Embolism in acute middle cerebral artery stenosis

Association between triglyceride glucose index and all-cause mortality in patients with cerebrovascular disease: a retrospective study

BACKGROUND

Triglyceride glucose (TyG) is associated with stroke, atherosclerosis, and adverse clinical outcomes. However, its correlation with cerebrovascular disease (CVD) mortality remains unclear. This study aimed to investigate the relationship between TyG index and mortality in patients with CVD.

METHODS

Patient data sourced from the Medical Information Mart for Intensive Care -IV database were categorized based on TyG quartiles. Kaplan-Meier survival analysis was used to estimate survival disparities among the TyG subgroups. Cox proportional risk modeling was used to examine the association between the TyG index and mortality. Generalized summation models were applied to fit the smoothed curves. log-likelihood ratio test were used to analyze the non-linear relationship.

RESULTS

The study comprised 1,965 patients (50.18% were male). The 28-day and 90-day mortality rates were 20.10% and 24.48%, respectively. The TyG index exhibited a linear relationship with the 28-day mortality (Hazards ratio (HR), 1.16; 95% confidence interval (CI), 0.99-1.36) and the 90-day mortality (HR, 1.18; 95% CI, 1.02-1.37). In the TyG Q4 group, each 1 mg/dl increase was linked to a 35% rise in the risk of 28-day mortality and a 38% increase in the risk of 90-day mortality. Subgroup analyses highlighted a more substantial association between TyG index and 90-day mortality in the diabetic group.

CONCLUSION

Our findings underscore the positive association between TyG and the 28- and 90-day mortality rates in patients with CVD. This insight may prove pivotal for identifying at-risk populations and enhancing risk prediction in the clinical management of CVD.

Research progress on risk factors related to intracranial artery, carotid artery, and coronary artery stenosis

In recent decades, with the rapid development of economy, the acceleration of social aging and urbanization, and the prevalence of unhealthy lifestyles, the number of patients with cardiovascular and cerebrovascular diseases has shown an increasing trend year by year. It has also become one of the important causes of disability and death in all ages and groups. Atherosclerosis is the main pathological change of ischemic cardiovascular and cerebrovascular diseases, which mainly invades the large and medium arteries of the body circulation. In particular, cerebral artery and coronary artery lesions have the most significant impact on life. There is the same pathogenic mechanism between intracranial and extracranial arteries and coronary atherosclerosis, so there is a certain relationship between the degree of atherosclerosis. In this paper, the risk factors related to intracranial and extracranial arteries and coronary artery stenosis were reviewed. It provides a theoretical basis for early detection, early diagnosis and early treatment of intracranial and extracranial artery and coronary artery stenosis to reduce the occurrence and development of cardiovascular and cerebrovascular diseases.

Association of triglyceride-glucose index with intra- and extra-cranial arterial stenosis: a combined cross-sectional and longitudinal analysis

PURPOSE

This study aimed to assess the cross-sectional and longitudinal associations of the triglyceride glucose (TyG) index, a simple surrogate marker of insulin resistance, with intra-cranial and extra-cranial artery stenosis (ICAS and ECAS) in Chinese adults.

METHODS

Participants were recruited from the Asymptomatic Polyvascular Abnormalities Community study, 5381 participants were enrolled in the cross-sectional analysis, then 3447 and 1853 participants in the longitudinal analysis for incident ICAS and ECAS, respectively. The TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Multivariable logistic analysis was used to calculate odds ratio (OR) and 95% confidence interval (CI).

RESULTS

The results of the cross-sectional and longitudinal analysis were basically the same, as the fully adjusted OR comparing participants in the highest tertile versus lowest tertile of the TyG index was 1.34 (95% CI, 1.13-1.59) for the prevalence of ECAS and 1.85 (95% CI, 1.26-2.71) for incident ECAS, respectively. The addition of TyG index to a conventional model had an incremental effect on the predictive value for ECAS. However, we did not observe any significant association between the TyG index and ICAS.

CONCLUSIONS

Elevated TyG index was significantly associated with a higher risk of ECAS, but not with ICAS in Chinese adults. This conclusion lends support to the clinical significance of the TyG index for the assessment of artery stenosis, especially for ECAS.

Predictors of Early Infarct Recurrence in Patients With Symptomatic Intracranial Atherosclerotic Disease

BACKGROUND AND PURPOSE

While prior studies identified risk factors for recurrent stroke in patients with symptomatic intracranial atherosclerotic disease, few have assessed risk factors for early infarct recurrence.

METHODS

We performed a post hoc analysis of the MYRIAD study (Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease) of intracranial atherosclerotic disease patients with recent (<21 days) stroke/transient ischemic attack, 50% to 99% stenosis and who underwent 6- to 8-week magnetic resonance imaging (MRI) per protocol. Infarct recurrence was defined as new infarcts in the territory of the symptomatic artery on brain MRI at 6 to 8 weeks compared to index brain MRI. Qualifying events and clinical and imaging outcomes were centrally ascertained by 2 independent reviewers. We assessed the association between baseline clinical and imaging variables and recurrent infarct in bivariate models and multivariable logistic regression to identify independent predictors of infarct recurrence.

RESULTS

Of 105 enrolled patients in MYRIAD, 89 (84.8%) were included in this analysis (mean age, 64±12 years, 54 [60.7%] were male, and 53 [59.6%] were White). The median time from qualifying event to MRI was 51+16 days, on which 22 (24.7%) patients had new or recurrent infarcts. Younger age (57.7 versus 66.0 years; P<0.01), diabetes (32.6% versus 14.6%, P=0.05), index stroke (31.3% versus 4.6%, P=0.01), anterior circulation location of stenosis (29.7% versus 12.0%, P=0.08), number of diffusion-weighted imaging lesions (>1: 40.0%, 1: 26.9% versus 0: 4.4%, P<0.01), and borderzone infarct pattern (63.6% versus 25.0%, P=0.01) on baseline MRI were associated with new or recurrent infarcts. Age (adjusted odds ratio, 0.93 [95% CI, 0.89-0.98], P<0.01) and number of diffusion-weighted imaging lesions (adjusted odds ratio, 3.24 [95% CI, 1.36-7.71], P<0.01) were independently associated with recurrent infarct adjusting for hypertension, diabetes, and stenosis location (anterior versus posterior circulation).

CONCLUSIONS

An index multi-infarct pattern is associated with early recurrent infarcts, a finding that might be explained by plaque instability and artery-to-artery embolism. Further investigation of plaque vulnerability in intracranial atherosclerotic disease is needed. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02121028.

Association of Newly Found Asymptomatic Intracranial Artery Stenosis and Ideal Cardiovascular Health Metrics in Chinese Community Population

In the general population, there is a strong inverse relationship between the number of ideal cardiovascular health (CVH) metrics and the total incidence of cardiovascular diseases and stroke. However, the prevalence of ideal CVH is extremely low and there are few studies on its association with newly found asymptomatic intracranial arterial stenosis (AICAS). Therefore, we performed this prospective study to assess the relationship between the newly found AICAS and ideal CVH metrics in the Chinese community population. Seven ideal CVH metrics of 3,475 participants in the Asymptomatic Polyvascular Abnormalities Community study (APAC) conducted in China (1,962 men and 1,513 women between the ages of 45 and 75 years) were collected. Based on the occurrence of newly found AICAS, all participants were divided into the AICAS group and non-ICAS group. Prevalence of ideal CVH metrics was compared between the two groups. Logistic regression was used to estimate the association of newly found AICAS with ideal CVH metrics. The result was the number of ideal CVH metrics was strongly associated with age, gender, education levels and family income (each P < 0.0001). Among the seven CVH metrics total cholesterol (TC) was the only one showing significant difference between the newly found AICAS group and non-ICAS group in our 2 years observation. Participants with less ideal CVH metrics (≤3) were associated with significantly higher prevalence of AICAS than those with more (>3) ideal CVH metrics (OR, 1.27; P = 0.045). Furthermore, less (≤3) ideal CVH metrics was markedly associated with higher incidence of AICAS for all participants, younger participants (<60 years) (OR, 1.34; P = 0.046) and men participants (OR, 1.53; P = 0.032) after adjustment for gender, age, education level, family income and stroke history. Thus we conclude that participants with newly found AICAS have high prevalence of total cholesterol status, and Individuals with low ideal CVH metrics (≤3) are associated with significantly higher prevalence of asymptomatic ICAS, especially in high-risk population of young and men participants. Therefore, primordial prevention of stroke should also focus on those high-risk populations.

Validation of a basic neurosonology laboratory for detecting cervical carotid artery stenosis

INTRODUCTION

Most of the cases of ischaemic stroke in our setting are of atherothrombotic origin. Detecting intracranial and cervical carotid artery stenosis in patients with ischaemic stroke is therefore essential. Ultrasonography has become the tool of choice for diagnosing carotid artery stenosis because it is both readily accessibility and reliable. However, use of this technique must be validated in each laboratory. The purpose of this study is to validate Doppler ultrasound in our laboratory as a means of detecting severe carotid artery stenosis.

PATIENTS AND METHODS

We conducted an observational descriptive study to evaluate diagnostic tests. The results from transcranial and cervical carotid Doppler ultrasound scans conducted by neurologists were compared to those from carotid duplex scans performed by radiologists in patients diagnosed with stroke. Arteriography was considered the gold standard (MR angiography, CT angiography, or conventional arteriography).

RESULTS

Our sample included 228 patients. Transcranial and cervical carotid Doppler ultrasound showed a sensitivity of 95% and specificity of 100% for detection of carotid artery stenosis > 70%, whereas carotid duplex displayed a sensitivity of 87% and a specificity of 94%. Transcranial carotid Doppler ultrasound achieved a sensitivity of 78% and a specificity of 98% for detection of intracranial stenosis.

CONCLUSIONS

Doppler ultrasound in our neurosonology laboratory was found to be a useful diagnostic tool for detecting cervical carotid artery stenosis and demonstrated superiority to carotid duplex despite the lack of B-mode. Furthermore, this technique was found to be useful for detecting intracranial stenosis.

Dynamic Cerebral Autoregulation in Asymptomatic Patients With Unilateral Middle Cerebral Artery Stenosis

The aim of the study was to assess the capacity of dynamic cerebral autoregulation (dCA) in asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis.Fifty-seven patients with asymptomatic mild, moderate, and severe unilateral MCA stenosis and 8 patients with symptomatic severe unilateral MCA stenosis diagnosed by transcranial Doppler were enrolled. Twenty-four healthy volunteers served as controls. The noninvasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each subject in the supine position. Transfer function analysis was applied to determine the autoregulatory parameters (phase difference [PD] and gain).The PD values in the severe stenosis groups were significantly lower than those of the control group (60.71 ± 18.63°), the asymptomatic severe stenosis group was impaired ipsilaterally (28.94 ± 27.43°, P < 0.001), and the symptomatic severe stenosis group was impaired bilaterally (13.74 ± 19.21°, P < 0.001; 19.68 ± 14.50°, P = 0.006, respectively). The PD values in the mild and moderate stenosis groups were not significantly different than the controls (44.49 ± 27.93°; 48.65 ± 25.49°, respectively). The gain values in the mild and moderate groups were higher than in the controls (1.00 ± 0.58 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, and 1.20 ± 0.59 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, respectively). The gain values in the severe stenosis groups were significantly lower than that in the control group: the asymptomatic severe stenosis group was lower bilaterally (0.56 ± 0.32 cm/s/mm Hg, P = 0.003; 0.60 ± 0.32 cm/s/mm Hg, P < 0.05, respectively), whereas the symptomatic severe group was lower unilaterally (on the contralateral side) (0.53 ± 0.43 cm/s/mm Hg, P < 0.05).In asymptomatic patients with unilateral MCA stenosis, only the dCA of the severe stenosis was ipsilaterally impaired. Acute stroke may aggravate the impaired dCA and even spread contralaterally.

Advances in imaging of intracranial atherosclerotic disease and implications for treatment

OPINION STATEMENT

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide and is associated with a high risk of recurrent stroke despite aggressive therapy. ICAD may lead to cerebral ischemia through a variety of mechanisms, the interactions of which are largely unknown. The use of endovascular therapy for the prevention of stroke related to severe ICAD has been studied but was associated with a higher risk of recurrent stroke and death in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study. With advances in diagnostic testing, it may be possible to better delineate the specific mechanism of stroke from ICAD and identify those patients at higher risk for recurrent ischemia. There may be a subset of patients less responsive to medical interventions, such as those with hemodynamic failure as opposed to those with perforator syndromes, who would benefit from medical plaque stabilization or safer endovascular approaches such as angioplasty alone. These will need to be tested in future clinical trials. Overall, symptomatic ICAD remains a high risk condition with suboptimal treatment options.

Ideal cardiovascular health metrics on the prevalence of asymptomatic intracranial artery stenosis: a cross-sectional study

Background and Purpose

Intracranial Artery Stenosis (ICAS) is one of the most common causes of ischemic stroke in Asia. Previous studies have shown the number of ideal cardiovascular health (CVH) metrics was associated with lower risk of stroke. This study aimed to investigate the relationship between ideal CVH metrics and prevalence of ICAS.

Methods

A random sample of 5,412 participants (selected from Kailuan Study as a reference population) aged 40 years or older (40.10% women), free of stroke, transient ischemic attack, and coronary disease, were enrolled in the Asymptomatic Polyvascular Abnormalities Community study from 2010 to 2011. We collected information on the seven CVH metrics (including smoking, body mass index, dietary intake, physical activity, blood pressure, total cholesterol and fasting blood glucose); and assessed ICAS by transcranial Doppler. The relationship between the ideal CVH metrics and prevalence of ICAS was analyzed using the multivariate logistic regression.

Results

After adjusting for age, sex, and other potential confounders, the adjusted odds ratios(95% confidence interval) for ICAS were 0.76(0.58–0.99), 0.55(0.43–0.72), 0.49(0.37–0.65), 0.43(0.31–0.61), and 0.36(0.22–0.62), respectively, for those having 2, 3, 4, 5, and 6–7 ideal CVH metrics compared with those having 0–1 ideal metric(p-trend<0.0001). Similar inverse associations were observed in different age and gender groups (all p-trends<0.05).

Conclusion

We found a clear gradient relationship between the number of ideal CVH metrics and lower prevalence of ICAS in a Chinese population, which supports the importance of ideal health behaviors and factors in the prevention of ICAS.

[Detection of micro-embolic signals: a review of the literature]

BACKGROUND

The detection of micro-embolic signals (MES), by transcranial Doppler sonography might be useful for risk stratification in patients with symptomatic and asymptomatic carotid or cerebral artery stenosis, dissections, aortic atheroma, interventional procedures, and right to left cardiac shunts.

AIM

Review of the technique and clinical situations of MES detection.

METHODS

PubMed search from 1990 to 2012.

RESULTS

MES were found in 0,19, 48% versus 0,3, and 12% of patients with symptomatic and asymptomatic inferior than 30, 30 to 69, and 70 to 99% carotid stenosis, respectively. MES were related to the risk of recurrent stroke or transient ischemic attack (TIA). In the ACES study, the absolute annual risk of stroke or TIA after 2 years was 7% with vs 3% without MES. In patients with intracranial stenosis, the risk of stroke recurrence was 48% with vs 7% without MES at 13.6 months follow-up. MES were reported in 25% of the symptomatic versus none of the asymptomatic patients with intracranial stenosis.

CONCLUSION

Detection of MES is feasible and reproducible for multicenter studies, using rigourous methodology and long lasting recordings. It may contribute to risk stratification, especially in patients with extra- or intracranial stenosis.

Endovascular treatment of symptomatic intracranial atheromatous stenosis: a single center study of 21 consecutive cases

OBJECTIVES

This retrospective single-center study evaluated the technical success as well as the periprocedural and long-term complications of angioplasty with stenting of symptomatic intracranial atheromatous stenosis.

PATIENTS AND METHODS

From January 2005 to December 2010, 21 patients were treated by angioplasty with stent implantation for symptomatic atheromatous intracranial stenosis greater or equal to 50% at least 7 days after a stroke.

RESULTS

The median population age was 65 years (range: 41-88 years), and 76% (16/21) of the candidates had a history of transient ischemic attack (TIA) or stroke before the event qualifying them for an endovascular procedure. In addition, 86% (18/21) were taking antithrombotic medication at the time of the qualifying event. Technical success was obtained in all cases. The periprocedural stroke or death rate was 9.5% (2/21), and there was no other stroke or death after 30 days during the mean follow-up of 1.4 years.

CONCLUSION

Endovascular treatment of symptomatic intracranial atherothrombotic stenosis can lead to severe complications, particularly during the periprocedural period, but it also represents the only alternative treatment for patients who fail with medical therapy. Future studies need to focus on improvement of periprocedural complications. Essentially, this should include more rigorous selection of candidates as well as a better understanding of the pathophysiological mechanism(s) of the ischemic phenomenon related to stenosis.

Rate of Postprocedural Stroke and Death in SAMMPRIS Trial–Eligible Patients Treated With Intracranial Angioplasty and/or Stent Placement in Practice

BACKGROUND:

The SAMMPRIS (Stenting vs Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) trial, comparing aggressive medical vs stent treatment in patients with symptomatic intracranial stenosis, was halted after a 14% stroke and death rate was observed in the stent-treated group.

OBJECTIVE:

To study the 30-day stroke and death rate in intracranial angioplasty- and stent-treated patients meeting SAMMPRIS trial eligibility criteria.

METHODS:

A retrospective analysis of 96 patients treated with intracranial angioplasty and stent placement at 3 university-affiliated institutions was performed. Patients were divided into SAMMPRIS trial eligible and ineligible groups based on inclusion and exclusion criteria for the SAMMPRIS trial.

RESULTS:

Sixty-nine patients were determined to be SAMMPRIS eligible and 27 patients were ineligible. The SAMMPRIS-eligible group was divided into angioplasty- and stent-treated subgroups (30 and 39 patients, respectively). The overall 30-day postprocedure stroke and death rate was 7.2% in the SAMMPRIS-eligible group and 7.4% in the SAMMPRIS-ineligible group (P = .97). The 30-day postprocedure stroke and death rate was 3.3% in the SAMMPRIS-eligible, angioplasty-treated subgroup and 10.2% in the SAMMPRIS-eligible, stent-treated subgroup (P = .27).

CONCLUSION:

The overall 30-day postprocedure stroke and death rate in our study was lower in both SAMMPRIS-eligible and -ineligible groups than the reported 14% stroke and death rate in the SAMMPRIS trial. We hypothesize that a more judicious use of primary angioplasty may be responsible for better postprocedure outcomes and should be considered an acceptable treatment in future trials.

[Endovascular treatment of symptomatic intracranial stenoses: short- and long-term results in a single center]

OBJECTIVES

We present the short- and long-term results of a series of patients with symptomatic intracranial arterial stenoses treated with angioplasty and stenting.

MATERIAL AND METHODS

We reviewed patients with symptomatic intracranial stenoses greater than 50% who were treated with angioplasty, stenting, or both. We recorded demographic data and risk factors (hypertension, diabetes, dyslipemia, ischemic heart disease). We classified all lesions treated according to their location, degree of stenosis, and length. The degree of stenosis was classified as moderate (50%-70%) or severe (>70%). In the follow-up, we assessed cerebrovascular accidents, episodes of ischemic heart disease, and deaths in the first 30 days and in later follow-up.

RESULTS

Between 2006 and 2010, we treated 26 patients (21 men and 5 women; age range, 44-79 years; mean age, 63 years) with 29 intracranial lesions. The endovascular procedure (angioplasty+stenting) was successfully performed in 23 cases (92.0%). In the first 30 days after the procedure, 3 (11.5%) patients had adverse effects of vascular origin: 1 stroke, 1 hemorrhage, and 1 death due to thrombosis of the stent. Long-term follow-up (5-46 months) in the 25 patients who survived more than 30 days detected no recurrence of symptoms.

CONCLUSION

Endovascular treatment of intracranial stenosis is technically feasible. Short-term complications are highly prevalent. No recurrence of symptoms was detected during long-term follow-up.

Current diagnosis and management of symptomatic intracranial atherosclerotic disease

PURPOSE OF REVIEW

Intracranial atherosclerotic disease (IAD) is likely the most common cause of stroke world-wide and is associated with a very high risk of recurrence. It results in cerebral ischemia due to a variety of mechanisms, including artery-to-artery embolism, hemodynamic failure, and occlusion of penetrating arteries. New imaging modalities focused on physiological consequences of IAD have become available and recent treatment trials have been completed.

RECENT FINDINGS

We review the traditional imaging modalities, emphasizing the advantages and limitations of each method, and discuss the novel physiological approaches that interrogate physiological process to indicate specific mechanisms of ischemia. These allow deeper understanding of the pathophysiological processes that underlie IAD-related ischemia. The key findings of recent therapeutic trials are reviewed, including the landmark randomized studies showing advantage of antiplatelet agents and risk factor modification, and a significant risk of complications with endovascular approaches.

SUMMARY

Current evidence argues for aggressive medical management and suggests caution with interventional treatments. We propose that mechanistic information will further refine the risk assessment of patients with IAD to offer targeted therapy.

Cardiac workup of ischemic stroke

Stroke is the leading cause of disability in developed countries and the third cause of mortality. Up to 15-30% of ischemic strokes are caused by cardiac sources of emboli being associated with poor prognosis and high index of fatal recurrence. In order to establish an adequate preventive strategy it is crucial to identify the cause of the embolism. After a complete diagnostic workup up to 30% of strokes remain with an undetermined cause, and most of them are attributed to an embolic mechanism suggesting a cardiac origin.There is no consensus in the extent and optimal approach of cardiac workup of ischemic stroke. Clinical features along with brain imaging and the study of the cerebral vessels with ultrasonography or MRI/CT based angiography can identify other causes or lead to think about a possible cardioembolic origin.Atrial fibrillation is the most common cause of cardioembolic stroke. Identification of occult atrial fibrillation is essential. Baseline ECG, serial ECG('s), cardiac monitoring during the first 48 hours, and Holter monitoring have detection rates varying from 4 to 8% each separately. Extended cardiac monitoring with event loop recorders has shown higher rates of detection of paroxysmal atrial fibrillation.Cardiac imaging with echocardiography is necessary to identify structural sources of emboli. There is insufficient data to determine which is the optimal approach. Transthoracic echocardiography has an acceptable diagnostic yield in patients with heart disease but transesophageal echocardiography has a higher diagnostic yield and is necessary if no cardiac sources have been identified in patients with cryptogenic stroke with embolic mechanism.

Microemboli monitoring by trans-cranial doppler in patient with acute cardioemboliogenic stroke due to atrial myxoma

This is the first reported attempt to examine the emboliogenic potential of cardiac myxoma in patients with acute stroke through the monitoring of microembolic signals (MES) by transcranial doppler. A 43-year old woman was brought to the emergency department because of acute onset of generalized tonic-clonic seizures and left hemiplegia. A CT scan of the brain demonstrated a large acute infraction in the territory of the right middle cerebral artery (MCA) and another smaller one in the territory of the posterior cerebral artery on the same side. Trans-cranial doppler (TCD) microemboli monitoring did not reveal MES. Transesophagial echocardiography (TEE) identified a 5 cm left atrial mass, which was highly suspected to be an atrial myxoma attached to the interatrial septum and prolapsed through the mitral valve. After the TEE results were obtained, another TCD monitoring was performed. Again, there were no MES found in either of the MCAs.Our findings showed the absence of MES on two consecutive TCD examinations, suggesting a spontaneous occurrence, rather than the permanent presence, of embolization, even in the most acute phase of stroke. Thus, the tendency of myxomas to spontaneously produce multiple emboli emphasizes the need for the surgical excision of myxomas.

Update on the natural history of intracranial atherosclerotic disease: A critical review

Intracranial atherosclerotic disease (ICAD) contributes to a significant number of ischemic strokes. There is debate in the recent literature concerning the impact of the location of stenosis in ICAD on outcome. Some reports have suggested that disease processes and outcomes vary by vessel location, potentially altering the natural history and indications for intervention. Here we have performed a comprehensive, critical review of the natural history of ICAD by vessel in an attempt to assess the differences in disease specific to each of the vascular territories. Our assessment concludes that only minor differences exist between patients with different vessels affected in vessel-specific ICAD. We have found that middle cerebral artery disease confers a lower mortality than vessel-specific ICAD in other intracranial vessels, asymptomatic disease follows a more benign course than symptomatic disease, and that plaque progression or the detection of microemboli on transcranial Doppler may predict poor outcome. Given the expanding indications for treatment of ICAD and rapidly developing endovascular techniques to confront this disease, a thorough understanding of the natural history of ICAD aids the interventional neuroradiologist in determining when to treat and how to predict outcome in this patient population.

COMPARISON BETWEEN PRIMARY ANGIOPLASTY AND STENT PLACEMENT FOR SYMPTOMATIC INTRACRANIAL ATHEROSCLEROTIC DISEASE

OBJECTIVE

To compare the short- and long-term rates of stroke-and/or-death associated with primary angioplasty alone and angioplasty with stent placement using a meta-analysis of published studies. Both primary angioplasty alone and angioplasty with stent placement have been proposed as treatment strategies for symptomatic intracranial atherosclerotic disease to reduce the risk of stroke-and/or-death with best medical treatment alone. However, it remains unclear which of these endovascular techniques offers the best risk reduction.

METHODS

We identified pertinent studies published between January 1980 and May 2008 using a search on PubMed and Cochrane libraries, supplemented by a review of bibliographies of selected publications. The incidences of stroke-and/or-death were estimated for each report and pooled for both angioplasty alone and angioplasty with stent placement at 1 month and 1 year postintervention and then compared using a random-effects model. The association of year of publication and 1-year incidence of stroke-and/or-death was analyzed with meta-regression.

RESULTS

After applying our selection criteria, we included 69 studies (33 primary angioplasty-alone studies [1027 patients] and 36 studies of angioplasty with stent placement [1291 patients]) in the analysis. There were a total of 91 stroke-and/or-deaths reported in the angioplasty-alone–treated group (8.9%; 95% confidence interval [CI], 7.1%–10.6%), compared with 104 stroke-and/or-deaths in the angioplasty-with-stent–treated group (8.1%; 95% CI, 6.6%–9.5%) during a 1-month period (relative risk [RR], 1.1; P = 0.48). The pooled incidence of 1-year stroke-and/or-death in patients treated with angioplasty alone was 19.7% (95% CI, 16.6%–23.5%), compared with 14.2% (95% CI, 11.9%–16.9%) in the angioplasty-with-stent–treated patients (RR, 1.39; P = 0.009). The incidence of technical success was 79.8% (95% CI, 74.7%–84.8%) in the angioplasty-alone group and 95% (95% CI, 93.4%–96.6%) in the angioplasty-with-stent–treated group (RR, 0.84; P &lt; 0.0001). The pooled restenosis rate was 14.2% (95% CI, 11.8–16.6%) in the angioplasty-alone group, as compared with 11.1% (95% CI, 9.2%–13.0%) in the angioplasty-with-stent–treated group (RR, 1.28; P = 0.04). There was no effect of the publication year of the studies on the risk of stroke-and/or-death.

CONCLUSION

Risk of 1-year stroke-and/or-death and rate of angiographic restenosis may be lower in symptomatic intracranial atherosclerosis patients treated by angioplasty with stent placement compared with patients treated by angioplasty alone.

Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis

BACKGROUND AND PURPOSE

Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis.

SUMMARY OF REPORT

This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSION

In summary, the definitions proposed represent recommendations for constructing useful research data sets. The intent is to facilitate production of scientifically rigorous results capable of reliable comparisons between and among similar studies. In some cases, the definitions contained here are recommended by consensus of a panel of experts in this writing group for consistency in reporting and publication. These definitions should allow different groups to publish results that are directly comparable.

Reporting Standards for Angioplasty and Stent-Assisted Angioplasty for Intracranial Atherosclerosis

Background and Purpose— Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis.

Summary of Report— This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

Conclusion— In summary, the definitions proposed represent recommendations for constructing useful research data sets. The intent is to facilitate production of scientifically rigorous results capable of reliable comparisons between and among similar studies. In some cases, the definitions contained here are recommended by consensus of a panel of experts in this writing group for consistency in reporting and publication. These definitions should allow different groups to publish results that are directly comparable.

[Intracranial atherosclerosis]

Until recently, intracranial atheromatosis was a probably underdiagnosed clinicopathological entity that was rarely studied in depth. In the last years the advance and expansion in the use of non-invasive diagnostic tools have led intracranial atheromatosis to the front page among the most prevalent causes of stroke worldwide. Important efforts have been accomplished with the aim of identifying markers of poor outcome, which, besides the underlying mechanisms of cerebral ischemia in these patients, are the most important factors on which clinical and therapeutic decisions should be based. To date, the therapeutic armamentarium is scarce and far from optimun, regarding medical and endovascular measures. In this review we address the most important aspects of the natural history and cure treatment of intracranial atheromatosis.

Intravascular ultrasound of symptomatic intracranial stenosis demonstrates atherosclerotic plaque with intraplaque hemorrhage: a case report

BACKGROUND

Intracranial artery stenosis is assumed to represent atherosclerotic plaque. Catheter cerebral arteriography shows that intracranial stenosis may progress, regress, or remain unchanged. It is counterintuitive that atherosclerotic plaque should spontaneously regress, raising questions about the composition of intracranial stenoses. Little is known about this disease entity in vivo. We provide the first demonstration of in vivo atherosclerotic plaque with intraplaque hemorrhage using intravascular ultrasound (IVUS).

CASE DESCRIPTION

A 35-year-old man with multiple vascular risk factors presented with recurrent stroke failing medical therapy. Imaging demonstrated left internal carotid artery occlusion, severe intracranial right internal carotid artery stenosis, and cerebral perfusion failure. Cerebral arteriography with IVUS confirmed 85% stenosis of the petrous right carotid artery due to atherosclerotic plaque with intraplaque hemorrhage. Intracranial stent-supported angioplasty was performed with IRB approval. The patient recovered without complication.

CONCLUSIONS

This case supports the premise that symptomatic intracranial stenosis can be caused by atherosclerotic plaque complicated by intraplaque hemorrhage similar to coronary artery plaque. IVUS provides additional characteristics that define intracranial atherosclerosis and high-risk features. To our knowledge, this is the first report of stroke due to unstable atherosclerotic plaque with intraplaque hemorrhage in vivo.

Atherothrombosis and plaque heterology: different location or a unique disease?

Formation of unstable plaques frequently results in atherothrombosis, the major cause for ischaemic stroke, myocardial infarction and peripheral arterial disease. Patients who have symptomatic thrombosis in one vascular bed are at increased risk of disease in other beds. However, the development of the disease in carotid, coronary and peripheral arteries may have different pathophysiology suggesting that more complex treatment protocols may have to be designed to reduce plaque development at different locations. In this review we describe the known risk factors, compare the developmental features of coronary and carotid plaque development and determine their association with end-point ischaemic events. Differences are also seen in the genetic contribution to plaque development as well as in the deregulation of gene and protein expression and cellular signal transduction activity of active cells in regions susceptible to thrombosis. Differences between carotid and coronary artery plaque development might help to explain the differences in anatomopathological appearance and risk of rupture.

Applications and Advantages of Power Motion-Mode Doppler in Acute Posterior Circulation Cerebral Ischemia

Background and Purpose— Evaluation of posterior circulation with single-gate transcranial Doppler (TCD) is technically challenging and yields lower accuracy parameters in comparison to anterior circulation vessels. Transcranial power motion-mode Doppler (PMD-TCD), in addition to spectral information, simultaneously displays in real-time flow signal intensity and direction over 6 cm of intracranial space. We aimed to evaluate the diagnostic accuracy of PMD-TCD against angiography in detection of acute posterior circulation stenoocclusive disease.

Methods— Consecutive patients presenting to the emergency room with symptoms of acute (<24 hours) cerebral ischemia underwent emergent neurovascular evaluation with PMD-TCD and angiography (computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography). Previously published diagnostic criteria were prospectively applied for PMD-TCD interpretation independent of angiographic findings.

Results— A total of 213 patients (119 men; mean age 65±16 years; ischemic stroke 71%, transient ischemic attack 29%) underwent emergent neurovascular assessment. Compared with angiography, PMD-TCD showed 17 true-positive, 8 false-negative, 6 false-positive, and 182 true-negative studies in posterior circulation vessels (sensitivity 73% [55% to 91%], specificity 96% [93% to 99%], positive predictive value 68% [50% to 86%], negative predictive value 95% [92% to 98%], accuracy 93% [90% to 96%]). In 14 patients (82% of true-positive cases), PMD display showed diagnostic flow signatures complementary to the information provided by the spectral display: reverberating or alternating flow, distal basilar artery flow reversal, high-resistance flow, emboli tracks and, bruit flow signatures.

Conclusions— PMD-TCD yields a satisfactory agreement with urgent brain angiography in the evaluation of patients with acute posterior circulation cerebral ischemia. PMD display can depict flow signatures that are complimentary to and can increase confidence in standard single-gate TCD spectral findings.

Use of stents to treat intracranial cerebrovascular disease

Intracranial atherosclerosis is a common cause of stroke. Although it has been recognized for decades, the lack of successful treatment strategies has limited clinical interest until recently. We review the natural history and pathophysiology of intracranial atherosclerosis. Vascular biomechanics are important to define differences between cerebral arteries and extracranial vessels and partly explain the technical challenges facing cerebral artery revascularization as compared with revascularization of coronary arteries. Pharmacological interventions to prevent stroke have had limited success, but technological developments offer improved methods for endovascular revascularization of symptomatic and asymptomatic cerebral artery stenosis. Identification of appropriate candidates for treatment also remains a challenge, and our knowledge about the natural history of the disease is limited. At this time, patients with significant intracranial stenosis should receive information on the benefits and risks of revascularization therapy. Determining which patients should undergo revascularization procedures will require carefully planned, randomized clinical trials.

Clinical application of transcranial Doppler monitoring for embolic signals

A major advantage of transcranial ultrasound is its suitability for continuous monitoring. Microembolic signals (MES) are brief, high-intensity transients that occur when particulate microemboli or gaseous microbubbles pass through the ultrasound beam. These MES have been detected in several clinical scenarios, but rarely in age-matched controls. The detection of MES provides important pathophysiological information in a variety of disorders, but their clinical importance and possible therapeutic implications are still under debate. The present article summarizes the significance of MES in different clinical settings and outlines some of the problems to be resolved so that transcranial ultrasound can be applied in clinical practice.

Analysis of the lesion distributions and mechanism of acute middle cerebral artery infarctions involving the striatocapsular region

BACKGROUND AND PURPOSE

There is no clear description about the patterns of each mechanism of striatocapsular infarctions. The aims of our study were to elucidate differences in the distributions of lesions of acute middle cerebral artery (MCA) infarctions involving the striatocapsular region and to compare those following embolic striatocapsular infarctions with those originating from MCA disease.

METHODS

We prospectively enrolled patients with acute infarcts located in the lenticulostriate artery territory that were not lacunar infarcts. Brain coronal diffusion-weighted imaging (DWI) was obtained and magnetic resonance angiography (MRA) was carried out to evaluate the distribution of infarct lesions and MCA stenosis in all patients. The types of infarct distribution were divided into three categories: (1) dominant in the distal territory (DD), (2) distributed equally between the distal and proximal territories (DE), and (3) dominant in the proximal territory. We performed tests for embolic sources (transthoracic echocardiography, transesophageal echocardiography, Holter monitoring, and contrast-enhanced MRA including the aortic arch) in most patients. Stroke mechanisms were classified into stroke from proximal embolism, MCA disease, and stroke of undetermined etiology.

RESULTS

A total of 47 patients (28 men and 19 women; mean age, 62 years) were recruited. A proximal embolic source was significantly more prevalent in patients with a DE lesion than in those with a DD lesion. The most common proximal embolic source was of cardiac origin. In contrast, symptomatic MCA stenoses were more common in patients with a DD lesion than in those with a DE lesion.

CONCLUSIONS

These results suggest that the dominant area of striatocapsular infarction on coronal DWI is an important clue for stroke etiology. Coronal DWI could therefore be helpful to determining the mechanisms in patients with striatocapsular infarctions that are currently described as having an "undetermined etiology" according to the Trial of Org 10172 in Acute Stroke Treatment classification.

Natural history of intracranial atherosclerosis: a critical review

Intracranial atherosclerosis is responsible for a significant number of strokes. Medical therapy for this condition may fail, leaving patients at high risk for cerebral infarction and death. With advances in endovascular techniques on the horizon, understanding the prognosis of conservative treatment is essential for appropriate patient management. Although several small studies have attempted to address this issue, a comprehensive review regarding the natural history of intracranial atherosclerosis in a vessel-specific manner is lacking. Owing to heterogeneity in vascular anatomy and physiology, atherosclerosis in different vessels may represent diseases with fundamentally distinct courses. Therefore, it is important to distinguish vascular territories when studying the natural history of this condition. To this end, we critically review the literature investigating medical management of patients with intracranial atherosclerosis, segregating our findings by vessel. Analysis by this method suggests that middle cerebral artery atherosclerosis carries a lower mortality rate than stenoses involving other intracranial vessels, and that asymptomatic disease follows a more benign course. In addition, plaque progression and transcranial Doppler-detected microemboli seem to predict outcome according to limited data. This comprehensive review may help guide clinical decision-making and therapeutic developments in this patient population.

Aspirin or Anticoagulants in Stenosis of the Middle Cerebral Artery:A Randomized Trial

BACKGROUND

We report the results of an open, randomized, multicenter trial that compared the efficacy of aspirin to oral anticoagulants (OA) for the prevention of vascular events in patients with symptomatic stenosis of the middle cerebral artery (MCA).

METHODS

Participants were randomly assigned to receive 300 mg/day of aspirin or a dose of OA (target INR 2-3). The MCA stenosis was demonstrated by conventional angiography or by at least two noninvasive examinations. Patients had either transient ischemic attack or cerebral infarct (CI) attributable to the MCA stenosis within 90 days before inclusion. The primary endpoint was: nonfatal CI, nonfatal acute myocardial infarct, vascular death and major hemorrhage. The patients were followed-up for a minimum of 1 year and a maximum of 3 years.

RESULTS

The study included 28 patients (14 in each treatment group); the average age was 67 +/- 9.9 years. Men constituted 68% of the patients. After a mean follow-up of 23.1 +/- 10.9 months, there were no recurrences of CI in both groups. No endpoint was reported in the aspirin group, but 2 patients in the OA group (14.3%) exhibited vascular events: 1 acute myocardial infarct and 1 intracerebral hemorrhage). However, this difference was not statistically significant (p = 0.48).

CONCLUSIONS

Our study suggests that aspirin is the treatment of choice for the prevention of vascular events in patients with symptomatic MCA stenosis.

Intracranial angioplasty and stenting for cerebral atherosclerosis: new treatments for stroke are needed!

INTRODUCTION

Intracranial atherosclerosis is a common cause of stroke.

INTRACRANIAL ANGIOPLASTY AND STENT REVASCULARIZATION

Recent technological developments offer improved methods for endovascular revascularization of symptomatic and asymptomatic cerebral artery stenosis. Identification of appropriate patients remains a diagnostic challenge, and our knowledge about the natural history of the disease remains limited.

RECOMMENDATIONS

At this time, patients with significant intracranial stenosis should receive counseling on the benefits and risks of revascularization therapy. Ultimately, determination of which patients should undergo revascularization procedures will require carefully planned, randomized clinical trials.

Basic Mechanisms in Intracranial Large-Artery Atherosclerosis: Advances and Challenges

Intracranial large-artery atherosclerosis is a major cause of ischemic stroke worldwide. Patients affected by this disease are at a high risk of suffering recurrent ischemic events despite antithrombotic therapy. Progression and a greater extent of intracranial atherosclerosis imply a higher risk for recurrence. Studies performed by our group in patients with symptomatic intracranial large-artery atherosclerosis have shown that: (1) C-reactive protein predicts its progression and recurrence, suggesting that inflammation may play a deleterious role in this condition; (2) a high level of the anti-angiogenic endostatin is also associated with a progressive and recurrent intracranial atherosclerosis, which might support a beneficial role for angiogenesis in this group of patients; and (3) elevated lipoprotein(a) concentration and diabetes mellitus characterize those patients with a higher number of intracranial stenoses.

Middle cerebral artery stenosis: endovascular and surgical options

Atherosclerotic middle cerebral artery stenosis is a rare but potentially devastating cause of cerebral ischemia and stroke. While medical management remains the mainstay for stroke prevention, surgical and/or endovascular intervention is indicated in selected patients. This article reviews the role of surgery and endovascular techniques in the treatment of middle cerebral artery stenosis based on its natural history, pathophysiology, and prognosis when treated medically.

Current endovascular treatment options for intracranial carotid artery atherosclerosis

A substantial number of strokes are caused by intracranial atherosclerosis, a disease that traditionally has been treated medically. Recent technological advancements, however, have revolutionized the treatment of this condition by enabling the use of endovascular methods. In this paper the authors focus on the internal carotid artery, and review relevant studies concerning angioplasty with stent placement for the management of intracranial atherosclerosis in this vessel. With continued experience and a multidisciplinary approach in the evaluation of these patients, favorable outcomes may be achieved.