Stroke prevention. An opportunity for efficient utilization of health care resources during the coming decade

The interaction between dysfunction of vasculature and tauopathy in Alzheimer's disease and related dementias

Tauopathy is one of the pathological features of Alzheimer's disease and related dementias (ADRD). At present, there have been many studies on the formation, deposition, and intercellular transmission of tau in neurons and immune cells. The vasculature is an important component of the central nervous system. This review discusses the interaction between vasculature and tau in detail from three aspects. (1) The vascular risk factors (VRFs) discussed in this review include diabetes mellitus (DM), abnormal blood pressure (BP), and hypercholesterolemia. (2) In ADRD pathology, the hyperphosphorylation and deposition of tau interact with disrupted vasculature, such as different cells (endothelial cells, smooth muscular cells, and pericytes), the blood-brain barrier (BBB), and the cerebral lymphatic system. (3) The functions of vasculature are regulated by various signaling transductions. Endothelial nitric oxide synthase/nitric oxide, calcium signaling, Rho/Rho-associated coiled-coil containing Kinase, and receptors for advanced glycation end products are discussed in this review. Our findings indicate that the prevention and treatment of vascular health may be a potential target for ADRD combination therapy. HIGHLIGHTS: Persistent VRFs increase early disruption of vascular mechanisms and are strongly associated with tau pathology in ADRD. Cell dysfunction in the vasculature causes BBB leakage and drainage incapacity of the cerebral lymphatic system, which interacts with tau pathology. Signaling molecules in the vasculature regulate vasodilation and contraction, angiogenesis, and CBF. Abnormal signaling transduction is related to tau hyperphosphorylation and deposition.

Effect of Lifestyle Coaching or Enhanced Pharmacotherapy on Blood Pressure Control Among Black Adults With Persistent Uncontrolled Hypertension: A Cluster Randomized Clinical Trial

IMPORTANCE

Greater difficulty in controlling blood pressure (BP) and adverse lifestyle practices such as higher salt intake or less physical activity may account for some of the differences between BP control rates in Black vs White adults, thereby exposing Black adults to a higher risk of vascular events.

OBJECTIVE

To determine whether a lifestyle coaching intervention or an enhanced pharmacotherapy protocol is more effective than usual care in improving BP control rates in Black adults treated within an integrated health care delivery system.

DESIGN, SETTING, AND PARTICIPANTS

Shake, Rattle & Roll, a cluster randomized clinical trial, was conducted from June 5, 2013, to June 11, 2018, in a large integrated health care delivery system. Enrollment was completed during a 12-month period and interventions were implemented for 12 months. Follow-up lasted 48 months after enrollment. Panels of Black adult members of the health care delivery system with BP of at least 140/90 mm Hg from 98 adult primary care physicians were randomly assigned at the primary care physician level to usual care (UC group [n = 1129]), enhanced pharmacotherapy monitoring (EP group [n = 346]) of current BP management protocol, or diet and lifestyle coaching consisting of photographs, stories, and recipes, for example, that are appropriate for Black adults (LC group [n = 286]) focused on the Dietary Approaches to Stop Hypertension (DASH) diet. Data were analyzed from June 1, 2016, to March 25, 2022.

INTERVENTIONS

The UC group received care per customary protocol. The EP group was contacted by a research nurse and/or a clinical pharmacist to discuss barriers to hypertension control, and drug therapy emphasized the use of thiazide diuretic intensification and addition of spironolactone as needed. The LC group received as many as 16 telephone sessions with a lifestyle coach and an emphasis on implementing reduction of sodium intake and the DASH diet.

MAIN OUTCOMES AND MEASURES

Intention-to-treat analysis of BP control rates at end of the 12-month intervention.

RESULTS

Among the 1761 participants, the mean (SD) age was 61 (13) years, and 1214 (68.9%) were women. At the end of the 12-month intervention period, there was no significant difference in BP control rate among study groups (UC, 61.8% [95% CI, 58.8%-64.9%]; EP, 64.5% [95% CI, 59.0%-69.4%]; LC, 67.8% [95% CI, 62.1%-73.2%]; LC vs EP, P = .07). However, greater BP control was present in the LC group vs UC at 24 months (UC, 61.2% [95% CI, 57.3%-64.7%]; EP, 67.6% [95% CI, 61.9%-72.8%]; LC, 72.4% [95% CI, 66.9%-78.1%]; LC vs UC, P = .001), and 48 months (UC, 64.5% [95% CI, 61.6%-67.2%]; EP, 66.5% [95% CI, 61.3%-71.3%]; LC, 73.1% [95% CI, 67.6%-77.9%]; LC vs UC, P = .006) after enrollment. The contribution of BP medication adherence to explain group differences was inconclusive.

CONCLUSIONS AND RELEVANCE

In this cluster randomized clinical trial including Black adults with persistent uncontrolled hypertension, a 12-month LC intervention was more effective at controlling BP than UC at 24 and 48 months after enrollment. Further research is needed to explore the potential implementation of this intervention into clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01892592.

Association between Previous Statin Use and Alzheimer's Disease: A Nested Case-Control Study Using a National Health Screening Cohort

A number of studies report the incidence of Alzheimer’s disease (AD) in patients taking statins, but the results are inconsistent. (1) Background: The present study investigated the cross-sectional association between previous statin use and the risk of AD development in Korean residents. (2) Methods: We used the Korean National Health Insurance Service-National Sample Cohort; 17,172 AD patients were matched by age, gender, income, and region of residence with 68,688 control participants at a ratio of 1:4. We used a multiple conditional logistic regression model to analyse the association between the number of days of statin use and AD occurrence. Further analyses were performed to identify whether this association is maintained for different ages, genders, socioeconomic status groups, and covariates. (3) Results: The odds ratio, which was adjusted for potential confounders, for the days of statin use per year in the AD group compared to the control group was 0.95 (95% confidence interval = 0.92–0.98; p = 0.003). The number of days of statin use in the AD group was significantly smaller in the subgroups of non-smokers and individuals with normal weight, alcohol consumption less than once a week, total cholesterol level below 200 mg/dL, systolic blood pressure below 140, diastolic blood pressure below 90, and fasting blood glucose below 100 mg/dL. (4) Conclusions: Our results suggest that statin use prevents the occurrence of AD. The effects of statin use in preventing AD may be greater in individuals at relatively low risk.

Impact of obstructive sleep apnea on cardiac organ damage in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Both obstructive sleep apnea (OSA) and cardiac organ damage have a crucial role in acute ischemic stroke. Our aim is to explore the relationship between OSA and cardiac organ damage in acute stroke patients.

METHODS

A total of 130 consecutive patients with acute ischemic stroke were enrolled. Patients underwent full multichannel 24-h polysomnography for evaluation of OSA and echocardiography to evaluate left ventricle (LV) mass index (LV mass/BSA, LV mass/height), thickness of interventricular septum (IVS) and posterior wall (LVPW), LV ejection fraction and left atrium enlargement. Information on occurrence of arterial hypertension and its treatment before stroke was obtained from patients' history.

RESULTS

61.9% (70) of patients, mostly men (67.1%), with acute stroke had OSA (AHI > 10). Patients with acute stroke and OSA showed a significant increase (P < 0.05) of LV mass index, IVS and LVPW thickness and a significant left atrial enlargement as compared with patients without OSA. LV ejection fraction was not significantly different in stroke patients with and without OSA and was within normal limits. No relationship was found among cardiac alterations, occurrence of OSA and history of hypertension.

CONCLUSION

Acute stroke patients with OSA had higher LV mass and showed greater left atrial enlargement than patients without OSA. This study confirms the high prevalence of OSA in stroke patients, suggesting also an association between OSA and cardiac target organ damage. Our finding of structural LV abnormalities in acute stroke patients with OSA suggests a potential role of OSA as contributing factor in determining both cerebrovascular and cardiac damage, even in absence of clear link with a history of blood pressure elevation.

Does Treating Vascular Risk Factors Prevent Dementia and Alzheimer's Disease? A Systematic Review and Meta-Analysis

BACKGROUND

Epidemiological evidence has associated Alzheimer's disease (AD) with vascular risk factors (VRFs), but whether treatment of VRFs reduces the incidence of dementia and AD is uncertain.

OBJECTIVE

To conduct a systematic review and meta-analysis to summarize available data on the impact of treatment of VRFs on dementia and AD incidence.

METHODS

Pertinent studies published until 1 January 2018 were identified from PubMed. Both randomized controlled trials (RCT) and prospective studies that investigated the impact of treatment of VRFs on dementia or AD incidence were included.

RESULTS

Eight RCTs and 52 prospective studies were identified. Antihypertensive treatment was associated with a non-significant reduced risk of dementia in RCTs (n = 5; relative risk [RR], 0.84; 95% confidence interval [CI], 0.69-1.02) and prospective studies (n = 3; RR, 0.77; 95% CI, 0.58-1.01) and with reduced AD risk in prospective studies (n = 5; RR = 0.78; 95% CI, 0.66-0.91). In prospective studies, treatment of hyperlipidemia with statins, but not nonstatin lipid-lowering agents, was associated with reduced risk of dementia (n = 17; RR, 0.77; 95% CI, 0.63-0.95) and AD (n = 13; RR, 0.86; 95% CI, 0.80-0.92). The single RCT on statins and dementia incidence showed no association. Data from one RCT and six prospective studies did not support a beneficial impact of antidiabetic drugs or insulin therapy on dementia risk.

CONCLUSION

Current evidence indicates that antihypertensives and statins might reduce the incidence of dementia and AD. Further trials to determine the effect of VRF on AD are needed.

Farmalarm

Background and Purpose- Risk factor control and treatment compliance in the following months after stroke are poor. We aim to validate a digital platform for smartphones to raise awareness among patients about the need to adopt healthy lifestyle, improve communication with medical staff, and treatment compliance. Methods- Farmalarm is an application (app) for smartphones designed to increase stroke awareness by medication alerts and compliance control, chat communication with medical staff, didactic video files, exercise monitoring. Patients with stroke discharged home were screened for participation and divided into groups: to follow the FARMALARM program for 3 to 4 weeks or standard of care follow-up. We determined achievement of risk factor control goals at 90 days. Results- From August 2015 to December 2016, from the 457 patients discharged home, 159 (34.8%) were included: Farmalarm (n=107); age 57±12, Control (n=52), age 59±10; without significant differences in baseline characteristics between groups. At 90 days, knowledge of vascular risk factors was higher in FARMALARM group (86.0% versus 69.2%, P<0.01). The rate of patients with diabetes mellitus (83.2% versus 63.5%, P<0.01) and hypercholesterolemia (80.3% versus 63.5%, P=0.03) under control and the rate of patients with 4 out of 4 risk factors under control was higher in FARMALARM group (50.4% versus 30.7%, P=0.02). A regression model showed that the use of Farmalarm was independently associated with all risk factors under control at 90 days (odds ratio, 2.3; 95% CI, 1.14-4.6; P=0.02). Conclusions- In patients with stroke discharged home, the use of mobile apps to monitor medication compliance and increase stroke awareness is feasible and seems to improve the control of vascular risk factors.

Efficacy of acupuncture for lifestyle risk factors for stroke: A systematic review

BACKGROUND

Modifications to lifestyle risk factors for stroke may help prevent stroke events. This systematic review aimed to identify and summarise the evidence of acupuncture interventions for those people with lifestyle risk factors for stroke, including alcohol-dependence, smoking-dependence, hypertension, and obesity.

METHODS

MEDLINE, CINAHL/EBSCO, SCOPUS, and Cochrane Database were searched from January 1996 to December 2016. Only randomised controlled trials (RCTs) with empirical research findings were included. PRISMA guidelines were followed and risk of bias was assessed via the Cochrane Collaboration risk of bias assessment tool. The systematic review reported in this paper has been registered on the PROSPERO (#CRD42017060490).

RESULTS

A total of 59 RCTs (5,650 participants) examining the use of acupuncture in treating lifestyle risk factors for stroke met the inclusion criteria. The seven RCTs focusing on alcohol-dependence showed substantial heterogeneity regarding intervention details. No evidence from meta-analysis has been found regarding post-intervention or long-term effect on blood pressure control for acupuncture compared to sham intervention. Relative to sham acupuncture, individuals receiving auricular acupressure for smoking-dependence reported lower numbers of consumed cigarettes per day (two RCTs, mean difference (MD) = -2.75 cigarettes/day; 95% confidence interval (CI) = -5.33, -0.17; p = 0.04). Compared to sham acupuncture those receiving acupuncture for obesity reported lower waist circumference (five RCTs, MD = -2.79 cm; 95% CI: -4.13, -1.46; p<0.001). Overall, only few trials were considered of low risk of bias for smoking-dependence and obesity, and as such none of the significant effects in favour of acupuncture interventions were robust against potential selection, performance, and detection bias.

CONCLUSIONS

This review found no convincing evidence for effects of acupuncture interventions for improving lifestyle risk factors for stroke.

CDC Grand Rounds: Public Health Strategies to Prevent and Treat Strokes

Worldwide, stroke is the second leading cause of death and a leading cause of serious long-term disability. In the United States, nearly 800,000 strokes occur each year; thus stroke is the fifth leading cause of death overall and the fourth leading cause of death among women (1). Major advances in stroke prevention through treatment of known risk factors has led to stroke being considered largely preventable. For example, in the United States, stroke mortality rates have declined 70% over the past 50 years, in large part because of important reductions in hypertension, tobacco smoking, and more recently, increased use of anticoagulation for atrial fibrillation (2,3). Although the reduction in stroke mortality is recognized as one of the 10 great public health achievements of the 20th century (4), gains can still be made. Approximately 80% of strokes could be prevented by screening for and addressing known risks with measures such as improving hypertension control, smoking cessation, diabetes prevention, cholesterol management, increasing use of anticoagulation for atrial fibrillation, and eliminating excessive alcohol consumption (5,6).

Interlimb Coordination During Step-to-Step Transition and Gait Performance

Most energy spent in walking is due to step-to-step transitions. During this phase, the interlimb coordination assumes a crucial role to meet the demands of postural and movement control. The authors review studies that have been carried out regarding the interlimb coordination during gait, as well as the basic biomechanical and neurophysiological principles of interlimb coordination. The knowledge gathered from these studies is useful for understanding step-to-step transition during gait from a motor control perspective and for interpreting walking impairments and inefficiency related to pathologies, such as stroke. This review shows that unimpaired walking is characterized by a consistent and reciprocal interlimb influence that is supported by biomechanical models, and spinal and supraspinal mechanisms. This interlimb coordination is perturbed in subjects with stroke.

Fully automatic plaque segmentation in 3-D carotid ultrasound images

Automatic segmentation of the carotid plaques from ultrasound images has been shown to be an important task for monitoring progression and regression of carotid atherosclerosis. Considering the complex structure and heterogeneity of plaques, a fully automatic segmentation method based on media-adventitia and lumen-intima boundary priors is proposed. This method combines image intensity with structure information in both initialization and a level-set evolution process. Algorithm accuracy was examined on the common carotid artery part of 26 3-D carotid ultrasound images (34 plaques ranging in volume from 2.5 to 456 mm(3)) by comparing the results of our algorithm with manual segmentations of two experts. Evaluation results indicated that the algorithm yielded total plaque volume (TPV) differences of -5.3 ± 12.7 and -8.5 ± 13.8 mm(3) and absolute TPV differences of 9.9 ± 9.5 and 11.8 ± 11.1 mm(3). Moreover, high correlation coefficients in generating TPV (0.993 and 0.992) between algorithm results and both sets of manual results were obtained. The automatic method provides a reliable way to segment carotid plaque in 3-D ultrasound images and can be used in clinical practice to estimate plaque measurements for management of carotid atherosclerosis.

Relation between left atrial enlargement and stroke subtypes in acute ischemic stroke patients

Objective

Increased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients.

Methods

One hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m². Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification.

Results

There were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease.

Conclusion

Increased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.

Left atrial size in hypertension and stroke

INTRODUCTION

An enlarged left atrium is associated with increased risk for stroke. However, there are controversies regarding how left atrial size should be measured.

MATERIAL AND METHODS

Echocardiography and carotid artery ultrasound were performed in 120 patients with essential hypertension (HT group) and in 64 hypertensive patients admitted with a first-ever ischemic stroke (HT-stroke group). Left atrial size was measured as antero-posterior diameter (LAD) and as left atrial volume (LAV) and indexed to body surface area (LADi/LAVi). All patients were in sinus rhythm and without mitral valve disease.

RESULTS

In the HT-stroke group, LAVi and LADi were significantly larger as compared with the HT group (P ≤ 0.03 for all). In bivariate correlations, larger left atrial size was associated with higher SBPs and DBPs and significant carotid artery stenosis both in HT and HT-stroke groups (all P < 0.05). In multivariate logistic regression analysis, stroke was associated significantly with larger LAVi [odds ratio (OR) 1.73, 95% confidence interval (CI) 1.06-2.65]; left ventricular mass index (OR 1.11, 95% CI 1.03-1.21); significant carotid artery stenosis (OR 1.09, 95% CI 1.03-1.24); and any carotid artery stenosis (OR 1.07, 95% CI 1.03-1.14). Analysis of receiver operating characteristic curves revealed that LAVi was the best left atrial measurement for prediction of stroke (OR 0.77, 95% CI 0.70-0.84).

CONCLUSION

In hypertensive patients, a first-ever ischemic stroke was associated with larger left atrial size, left ventricular mass index and internal carotid artery stenosis. LAVi was the left atrial measurement most closely associated with ischemic stroke.

What is the future of stroke prevention?: debate: polypill versus personalized risk factor modification

BACKGROUND AND PURPOSE

The control of stroke risk factors remains challenging. The "polypill" concept represents a novel approach for reducing stroke and cardiovascular risk factors in the entire population. The polypill would include several components and be provided without prescription to all adults of a certain age.

RESULTS

A polypill aimed at lowering blood pressure and cholesterol levels is estimated to potentially reduce the risk of a first ischemic stroke by 53%; this would translate to about 400 000 fewer strokes each year in the United States alone. Recommending a polypill for the entire older adult population would, however, include many individuals without the multiple risk factors targeted by its components, putting them at risk for drug-related side effects and responsible for the costs of a medication from which they would not derive benefit. Additional arguments for and against the polypill approach are discussed.

CONCLUSIONS

Only clinical trials can provide the evidence needed to determine the usefulness of the polypill approach. Issues related to defining the components of the polypill, evaluating the pharmacodynamics and pharmacokinetics of a multiple-component formulation, and establishing safety and cost-effectiveness when given to large populations, however, are not trivial.

Three-dimensional carotid ultrasound segmentation variability dependence on signal difference and boundary orientation

Quantitative measurements of the progression (or regression) of carotid plaque burden are important in monitoring patients and evaluating new treatment options. We previously developed a quantitative metric to analyze changes in carotid plaque morphology from 3-D ultrasound (US) on a point-by-point basis. This method requires multiple segmentations of the arterial wall and lumen boundaries to obtain the local standard deviation (SD) of vessel-wall-plus-plaque thickness (VWT) so that t-tests could be used to determine whether a change in VWT is statistically significant. However, the requirement for multiple segmentations makes clinical trials laborious and time-consuming. Therefore, this study was designed to establish the relationship between local segmentation SD and local signal difference on the arterial wall and lumen boundaries. We propose metrics to quantify segmentation SD and signal difference on a point-by-point basis, and studied whether the signal difference at arterial wall or lumen boundaries could be used to predict local segmentation SD. The ability to predict the local segmentation SD could eliminate the need of repeated segmentations of a 2-D transverse image to obtain the local segmentation standard deviation, thereby making clinical trials less laborious and saving time. Six subjects involved in this study were associated with different degrees of atherosclerosis: three carotid stenosis subjects with mean plaque area >3 cm(2) and >60% carotid stenosis were involved in a clinical study evaluating the effect of atorvastatin, a cholesterol-lowering and plaque-stabilizing drug; and three subjects with carotid plaque area >0.5 cm(2) were subjects with moderate atherosclerosis. Our results suggest that when local signal difference is higher than 8 greyscale value (GSV), the local segmentation SD stabilizes at 0.05 mm and is thus predictable. This information provides a target value of local signal difference on the arterial boundaries that should be achieved to obtain an accurate prediction of local segmentation SD. (E-mail: bcychiu@alumni.uwo.ca).

Physical activity and risk of ischemic stroke in the Northern Manhattan Study

BACKGROUND

It is controversial whether physical activity is protective against first stroke among older persons. We sought to examine whether physical activity, as measured by intensity of exercise and energy expended, is protective against ischemic stroke.

METHODS

The Northern Manhattan Study is a prospective cohort study in older, urban-dwelling, multiethnic, stroke-free individuals. Baseline measures of leisure-time physical activity were collected via in-person questionnaires. Cox proportional hazards models were constructed to examine whether energy expended and intensity of physical activity were associated with the risk of incident ischemic stroke.

RESULTS

Physical inactivity was present in 40.5% of the cohort. Over a median follow-up of 9.1 years, there were 238 incident ischemic strokes. Moderate- to heavy-intensity physical activity was associated with a lower risk of ischemic stroke (adjusted hazard ratio [HR] 0.65, 95% confidence interval [0.44-0.98]). Engaging in any physical activity vs none (adjusted HR 1.16, 95% CI 0.88-1.51) and energy expended in kcal/wk (adjusted HR per 500-unit increase 1.01, 95% CI 0.99-1.03) were not associated with ischemic stroke risk. There was an interaction of sex with intensity of physical activity (p = 0.04), such that moderate to heavy activity was protective against ischemic stroke in men (adjusted HR 0.37, 95% CI 0.18-0.78), but not in women (adjusted HR 0.92, 95% CI 0.57-1.50).

CONCLUSIONS

Moderate- to heavy-intensity physical activity, but not energy expended, is protective against risk of ischemic stroke independent of other stroke risk factors in men in our cohort. Engaging in moderate to heavy physical activities may be an important component of primary prevention strategies aimed at reducing stroke risk.

Quantification of carotid vessel wall and plaque thickness change using 3D ultrasound images

Quantitative measurements of carotid plaque burden progression or regression are important in monitoring patients and in evaluation of new treatment options. 3D ultrasound (US) has been used to monitor the progression or regression of carotid artery plaques. This paper reports on the development and application of a method used to analyze changes in carotid plaque morphology from 3D US. The technique used is evaluated using manual segmentations of the arterial wall and lumen from 3D US images acquired in two imaging sessions. To reduce the effect of segmentation variability, segmentation was performed five times each for the wall and lumen. The mean wall and lumen surfaces, computed from this set of five segmentations, were matched on a point-by-point basis, and the distance between each pair of corresponding points served as an estimate of the combined thickness of the plaque, intima, and media (vessel-wall-plus-plaque thickness or VWT). The VWT maps associated with the first and the second US images were compared and the differences of VWT were obtained at each vertex. The 3D VWT and VWT-Change maps may provide important information for evaluating the location of plaque progression in relation to the localized disturbances of flow pattern, such as oscillatory shear, and regression in response to medical treatments.

The predictive value of left atrial size for incident ischemic stroke and all-cause mortality in African Americans: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND PURPOSE

The association between left atrial (LA) size, ischemic stroke, and death has not been well established in African Americans despite their disproportionately higher rates of stroke and cardiovascular mortality compared to non-Hispanic whites.

METHODS

For the analysis, participants in the Jackson cohort of the Atherosclerosis Risk in Communities Study were followed from the date of the echocardiogram in cycle three to the date of the first ischemic stroke event (or death) or to December 31, 2004 if no ischemic stroke event (or death) was detected.

RESULTS

There were 1886 participants in the study population (mean age 58.9 years, 65% women). Participants in the top quintile of LA diameter indexed to height (LA diameter/height; 2.57 to 3.55 cm/m) were more likely women, hypertensive, diabetic, and obese compared to those not in the top quintile. Over a median follow-up of 9.8 years for ischemic stroke and 9.9 years for all-cause mortality, there were 106 strokes and 242 deaths. In a multivariable model adjusting for traditional clinical risk factors, the top quintile of LA diameter/height was significantly related to ischemic stroke (HR 1.7; 95% CI: 1.1, 2.7) and all-cause mortality (HR 2.0; 95% CI: 1.5, 2.7). After further adjustment for left ventricular (LV) hypertrophy and low LV ejection fraction, the top quintile remained significantly related to all-cause mortality (HR 1.8; 95% CI: 1.3, 2.5).

CONCLUSIONS

In this population-based cohort of African Americans, LA size was a predictor of all-cause mortality after adjusting for traditional cardiovascular risk factors, LV hypertrophy, and low LV ejection fraction.

Stroke awareness among cardiovascular disease patients

BACKGROUND: The early recognition of stroke signs and symptoms is of great relevance concerning the outcome, since it enhances the chances of thrombolytic therapy use. PURPOSE: To compare the knowledge of stroke among a community-based sample and patients treated in a cardiologic clinic. METHOD: We applied a questionnaire during one morning to people who were walking in a park (Pa) and spontaneously stopped at a health tent and during one week to patients of a cardiologic clinic (Ca). The survey assessed demographic details, awareness of stroke symptoms and signs, risk factors and general concepts of stroke. RESULTS: A total of 222 questionnaires were answered, 109 by the cardiologic clinic group and 113 by the park group. The park group recognized better three associated symptoms: headache (Ca: 39%; Pa: 61%; p: 0.001), loss of vision (Ca: 15.8%; Pa: 30.9%; p: 0.007) and unilateral paralysis/weakness (Ca: 26%; Pa: 41%; p: 0.026). The park group recognized better 3 risk factors: diabetes (Ca: 22.9%; Pa: 37.2%; p: 0.021), smoking (Ca: 51.4%; Pa: 67.2%; p: 0.011) and high cholesterol (Ca: 54.1%; Pa: 69.9%; p: 0.015). CONCLUSION: Our results suggest that patients treated in a cardiologic clinic do not show a better knowledge of stroke when compared to a community-based sample. Campaigns to increase stroke knowledge can have a great impact on public health, especially among enhanced risk groups, such as cardiovascular patients.

Diagnosis and management of vascular cognitive impairment

Accurate diagnosis of vascular cognitive impairment (VCI) is important but may be difficult. VCI diagnoses depend on determinations of the presence of both cognitive impairment and cerebrovascular disease (CVD), temporal causal links between cognitive impairment and CVD, and the presence or absence of other potential contributors to cognitive impairment, such as Alzheimer's disease (AD). Diagnostic criteria differ across currently utilized systems, resulting in widely differing VCI prevalence rates. Also, current systems may not be able to differentiate "pure" VCI from "mixed" AD and CVD. National Institute of Neurological Disorders and Stroke harmonization criteria for VCI have been developed for study and validation to help bridge gaps in our understanding of VCI diagnosis. VCI management begins with atherogenic risk factor control. Current VCI treatment options demonstrate statistical improvement but not consistent global clinical efficacy. Future clinical trials should concentrate on both primary risk factor control and development of new therapeutic agents to treat patients already diagnosed with VCI.

Recent advances in stroke management

Major advances in stroke treatment and prevention have, occurred over the last several years. Recent studies have documented that appropriate modification of stroke risk factors can lead to, a substantial reduction in stroke incidence. In addition, a variety of new risk factors, such as elevated plasma homocysteine levels, antiphospholipid antibodies, and specific genetic factors, are being recognized. The most significant advance in acute stroke therapy is the use of intravenous tissue plasminogen activator, (t-PA) for treatment of patients with ischemic stroke within 3 hours of symptom onset. T-PA is currently the only stroke treatment approved by the Federal Drug Administration. There continues to be uncertainty and misunder-standing regarding the risks and benefits of this therapy. A variety of neuroprotective agents have been highly successful for reducing ischemic brain injury in animal stroke models. Recent clinical trials with these agents, however, have not produced beneficial effects in humans. Newer neuroprotective agents with more favorable safety profiles and improvements in clinical trial design may lead to therapeutic successes in the near future. It is apparent that both thrombolytic and neuroprotective treatments for acute stroke must be administered very rapidly, after stroke onset. Therefore, acute stroke teams are being developed to facilitate rapid diagnostic evaluation and treatment of stroke patients.

Stroke in China: epidemiology, prevention, and management strategies

In this review, we examine the current status of stroke epidemiology, prevention, and management strategies in mainland China. The main findings suggested that total age-adjusted incidence of first-ever stroke in China is not very different from that in developed countries. Stroke incidence, mortality, and prevalence varied widely among different regions within China, with a noticeable north-south gradient. The proportion of intracerebral haemorrhage was high and reached 55% in one city. Hypertension is the most important risk factor for stroke. The mass approach combined with a high-risk approach for stroke prevention showed encouraging effects, and various unconventional local therapeutic traditions are commonly used to treat stroke in China. Several national guidelines on stroke prevention and treatment have been developed. Because of methodological limitations in the epidemiology studies, data are unreliable in terms of making any firm conclusions. Up-to-date, well-designed, and well-done epidemiological studies and therapeutic trials in China are urgently needed.

Additional impact of electrocardiographic over echocardiographic diagnosis of left ventricular hypertrophy for predicting the risk of ischemic stroke

BACKGROUND

Patients with left ventricular hypertrophy (LVH) have an increased risk of ischemic stroke. Although echocardiography is commonly used for the diagnosis of LVH, there is little information about the potential role of electrocardiography in providing additional prognostic information. The purpose of this study is to determine if electrocardiographically derived criteria for LVH provide additional prognostic value over echocardiography for predicting ischemic stroke in a multiethnic population.

METHODS

A population-based, case-control study was conducted in 177 patients who had had a first ischemic stroke and in 246 control patients matched for age, gender, and race or ethnicity. Left ventricular mass was measured by using 2-dimensional transthoracic echocardiography. Logistic regression analysis was performed to assess the risk of stroke associated with the presence of LVH diagnosed by electrocardiography (defined by 4 established criteria) after adjustment for the presence of other stroke risk factors and for echocardiographically determined LVH.

RESULTS

After adjustment for the presence of other established stroke risk factors, ECG-LVH was associated with ischemic stroke, using Sokolow-Lyon (odds ratio [OR] 2.12, 95% CI 1.05-4.30), Cornell voltage (OR 2.06, 95% CI, 1.26-3.35), and Cornell product criteria (OR 2.12, 95% CI, 1.13-3.97). Cornell voltage criterion (men, >2.8 mV; women, >2.0 mV) was associated with ischemic stroke even after adjustment for echocardiographically determined LVH (OR 1.73, 95% CI, 1.04-2.88). The combination of echo-LVH and a positive Cornell voltage criterion was associated with a 3.5-fold increase in stroke risk.

CONCLUSIONS

Our study indicates that the presence of ECG-LVH is associated with an increased risk of ischemic stroke after adjustment for other stroke risk factors. For Cornell voltage criteria, this relationship persisted even after adjustment for echocardiographic LVH. Electrocardiographic results can provide independent information for left ventricular myocardial changes and should be considered together with echocardiographic results to fully assess the risk of ischemic stroke.

Quality of care in stroke prevention: results of an audit study among general practitioners

BACKGROUND

In identifying opportunities to improve the quality of stroke prevention in general practice, insight in areas of suboptimal care is essential. This study investigated the quality of care in stroke prevention in general practice and its relation to the occurrence of stroke.

METHODS

Retrospective case-based audit with guideline-based review criteria and final judgment of suboptimal care by an expert panel.

RESULTS

A total of 292 stroke patients were identified through stroke registers of two main referral hospitals for stroke in Rotterdam. The general practitioners (GPs) (n = 95) of these patients were approached. The overall response rate from GPs was 81%, and a total of 193 patients from 77 GPs were included in the study. Data on the process of care at patient level were collected by chart review and by structured interviews with GPs during site visits. All cases were presented to a six-member panel of GPs and neurologists. In 44% of the cases, suboptimal care was identified (31% judged as possibly or likely failing to prevent stroke). Of the total number of identified shortcomings, 52% was related to inadequate hypertension control, particularly lack of follow-up after established hypertension. Another 17% of identified shortcomings concerned inadequate cardiovascular risk assessment.

CONCLUSIONS

A substantial number of shortcomings in care, particularly in the domain of hypertension control and the assessment of patient's risk profiles for cardiovascular disease (CVD), were identified. This study suggests that improving preventive care delivery in general practice could reduce the occurrence of stroke.

Conhecimento leigo sobre doença vascular encefálica

A magnitude das doenças vasculares encefálicas (DVE), com a sua prevalência, gravidade e elevados índices de morbi-mortalidade, faz com que se busquem formas de prevenção e de diagnóstico precoce. Considerando que as informações sobre os fatores de risco e os sintomas de DVE, pelos doentes de risco e pela população em geral, tem um papel preponderante nesta estratégia de tratamento, os autores buscaram conhecer qual o grau deste conhecimento em um grupo populacional amplo e variado. Assim, aplicou-se em 500 pessoas leigas um questionário de que constavam questões sobre os fatores de risco e sobre os sintomas de DVE com termos não médicos. Os resultados da análise estatística mostraram surpreendente conhecimento sobre os fatores de risco, a par de menor reconhecimento sobre os sintomas e sinais de doença vascular. Os autores detalham os achados e comentam sobre este aspecto importante das DVE.

Smoking raises the risk of total and ischemic strokes in hypertensive men

To examine the relation between cigarette smoking and risk of stroke and coronary heart disease among Japanese, we conducted a 14-year prospective study of 3,626 men aged 40-69, initially free from history of stroke and coronary heart disease. We identified 257 strokes (75 hemorrhagic and 173 ischemic strokes) and 100 coronary heart disease events. When we adjusted for age and other cardiovascular risk factors, a significant excess risk among current smokers of > 20 cigarettes/day vs. never-smokers was found for total stroke (relative risk (RR) = 1.6 (95% confidence interval (CI), 1.1-2.4)). The excess risk of total stroke was particularly evident among hypertensives (RR = 2.3 (1.2-4.4)). The multivariate RR of ischemic stroke was 1.6 (1.0-2.5) for total subjects, and 2.2 (1.0-5.0) among hypertensives. Significant excess risks among current smokers of > 20 cigarettes/day vs. never-smokers were also found for coronary heart disease (RR = 4.6 (1.6-12.9)) and total cardiovascular disease (1.9 (1.3-2.7)). The estimated proportion of the events attributable to current smoking was 30 (95% CI, 11-44)% for total stroke and 34 (5-54)% for coronary heart disease. In conclusion, current smoking of > 20 cigarettes per day increased the risk of both total stroke and ischemic stroke among Japanese middle-aged men, and particularly among middle-aged hypertensive men.

Smoking cessation in the elderly

Today, two generations after the first Surgeon General's report, and with abundant evidence of the catastrophic consequences of smoking, no serious person can be unaware that smokers risk their lives and health. We also know that quitting smoking--at any age--promises significant health benefits. When offered the tools they need, older smokers quit smoking at rates comparable to those of younger smokers despite their skepticism, fatalism, and self-doubt. Older smokers should be encouraged to enter programs that stress the health benefits derived and identify the risks they are avoiding by quitting smoking. These programs establish quit dates, use sound behavioral modification techniques, provide strategies for stress management and relaxation, treat withdrawal symptoms, and provide regular and continuing follow-up. The patient is asked to make an existential change, and the physician should provide encouragement and promote self-confidence by emphasizing that, despite setbacks, with repeated efforts, success can be achieved. Clinicians can influence patients to quit smoking, and they should.

Stroke risk from multiple risk factors combined with hypertension: a primary care based case-control study in a defined population of northwest England

PURPOSE

To examine how hypertension interacts with other known risk factors in affecting the risk of stroke in a primary care based setting.

METHODS

Cases were patients with first-ever stroke identified from the community-based stroke register in 1994-95 in northwest England. Two controls per case were randomly selected from the same primary care site and matched by age and sex. Information on predefined risk factors was extracted from medical records.

RESULTS

267 cases and 534 controls were included. Adjusted odds ratio (OR) for stroke from hypertension was 2.6 (95% confidence interval: 1.7-3.9). In hypertensives who were current smokers, risk of stroke was increased 6 fold as compared to non-smokers without hypertension. Hypertensives who had a preexisting history of myocardial infarction or obesity or diabetes had 3 fold higher risks of stroke. Subjects with hypertension and with a history of transient ischemic attack or atrial fibrillation had > or = 8 fold excess risk of stroke. Among them, the risk was greater in those with poorly controlled or untreated hypertension and in those with well or moderately controlled as compared to subjects without both risk factors. There appeared to be a steady increase in risk of stroke according to the number of risk factors present, particularly in hypertensive subjects.

CONCLUSIONS

Stroke risks in hypertensives associated with combinations of other risk factors appeared to follow an additive model. Subjects with multiple risk factors should be targeted in order to reduce the overall risk for stroke.

Accuracy and variability assessment of a semiautomatic technique for segmentation of the carotid arteries from three-dimensional ultrasound images

In this paper, we report on a semiautomatic method for segmentation of three-dimensional (3D) carotid vascular ultrasound (US) images. Our method is based on a dynamic balloon model represented by a triangulated mesh. The mesh is manually placed within the interior of the carotid vessels, then is driven outward until it reaches the vessel wall by applying an inflation force to the mesh. Once the mesh is in close proximity to the vessel wall, it is further deformed using an image-based force, in order to better localize the boundary. Since the method requires manual initialization, there is inherent variability in the position and shape of the final segmented boundary. Using a 3D US image of a patient's carotids, we have examined the local variability in boundary position as the initialization position is varied throughout the interior of the carotid vessels in the 3D image. We have compared the semiautomatic segmentation method to a fully manual segmentation method, and found that the semiautomatic approach is less variable than the intraobserver variability for manual segmentation. We have furthermore examined the accuracy of the semiautomatic method by comparing the average surface to an "ideal" surface, determined by the average manually segmented surface. We have found, in general, good agreement between the semiautomatic and manual segmentation methods. For the 3D US image in question, the mean separation between the average segmented surface and the gold standard was found to be 0.35 mm. The two surfaces were determined to agree with each other, within uncertainty, at 65% of the mesh points comprising the two surfaces.

Stroke risk factors

Despite advances in the treatment of acute cerebral infarction, the most effective method of reducing stroke morbidity and mortality is the identification and modification of stroke risk factors. Modifiable stroke risk factors include hypertension, atrial fibrillation, hypercholesterolemia, cigarette smoking, hyperhomocystinemia, and carotid stenosis. Improved identification of individuals at increased stroke risk due to these factors can reduce individual risk and the cost to society of the consequences of stroke.

Common perceptions about strokes

The frequency with which strokes occur and the devastating effects they can have make provision of general stroke information an essential element of public health education. This survey study sought to explore the general public's knowledge about various aspects of strokes. A questionnaire consisting of 4 open-ended, free-recall questions and 27 yes/no questions about the physiological processes, risk factors, warning signs, and functional consequences of strokes was administered orally to 190 individuals at a regional shopping mall. Additional items provided information about respondents' ages, ethnicity, educational status, and personal experiences with strokes. Free recall results indicated that approximately two-thirds of the survey respondents could provide correct or partially correct explanations of stroke physiology and could name at least one stroke warning sign; over 90% of respondents could name at least one stroke risk factor and one functional consequence of stroke. Most respondents reported acquiring information about strokes through personal acquaintances, popular media, or general life experiences rather than from professionals or as part of their formal schooling. Suggestions about needed content in general educational programs came from respondents' misconceptions about physiological processes, risk factors, warning signs, and functional consequences of strokes.

Transesophageal echocardiography and unexplained cerebral ischemia: a multicenter follow-up study. The STEPS Investigators. Significance of Transesophageal Echocardiography in the Prevention of Recurrent Stroke

BACKGROUND

Transesophageal echocardiography (TEE) continues to play a prominent role in the evaluation of patients with unexplained cerebral ischemia. The STEPS Study Group (Significance of Transesophageal Echocardiography in the Prevention of Recurrent Stroke) was established to further examine the clinical significance of TEE findings in patients with suspected cardiac source of embolus and to assess the impact of these findings with respect to specific therapy and the prevention of recurrent events.

METHODS

A total of 242 patients from 15 institutions within the United States underwent TEE study for evaluation of unexplained cerebral ischemia. Over a 1-year period, detailed follow-up was obtained with respect to recurrent stroke, transient ischemia attacks, or documented embolic events as well as detailed information concerning nonrandomized antithrombotic therapy.

RESULTS

Recurrent stroke occurred in 17 of 132 (13%) of the patients in the aspirin group versus 5 of 110 (5%) of the patients receiving warfarin therapy (P <.02). This decrease in cerebral ischemic events in the warfarin group was noted, despite the higher prevalence of atrial fibrillation and impaired ventricular function in the warfarin group. The selection of antithrombotic therapy appears, at least in part, to have been influenced by the TEE findings. Among patients receiving aspirin, a higher recurrent stroke rate was noted in those with left ventricular enlargement and atherosclerotic aortic plaque.

CONCLUSION

Abnormalities are commonly found by TEE in patients with unexplained cerebral ischemia. Patients with left ventricular enlargement and demonstrable aortic plaque on TEE study are at increased risk for recurrent stroke when receiving aspirin therapy alone. Empiric therapy with systemic anticoagulation may be indicated in patients with stroke unexplained by carotid atherosclerotic disease.

Echo-enhanced ultrasound for diagnosis and management in stroke patients

Early diagnosis of stroke and recognition of preceding transient ischemic attacks (TIAs) is important for clinical outcome. Better education of the signs and symptoms of TIA and stroke and improved diagnostic procedures will help to reduce the impact of stroke. Magnetic resonance imaging (MRI), computed tomography (CT) and single photon emission computed tomography (SPECT) are used to diagnose cerebral infarctions. MRI is the most effective diagnostic modality, however, MRI equipment is expensive and not always available. CT is therefore usually used but it has limitations, in detecting small infarctions, particularly in the posterior fossa. Ultrasound is a safe and inexpensive bedside diagnostic procedure. Ultrasound is often used in patients after TIA or stroke, however, it may be inadequate due to poor insonation conditions through the skull, or because the relevant vessel lies deep within the brain. Arteries with slow flowing blood are also difficult to image. The application of ultrasound has expanded with the development of two-dimensional transcranial color-coded sonography (TCCS) which provides both anatomical and functional information about the major cerebral vessels. In addition, the use of echo-enhancing agents now provides better images of vessels within the skull and enables ultrasound examinations to be performed even in patients with a poor transtemporal window. Echo-enhanced ultrasound can also provide images of vessels deep within the brain, which were previously non-evaluable. The echo-enhancing agent Levovist(R) has been extensively studied in patients undergoing ultrasound examination to detect cerebrovascular disease. Levovist improves diagnostic confidence without compromising safety. The improvement in images obtained of the cerebral vessels, including both arteries and veins, using echo-enhanced ultrasound may make this technique the future method of choice for patients with cerebrovascular disease.

Stroke prevention screening program

Stroke undoubtedly is one of the most devastating events experienced by humans. Stroke is the third leading cause of death in the adult population in the United States and the No. 1 cause of disability after 60 years of age. One out of four stroke victims die within 1 month. Many stroke victims would rather die than live without their dignity and quality of life. With the increase in the elderly population and the risk of stroke almost doubling every decade after 55 years of age, it is increasingly important to reduce the incidence of strokes. Stroke prevention screenings are an excellent opportunity to identify and educate persons who have significant stroke risk factors. Guidelines outlined by the National Stroke Association are described clearly in this step-by-step process of a stroke prevention screening. A unique modification of the National Stroke Association guidelines was the use of a carotid artery ultrasound screening to detect persons with significant carotid artery disease. This step in the screening replaced listening for carotid bruits. Seven carotid artery endarterectomies (of 385 participants) have been performed as a result of the screenings. Prevention of strokes through aggressive risk factor reduction cannot be overemphasized.