinal findings imaged during 1993 to 1995 with the incidence of hospitalized ischemic strokes through 2005.

RESULTS

During a median of 11.2 years of follow-up, 338 incident ischemic strokes occurred (66 lacunar, 192 nonlacunar thrombotic, and 80 cardioembolic). Generalized arteriolar narrowing as measured by the central retinal arteriole equivalent was associated with an increased incidence of lacunar stroke (multivariate-adjusted hazard ratio [HR] per 1-SD decrement of central retinal arteriole equivalent=1.67; 95% CI, 1.23-2.26) but was not associated with other ischemic stroke subtypes. Generalized venular widening as measured by the central retinal venule equivalent was also positively associated with only lacunar stroke (multivariate-adjusted HR per 1-SD increment=1.44; 95% CI, 1.09-1.91). Retinal microvascular abnormalities were positively associated with lacunar stroke incidence (HR for focal arteriolar narrowing=2.22; 95% CI, 1.11=4.48; for arteriovenous nicking, HR=2.38; 95% CI, 1.20-4.71), whereas retinopathy signs (microaneurysms, retinal hemorrhages, and others) were positively associated with nonlacunar thrombotic (HR=2.41; 95% CI, 1.47-3.95) and cardioembolic (HR=2.25; 95% CI, 1.09-4.65) stroke incidence.

CONCLUSIONS

A narrower central retinal arteriole equivalent, wider central retinal venule equivalent, focal arteriolar narrowing, and arteriovenous nicking were predictive of lacunar stroke. Retinal imaging is useful in understanding the pathophysiology and mechanisms of cerebral small-vessel disease.

Searching for prognostic variables for secondary worsening after ischaemic stroke

Secondary worsening of stroke symptoms is described in 13-37% of stroke patients, but the exact mechanism of this phenomenon remains unclear. The aim of this study is to find prognostic variables in correlation to secondary worsening of stroke symptoms in patients with lacunar or cortical strokes. In this prospective observational study we included all patients with ischaemic stroke; patients with transient ischaemic attack were excluded. Patients undergoing thrombolysis and becoming symptom-free after 24 h were still included in our analyses. Secondary worsening of stroke symptoms was defined as an increase of two or more points on the NIH Stroke Scale (NIHSS). The NIHSS score was assessed on admission, at discharge, and when patients had symptoms that indicated worsening of stroke. Applying univariate and multivariable analysis, we studied the relation between symptoms indicating secondary worsening of stroke and prognostic variables such as extreme nocturnal blood pressure falls (>20% of the average blood pressure), infection, diabetes mellitus, hypertension, smoking, dyslipidaemia, a history of cardiovascular or cerebrovascular disease and thrombolysis. This study included 202 patients with a mean age of 72 years, 48.8% were men and 43% had a lacunar stroke. Secondary worsening of stroke symptoms occurred in 13.5% of all patients, more often but not significantly (NS) after lacunar than cortical strokes (16.8 and 11.4%, respectively), and in patients with extreme nocturnal blood pressure falls versus without (15.6 and 11.8%, respectively (NS)). There was no significant relation between the analysed prognostic variables and secondary worsening of stroke symptoms. This study did not show significant correlation between several variables and secondary worsening of stroke symptoms in patients with recent ischaemic stroke.