Relationship Between Blood Pressure and Stroke Recurrence in Patients With Intracranial Arterial Stenosis

Hemodynamic Impairment of Blood Pressure and Stroke Mechanisms in Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND

Hemodynamic impairment of blood pressure may play a crucial role in determining the mechanisms of stroke in symptomatic intracranial atherosclerotic stenosis). We aimed to elucidate this issue and assess the impacts of modifications to blood pressure on hemodynamic impairment.

METHODS

From the Third China National Stroke Registry III, computed fluid dynamics modeling was performed using the Newton-Krylov-Schwarz method in 339 patients with symptomatic intracranial atherosclerotic stenosis during 2015 to 2018. The major exposures were translesional systolic blood pressure (SBP) drop and poststenotic mean arterial pressure (MAP), and the major study outcomes were cortex-involved infarcts and borderzone-involved infarcts, respectively. Multivariate logistic regression models and the bootstrap resampling method were utilized, adjusting for demographics and medical histories.

RESULTS

In all, 184 (54.3%) cortex-involved infarcts and 70 (20.6%) borderzone-involved infarcts were identified. In multivariate logistic model, the upper quartile of SBP drop correlated with increased cortex-involved infarcts (odds ratio, 1.92 [95% CI, 1.03-3.57]; bootstrap analysis odds ratio, 2.07 [95% CI, 1.09-3.93]), and the lower quartile of poststenotic MAP may correlate with increased borderzone-involved infarcts (odds ratio, 2.07 [95% CI, 0.95-4.51]; bootstrap analysis odds ratio, 2.38 [95% CI, 1.04-5.45]). Restricted cubic spline analysis revealed a consistent upward trajectory of the relationship between translesional SBP drop and cortex-involved infarcts, while a downward trajectory between poststenotic MAP and borderzone-involved infarcts. SBP drop correlated with poststenotic MAP negatively (rs=-0.765; P<0.001). In generating hemodynamic impairment, simulating blood pressure modifications suggested that ensuring adequate blood pressure to maintain sufficient poststenotic MAP appears preferable to the reverse approach, due to the prolonged plateau period in the association between the translesional SBP drop and cortex-involved infarcts and the relatively short plateau period characterizing the correlation between poststenotic MAP and borderzone-involved infarcts.

CONCLUSIONS

This research elucidates the role of hemodynamic impairment of blood pressure in symptomatic intracranial atherosclerotic stenosis-related stroke mechanisms, underscoring the necessity to conduct hemodynamic assessments when managing blood pressure in symptomatic intracranial atherosclerotic stenosis.

A bibliometric analysis of the 100 most-cited clinical articles in the research of intracranial artery stenosis and intracranial atherosclerosis

Background

Intracranial arterial stenosis (ICAS), caused by intracranial atherosclerosis, is one of the major causes of ischemic stroke. This study identified the top 100 most-cited publications on ICAS through a bibliometric analysis.

Methods

Two independent authors conducted a search in the Web of Science database for clinical articles on ICAS published between 1993 and 2022. The top 100 most-cited articles were then extracted. For each article, the analysis covered the title, author, country of origin/affiliation, journal, total number of citations, number of citations per year, and type of study.

Results

The top 100 most-cited papers in the ICAS were authored by 565 authors from 12 countries and published in 29 journals. In terms of the 5-year trend, the largest number of papers were published between 2003 and 2007 (n = 31). The median number of citations for the 100 papers was 161 (range 109-1,115). The journal with the highest proportion of the 100 most published articles was Stroke, accounting for 41% of articles and 37% of the citations. According to country of origin, the United States of America accounted for the largest number of articles, followed by China, Japan, and South Korea, with these four countries together accounting for 81% of the total number of articles and 88% of the citations. Trends in the past five years included the use of terms such as acute ischemic stroke and mechanical thrombectomy.

Conclusion

The findings of this study provide novel insight into this field and will facilitate future research endeavors.

Optimal Medical Management of Atherosclerotic Intracranial Stenosis

Reducing the high risk of recurrent stroke in patients with symptomatic intracranial atherosclerotic stenosis (sICAS) has proven to be challenging, but aggressive medical management, with intensive risk factor control and antithrombotic therapy, has been shown to be beneficial. High-intensity statins are recommended for patients with atherosclerotic stroke, including sICAS. Ezetimibe and PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors are beneficial for those who fail to reach low-density lipoprotein targets or those with statin intolerance. The treatment target for sICAS is low-density lipoprotein <70 mg/dL. In neurologically stable patients, blood pressure should be treated to goal <140/90 mm Hg with the use of thiazide diuretics, angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers preferentially. For those with diabetes, treat to goal hemoglobin A1C ≤7% for most patients through combination of diet, insulin, and hypoglycemic drugs. Some degree of physical activity (eg, walking, stationary biking with arms or legs, etc) should be encouraged in all patients with sICAS who are not severely disabled. A minimum of 10 minutes of moderate-intensity aerobic activity 4 times a week is recommended for patients who are capable of exercise. For all patients with severe sICAS (70%-99% stenosis), dual antiplatelet therapy for up to 90 days followed by single antiplatelet agent is recommended.

Emergent Large Vessel Occlusion due to Intracranial Stenosis: Identification, Management, Challenges, and Future Directions

This comprehensive literature review focuses on acute stroke related to intracranial atherosclerotic stenosis (ICAS), with an emphasis on ICAS-large vessel occlusion. ICAS is the leading cause of stroke globally, with high recurrence risk, especially in Asian, Black, and Hispanic populations. Various risk factors, including hypertension, diabetes, hyperlipidemia, smoking, and advanced age lead to ICAS, which in turn results in stroke through different mechanisms. Recurrent stroke risk in patients with ICAS with hemodynamic failure is particularly high, even with aggressive medical management. Developments in advanced imaging have improved our understanding of ICAS and ability to identify high-risk patients who could benefit from intervention. Herein, we focus on current management strategies for ICAS-large vessel occlusion discussed, including the use of perfusion imaging, endovascular therapy, and stenting. In addition, we focus on strategies that aim at identifying subjects at higher risk for early recurrent risk who could benefit from early endovascular intervention The review underscores the need for further research to optimize ICAS-large vessel occlusion treatment strategies, a traditionally understudied topic.

Long-term recurrence of ischemic events in patients with intracranial atherosclerotic stenosis stratified by symptoms and pathogenesis

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) can cause either transient ischemic attack (TIA) or acute ischemic stroke (AIS). Pathogenesis of ICAS-AIS can be divided into artery-to-artery embolism(A-A), hypoperfusion(HP), and parent-artery atherosclerosis occluding penetrating artery(POPA). However, the prognosis of each type remains uncertain. Our study aimed to investigate potential disparities in the recurrent risk among these four subtypes of symptomatic ICAS.

METHODS

From a prospective, single-center cohort study of acute cerebrovascular diseases from January 2017 to November 2021, we recruited 120 ICAS patients and classified them into four groups based on diffusion weighted imaging. Patients were retrospectively followed up for recurrence in December 2022. The primary outcome was recurrent cerebral vascular events (RCVE) in the same territory.

RESULTS

Among 120 recruited patients, POPA(33%) was the most common subtype, followed by A-A(32%), HP(29%), and TIA(6%). Cumulative recurrent rate was 31.2% with median months of follow-up as 27(20-45.5). There was no significant difference in the risk of RCVE in the same territory among four subgroups within three months. However, when considering the risk after three months, TIA(57%) had the highest risk of RCVE, followed by A-A(26%), while HP(4%) and POPA(8%) had lower risks (P = 0.001). Cox regression model indicated that symptom and pathogenesis was an independent risk factor for RCVE in long-term prognosis (P = 0.022), after adjusting for a history of hypertension and cerebral infarction.

CONCLUSIONS

Distinctive symptoms and pathogenesis of ICAS exhibit varying risks of RCVE in long-term prognosis. The differentiation in recurrent risk may provide valuable insights for guiding secondary prevention strategies.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Major intracranial arterial stenosis influence association between baseline blood pressure and clinical outcomes after thrombolysis in ischemic stroke patients

BACKGROUND

This study aimed to investigate the relationship between baseline blood pressure (BP) and clinical outcomes after thrombolysis for acute ischemic stroke (AIS) in different intracranial arterial stenosis subgroups.

METHODS

AIS patients from multicenter with intravenous thrombolysis were retrospectively enrolled from January 2013 to December 2021. We categorized participants into severe (≥ 70%) and nonsevere (< 70%) stenosis of major intracranial arteries subgroups. The primary outcome was unfavorable functional outcome defined as 3-month modified Rankin Scale (mRS) ≥2. The association coefficients between baseline BP and functional outcomes were estimated in general linear regression model. The interactive effect was tested to determine the influence of intracranial arterial stenosis on the association between BP and clinical outcomes.

RESULTS

A total of 329 patients were included. Severe subgroup was detected in 151 patients with average age of 70.5. Association between baseline diastolic BP (DBP) and unfavorable functional outcome in intracranial artery stenosis subgroups was significantly different (p for interaction < .05). In nonsevere subgroup, higher baseline DBP was associated with higher risk of unfavorable outcome (OR 1.11, 95% CI 1.03 to 1.20, p = .009) compared with severe subgroup (OR 1.02, 95% CI 0.97 to 1.08, p = .341). Besides, intracranial artery stenosis also modified association between baseline systolic BP (SBP) and 3-month death (p for interaction < .05). In severe subgroup, higher baseline SBP was associated with decreased 3-month death risk (OR 0.88, 95% CI 0.78 to 1, p = .044) compared with nonsevere subgroup (OR 1, 95% CI 0.93 to 1.07, p = .908).

CONCLUSIONS

The major intracranial artery state modulates association between baseline BP and 3-month clinical outcomes after intravenous thrombolysis.

Association Between Magnitude of Differential Blood Pressure Reduction and Secondary Stroke Prevention: A Meta-analysis and Meta-Regression

Importance

The degree to which more intensive blood pressure reduction is better than less intensive for secondary stroke prevention has not been delineated.

Objective

To perform a standard meta-analysis and a meta-regression of randomized clinical trials to evaluate the association of magnitude of differential blood pressure reduction and recurrent stroke in patients with stroke or transient ischemic attack (TIA).

Data Sources

PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched from January 1, 1980, to June 30, 2022.

Study Selection

Randomized clinical trials that compared more intensive vs less intensive blood pressure lowering and recorded the outcome of recurrent stroke in patients with stroke or TIA.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was used for abstracting data and assessing data quality and validity. Risk ratio (RR) with 95% CI was used as a measure of the association of more intensive vs less intensive blood pressure lowering with primary and secondary outcomes. The univariate meta-regression analyses were conducted to evaluate a possible moderating effect of magnitude of differential systolic blood pressure (SBP) and diastolic blood pressure (DBP) reduction on the recurrent stroke and major cardiovascular events.

Main Outcomes and Measures

The primary outcome was recurrent stroke and the lead secondary outcome was major cardiovascular events.

Results

Ten randomized clinical trials comprising 40 710 patients (13 752 women [34%]; mean age, 65 years) with stroke or TIA were included for analysis. The mean duration of follow-up was 2.8 years (range, 1-4 years). Pooled results showed that more intensive treatment compared with less intensive was associated with a reduced risk of recurrent stroke in patients with stroke or TIA (absolute risk, 8.4% vs 10.1%; RR, 0.83; 95% CI, 0.78-0.88). Meta-regression showed that the magnitude of differential SBP and DBP reduction was associated with a lower risk of recurrent stroke in patients with stroke or TIA in a log-linear fashion (SBP: regression slope, -0.06; 95% CI, -0.08 to -0.03; DBP: regression slope, -0.17; 95% CI, -0.26 to -0.08). Similar results were found in the association between differential blood pressure lowering and major cardiovascular events.

Conclusions and Relevance

More intensive blood pressure-lowering therapy might be associated with a reduced risk of recurrent stroke and major cardiovascular events. These results might support the use of more intensive blood pressure reduction for secondary prevention in patients with stroke or TIA.

European Stroke Organisation guidelines on treatment of patients with intracranial atherosclerotic disease

The aim of the present European Stroke Organisation guideline is to provide clinically useful evidence-based recommendations on the management of patients with intracranial atherosclerotic disease (ICAD). The guidelines were prepared following the Standard Operational Procedure of the European Stroke Organisation guidelines and according to GRADE methodology. ICAD represents a major cause of ischemic stroke worldwide, and patients affected by this condition are exposed to a high risk for future strokes and other major cardiovascular events, despite best medical therapy available. We identified 11 relevant clinical problems affecting ICAD patients and formulated the corresponding Population Intervention Comparator Outcomes (PICO) questions. The first two questions refer to the asymptomatic stage of the disease, which is being increasingly detected thanks to the routine use of noninvasive vascular imaging. We were not able to provide evidence-based recommendations regarding the optimal detection strategy and management of asymptomatic ICAD, and further research in the field is encouraged as subclinical ICAD may represent a big opportunity to improve primary stroke prevention. The second block of PICOs (3-5) is dedicated to the management of acute large vessel occlusion (LVO) ischemic stroke caused by ICAD, a clinical presentation of this disease that is becoming increasingly relevant and problematic, since it is associated with more refractory endovascular reperfusion procedures. An operational definition of probable ICAD-related LVO is proposed in the guideline. Despite the challenging context, no dedicated randomized clinical trials (RCTs) were identified, and therefore the guideline can only provide with suggestions derived from observational studies and our expert consensus, such as the escalated use of glycoprotein IIb-IIIa inhibitors and angioplasty/stenting in cases of refractory thrombectomies due to underlying ICAD. The last block of PICOs is devoted to the secondary prevention of patients with symptomatic ICAD. Moderate-level evidence was found to recommend against the use of oral anticoagulation as preferred antithrombotic drug, in favor of antiplatelets. Low-level evidence based our recommendation in favor of double antiplatelet as the antithrombotic treatment of choice in symptomatic ICAD patients, which we suggest to maintain during 90 days as per our expert consensus. Endovascular therapy with intracranial angioplasty and or stenting is not recommended as a treatment of first choice in high-grade symptomatic ICAD (moderate-level evidence). Regarding neurosurgical interventions, the available evidence does not support their use as front line therapies in patients with high-grade ICAD. There is not enough evidence as to provide any specific recommendation regarding the use of remote ischemic conditioning in ICAD patients, and further RCTs are needed to shed light on the utility of this promising therapy. Finally, we dedicate the last PICO to the importance of aggressive vascular risk factor management in ICAD, although the evidence derived from RCTs specifically addressing this question is still scarce.

2021 Taiwan Stroke Society Guidelines of blood pressure control for ischemic stroke prevention

BACKGROUND

Since the publication of the 2015 Taiwan Stroke Society Blood Pressure for Treatment and Prevention of Stroke Guideline (2015 TSS BP Guideline), several new clinical studies have addressed whether a stricter blood pressure (BP) target would be effective for stroke prevention.

METHODS

TSS guideline consensus group provides recommendations on BP targets for stroke prevention based on updated evidences.

RESULTS

The present guideline covers five topics: (1) diagnosis of hypertension; (2) BP control and primary prevention of ischemic stroke; (3) BP control and secondary prevention of ischemic stroke; (4) BP control and secondary prevention of large artery atherosclerosis ischemic stroke; and (5) BP control and secondary prevention of small vessel occlusion ischemic stroke.

CONCLUSION

The BP target for most stroke patients with hypertension is <130/80 mm Hg.

Advances in Recurrent Stroke Prevention: Focus on Antithrombotic Therapies

The past decade has seen significant advances in stroke prevention. These advances include new antithrombotic agents, new options for dyslipidemia treatment, and novel techniques for surgical stroke prevention. In addition, there is greater recognition of the benefits of multifaceted interventions, including the role of physical activity and dietary modification. Despite these advances, the aging of the population and the high prevalence of key vascular risk factors pose challenges to reducing the burden of stroke. Using a cause-based framework, current approaches to prevention of cardioembolic, cryptogenic, atherosclerotic, and small vessel disease stroke are outlined in this paper. Special emphasis is given to recent trials of antithrombotic agents, including studies that have tested combination treatments and responses according to genetic factors.

Stroke Prevention in Symptomatic Large Artery Intracranial Atherosclerosis Practice Advisory: Report of the AAN Guideline Subcommittee

BACKGROUND AND OBJECTIVES

To review treatments for reducing the risk of recurrent stroke or death in patients with symptomatic intracranial atherosclerotic arterial stenosis (sICAS).

METHODS

The development of this practice advisory followed the process outlined in the American Academy of Neurology Clinical Practice Guideline Process Manual, 2011 Edition, as amended. The systematic review included studies through November 2020. Recommendations were based on evidence, related evidence, principles of care, and inferences.

MAJOR RECOMMENDATIONS

Clinicians should recommend aspirin 325 mg/d for long-term prevention of stroke and death and should recommend adding clopidogrel 75 mg/d to aspirin for up to 90 days to further reduce stroke risk in patients with severe (70%-99%) sICAS who have low risk of hemorrhagic transformation. Clinicians should recommend high-intensity statin therapy to achieve a goal low-density lipoprotein cholesterol level <70 mg/dL, a long-term blood pressure target of <140/90 mm Hg, at least moderate physical activity, and treatment of other modifiable vascular risk factors for patients with sICAS. Clinicians should not recommend percutaneous transluminal angioplasty and stenting for stroke prevention in patients with moderate (50%-69%) sICAS or as the initial treatment for stroke prevention in patients with severe sICAS. Clinicians should not routinely recommend angioplasty alone or indirect bypass for stroke prevention in patients with sICAS outside clinical trials. Clinicians should not recommend direct bypass for stroke prevention in patients with sICAS. Clinicians should counsel patients about the risks of percutaneous transluminal angioplasty and stenting and alternative treatments if one of these procedures is being contemplated.

Long-Term Secondary Prevention: Management of Blood Pressure After a Transient Ischemic Attack or Stroke

Reducing blood pressure (BP) is a highly effective strategy for long-term stroke prevention. Despite overwhelmingly clear evidence from randomized trials that antihypertensive therapy substantially reduces the risk of stroke in primary prevention, uncertainty still surrounds the issue of BP lowering after cerebrovascular events, and the risk of recurrent stroke, coronary events, and vascular death remains significant. Important questions in a secondary prevention setting include should everyone be treated regardless of their poststroke BP, how soon after a stroke should BP-lowering treatment be commenced, how intensively should BP be lowered, what drugs are best, and how should long-term BP control be optimized and monitored. We review the evidence on BP control after a transient ischemic attack or stroke to address these unanswered questions and draw attention to some recent developments that hold promise to improve management of BP in current practice.

Determinants and Outcomes of Asymptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide and confers a high risk of stroke recurrence, despite aggressive management of risk factors.

OBJECTIVES

This study identified the role of risk factors and risk of vascular events in subjects with asymptomatic ICAS for improved risk stratification.

METHODS

Stroke-free participants in the NOMAS (Northern Manhattan Study) trial, prospectively followed since 1993, underwent a brain magnetic resonance angiogram from 2003 to 2008. The study rated stenosis in 11 brain arteries as: 0: no stenosis; 1: <50% or luminal irregularities; 2: 50%-69%; and 3: ≥70% stenosis or flow gap. The study ascertained vascular events during the post-magnetic resonance imaging (MRI) period. Proportional odds regression quantified the association of pre-MRI exposures, and proportional hazard adjusted models were built to identify the risk of events in the post-MRI period.

RESULTS

The included sample included 1,211 participants from NOMAS (mean age: 71 ± 9 years; 59% women; 65% Hispanic; 45% had any stenosis). Older age (OR: 1.02 per year; 95% CI: 1.01 to 1.04), hypertension duration (OR: 1.01 per year; 95% CI: 1.00 to 1.02), higher number of glucose-lowering drugs (OR: 1.64 per each medication; 95% CI: 1.24 to 2.15), and high-density lipoprotein (OR: 0.96 per mg/dL; 95% CI: 0.92 to 0.99) were associated with ICAS. The highest event risk was noted among participants with ICAS ≥70% (5.5% annual risk of vascular events; HR: 2.1; 95% CI:1.4 to 3.2; compared with those with no ICAS).

CONCLUSIONS

ICAS is an imaging marker of established atherosclerotic disease in stroke-free subjects, and incidental diagnosis of ICAS should trigger a thorough assessment of vascular health.

Effect of Lomerizine Hydrochloride on Preventing Strokes in Patients With Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an orphan disease clinically characterized by migraine, recurrent strokes, and dementia. Currently, there are no disease-modifying therapies, and it is difficult to prevent cerebral ischemic events in CADASIL patients by conventional antithrombotic medication. We hypothesized that an antimigraine agent, lomerizine hydrochloride, may prevent strokes in CADASIL patients, based on its effect on increasing cerebral blood flow.

SUBJECTS AND METHODS

This was an open-labeled clinical trial in which 30 adult CADASIL patients received lomerizine at 10 mg/d. Numbers of symptomatic strokes during the 2 years after the start of lomerizine administration were compared with those in the 2 years before its initiation. The effect of lomerizine on preventing strokes was evaluated based on the incidence rate ratio (IR) calculated with the Mantel-Haenszel method.

RESULTS

When including all 30 patients (analysis 1), the IR was less than 1 (0.46; 95% confidence interval [CI], 0.19-1.12) but did not reach significance. To evaluate the effect of lomerizine on secondary prevention, subgroups of 15 patients with stroke episodes occurring any time before lomerizine administration (analysis 2) and 10 patients with stroke episodes during the 2 years before lomerizine administration (analysis 3) were analyzed. The IR values were 0.33 (95% CI, 0.12-0.94) in analysis 2 and 0.17 (95% CI, 0.04-0.67) in analysis 3.

CONCLUSIONS

Our results suggest the effect of lomerizine on preventing secondary stroke in CADASIL patients.

Risk Factors Control and Early Recurrent Cerebral Infarction in Patients with Symptomatic Intracranial Atherosclerotic Disease

BACKGROUND

The risk of early recurrent cerebral infarction (RCI) is high in patients with symptomatic intracranial atherosclerotic disease (IAD). We sought to determine the relationship between risk factor control and early RCI risk among patients with symptomatic IAD.

METHODS

We analyzed participants with symptomatic IAD in the multi-center prospective observational MYRIAD study. Risk factor control was assessed at 6-8-week follow-up. Optimal risk factor control was defined by target systolic blood pressure, being non-smoker, target physical activity, and antiplatelet and antilipidemic therapy compliance. Age-adjusted associations were calculated between risk factor control and RCI determined by MRI-evident new infarcts in the territory of the stenotic vessel at 6-8 weeks from the index event.

RESULTS

Among 82 participants with clinical and brain MRI information available 6-8 weeks after the index event (mean age 63.5 ±12.5 years, 62.2% men), RCI occurred in 21 (25.6%) cases. At 6-8-week follow-up, 37.8% had target systolic blood pressure, 92.7% were non-smokers, 51.2% had target physical activity, and 98.8% and 86.6% were compliant with antiplatelet and antilipidemic therapy, respectively. Optimal risk factor control increased from 4.9% at baseline to 19.5% at 6-8-week follow-up (p=0.01). None of the participants with optimal risk factor control at follow-up had RCI (0% vs. 31.8%, p<0.01).

CONCLUSIONS

Only one-fifth of MYRIAD participants had optimal risk factor control during early follow-up. Approximately half and two-thirds had physical inactivity and uncontrolled systolic blood pressure, respectively. These risk factors may represent important therapeutic targets to prevent early RCI in patients with symptomatic IAD.

Prevalence, prognosis, and treatment of atherosclerotic intracranial stenosis in Caucasians

BACKGROUND

Intracranial atherosclerotic stenosis is a highly prevalent cause of stroke worldwide with important ethnic disparities. Widely considered to be a common cause of stroke in Asian and Afro-Caribbean populations, relatively less is known about the burden and significance of intracranial atherosclerotic stenosis in Caucasians.

AIMS

We aim to highlight recent insights and advances into the prevalence, prognosis, and treatment of symptomatic and asymptomatic atherosclerotic intracranial atherosclerotic stenosis in Caucasian patients.

SUMMARY OF REVIEW

We identified 48 articles studying intracranial atherosclerotic stenosis in Caucasian patients with ischemic stroke or transient ischemic attack. Most studies were on hospital-based cohorts of consecutive patients and half were graded as "fair" quality. There was significant variation between studies in the definition of intracranial atherosclerotic stenosis and in the imaging modalities used to detect intracranial atherosclerotic stenosis. Overall, 12.1% of Caucasian patients were found to have any intracranial atherosclerotic stenosis, 6.4% symptomatic intracranial atherosclerotic stenosis and 11.1% asymptomatic intracranial atherosclerotic stenosis, with higher rates at older ages. In studies reporting prognosis, there were 61 and 10 same-territory ischemic strokes in 1000 person-years in patients with symptomatic and asymptomatic intracranial atherosclerotic stenosis, respectively. Percutaneous stenting and angioplasty have not proven superior to intensive medical management in patients with symptomatic intracranial atherosclerotic stenosis.

CONCLUSIONS

Intracranial atherosclerotic stenosis has previously been neglected as a cause of stroke in Caucasians but is highly prevalent at older ages and frequently discovered with the growing use of noninvasive angiography. Intensive medical therapy is the treatment of choice, but there is a need to develop novel treatments or therapeutic approaches to lower the risk of stroke in higher risk patients.

Anatomical Variations in the Circulus Arteriosus Cerebri with Clinical Importance - Results of an Magnetic Resonance Angiography Study and Review of Literature

Objectives:

Anatomy of circulus arteriosus cerebri (CAC) shows wide variation in different individuals, and population groups and has vital clinical significance in causation and presentation of clinical disease. The literature revealed a connection between the variations of CAC and cerebrovascular disease, ischemia, stroke, aneurysms, and atherosclerosis.

Material and Methods:

In this study, 513 patients without clinical manifestation in regard to cerebrovascular diseases, who are considered healthy on CAC anatomy, are included. Patients were instructed by clinicians for head imagery with magnetic resonance angiography examination during 2016–2017 periods.

Results:

After statistical analysis, 43.27% were male while 56.72% female, 39% were younger than 40 years old. Age interval lies from 11 to 84 years old, mean age 46. The most common variations or 9.74% is when communicant anterior artery absence and absence of both posterior communicant arteries (Type G*/E) more rarely is H*/G (0.2%), G*/D (1.75%), G*/G (0.6%), H*/D (0.4%), H*/E (3.39%), H*/H (0.4%), J*/E (0.6%), while combination J*/D, J*/G, J*/H, G*/H not found. The most often combination is absence of anterior communicant artery and absence of both posterior communicant artery (Type G*/E), more in male 10.36% than female 9.6%.

Conclusion:

The CAC is considered to play a critical role in preventing future stroke events in patients with absent of any of the arteries. Knowledge on variations in arteries forming the CAC is with clinical significance, as it is one of the components of CAC which stabilizes cerebral blood flow when principle conduits fail. Knowing the structure of arteries provide clinical knowledge to the surgeons before planning neurovascular surgeries.

Bypass for flow-augmentation in atherosclerotic carotid occlusion: a review of the literature and career experience

Atherosclerosis of the internal carotid artery and intracranial vessels can compromise cerebral hemodynamics and cause stroke. Cerebral bypass has a half-century history in augmenting or replacing blood flow the brain. Several trials have investigated various applications of cerebral bypass in flow augmentation for atherosclerotic disease. This review discusses the clinical science of cerebrovascular atherosclerosis to provide the context in which cerebral bypass is currently applied. This includes prior clinical trials, ongoing clinical trials, and consensus guidelines, and is complemented by studies in the physiologic science of cerebrovascular flow. The scientific background is supplemented by the description of the technical art of bypass surgery based on a three-decade experience. Successful application of cerebral bypass to augment flow in atherosclerotic cerebrovascular disease requires correct diagnosis of compromised hemodynamic reserve refractory to medical optimization and an appropriate matching of bypass flow with cerebral demand.

Intervention for symptomatic vertebrobasilar disease

Disease of the vertebral (VA) and basilar arteries (BA) can lead to stroke of the posterior circulation and may warrant management strategies which differ from the anterior circulation. The mechanism and location of the disease determine its natural history and therefore affect the relative risks and benefits of the possible treatment options. Vertebrobasilar (VB) atherosclerotic disease is a source of both hemodynamic and embolic posterior circulation stroke. Advances in medical therapy have decreased the rate of stroke after initial symptomatic presentation. Antiplatelet therapy, blood pressure control, and optimization of secondary risk factors can reduce recurrent stroke risk in both intracranial and extracranial VB disease. However, symptomatic intracranial disease is still associated with a high risk of subsequent stroke, particularly those with hemodynamic compromise who represent a higher risk population. Patients with hemodynamic impairment may benefit from judicious application of endovascular and microsurgical interventions to augment blood flow. Stenting, angioplasty alone, bypass surgery, and endarterectomy, represent endovascular and surgical tools available to address medically refractory VB disease. Apart from atherosclerotic disease, dissection is another etiology of VB stroke, most frequently affecting the extracranial VA. Treatment is predominantly antithrombotic therapy although surgical or endovascular intervention can be required in rare cases of persistent embolism or hemodynamic compromise. In contrast, extrinsic compromise of the VA represents a separate extracranial pathology and is best treated with mechanistically targeted surgeries or extracranial bypass.

Neurological complications of systemic hypertension

Systemic hypertension is the most common, most easily diagnosed, and one of the most reversible risk factors for neurologic pathology. Acute severe hypertension above a mean arterial pressure of approximately 150mmHg exceeds the brain's autoregulatory capacity and results in increased cerebral blood flow leading to hypertensive encephalopathy. Chronic hypertension predisposes to cerebral vasculature atherosclerosis, medial hypertrophy, luminal narrowing, endothelial dysfunction, impaired arterial relaxation, and decreased ability to augment cerebral blood flow at low blood pressures. The pathologic effects of hypertension increase stroke risk by three- to fivefold. With three-fourths of strokes incident events, primary prevention is essential. Multiple studies have demonstrated the benefit of blood pressure lowering in reducing incident and recurrent strokes. Even more, hypertension is a risk factor for cognitive impairment and dementia through multifactorial mechanisms including vascular compromise, cerebral small vessel disease, white matter disease (leukoaraiosis), cerebral microbleeds, cerebral atrophy, amyloid plaque deposition, and neurofibrillary tangles. In patients without hypotension, treatment with antihypertensives slows progression and assuages the degree of cognitive decline. While the choice of antihypertensive did not make a significant difference in most cognitive outcome studies, some large meta-analyses have pointed to angiotensin receptor blockers as the favored agent. Because of the well-documented morbidity and mortality associated with unchecked hypertension, treating and preventing hypertension are universally critical pillars in healthcare.

Endovascular stenting of medically refractory intracranial arterial stenotic (ICAS) disease (clinical and sonographic study)

Background

Atherosclerotic intracranial arterial stenosis (ICAS) is one of the most common causes of stroke worldwide and is associated with a high risk of recurrent stroke. Patients with a recent transient ischemic attack (TIA) or stroke and severe stenosis (70 to 99% of the diameter of a major intracranial artery) are at particularly high risk for recurrent stroke in the territory of the stenotic artery (approximately 23% at 1 year) despite medical treatment. Therefore, alternative therapies are urgently needed for these patients.

Objective

To determine the efficacy and safety of angioplasty with stenting in medically refractory ICAS and to compare its effectiveness with optimal medical treatment.

Subjects and methods

Fifty patients with symptomatic ICAS despite medical treatment (i.e, recurrent stroke or TIA) were enrolled and equally randomized in a prospective study where twenty-five patients underwent angioplasty with stenting and twenty-five patients received optimal medical treatment. Clinical assessment with NIHSS and mRS were done at 0, 3, and 6 months, and transracial Doppler (TCD) assessment of ICAS was done at 0 and 3 months after treatment.

Results

The interventional group had a better clinical outcome with mean NIHSS scores (5.2 ± 4.2, 4.43 ± 4.28 and 3.9 ± 4.7) at baseline, 3 and 6 months, respectively, in comparison to the medical group with mean NIHSS (4.5 ± 4.2, 11.42 ± 6.3, and 8.5 ± 5.1) and better functional outcome with mean mRS scores (1.3 ± 0.96, 1.2 ± 1.13, and 1.0 ± 1.13) at baseline, 3 and 6 months, respectively, in comparison to the medical group (0.84 ± 0.75, 2.28 ± 1.2, and 2 ± 1.24). TCD assessment of ICAS showed a marked reduction of the percentage of stenosis on 3 months of follow-up among the interventional groups (only 5.6% had > 70% stenosis) in comparison to the medical group (85.7% had > 70% stenosis). Recurrent ischemic events on 6 months of follow-up were 16% among interventional groups in comparison to 84% among medical groups. The mortality rate was 8% among interventional groups due to subarachnoid hemorrhages (SAH) related to procedure in comparison to 28% among medical groups secondary to ischemic events. The intraoperative success rate was 96% with the failure of stent deployment in 1 patient due to the tortuous anatomy of vessels. Early post interventional complication rate, i.e, SAH was 8%. Late post interventional restenosis and occlusion rates were 8% on 3 months of follow-up.

Conclusion

Endovascular stenting of medically refractory ICAS is more efficacious and effective with better clinical and functional outcomes than optimal medical treatment; however, its safety is still debatable.

Trial registration

Done at ClinicalTrials.gov. Trial ID (NCT Number) NCT04393025.

Intracranial Atherosclerotic Stenoses: Pathophysiology, Epidemiology, Risk Factors and Current Therapy Options

Intracranial atherosclerotic stenoses (ICAS) are one of the most common causes of first and recurrent cerebrovascular ischaemic events worldwide, with highest prevalence in Asian, Hispanic and African populations. Clinical trials have improved the understanding of epidemiology, risk factors and imaging characteristics of patients with ICAS. Current therapeutic approaches concerning these patients include management of risk factors, best medical therapy, potentially endovascular and rarely surgical therapy. In our review, we elucidate the current epidemiology and evidence in evaluation of risk factors and therapeutic options for providing favourable outcome for patients with ICAS.

Translesional Pressure Gradient Alters Relationship Between Blood Pressure and Recurrent Stroke in Intracranial Stenosis

Background and Purpose- There is debate over an optimal systolic blood pressure (SBP) in secondary stroke prevention of patients with symptomatic intracranial atherosclerotic stenosis (sICAS). We investigated whether translesional pressure gradient across sICAS would alter the relationship between SBP and risk of recurrent stroke in such patients. Methods- We recruited patients with sICAS (50%-99% stenosis) confirmed in computed tomography angiography. We simulated blood flow across sICAS with computed tomography angiography-based computational fluid dynamics models. Translesional pressure ratio (PR=Pressure_{post-stenotic}/Pressure_pre-stenotic) was calculated in each case. Pressure ratio (PR) ≤ median was defined as low PR, indicating larger translesional pressure gradient across sICAS. All patients received optimal medical treatment. We investigated the interaction of translesional PR and mean SBP during follow-up (SBP_FU) in determining the risk of the primary outcome, recurrent ischemic stroke in the same territory within 1 year. Results- Among 157 patients with sICAS, the median PR was 0.93. Multivariate Cox regression revealed significant PR-SBP_FU interaction on the primary outcome (P=0.008): in patients with normal PR, risk of primary outcome significantly decreased with lower SBP_FU (hazard ratio for 10 mm Hg decrement =0.46; P=0.018); however, in those with low PR, SBP_FU≤130 mm Hg was associated with significantly increased risk of primary outcome, compared with 130<SBP_FU<150 mm Hg (hazard ratio=5.08; P=0.043). Conclusions- Low SBP level may be associated with increased risk of stroke recurrence in patients with sICAS with a large translesional pressure gradient. Translesional PR by computational fluid dynamics models may yield a promising indicator to guide more individualized blood pressure management in patients with sICAS, warranting future studies.

Current Opinion on Endovascular Therapy for Emergent Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Stenosis

For recanalization of emergent large vessel occlusions (ELVOs), endovascular therapy (EVT) using newer devices, such as a stent retriever and large-bore catheter, has shown better patient outcomes compared with intravenous recombinant tissue plasminogen activator only. Intracranial atherosclerotic stenosis (ICAS) is a major cause of acute ischemic stroke, the incidence of which is rising worldwide. Thus, it is not rare to encounter underlying ICAS during EVT procedures, particularly in Asian countries. ELVO due to underlying ICAS is often related to EVT procedure failure or complications, which can lead to poor functional recovery. However, information regarding EVT for this type of stroke is lacking because large clinical trials have been largely based on Western populations. In this review, we discuss the unique pathologic basis of ELVO with underlying ICAS, which may complicate EVT procedures. Moreover, we review EVT data for patients with ELVO due to underlying ICAS and suggest an optimal endovascular recanalization strategy based on the existing literature. Finally, we present future perspectives on this subject.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

Blood pressure fluctuation pattern and stroke outcomes in acute ischemic stroke

Blood pressure (BP) fluctuates widely during the acute phase of stroke. Compared to single BP assessment, patterns of BP over time may have greater power in predicting stroke outcome. This study aims to investigate the effect of BP fluctuation patterns on stroke outcomes in acute ischemic stroke (IS) patients. IS patients within 24 h of onset registered in the BOSS registry between 2012 and 2014 were analyzed. Fluctuation of BP was predefined as the change trend in systolic BP (SBP) from Day 1 to Day 7 after onset and was used to divide patients into groups with sustained high SBP (≥160 mmHg) during the first 7 days (C1); rapid (C2: within the first 2 days) or delayed (C3: after 2 days) decline from high (≥160 mmHg) to low (<160 mmHg); consistently low SBP (C4); and elevation from low to high (C5). The primary stroke outcome was defined as a modified Rankin Scale score ≥3 at 3 months after onset. Of 1,095 IS patients, C1 (n = 90) had the highest risk of poor outcome (23.3%), while C2 (n = 198, risk = 11.6%) and C4 (n = 650, risk = 12.2%) had the lowest risk. C2 and C4 had a significant reduction in poor outcome risk when compared to C1, even after adjustment for average BP and BP variability (BPV) during the first 7 days (adjusted odds ratio[OR]_C2 = 0.32, 95% CI: 0.12-0.80; OR_C4 = 0.37, 95% CI: 0.14-0.97). The BP fluctuation pattern in the acute phase of IS might be a useful predictive parameter for functional outcome independent of average BP and BPV.

Blood Pressure Variability Is Associated With White Matter Lesion Growth in Intracranial Atherosclerosis

BACKGROUND

High blood pressure variability (BPV) is associated with recurrent stroke. We investigated the association between BPV, new ischemic lesions (NILs), and white matter lesion (WML) growth in patients with ischemic stroke due to intracranial atherosclerosis (ICAS).

METHODS

This study was performed as a post-hoc analysis of the STABLE-ICAS trial, which enrolled subacute ischemic stroke patients with symptomatic ICAS (>50% stenosis) and hypertension. BPV was measured at the office (visit by visit) and at home (day by day). Patients were divided into 3 groups (tertiles) according to their home BPV. WML growth and the occurrence of NILs were compared among the 3 groups. Multivariable analyses were performed to identify the independent risk factors of WML growth and NILs.

RESULTS

Of the 111 enrolled patients, 69 patients (67.6%) demonstrated WML growth and 15 patients (13.7%) had NILs. Patients with higher BPV demonstrated a more WML growth (50% vs. 61.8% vs. 83.8; P = 0.02, by tertiles) and more NILs (5.4% vs. 5.4% vs. 29.7%; P = 0.002, by tertiles). In multivariable analyses, old age [odds ratio (OR) = 1.052 (95% confidence interval (CI) = 1.005-1.101); P = 0.03] and home BPV [OR = 1.149 (95% CI = 1.013-1.304); P = 0.02] were independently associated with WML growth. Low mean diastolic blood pressure [OR = 0.913 (95% CI = 0.874-0.984); P = 0.02] and high home BPV [OR = 1.287 (95% CI = 1.086-1.526); P = 0.004] were independently associated with NILs at follow-up.

CONCLUSIONS

High BPV is associated with WML growth and NIL in ischemic stroke patients with symptomatic ICAS. BPV monitoring at home may be helpful.

Risk factors outperform intracranial large artery stenosis predicting unfavorable outcomes in patients with stroke

Background

This study examined how intracranial large artery stenosis (ILAS), symptomatic and asymptomatic ILAS, and risk factors affect unfavorable outcome events after medical treatment in routine clinical practice.

Methods

This was a 24-month prospective observational study of consecutively recruited stroke patients. All participants underwent magnetic resonance angiography, and their clinical characteristics were assessed. Outcome events were vascular outcome, recurrent stroke, and death. Cox regression analyses were performed to identify potential factors associated with an unfavorable outcome, which included demographic and clinical characteristics, the risk factors, and stenosis status.

Results

The analysis included 686 patients; among them, 371 were assessed as ILAS negative, 231 as symptomatic ILAS, and 84 as asymptomatic ILAS. Body mass index (p < .05), hypertension (p = .01), and old infarction (p = .047) were factors relating to vascular outcomes. Hypertension was the only factor for recurrent stroke (p = .035). Poor glomerular filtration rate (< 30 mL/min/1.73 m²) (p = .011) and baseline National Institutes of Health Stroke Scale scores (p < .001) were significant predictors of death.

Conclusions

This study extended previous results from clinical trials to a community-based cohort study by concurrently looking at the presence/absence of stenosis and a symptomatic/asymptomatic stenotic artery. Substantiated risk factors rather than the stenosis status were predominant determinants of adverse outcome. Although the degree of stenosis is often an indicator for treatment, we suggest risk factors, such as hypertension and renal dysfunction, should be monitored and intensively treated.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Outcomes after ischemic stroke caused by intracranial atherosclerosis vs dissection

OBJECTIVE

To compare the outcomes between patients with nontraumatic intracranial arterial dissection (ICAD) and intracranial atherosclerotic stenosis (ICAS) using high-resolution MRI (HR-MRI).

METHODS

We conducted a prospective study using HR-MRI in patients with acute symptomatic cerebrovascular disease due to intracranial occlusive disease and no dissection on luminal images. Patients were followed-up for 27.9 ± 19.3 months. We compared the functional outcome, recurrence, and changes in vascular status between patients with ICAD (dissection and no plaque on HR-MRI) and ICAS (atherosclerosis plaque on HR-MRI).

RESULTS

We included 312 patients (mean age, 59.0 ± 14.2 years; men, 58.3%), of whom 113 had ICAD and 199 had ICAS. The functional outcome (as measured by modified Rankin Scale score) on the 90th day after symptom onset was not different between the groups, after adjusted for other factors (p = 0.095). However, recurrent ischemic cerebrovascular disease on the relevant vascular territory was lower in the ICAD group (7 patients, 6.2%) than in the ICAS group (37 patients, 18.6%). ICAD was a significant independent determinant of disease recurrence (hazard ratio, 0.43; 95% confidence interval, 0.19-0.98). Improvement in vascular stenosis on follow-up vascular studies was more frequently observed in ICAD (50.7%) than in ICAS (11.6%). ICAD was an independent determinant of vascular improvement (odds ratio, 7.94; 95% confidence interval, 3.32-19.01).

CONCLUSION

Considering the high prevalence of ICAD in the patients with presumed ICAS and the differential outcomes between ICAD and ICAS, HR-MRI may be a useful diagnostic tool in this population.

The Assessment of Diagnostic Accuracy for Basilar Artery Stenosis by Transcranial Color-Coded Sonography

This study aimed to determine the optimal criteria for evaluating basilar artery stenosis (BAS) by transcranial color-coded sonography (TCCS). A total of 403 cases with both TCCS and digital subtraction angiography (DSA) were enrolled. Peak systolic velocity (PSV), end diastolic velocity (EDV) and mean flow velocity (MFV) of the basilar artery (BA), intracranial vertebral artery (IVA) and posterior cerebral artery (PCA) were measured. The ratios PSV_BA/PSV_IVA and PSV_BA/PSV_PCA were calculated. With DSA as the reference, the optimal criteria for grading BAS were determined by receiver operating characteristic analysis. They were as follows: PSV ≥110 cm/s, MFV ≥70 cm/s and PSV_BA/PSV_IVA ≥1.5 for <50% BAS; PSV ≥150 cm/s, MFV ≥90 cm/s and PSV_BA/PSV_IVA ≥2.0 for 50%-69% BAS; PSV ≥210 cm/s, MFV ≥120 cm/s and PSV_BA/PSV_IVA ≥3.0 for 70%-99% BAS. The combination of PSV, MFV and PSV_BA/PSV_IVA may increase the accuracy for diagnosing 70%-99% BAS.

Recent Advances in Primary and Secondary Prevention of Atherosclerotic Stroke

Atherosclerosis is a major cause of ischemic stroke that can be effectively prevented with appropriate lifestyle modifications and control of cardiovascular risk factors. Medical advances in recent years along with aggressive cardiovascular risk factor modifications have resulted in decreased recurrence rates of atherosclerotic stroke. Non-statin lipid-lowering molecules have recently shown clinical benefit and are recommended for very high-risk patients to reduce their risk of stroke. Aggressive hypertension treatment is crucial to reduce atherosclerotic stroke risk. Advances in antithrombotic treatments include combinations of antiplatelets and new antiplatelet agents in the acute phase post-stroke, which carries a high risk of recurrence. Intensive medical treatment has also limited the indications for carotid interventions, especially for asymptomatic disease. Intracranial atherosclerotic disease may provoke stroke through various mechanisms; it is increasingly recognized as a cause of ischemic stroke with advanced imaging and is best managed with lifestyle modifications and medical therapy. The diagnostic search for the vulnerable culprit atherosclerotic plaque is an area of intense research, from the level of the intracranial arteries to that of the aortic arch. Ultrasonography and novel magnetic resonance imaging techniques (high-resolution vessel-wall imaging) may assist in the identification of vulnerable atherosclerotic plaques as the underlying cause in cryptogenic or misdiagnosed non-atherosclerotic ischemic stroke. Vertebrobasilar atherosclerotic disease is less common than carotid artery disease; thus, high-quality data on effective prevention strategies are scarcer. However, aggressive medical treatment is also the gold standard to reduce cerebrovascular disease located in posterior circulation.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Association of Systolic Blood Pressure with Progression of Symptomatic Intracranial Atherosclerotic Stenosis

Background and Purpose

Elevated blood pressure (BP) is associated with greater severity of intracranial atherosclerotic stenosis (ICAS) and increased risk of ischemic stroke. Because little is known about the relationship of maintained BP level with progression of symptomatic ICAS (sICAS), we evaluated the independent association of maintained systolic BP (SBP) with risk of sICAS progression.

Methods

We analyzed the Trial of cilOstazol in Symptomatic intracranial Stenosis 2, which evaluated 402 stroke patients with sICAS (mean age, 64.5±11.3 years; male, 52.2%). Study participants were categorized into four groups according to mean SBP level: low-normal (<120 mm Hg), normal to high-normal (120 to 139 mm Hg), high (140 to 159 mm Hg), and very-high (≥160 mm Hg). Progression of sICAS was defined as worsening in the degree of stenosis by ≥1 grade on the 7-month magnetic resonance angiography follow-up.

Results

sICAS progression was observed in 52 (12.9%) subjects. Percentages of sICAS progression by mean SBP category showed a J-shape pattern: low-normal (21.4%), normal to high-normal (10.7%), high (11.4%), and very-high (38.9%). In multivariable analysis, compared to the normal to high-normal SBP group, odds ratios (95% confidence intervals) were low-normal, 1.88 (0.62–5.67); high, 1.06 (0.47–2.37); and very-high, 8.75 (2.57–29.86). Rate of sICAS progression by 10-mm Hg strata showed a similar pattern to findings from mean SBP category (9.47; 2.58–34.73 for SBP ≥160 mm Hg).

Conclusions

Among individuals with a recent ICAS stroke, very-high SBP level during the short-term period after the index stroke was associated with significantly greater odds of sICAS progression.

Medical Treatment of Intracranial Atherosclerosis: An Update

For patients with symptomatic intracranial atherosclerosis (ICAS), antithrombotic agents are the mainstay of therapy. Anticoagulation (warfarin) is not widely used since it is not more effective than aspirin and carries a high risk of bleeding. New oral anticoagulants are showing promise, but their use has not been investigated in appropriate clinical trials. Since the recurrent stroke risk is high with aspirin monotherapy, dual antiplatelets are considered in the early stage of symptomatic ICAS. Based on the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) and Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) results, aspirin plus clopidogrel has been recommended. However, this combination was not superior to aspirin monotherapy in patients with ICAS in the CHANCE substudy. Progression of ICAS is common, and it is associated with recurrent strokes. In the Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis (TOSS) study, aspirin plus cilostazol was more effective than aspirin monotherapy in preventing progression. The TOSS II trial showed that the overall change in stenosis was better with aspirin plus cilostazol than with aspirin plus clopidogrel. Aside from antithrombotic therapy, risk factor management is critical for secondary prevention, and high blood pressure is clearly linked to recurrent stroke. However, blood pressure may have to be cautiously managed in the early stage of stroke. Considering that ICAS is the major cause of stroke worldwide, further investigations are needed to establish optimal management strategies for patients with ICAS.

Symptomatic Carotid Artery Stenosis: Surgery, Stenting, or Medical Therapy?

Symptomatic carotid artery disease is a significant cause of ischemic stroke, and these patients are at high risk for recurrent vascular events. Patients with symptoms of stroke or transient ischemic attack attributable to a significantly stenotic vessel (70–99% luminal narrowing) should be treated with intensive medical therapy. Intensive medical therapy is a combination of pharmacologic and lifestyle interventions consistent with best-known practices as follows: initiation of antiplatelet agent or anticoagulation if medically indicated, high potency statin medication, blood pressure control with goal blood pressure of greater than 140/90, Mediterranean-style diet, exercise, and smoking cessation. Further, patients who have extracranial culprit lesions should be considered for revascularization with either carotid endarterectomy or carotid angioplasty and stenting depending on several factors including the patient’s anatomy, age, gender, and procedural risk. Based on current evidence, patients with symptomatic intracranial stenosis should be managed with intensive medical therapy, including the use of dual antiplatelet therapy with aspirin and clopidogrel for the first 90 days following the ischemic event. While the literature has shown a stronger benefit of revascularization of extracranial symptomatic disease among certain subgroups of patients with greater than 70% stenosis, there is less benefit from revascularization with endarterectomy in patients with moderate stenosis of 50–69% if the surgeon’s risk of perioperative stroke or death rate is greater than 6%.

Blood Pressure Management for Stroke Prevention and in Acute Stroke

Elevated blood pressure (BP) is the leading modifiable risk factor for stroke and the benefit of BP lowering therapy on the stroke risk reduction is well established. The optimal BP target for preventing stroke and other vascular events have been controversial, but the evidences from epidemiological studies and randomized controlled trials (RCTs) support intensive BP lowering for greater vascular protection, particularly for stroke prevention. For secondary stroke prevention, the evidence of intensive BP lowering benefit is limited since only a single RCT for patients with lacunar infarctions was conducted and most data were driven by exploratory analyses. In acute intracerebral hemorrhage, immediate BP lowering targeting systolic BP<140 mm Hg is recommended by guidelines based on the results from RCTs. In contrast, in acute ischemic stroke, early BP lowering is not usually recommended because of no benefit on functional outcome and future vascular events and potential harm of stroke progression. This review aims to summarize the updated evidence for optimal BP management for primary and secondary stroke prevention and in patients with acute stroke.

Large Artery Atherosclerotic Occlusive Disease

PURPOSE OF REVIEW

Extracranial or intracranial large artery atherosclerosis is often identified as a potential etiologic cause for ischemic stroke and transient ischemic attack. Given the high prevalence of large artery atherosclerosis in the general population, determining whether an identified atherosclerotic lesion is truly the cause of a patient's symptomatology can be difficult. In all cases, optimally treating each patient to minimize future stroke risk is paramount. Extracranial or intracranial large artery atherosclerosis can be broadly compartmentalized into four distinct clinical scenarios based upon the individual patient's history, examination, and anatomic imaging findings: asymptomatic and symptomatic extracranial carotid stenosis, intracranial atherosclerosis, and extracranial vertebral artery atherosclerotic disease. This review provides a framework for clinicians evaluating and treating such patients.

RECENT FINDINGS

Intensive medical therapy achieves low rates of stroke and death in asymptomatic carotid stenosis. Evidence indicates that patients with severe symptomatic carotid stenosis should undergo carotid revascularization sooner rather than later and that the risk of stroke or death is lower using carotid endarterectomy than with carotid stenting. Specific to stenting, the risk of stroke or death is greatest among older patients and women. Continuous vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy is the mainstay for stroke prevention in the setting of intracranial and vertebral artery origin atherosclerosis.

SUMMARY

Lifelong vascular risk factor optimization via sustained behavioral modifications and intensive medical therapy are the key elements to reduce future stroke risk in the setting of large artery atherosclerosis. When considering a revascularization procedure for carotid stenosis, patient demographics, comorbidities, and the periprocedural risks of stroke and death should be carefully considered.

Stroke Caused by Atherosclerosis of the Major Intracranial Arteries

Our goal in this review is to discuss the pathophysiology, diagnosis, and treatment of stroke caused by atherosclerosis of the major intracranial arteries. References for the review were identified by searching PubMed for related studies published from 1955 to June 2016 using search terms intracranial stenosis and intracranial atherosclerosis. Reference sections of published randomized clinical trials and previously published reviews were searched for additional references. Intracranial atherosclerotic disease is a highly prevalent cause of stroke that is associated with a high risk of recurrent stroke. It is more prevalent among blacks, Hispanics, and Asians compared with whites. Diabetes mellitus, hypertension, metabolic syndrome, smoking, hyperlipidemia, and a sedentary lifestyle are the major modifiable risk factors associated with intracranial atherosclerotic disease. Randomized clinical trials comparing aggressive management (dual antiplatelet treatment for 90 days followed by aspirin monotherapy and intensive management of vascular risk factors) with intracranial stenting plus aggressive medical management have shown medical management alone to be safer and more effective for preventing stroke. As such, aggressive medical management has become the standard of care for symptomatic patients with intracranial atherosclerotic disease. Nevertheless, there are subgroups of patients who are still at high risk of stroke despite being treated with aggressive medical management. Future research should aim to establish clinical, serological, and imaging biomarkers to identify high-risk patients, and clinical trials evaluating novel therapies should be focused on these patients.

Relationship between risk factor control and vascular events in the SAMMPRIS trial

OBJECTIVE

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study is the first stroke prevention trial to include protocol-driven intensive management of multiple risk factors. In this prespecified analysis, we aimed to investigate the relationship between risk factor control during follow-up and outcome of patients in the medical arm of SAMMPRIS.

METHODS

Data from SAMMPRIS participants in the medical arm (n = 227) were analyzed. Risk factors were recorded at baseline, 30 days, 4 months, and then every 4 months for a mean follow-up of 32 months. For each patient, values for all risk factor measures were averaged and dichotomized as in or out of target.

RESULTS

Participants who were out of target for systolic blood pressure and physical activity, as well as those with higher mean low-density lipoprotein cholesterol and non-high-density lipoprotein, were more likely to have a recurrent vascular event (stroke, myocardial infarction, or vascular death) at 3 years compared to those who had good risk factor control. In the multivariable analysis, greater physical activity decreased the likelihood of a recurrent stroke, myocardial infarction, or vascular death (odds ratio 0.6, confidence interval 0.4-0.8).

CONCLUSIONS

Raised blood pressure, cholesterol, and physical inactivity should be aggressively treated in patients with intracranial atherosclerosis to prevent future vascular events. Physical activity, which has not received attention in stroke prevention trials, was the strongest predictor of a good outcome in the medical arm in SAMMPRIS.

CLINICALTRIALSGOV IDENTIFIER

NCT00576693.