New horizons for stroke prevention: PROGRESS and HOPE

Population-based approaches for reducing stroke risk: an update on their success and the challenges ahead

INTRODUCTION

Stroke is a significant public health challenge as it is the second most common cause of death and the third leading cause of disability globally. Additionally, stroke incidence and the number of stroke deaths have been rising. Efforts to prevent stroke have been made, including high-risk approaches where patients are screened for cardiovascular risk factors, and population-based approaches which attempt to reduce stroke rates by improving overall population health.

AREAS COVERED

We summarize studies of population-based approaches to stroke prevention involving greater than 1,000 participants identified on a PubMed database search. Based on these programs, challenges of population-based stroke prevention programs are discussed and potential keys to success are highlighted.

EXPERT OPINION

Population-based stroke prevention programs face challenges including cost and interest of the public and certain stakeholders. Additionally, secular trends for improvement in risk factors and catastrophic adverse environmental circumstances add to the complexity of analyzing program success. Factors leading to successful programs include validated digital solutions for self-monitoring of risks, backing by global policy and legislation, flexibility to the needs of the population, intersectoral programs, community engagement, information dissemination back to the populations, and high-risk screening to develop a complementary combination approach to stroke prevention.

Effects of calcium channel blockers on perioperative ischemic events in hypertensive patients with intracranial aneurysms undergoing neurointervention

BACKGROUND

Although calcium channel blockers (CCBs) are useful in stroke prevention, their specific role in preventing stroke in hypertensive patients with intracranial aneurysms undergoing endovascular stent placement remains unclear.

METHODS

We retrospectively examined 458 hypertensive patients with intracranial aneurysms who underwent stent treatment, drawn from a larger multicenter cohort comprising 1326 patients across eight centers. Patients were dichotomized into two groups according to use of a CCB. Propensity score matching (PSM) was performed to balance group differences in patient and aneurysm characteristics. We conducted a comparison of patient and aneurysm characteristics, ischemic complications, and clinical outcomes between the two groups.

RESULTS

The CCB and non-CCB groups comprised 279 and 179 patients, respectively. PSM resulted in 165 matched pairs. After PSM, the incidence of ischemic events within 1 month of the procedure (4.2% vs 10.9%; P=0.022) and proportion of patients with modified Rankin Scale score >2 at last follow-up (1.5% vs 7.8%; P=0.013) were significantly lower in the CCB group. Among patients treated with combination therapy, inclusion of a CCB was associated with a lower incidence of ischemic events (1.5% vs 13.3%; P=0.345), but the difference was not statistically significant after correction.

CONCLUSIONS

CCB use in hypertensive patients undergoing endovascular stenting for treatment of intracranial aneurysms is associated with a lower incidence of ischemic events and a lower incidence of unfavorable neurological outcomes, especially when used in combination therapy.

Blood pressure levels within normotensive range are independently associated with increased risk of arterial stiffness in adults without hypertension or prehypertension

BACKGROUND AND AIMS

High blood pressure (BP) indices, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) predict cardiovascular diseases and mortality. However, the association of these BP indices with arterial stiffness (AS) in the normotensive population (BP < 120/80 mmHg) remains unclear.

METHODS AND RESULTS

Study participants who underwent health checkups at a tertiary referred center were recruited between November 2018 to December 2019. 2129 participants were enrolled after excluding those aged <18 years old, with elevated BP, history of hypertension, cardiovascular disease, and stroke, or with incomplete data. The brachial-ankle pulse wave velocity (baPWV) values were examined for evaluation of AS. Participants with higher blood pressure indices had significantly higher baPWV. Multiple linear regression revealed that all BP indices were positively associated with baPWV. According to the binary logistic regression analysis, participants in the higher SBP and MAP quartiles were significantly related to AS. The odds ratio (OR) for SBP Q2, Q3 and Q4 vs. Q1 were 6.06, 10.06 and 17.78 whereas the OR for MAP Q2, Q3 and Q4 vs. Q1 were: 5.07, 5.28 and 10.34. For DBP and PP, only participants belonging to the highest quartile were associated with AS(OR for DBP Q4 vs. Q1: 2.51; PP Q4 vs Q1: 1.94).

CONCLUSIONS

BP indices were linearly related to the baPWV. Normotensive participants with higher quartiles of SBP, DBP, MAP, and PP, remained associated with increased AS. The SBP and MAP levels exhibited a more prominent relationship with AS.

Quantum binding energy features of the drug olmesartan bound to angiotensin type-1 receptors in the therapeutics of stroke

We investigated the binding energies of 105 residues within a 10 Å pocket radius, predicted the energetic relevance of olmesartan regions, and the influence of individual protein segments on OLM -AT1 binding.

Management of blood pressure in stroke

Objective

In this review and opinion piece, we discuss recent United States (US)-based guidance statements on the management of BP in stroke according to stroke type and stage of stroke.

Methods

We reviewed the most recent guidance statements on BP control from United States (US)-based organizations such as the American Heart Association/American Stroke Association (AHA/ASA) and American College of Cardiology (ACC), and articles available to the authors in their personal files.

Results

The key BP target before starting alteplase (t-PA) is < 185/110 mm Hg, and the maintenance BP after tPA administration is < 180/105 mm Hg. For IPH patients with systolic BP between 150 and 220 mm Hg and no contraindication to acute BP reduction therapy, acute lowering to 140 mm Hg systolic BP is safe. For persons with small vessel or lacunar cerebral ischemia, a reasonable BP lowering target is < 130 mm Hg systolic. For primary stroke prevention, the target BP for those with hypertension is < 140/90 mm Hg and self-measured BP is recommended to assist in BP control. Recent study and guidance suggest a BP target of <130/80 mm Hg for both primary and recurrent stroke prevention. BP control is reasonable for the prevention of cognitive decline or dementia.

Conclusions

BP targets for the proper management of stroke vary by chronological stage of stroke and by stroke subtype. Furthermore, consideration should be given to control of BP variability, especially in the acute phases of stroke, as it may play a role in conferring longer term outcomes.

•

Stroke is an important cause of morbidity and mortality worldwide, and is well suited for prevention and acute treatment with proper BP management.

•

BP targets in acute ischemic stroke vary whether intravenous alteplase is administered or an endovascular intervention is implemented or not.

•

In acute intraparenchymal hemorrhage of the brain (IPH), it is reasonable to lower BP to a systolic level of 140–150 or up to 160 mm Hg.

•

For both first and recurrent stroke prevention it is reasonable to aim for a BP target of <130/80 mm Hg based on the recent data.

•

The revised BP target has been lowered to <130/80 mm Hg for prevention of major cardiovascular outcomes including stroke.

•

Intensive BP control potentially preserves cognition, brain health, and brain structural integrity.

•

Blood pressure variability is a new target for study in the acute treatment and prevention of stroke.

Does the model of additive effect in placebo research still hold true? A narrative review

Personalised and contextualised care has been turned into a major demand by people involved in healthcare suggesting to move toward person-centred medicine. The assessment of person-centred medicine can be most effectively achieved if treatments are investigated using ‘with versus without’ person-centredness or integrative study designs. However, this assumes that the components of an integrative or person-centred intervention have an additive relationship to produce the total effect. Beecher’s model of additivity assumes an additive relation between placebo and drug effects and is thus presenting an arithmetic summation. So far, no review has been carried out assessing the validity of the additive model, which is to be questioned and more closely investigated in this review.

Initial searches for primary studies were undertaken in July 2016 using Pubmed and Google Scholar. In order to find matching publications of similar magnitude for the comparison part of this review, corresponding matches for all included reviews were sought.

A total of 22 reviews and 3 clinical and experimental studies fulfilled the inclusion criteria. The results pointed to the following factors actively questioning the additive model: interactions of various effects, trial design, conditioning, context effects and factors, neurobiological factors, mechanism of action, statistical factors, intervention-specific factors (alcohol, caffeine), side-effects and type of intervention.

All but one of the closely assessed publications was questioning the additive model. A closer examination of study design is necessary. An attempt in a more systematic approach geared towards solutions could be a suggestion for future research in this field.

Efficacy of transcranial alternating current stimulation over bilateral mastoids (tACSbm) on enhancing recovery of subacute post-stroke patients

BACKGROUND AND AIMS

Transcranial alternating current stimulation (tACS) offers another method of non-invasive brain stimulation in post-stroke rehabilitation. Because it is not known if tACS over bilateral mastoids (tACS_bm) can promote the functional recovery in subacute post-stroke patients, we wish to learn the effect of tACS_bm on improving neurological function and intracranial hemodynamics of subacute post-stroke patients.

METHODS

Sixty subacute post-stroke patients (mean age: 65.4 ± 9.8 years), 15 to 60 days after the onset, were randomly assigned to receiving 15 sessions of usual rehabilitation program without (n = 30) or with tACS_bm (20 Hz and < 400 μA for 30-min; n = 30). The outcome measures included the NIH Stroke Scale (NIHSS) and measures of intracranial hemodynamics before and after treatment.

RESULTS

At the fifteenth session, when compared with the baseline, the mean NIHSS scores of the patients in the tACS_bm group had significantly a larger decrease [18.3 ± 2.6 vs. 10.8 ± 2.7; p < 0.001] than that of the control group [19.1 ± 2.7 vs. 13.0 ± 2.4] [F(1,54) = 4.29, p = 0.043]. After both the first and fifteenth sessions, compared with the control group, the mean blood flow velocity (MFVs) of the tACS_bm group had significantly larger increase in the MCA, ACA, and PCA (p < 0.001), the Gosling pulsatility index (PI) of the tACS_bm group had also significantly larger decline in the MCA, ACA, and PCA than that of the control group (p < 0.001). The best predictor of the changes in the NIHSS scores was the decline in the pulsatility index in the vascular territory of both lesional and non-lesional MCA measured by the end of the last treatment session.

CONCLUSIONS

tACS_bm appeared to be effective for enhancing patients' functional recovery and cerebral hemodynamics in the subacute phase. The extent of recovery seems to be associated with the decline of the resistance in vascular bed of the main cerebral arteries. The mechanisms behind this effect should be explored further through research.

Inhibition of MMP-9 attenuates hypertensive cerebrovascular dysfunction in Dahl salt-sensitive rats

Hypertensive cerebropathy is a pathological condition associated with cerebral edema and disruption of the blood-brain barrier. However, the molecular pathways leading to this condition remains obscure. We hypothesize that MMP-9 inhibition can help reducing blood pressure and endothelial disruption associated with hypertensive cerebropathy. Dahl salt-sensitive (Dahl/SS) and Lewis rats were fed with high-salt diet for 6 weeks and then treated without and with GM6001 (MMP inhibitor). Treatment of GM6001 (1.2 mg/kg body weight) was administered through intraperitoneal injections on alternate days for 4 weeks. GM6001 non-administered groups were given vehicle (0.9% NaCl in water) treatment as control. Blood pressure was measured by tail-cuff method. The brain tissues were analyzed for oxidative/nitrosative stress, vascular MMP-9 expression, and tight junction proteins (TJPs). GM6001 treatment significantly reduced mean blood pressure in Dahl/SS rats which was significantly higher in vehicle-treated Dahl/SS rats. MMP-9 expression and activity was also considerably reduced in GM6001-treated Dahl/SS rats, which was otherwise notably increased in vehicle-treated Dahl/SS rats. Similarly MMP-9 expression in cerebral vessels of GM6001-treated Dahl/SS rats was also alleviated, as devised by immunohistochemistry analysis. Oxidative/nitrosative stress was significantly higher in vehicle-treated Dahl/SS rats as determined by biochemical estimations of malondialdehyde, nitrite, reactive oxygen species, and glutathione levels. RT-PCR and immunohistochemistry analysis further confirmed considerable alterations of TJPs in hypertensive rats. Interestingly, GM6001 treatment significantly ameliorated oxidative/nitrosative stress and TJPs, which suggest restoration of vascular integrity in Dahl/SS rats. These findings determined that pharmacological inhibition of MMP-9 in hypertensive Dahl-SS rats attenuate high blood pressure and hypertension-associated cerebrovascular pathology.

Topological data analysis for discovery in preclinical spinal cord injury and traumatic brain injury

Data-driven discovery in complex neurological disorders has potential to extract meaningful syndromic knowledge from large, heterogeneous data sets to enhance potential for precision medicine. Here we describe the application of topological data analysis (TDA) for data-driven discovery in preclinical traumatic brain injury (TBI) and spinal cord injury (SCI) data sets mined from the Visualized Syndromic Information and Outcomes for Neurotrauma-SCI (VISION-SCI) repository. Through direct visualization of inter-related histopathological, functional and health outcomes, TDA detected novel patterns across the syndromic network, uncovering interactions between SCI and co-occurring TBI, as well as detrimental drug effects in unpublished multicentre preclinical drug trial data in SCI. TDA also revealed that perioperative hypertension predicted long-term recovery better than any tested drug after thoracic SCI in rats. TDA-based data-driven discovery has great potential application for decision-support for basic research and clinical problems such as outcome assessment, neurocritical care, treatment planning and rapid, precision-diagnosis.

Sleep Apnea and Stroke

Stroke is the second leading cause of death worldwide and often has devastating consequences for affected individuals in terms of chronic disability. Traditional risk factors such as age, male sex, ethnicity, hypertension, and atrial fibrillation explain 60%-80% of the risk of stroke. Obstructive sleep apnea (OSA) is highly prevalent in individuals who have had a stroke and its emerging role as a potential modifiable risk factor for stroke has been recognized in the most recent American Heart Association stroke guidelines, which recommend consideration of screening for and treatment of OSA in this regard. In this article we provide an overview of the current evidence-based knowledge related to stroke and sleep apnea. The main focus of this article is key pathophysiological mechanisms by which OSA might increase the risk for stroke. The effect of OSA on stroke outcomes and the efficacy of treatment of OSA on these outcomes is also discussed.

[Update on the genetics of stroke]

Stroke is a disease with significant morbidity, mortality, and economic and social impacts. It is a complex entity whose pathogenesis involves multiple environmental and genetic factors, with the latter having a role in up to 50% of strokes. The objective of the review is to analyze the available methods for the genetic diagnosis including linkage studies of variation in copy number, gene - candidate approximations, or whole genome (GWAS) and polymorphisms associated with its pathogenesis. We describe several single nucleotide polymorphisms (SNPs) associated with stroke in association studies and GWAS such as SNPs of angiotensin, the aldosterone system, paraoxonases, nitric oxide, coagulation, and fibrinolysis system, among others. We also analyze the role of certain polymorphisms in the phenotype of the carotid plaque, intracranial aneurysms and lobar hemorrhages. Pharmacogenomic aspects in which SNPs affect the response and safety regarding the use of different drugs are also described. Several SNPs that significantly contribute to the risk of stroke are also described. The advent of techniques like GWAS has contributed to the understanding of genetics and pharmacogenomics of stroke.

Effects of combination therapy with levamlodipine and bisoprolol on stroke in rats

AIM

To examine the effects of combination with levamlodipine and bisoprolol on stroke in rats.

METHODS

For acute study, Systolic blood pressure (SBP) and heart period (HP) were monitored in conscious stroke prone-spontaneously hypertensive rats (SHR-SP) and sinoaortic denervation (SAD) rats before and after intragastric administration of either drug at a single dose. Rats were subjected to middle cerebral arterial occlusion (MCAO) half an hour after drug administration; sacrificed 24 h later to measure the infarct size. For long-term study, drugs (either alone or in combination) were delivered via food to SHR-SP. The survival time was recorded.

RESULTS

SBP was significantly reduced by combination therapy both in SHR-SP and SAD rats. Neutralization on heart rate (HR) was observed in combination. The drug combination increased baroreflex sensitivity (BRS) and reduced SBP variability (SBPV). In chronic experiments, the lifespan of SHR-SP rats exposed to the drug combination was longer than that in rats exposed to either drug alone. The infarct area was the smallest in subjects receiving drug combination in SD rats both with and without SAD.

CONCLUSION

Combined use of levamlodipine and bisoprolol produced better protection against stroke.

Frequency of angiotensin II type 1 receptor gene polymorphism in Turkish acute stroke patients

This study was performed in acute stroke patients in the Turkish population to determine the frequency of the A1166C polymorphism in the AT1 gene and to examine the role of this polymorphism in acute stroke development. In this study, 257 genomic DNA samples were analysed (from 206 acute stroke patients and 51 healthy individuals). Genomic DNA was prepared from peripheral blood using the salt-extraction method. The presence of the A1166C polymorphism in the AT1 gene was determined using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. PCR products were separated by 2% agarose gel electrophoresis and visualized by a charge-coupled device (CCD) camera. In this study, the allele frequency at the A1166C position was 92% A and 8% C for control and 97% A and 3% C for patients. This difference in allele frequency between the control group and the patient group was not statistically significant. However, genotype and allele frequencies showed a significant difference (P < 0.001) in the control and the patient groups. The results of this study show no relationship between the A1166C polymorphism in the AT1 gene and acute stroke in the Turkish population.

Synergic effects of levamlodipine and bisoprolol on blood pressure reduction and organ protection in spontaneously hypertensive rats

AIMS

Stroke is a major cause of disability and death worldwide. Hypertension is one of the most important risk factors for stroke. The objective of this work was to study the synergic effects of levamlodipine and bisoprolol on blood pressure reduction and organ protection in spontaneously hypertensive rats (SHR).

METHODS

Blood pressure was continuously monitored in conscious SHR. For acute study, a single dose of drugs was administrated via an intragastric catheter. For chronic study (4 months), drugs were delivered via rat chow.

RESULTS

A single dose of levamlodipine (from 1 mg/kg), bisoprolol (from 0.125 mg/kg), and their combinations significantly decreased blood pressure. The levamlodipine-induced tachycardia and the bisoprolol-induced bradycardia were temporized by the combination of these two drugs. Upon chronic treatment, this combination also decreased blood pressure variability and reduced organ damage.

CONCLUSION

Levamlodipine and bisoprolol produce synergic effects on blood pressure reduction and organ protection in SHR.

From hypertension to stroke: mechanisms and potential prevention strategies

Stroke is a major cause of disability and death worldwide. Prevention aimed at risk factors of stroke is the most effective strategy to curb the stroke pandemic. Hypertension is one of the most important risk factors for stroke. Despite the substantial evidence of the benefits of lowering blood pressure, conventional treatment does not normalize the burden of major cardiovascular events in patients with hypertension. Fully understanding the factors involved in the hypertension-induced stroke helps to develop new strategies for stroke prevention. Antihypertensive therapies selected should have positive blood pressure-independent effects on stroke risk. This review summarizes the factors involved in the hypertension-induced stroke, such as oxidative stress, inflammation, and arterial baroreflex dysfunction, and potential strategies for its prevention, therefore, provides clues for clinicians.

Primary stroke prevention and hypertension treatment: which is the first-line strategy?

Hypertension (HT) is considered the main classic vascular risk factor for stroke and the importance of lowering blood pressure (BP) is well established. However, not all the benefit of antihypertensive treatment is due to BP reduction per se, as the effect of reducing the risk of stroke differs among classes of antihypertensive agents. Extensive evidences support that angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), dihydropyridine calcium channel blockers (CCB) and thiazide diuretics each reduced risk of stroke compared with placebo or no treatment. Therefore, when combination therapy is required, a combination of these antihypertensive classes represents a logical approach. Despite the efficacy of antihypertensive therapy a large proportion of the population, still has undiagnosed or inadequately treated HT, and remain at high risk of stroke. In primary stroke prevention current guidelines recommend a systolic/diastolic BP goal of <140/<90 mmHg in the general population and <130/80 mmHg in diabetics and in subjects with high cardiovascular risk and renal disease. The recent release in the market of the fixed-dose combination (FDC) of ACEI or ARB and CCB should provide a better control of BP. However to confirm the efficacy of the FDC in primary stroke prevention, clinical intervention trials are needed.

Disruption of Na+,HCO₃⁻ cotransporter NBCn1 (slc4a7) inhibits NO-mediated vasorelaxation, smooth muscle Ca²⁺ sensitivity, and hypertension development in mice

BACKGROUND

Disturbances in pH affect artery function, but the mechanistic background remains controversial. We investigated whether Na(+), HCO₃- transporter NBCn1, by regulating intracellular pH(pH₁), influences artery function and blood pressure regulation.

METHODS AND RESULTS

Knockout of NBCn1 in mice eliminated Na+, HCO₃⁻ cotransport and caused a lower steady-state pH(i) in mesenteric artery smooth muscle and endothelial cells in situ evaluated by fluorescence microscopy. Using myography, arteries from NBCn1 knockout mice showed reduced acetylcholine-induced NO-mediated relaxations and lower rho-kinase-dependent norepinephrine-stimulated smooth muscle Ca²⁺ sensitivity. Acetylcholine-stimulated NO levels (electrode measurements) and N-nitro-l-arginine methyl ester-sensitive l-arginine conversion (radioisotope measurements) were reduced in arteries from NBCn1 knockout mice, whereas relaxation to NO-donor S-nitroso-N-acetylpenicillamine, acetylcholine-induced endothelial Ca²⁺ responses (fluorescence microscopy), and total and Ser-1177 phosphorylated endothelial NO-synthase expression (Western blot analyses) were unaffected. Reduced NO-mediated relaxations in arteries from NBCn1 knockout mice were not rescued by superoxide scavenging. Phosphorylation of myosin phosphatase targeting subunit at Thr-850 was reduced in arteries from NBCn1 knockout mice. Evaluated by an in vitro assay, rho-kinase activity was reduced at low pH. Without CO₂/HCO₃⁻, no differences in pH(i), contraction or relaxation were observed between arteries from NBCn1 knockout and wild-type mice. Based on radiotelemetry and tail-cuff measurements, NBCn1 knockout mice were mildly hypertensive at rest, displayed attenuated blood pressure responses to NO-synthase and rho-kinase inhibition and were resistant to developing hypertension during angiotensin-II infusion.

CONCLUSIONS

Intracellular acidification of smooth muscle and endothelial cells after knockout of NBCn1 inhibits NO-mediated and rho-kinase-dependent signaling in isolated arteries and perturbs blood pressure regulation.

Role of angiotensin II in the response to endothelin-1 of goat cerebral arteries after ischemia-reperfusion

As angiotensin II may underlie the deleterious effects of some vascular diseases, we have examined the role of this peptide on the cerbrovascular endothelin-1 action after ischemia-reperfusion. In anesthetized goats, 1 hour-occlusion followed by 1 hour-reperfusion of the left middle cerebral artery (MCA) was induced, and then segments 3-mm in length from branches of the right MCA (control) and the left MCA (ischemic) were obtained for isometric tension recording. Endothelin-1 (10(-11)-10(-7) M) produced a contraction that was higher in ischemic than in control arteries, and in control but not in ischemic arteries this contraction was potentiated by angiotensin II (10(-7) M). Losartan (3 x 10(-6) M), antagonist of AT1 receptors, did not affect the response to endothelin-1 in control arteries, but reduced it both in ischemic arteries and angiotensin II-treated control arteries. PD123,319 (3 x 10(-6) M), antagonist of AT2 receptors, or the inhibitor of nitric oxide synthesis L-NAME (10(-4) M) did not alter the arterial effects of endothelin-1. Therefore, angiotensin II may potentiate the constriction to endothelin-1 in normal cerebral arteries by activating AT1 receptors. The observed cerebrovascular increased response to endothelin-1 after ischemia-reperfusion might be related in part to activation of AT1 receptors under this condition.

A combined role of calcium channel blockers and angiotensin receptor blockers in stroke prevention

Stroke is a leading cause of death and disability worldwide. The importance of lowering blood pressure for reducing the risk of stroke is well established. However, not all the benefits of antihypertensive treatments in stroke can be accounted for by reductions in BP and there may be differences between antihypertensive classes as to which provides optimal protection. Dihydropyridine calcium channel blockers, such as amlodipine, and angiotensin receptor blockers, such as valsartan, represent the two antihypertensive drug classes with the strongest supportive data for the prevention of stroke. Therefore, when combination therapy is required, a combination of these two antihypertensive classes represents a logical approach.

Arterial Hypertension and Stroke Prevention: An Update

High blood pressure (BP) is the most important modifiable risk factor for stroke and other vascular diseases. Evidence from randomized controlled trials supports the use of antihypertensive drugs to lower blood pressure for stroke prevention. There is some evidence that specific classes of antihypertensive drugs have different effects and/or their pharmacological actions differ in patient subgroups. This review evaluates the development of antihypertensive therapies and the latest studies of arterial hypertension and stroke prevention: HOPE trial (ramipril versus placebo), ALLHAT trial (CCB or/ and Angiotensin-Conventing enzyme Inhibitors (ACE-Is) versus diuretic), LIFE trial (losartan versus atenolol), and PROGRESS trial (perindopril or/and indapamide versus placebo). Despite the results of these relevant clinical trails, some aspects still remain unresolved. Future clinical trials on hypertension and stroke prevention should answer the following questions: Does lowering BP reduce stroke risk due to specific drug effect or class effect? Are angiotensin II receptor blockers (ARBs) better than ACE-Is? Should ACE-Is and ARBs be considered routinely for either high-risk stroke patients or patients with history of stroke or transient ischemic attack, irrespective of blood pressure? What is the role of lifestyle in BP control?

Trend in incidence of cardiovascular risk factors in elderly and over-aged stroke patients between 2003 and 2007 in Greece

The aim of this study is to identify the main cardiovascular risk factors (CRFs) in patients over 65 years with ischemic stroke. This is a retrospective study in 175 patients that were hospitalized in our department due to ischemic stroke in the period 2006-2007. The patients were divided in two groups: Group I--elderly (65-80 years) and Group II--over-aged (>or=81 years). The results were compared with a similar study performed in our department in the period 2002-2003 in 160 ischemic stroke patients. Statistical analysis was made by the chi2-test. Hypertension, either alone or in combination with other CRFs, constitutes the main CRF. Diabetes mellitus (DM) is not frequently the sole CRF but its coexistence with other CRFs ranks DM as the second most important CRF, with the largest percentage in the elderly. Dyslipipidemia is 4th CRF in order following the coronary heart disease (CHD). Taking into account that the provision of acute therapeutic intervention in elderly and over-aged ischemic stroke patients is in most cases difficult, because of their age and the high risk of thrombolysis in these patients, there is increased need to focus on primary prevention of ischemic stroke by treating associated CRF.

Action on vascular risk factors: importance of blood pressure and lipid lowering in stroke secondary prevention

INTRODUCTION

Secondary stroke prevention comprises a broad spectrum of therapeutic actions that includes the appropriate management of risk factors and the action on blood pressure and serum lipids that are of great importance to decrease stroke recurrences.

METHODS

We conducted a review of the published studies analyzing the relevance of the treatment of blood pressure and serum lipids, with special attention to recent findings of clinical trials and current guidelines on stroke secondary prevention.

RESULTS

The relationship between blood pressure and stroke has been widely demonstrated; however, the role of serum lipids has been discussed for a long time. Recent results from epidemiological studies and clinical trials have demonstrated its role as modifiable risk factor for stroke. Blood pressure and lipid lowering are associated with significant reductions in recurrent strokes as well as in other vascular events in transient ischemic attack (TIA) or stroke patients. The PROGRESS and MOSES trials suggest that diuretics, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers could confer additional benefits in stroke patients, and the SPARCL study did so for statins. These drugs are not only efficacious in the reduction of stroke recurrences, but also in other cardiovascular events.

CONCLUSIONS

Blood pressure and serum lipids are two important and modifiable vascular risk factors that should be taken into consideration when planning secondary stroke prevention measures. This approach should include hypotensive drugs (mainly the combination of diuretics and ACE inhibitors) with the objective to maintain normal blood pressure, avoiding levels >130/80 mm Hg in all stroke patients, and statins (atorvastatin 80 mg) in patients with noncardioembolic TIA or stroke.

Therapeutic issues in vascular dementia: studies, designs and approaches

Vascular dementia (VaD) is a heterogeneous disorder resulting from various cerebrovascular diseases (CVD) causing cognitive impairment that reflects severity and location of damage. Epidemiological studies suggest VaD is the second commonest cause of dementia, but autopsy series report that pure VaD is infrequent, while combined CVD and Alzheimer's Disease(AD) is likely the commonest pathological-dementia correlate. Both diseases share vascular risk factors and benefit from their treatment. The most widely used diagnostic criteria for VaD are highly specific but not sensitive. Vascular Cognitive Impairment (VCI) is a dynamic, evolving concept that embraces VaD, Vascular Cognitive Impairment No Dementia (VCIND) and mixed AD and CVD. Clinical trials to date have focused on probable and possible VaD with beneficial effects evident for different drug classes, including cholinergic agents and NMDA agonists. Limitations have included use of cognitive tools suitable for AD that are insensitive to executive dysfunction. Disease heterogeneity has not been adequately controlled and subtypes require further study. Diagnostic VaD criteria now 13 years old need updating. More homogeneous subgroups need to be defined and therapeutically targeted to improve cognitive-behavioural outcomes including optimal control of vascular risk factors. More sensitive testing of executive function outlined in recent VCI Harmonization criteria and longer trial duration are needed to discern meaningful effects. Imaging criteria must be well-defined, with centralized review and standardized protocols. Serial scanning with quantification of tissue atrophy and lesion burden is becoming feasible, and cognitive interventions, including rehabilitation pharmacotherapy, with drugs strategically coupled to cognitive -behavioural treatments, hold promise and need further development.

Infection as a risk factor for stroke

Persisting disability requiring professional healthcare or help in daily life activities can be expected in a third to a half of all stroke survivors. It is mainly the elderly that are affected. For the increasingly aging population of Western societies, stroke represents an increasing social and economic burden. Besides the existing therapeutic options, additional treatment and prevention strategies are needed. Traditional risk factors do not explain all clinical and epidemiological features of stroke. Recently, the association between infectious and inflammatory processes and the occurrence of vascular disease has been established. This review summarizes the current evidence of infections as stroke risk factors and of potential anti-infective strategies as future methods of stroke prevention.

Update on the management of hypertension to prevent stroke

Hypertension is the leading modifiable risk factor for stroke, including first-ever and recurrent stroke. The association between blood pressure (BP) and stroke risk is continuous and may be documented as low as 115/75 mm Hg. Because of this continuum of risk, and because most strokes occur in individuals with mild hypertension or even normal BP values, we are now beginning to recognize "prehypertension" as a stage in which early recognition and intervention may confer benefit. In addition to increased risk for ischemic and hemorrhagic stroke, hypertension may be associated with increased risk of cognitive impairment. Reductions in BP are reliably associated with reduced stroke risk. Some evidence suggests that certain agents, including angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, may have protective effects beyond BP lowering. Overall, the degree of BP lowering is key, and therefore most classes of BP-lowering agents may be recommended at this point. Many patients with hypertension will require more than one BP-lowering agent to control BP. Lifestyle modification is appropriate at all levels of intervention. Further studies are needed to ascertain the mechanisms of benefit of different classes of antihypertensive agents in the reduction of stroke and cardiovascular disease risk.

Cerebral White Matter Hyperintensities on MRI: Current Concepts and Therapeutic Implications

BACKGROUND

White matter hyperintensities (WMH) are commonly observed MRI abnormalities in the elderly, which generally reflect covert vascular brain injury. WMH cumulatively produce substantial neurologic, psychiatric, and medical morbidity. This review provides an overview of current knowledge on vascular WMH, and describes some pharmacological agents that may have a role in mitigating this condition.

SUMMARY OF REVIEW

This review has two main focus areas. The first is a discussion of currently available knowledge regarding the public health burden, pathogenesis, and various risk factors associated with the presence of vascular white matter lesions noted on brain MRI. The second section of the article details the mechanistic and clinical basis for promising pharmacological treatment modalities that could potentially prevent progression of ischemic cerebral white matter brain injury. Many of these therapies are already of proven efficacy in preventing recurrent stroke.

CONCLUSIONS

Individuals with vascular white matter lesions on MRI may represent a potential target population likely to benefit from secondary stroke prevention therapies.

Blood Pressure as a Risk Factor for Stroke and the Impact of Antihypertensive Treatment

We review hypertension and blood pressure levels as risk factors for stroke and the impact of antihypertensive treatment on the prevention of first stroke event and of recurrent stroke, not only with respect to the prevention of vascular events but also the prevention of cognitive deterioration, dementia, and physical disability. We review whether pharmacological blockage of the renin-angiotensin system has additional long-term effects over that of control of blood pressure levels alone, and the benefit of treatment with antihypertensive drugs in normotensive patients. Therapeutic objectives for blood pressure levels after stroke are defined together with recommendations of drugs and doses which have been demonstrated to have the greatest benefit in the prevention of stroke.

Hypertensive retinopathy revisited: some answers, more questions

Hypertension is associated with cardiovascular risk and systemic target organ damage. Retinopathy is considered one of the indicators of target organ damage. This review focuses on recent studies on hypertensive retinopathy and their implications for clinical care. Early recognition of hypertensive retinopathy signs remains an important step in the risk stratification of hypertensive patients.

Renin-angiotensin-aldosterone system in brain infarction and vascular death

The renin-angiotensin-aldosterone system has functions that may contribute to brain infarction (BI). In 459 matched pairs of white patients and control subjects, we measured plasma angiotensin-converting enzyme (ACE) levels, seven polymorphisms (angiotensinogen T174M and M235T, ACE I/D and 4656 2/3CT repeat [rpt], angiotensin II type 1 receptor A1166C and A153G, and aldosterone synthase CYP11B2), and evaluated 5-year poststroke mortality. Mean plasma ACE levels (+/-standard error) were significantly greater in patients than control subjects (37.5 +/- 0.9 vs 33.9 +/- 0.9), in patients with lacunar stroke, and in patients with no previous vascular (cerebrovascular or cardiovascular) history. The risk for BI increased with tertiles of plasma ACE, without an interaction with hypertension. After adjustments, the association disappeared except among patients with cardioembolic BI and those without previous vascular events. Among the polymorphisms, there was a weak association of BI with angiotensin II type 1 receptor 1166C, a weak protective effect with angiotensinogen 174M, and a strong association of angiotensinogen 235T with 5-year vascular mortality. These results suggest that renin-angiotensin-aldosterone system activity and genes contribute to cerebrovascular disease and poststroke vascular death in white patients.

Treatments for stroke

Stroke is the third leading cause of death and the leading cause of disability in developed countries, yet remains a poorly treated condition. Treatments for stroke can be aimed at acutely improving blood flow or protecting brain tissue against ischaemia, enhancing stroke recovery or reducing the risk of stroke recurrence. This paper reviews each of these approaches, particularly focusing on mechanisms for which there are agents in clinical trials. There are a number of appealing neuroprotective agents in Phase II and III clinical trials. However, the majority of acute treatments are likely to suffer from a narrow therapeutic time window and hence limited patient access. Combinations of acute approaches are likely to offer the greatest benefit, but present challenges in development. Promotion of recovery following stroke offers enormous potential for successful therapeutic intervention. Excitingly, new developments in preclinical research have identified possible ways in which this may be achieved.

Determining the appropriateness of selected surgical and medical management options in recurrent stroke prevention: A guideline for primary care physicians from the National Stroke Association work group on recurrent stroke prevention

Despite a decade of successful clinical trials for stroke prevention, substantial gaps exist in the application and implementation of this information in community practice. The frequency of guideline use is low, and there remains controversy regarding the standard of practice. Patients with stroke may have multiple risk factors and concomitant stroke mechanisms, factors that are not addressed in stroke clinical trials and guideline statements. New guidelines are needed to account for these complexities and to provide primary care physicians a practical means to achieve stroke prevention. We sought to develop guidelines that can be implemented by primary care physicians to enhance the use of medical and surgical measures for recurrent stroke prevention. We sought to test the applicability of current evidence-based guidelines to daily practice with routine and complex patient case scenarios to determine whether these could be simplified into a more easily applied form for primary care physicians. We used RAND/UCLA Appropriateness Methodology to develop guidelines for the use of interventions supported by randomized controlled trials including carotid revascularization, anticoagulant therapy, antiplatelet therapy, and blood pressure management for the prevention of recurrent stroke. After a systematic literature review of randomized clinical trials we developed a comprehensive list of indications or clinical scenarios to capture decision making. A diverse multidisciplinary panel reviewed and rated each indication according to the RAND Appropriateness Method. First, panelists rated each scenario (1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate) without interaction with other panelists. "Appropriate" was defined as the expected health benefit exceeding its expected negative consequences by a sufficient margin. At a formal interactive session, panelists re-rated all indications. Overall carotid endarterectomy was rated as appropriate when there was 50% to 99% ipsilateral symptomatic carotid artery stenosis, inappropriate with <50% or 100% stenosis (total occlusion), and uncertain when the surgical risk was high. Carotid angioplasty was generally rated as of uncertain value. When there was atrial fibrillation, anticoagulation with warfarin was rated as appropriate when there was a low bleeding risk but of uncertain value when the bleeding risk was high. For patients who were not candidates for warfarin therapy, aspirin, aspirin plus extended-release dipyridamole, or clopidogrel were all rated as appropriate initial therapies. Ticlopidine was considered inappropriate and aspirin plus clopidogrel of uncertain value. With the exception of ticlopidine and aspirin, persons with a prior cerebral ischemic event while on aspirin could receive any of the aforementioned antiplatelet agents or combinations and be considered appropriately treated. The panelists rated a blood pressure of <130/80 mm Hg at 1 year after ischemic stroke as the target level and rated any of the following agents as appropriate initial therapies if there was no diabetes mellitus or proteinuria: diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin-converting enzyme receptor blockers, or combinations of a diuretic and an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Patient risk played a significant role in deterring the panel from recommending certain therapies; however, the presence of atrial fibrillation or large or small cerebral vessel syndromes rarely had significant influence on treatment decisions. Appropriateness was less where bleeding or surgical risk was excessive. Using consensus evidence from clinical trials, we have developed recurrent stroke prevention guidelines for routine and more complex patient scenarios according to appropriateness methodology. Broad application of these guidelines in primary practice promises to reduce the burden of recurrent stroke.

Postmarketing surveillance study of benazepril in chinese patients with hypertension: An open-label, experimental, epidemiologic study

BACKGROUND

Benazepril hydrochloride is an angiotensin-converting enzyme inhibitor. Previous clinical trials show that antihypertensive treatment with benazepril provides effective blood pressure (BP) control and is generally well tolerated by patients with hypertension. However, the long-term antihypertensive effects and tolerability of benazepril remain to be established in Chinese patients with hypertension.

OBJECTIVE

The aim of this study was to investigate the long-term efficacy and tolerability of benazepril in Chinese patients with essential hypertension.

METHODS

This 36-month, community-based, open-label, postmarketing surveillance study was conducted in the Nanshi District (Shanghai, China). Chinese patients with essential hypertension were to receive 1 or more benazepril tablets PO QD in the morning for 36 months. Data for BP and pulse pressure (PP) were collected at baseline (month 0) and throughout the surveillance period. The rate of patients achieving BP targets (systolic BP [SBP]/diastolic BP [DBP], <140/<90 mm Hg) was determined, as was the rate of decrease in BP. Subanalyses by sex and age group also were conducted.

RESULTS

A total of 1831 patients (1090 men, 741 women; mean [SD] age, 55.8 [10.1] years [range, 35-88 years]) entered the study. After the 36-month treatment period, 75.7% of patients receiving benazepril as prescribed (1289 patients) had achieved the SBP target, 87.4% achieved the DBP target, and 71.5% achieved both targets. After 36 months of treatment, the mean (SD) decreases in SBP, DBP, and PP were 15.1 (0.4) mm Hg, 11.0 (0.3) mm Hg, and 4.2 (0.4) mm Hg, respectively, among compliers. In general, the rate of BP decrease slowed over time. No serious adverse drug reactions (ADRs) were detected during the 36-month follow-up period. All ADRs except cough (19.9%) occurred at a relatively low incidence rate (<3.0%). The cumulative incidence of benazepril related cough was statistically significantly higher in women than in men (23.6% vs 18.8%, respectively; P = 0.007). Of the 1831 patients studied, 1360 patients (74.3%) persisted in taking benazepril and were considered optimally compliant at 36-month follow-up.

CONCLUSION

In this study of Chinese patients with hypertension, benazepril was associated with prolonged, stable efficacy in lowering BP and relatively low incidence of ADRs.

Are cholesterol-lowering medications and antihypertensive agents preventing stroke in ways other than by controlling the risk factor?

Statins and angiotensin-converting enzyme (ACE) inhibitors are an important component of our armamentarium for stroke prevention. Both of these classes of agents have a primary mechanism of action of reducing the level of the respective risk factor. They also have mechanisms of action that may confer benefits beyond what is believed to be the primary action of the agent. This has led to speculation that statins reduce stroke risk by means beyond cholesterol lowering, and ACE inhibitors reduce stroke risk by means beyond blood pressure lowering. We review the mounting evidence that suggests that statins and ACE inhibitors have so-called pleiotropic effects that may lead to stroke prevention.

Are cholesterol-lowering medications and antihypertensive agents preventing stroke in ways other than by controlling the risk factor?

Statins and angiotensin-converting enzyme (ACE) inhibitors are an important component of our armamentarium for stroke prevention. Both of these classes of agents have a primary mechanism of action of reducing the level of the respective risk factor. They also have mechanisms of action that may confer benefits beyond what is believed to be the primary action of the agent. This has led to speculation that statins reduce stroke risk by means beyond cholesterol lowering, and ACE inhibitors reduce stroke risk by means beyond blood pressure lowering. We review the mounting evidence that suggests that statins and ACE inhibitors have so-called pleiotropic effects that may lead to stroke prevention.