Validation of transcranial Doppler with magnetic resonance angiography in acute cerebral ischemia

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.

A New Transcranial Doppler Scoring System for Evaluating Middle Cerebral Artery Stenosis

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) criteria for cerebrovascular stenosis are only based on velocity with unsatisfactory positive predictive value (PPV) in previous studies. We refined a published scoring system that integrates several characteristics of TCD data in diagnosing middle cerebral artery (MCA) stenosis.

METHODS

Using the TCD-digital subtraction angiography (DSA) database from Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) trial, velocity, spectrum pattern, diffuse ratio, and asymmetry ratio were assessed. The cutpoints were defined for each parameter and a point value was assigned to each category within that parameter. A summed score was calculated for each MCA. The accuracy was assessed for different cutpoints in predicting ≥50% MCA stenosis measured by DSA. Logistic regression and C-statistics were used for analysis.

RESULTS

A total of 114 MCAs were included in vessel-based and 87 patients were included in patient-based analysis. Compared to the velocity-only cutpoints in SONIA, the score results in much improved PPV while negative predictive value (NPV) remains unchanged. The score based on mean velocity (score 0: <140 cm/s, score 3: ≥140 cm/s), spectrum pattern (score 0: no turbulence; score 1: mild turbulence; 2: significant turbulence), and asymmetry ratio (score 0: ratio <1.5, score 1: ratio 1.5-2; score 2: ratio ≥2.1) has the highest NPV while PPV remains favorable (PPV: 72% [95% CI 54-90%]; NPV: 84% [95% CI: 75-93%], area under curve [AUC]: .76 [95% CI: .66-.86]).

CONCLUSIONS

The multiparameter scoring system incorporating several characteristics of TCD measures yielded higher PPV while maintaining high NPV compared with the single-parameter velocity criteria in diagnosing MCA ≥50% stenosis.

Diagnostic value of transcranial ultrasonography for selecting subjects with large vessel occlusion: a systematic review

Introduction

A number of pre-hospital clinical assessment tools have been developed to triage subjects with acute stroke due to large vessel occlusion (LVO) to a specialised endovascular centre, but their false negative rates remain high leading to inappropriate and costly emergency transfers. Transcranial ultrasonography may represent a valuable pre-hospital tool for selecting patients with LVO who could benefit from rapid transfer to a dedicated centre.

Methods

Diagnostic accuracy of transcranial ultrasonography in acute stroke was subjected to systematic review. Medline, Embase, PubMed, Scopus, and The Cochrane Library were searched. Published articles reporting diagnostic accuracy of transcranial ultrasonography in comparison to a reference imaging method were selected. Studies reporting estimates of diagnostic accuracy were included in the meta-analysis.

Results

Twenty-seven published articles were selected for the systematic review. Transcranial Doppler findings, such as absent or diminished blood flow signal in a major cerebral artery and asymmetry index ≥ 21% were shown to be suggestive of LVO. It demonstrated sensitivity ranging from 68 to 100% and specificity of 78–99% for detecting acute steno-occlusive lesions. Area under the receiver operating characteristics curve was 0.91. Transcranial ultrasonography can also detect haemorrhagic foci, however, its application is largely restricted by lesion location.

Conclusions

Transcranial ultrasonography might potentially be used for the selection of subjects with acute LVO, to help streamline patient care and allow direct transfer to specialised endovascular centres. It can also assist in detecting haemorrhagic lesions in some cases, however, its applicability here is largely restricted. Additional research should optimize the scanning technique. Further work is required to demonstrate whether this diagnostic approach, possibly combined with clinical assessment, could be used at the pre-hospital stage to justify direct transfer to a regional thrombectomy centre in suitable cases.

Relation of Ideal Cardiovascular Health Metrics to Asymptomatic Polyvascular Disease in a Chinese Population

Atherosclerosis is a systemic disease with manifestations in multiple vascular beds. Ideal cardiovascular health (CVH) metrics relate to cardiovascular and cerebrovascular disease. However, the relation between ideal CVH metrics and asymptomatic polyvascular disease (polyVD) is unknown. We collected information on the 7 CVH metrics among 5,224 participants aged ≥40 years from 2010 to 2011. Intracranial artery stenosis, extracranial artery stenosis, and lower extremity artery disease were detected by transcranial Doppler, duplex sonography, and by calculating ankle-brachial index. Ordinal logistic regression and linear models were used to analyze the relation between ideal CVH metrics and polyVD. PolyVD was identified in 158 (3%) participants. We observed a significant inverse gradient relation between the number of ideal CVH metrics and prevalence of polyVD after adjustment for potential confounders. The adjusted odds ratios and 95% confidence intervals were 0.824 (0.657 to 1.032), 0.641 (0.511 to 0.804), 0.538 (0.423 to 0.684), 0.583 (0.442 to 0.769), and 0.530 (0.348 to 0.808) for those having 2, 3, 4, 5, and 6 or 7 ideal CVH metrics, respectively, compared with those having 0 or 1 ideal CVH metric (p-trend <0.0001). Similarly, a larger number of ideal CVH metrics was associated with a lower prevalence of polyVD in the linear models (adjusted β coefficient -0.030, 95% confidence interval -0.041 to -0.020). Stratification for gender and age yielded consistent results in all subgroups except for women subgroup. In conclusion, we observed a significant inverse gradient association between the number of ideal CVH metrics and prevalence of asymptomatic polyVD.

Asymptomatic polyvascular disease and the risks of cardiovascular events and all-cause death

BACKGROUND AND AIMS

Atherosclerosis is a diffuse and systemic disease. We aimed to assess prevalence and outcome of extracoronary polyvascular disease (polyVD) in the asymptomatic Chinese community population.

METHODS

A random sample of 5440 participants aged 40 years or older were enrolled in the Asymptomatic Polyvascular Abnormalities Community Study from 2010 to 2011. Intracranial artery stenosis, extracranial artery stenosis, and lower extremity artery disease were detected by transcranial Doppler and duplex sonography, and by calculating the ankle brachial index. The study endpoints included the first occurrence of stroke, myocardial infarction (MI) and all-cause death.

RESULTS

PolyVD (two or three affected vascular territories) was found in 3.0% of the participants, and was significantly higher in men (4.3%). Over a median follow-up of 4.1 years, we identified a total of 247 events (4.7%), including 83 strokes (68 ischemic), 45 MIs and 134 all-cause deaths. After adjusting for age, gender and other potential confounders, we found a significant increase in risk of major cardiovascular events as well as all-cause death in participants with polyVD. In multivariate Cox regression analyses, the adjusted hazard ratios (HR) (95% confidence interval, CI) for the composite of stroke, MI and all-cause death for single and poly-vascular disease (compared with 0 vascular disease) increased from 1.58 (1.19-2.12) to 1.95 (1.26-3.03). Similarly, the adjusted HR (95% CI) for all-cause death for single and poly-vascular disease increased from 1.53 (1.03-2.29) to 2.22 (1.27-3.86).

CONCLUSIONS

PolyVD significantly increased the risk of major cardiovascular events and all-cause death in the asymptomatic community population. Performing invasive screening tests for polyVD is useful in the high-risk asymptomatic population.

Italian symptomatic intracranial atherosclerosis study (ISIDE) : A multicenter transcranial ultrasound evaluation

There are currently no data available on the prevalence of symptomatic intracranial atherosclerosis (ICAS) in Italy. The aim of this prospective, multicenter, hospital-based, transcranial ultrasound study was to establish the prevalence of ICAS among patients hospitalized with acute ischemic stroke. At 11 stroke centers across Italy, patients consecutively admitted for their first ever acute ischemic stroke were assessed prospectively over a 24-month period either with transcranial color-coded Doppler sonography (TCCS) or transcranial Doppler (TCD) according to validated criteria. ICAS was diagnosed when there was an evidence of a cerebral infarction in the territory of a ≥50 % stenosis detected by TCCS/TCD and confirmed by magnetic resonance angiography or computed tomography angiography. A total of 1134 patients were enrolled, 665 of them (58.6 %) men, with a mean age of 71.2 ± 13.3 years. ICAS was recorded in 99 patients (8.7 % of the whole sample, 8.9 % among Caucasians), most commonly located in the anterior circulation (63 of 99, 5.5 %). After adjusting for potential confounders, multivariate analysis identified carotid/vertebral ≥50 % stenosis [odds ratio (OR) 2.59, 95 % (confidence interval) CI 1.77-6.33; P = 0.02] and hypercholesterolemia (OR 1.38, 95 % CI 1.02-1.89; P = 0.02) as being independently associated with ICAS. ICAS is a surprisingly relevant cause of ischemic stroke in Italy, identified in almost 9 % of first-ever stroke patients. It is more prevalent in the anterior circulation and independently associated with hemodynamically significant cervical vessel atherosclerosis and hypercholesterolemia. These findings support the systematic use of transcranial ultrasound to identify ICAS in patients presenting with acute ischemic stroke and in cases with ≥50 % cervical vessel stenoses.

Middle cerebral artery stenosis in patients with acute ischemic stroke and TIA in Israel

BACKGROUND AND PURPOSE

Middle cerebral artery stenosis is not frequent but a well-established cause of first and recurrent ischemic stroke. Our aim was to investigate middle cerebral artery stenosis in the biethnic (Jewish and Arab) population of patients with acute ischemic stroke and transient ischemic attack in northern Israel.

MATERIALS AND METHODS

The study population included 1344 patients from the stroke data registry who had been hospitalized in the neurologic department because of acute ischemic stroke (1041) or TIA (303) and had undergone transcranial Doppler sonographic examination during the hospitalization.

RESULTS

Of the 1344 patients, 120 (8.9%) were found to have MCA stenosis. The patients with intracranial stenosis were older and had more vascular risk factors (hypertension, diabetes, and hyperlipidemia) and vascular diseases (ischemic heart and peripheral vascular disease) than those without intracranial stenosis. Logistic regression analysis revealed that diabetes (P = .002) and peripheral vascular disease (P = .01), but not ethnicity, were independent and significant predictors for the presence of MCA stenosis.

CONCLUSIONS

An independent and significant correlation was found between MCA stenosis and vascular risk factors (diabetes mellitus) and vascular diseases, thus emphasizing the similarity of intracranial MCA stenosis and other vascular diseases originating from atherosclerosis. There was no influence of ethnicity on intracranial stenosis in our population.

Power motion-mode Doppler signature: a useful tool for assessing middle cerebral artery stenosis

PURPOSE

To identify power motion-mode Doppler (PMD) patterns and assess their diagnostic value for the diagnosis of middle cerebral artery (MCA) stenosis.

METHODS

Retrospective analyses of PMD data were performed for the identification of specific patterns related to MCA stenosis. The interrater reliability and the validity of these patterns were studied, using magnetic resonance angiography and conventional transcranial Doppler sonography as gold standards.

RESULTS

Three PMD patterns were identified: the so-called black-hole, the white-hole, and the diastolic-band patterns in 58 among 178 MCAs. The mean flow velocity was significantly higher in arterial segments with the black-hole patterns and lower in segments with the diastolic-band pattern compared with the segments with normal patterns. The interrater reliability was good for each pattern. The black-hole pattern or its combination with the white-hole pattern showed the highest validity.

CONCLUSION

Despite some limitations, the black-hole PMD pattern or its combination with the white-hole pattern appeared as a reliable and valid marker for the diagnosis of MCA stenosis.

Prehospital stroke diagnostics based on neurological examination and transcranial ultrasound

BACKGROUND

Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination.

METHODS

Following a '911 stroke code' call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care.

RESULTS

We enrolled '232 stroke code' patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as 'stroke mimics'. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis 'any stroke' showed a sensitivity of 94% and a specificity of 48%. 'Major MCA or ICA stroke' diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%.

CONCLUSIONS

The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment.

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.

Prevalence of symptomatic intracranial atherosclerosis in Caucasians: a prospective, multicenter, transcranial Doppler study

BACKGROUND

There are limited data available regarding symptomatic intracranial atherosclerosis (SIA) prevalence in Caucasians. We sought to investigate SIA prevalence among Caucasian patients hospitalized with acute cerebral ischemia (ACI) in a prospective, multicenter Transcranial Doppler sonography (TCD) study.

METHODS

Consecutive patients with ACI were prospectively evaluated with TCD over a 24-month-period. The previously validated criteria of SONIA trial were used for detection of >50% intracranial stenosis with TCD. Brain angiography was performed to confirm the diagnosis in cases with abnormal TCD findings. SIA was diagnosed when there was evidence of a cerebral infarction in the territory of the stenotic artery (identified by TCD and confirmed by Magnetic resonance angiography [MRA]/Computed tomography angiography [CTA]).

RESULTS

A total of 467 consecutive patients with ACI (60.4% men, mean age 58 ± 14 years) were evaluated. SIA was documented in 43 patients (9.2%; 95%CI: 6.9%-12.2%). The most common SIA location was M1MCA (34.9%) followed by TICA (18.8%). Diabetes mellitus (OR: 4.25, 95%CI: 2.18-8.26; P < .001) and hypertension (OR: 2.41, 95%CI: 1.02-5.67; P = .045) were independently associated with SIA on multivariate models adjusting for potential confounders.

CONCLUSIONS

SIA was identified in almost 10% of patients admitted with symptoms of ACI. These preliminary findings support further collaborative initiatives among stroke physicians to increase the yield of SIA detection in Caucasian patients with ACI.