Collateral Grade Research Articles

Neutrophil-To-Lymphocyte Ratio Predicts Coronary Collateral Circulation in Multivessel Coronary Artery Disease

Background: Coronary collateral circulation (CCC) is an adaptive response to chronic myocardial ischemia. Patients with coronary stenosis develop varying degrees of collateral. Levels of inflammatory cells were suggested as potential determinants of collateral development. Neutrophil to lymphocyte (N/L) ratio has been proposed as a prognostic marker to determine systemic inflammatory response and the development of CCC. Our aim was to determine the relationship between N/L ratio and development of CCC in patients with coronary artery disease (CAD) with multivessel disease.Method:A total of 151 patients with multivessel disease were included in this study. Coronary collateral grades were classified according to Rentrop collateral grades as either poorly developed CCC (Rentrop grade 0-1) or well developed CCC (Rentrop grades 2-3). Factors significant at the p≤0.25 in the bivariate models were put into multiple logistic regressions. The receiver–operating characteristic (ROC) analysis were performed to determine the cutoff value of NLR in predicting poor CCC.Result: Of the 151 CAD patients in this study, 76 patients had poorly developed CCC and 75 patients had well developed CCC. Poorly developed CCC had significantly higher N/L ratio than well developed CCC (2.25±1.189 vs. 3.03±1.527, p <0.001). Logistic regression analysis showed that N/L ratio (OR0.756; CI 95% 0.587 – 0.974, p 0.031) was independent predictor of poorly developed CCC. The ROC analysis provided a cut-off value of 1.99 (AUC 0.72, sensitivity 78.9%, specificity 52%) for N/L ratio to predict poorly developed CCC.Conclusion: Higher neutrophil to lymphocyte ratio was useful in predicting poor coronary collateral circulation in stable coronary heart disease with multivessel disease. Neutrophil to lymphocyte ratio >1.99 was independently associated with impairment in coronary collateralization. This value had a sensitivity of 78.9% and specificity of 52%.

Multiphase MR Angiography Collateral Map: Functional Outcome after Acute Anterior Circulation Ischemic Stroke.

Background Collateral circulation determines tissue fate and affects treatment result in acute ischemic stroke. A precise method for collateral estimation in an optimal imaging protocol is necessary to make an appropriate treatment decision for acute ischemic stroke. Purpose To verify the value of multiphase collateral imaging data sets (MR angiography collateral map) derived from dynamic contrast material-enhanced MR angiography for predicting functional outcomes after acute ischemic stroke. Materials and Methods This secondary analysis of an ongoing prospective observational study included data from participants with acute ischemic stroke due to occlusion or stenosis of the unilateral internal carotid artery and/or M1 segment of the middle cerebral artery who were evaluated within 8 hours of symptom onset. Data were obtained from March 2016 through August 2018. The collateral grading based on the MR angiography collateral map was estimated by using six-scale MR acute ischemic stroke collateral (MAC) scores. To identify independent predictors of favorable functional outcomes, age, sex, risk factors, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline diffusion-weighted imaging (DWI) lesion volume, site of steno-occlusion, collateral grade, mode of treatment, and early reperfusion were evaluated with multiple logistic regression analyses. Results One hundred fifty-four participants (mean age ± standard deviation, 69 years ± 13; 99 men) were evaluated. Younger age (odds ratio [OR], 0.45; 95% confidence interval [CI]: 0.29, 0.70; P < .001), lower baseline NIHSS score (OR, 0.85; 95% CI: 0.78, 0.94; P < .001), MAC score of 3 (OR, 27; 95% CI: 4.0, 179; P < .001), MAC score of 4 (OR, 17; 95% CI: 2.1, 134; P = .007), MAC score of 5 (OR, 27; 95% CI: 2.5, 306; P = .007), and successful early reperfusion (OR, 7.5; 95% CI: 2.6, 22; P < .001) were independently associated with favorable functional outcomes in multivariable analysis. There was a linear negative association between collateral perfusion grades and functional outcomes (P < .001). Conclusion An MR angiography collateral map was clinically reliable for collateral estimation in patients with acute ischemic stroke. This map provided patient-specific pacing information for ischemic progression. © RSNA, 2020.

Abstract 4: RESILIENT Collaterals and 24-Hour Infarct Growth: Revascularization is Essential

Background: The RESILIENT randomized trial of endovascular therapy for anterior circulation stroke within 8 hours of symptom onset excluded subjects with poor collaterals. We analyzed the relationship of CTA collateral grade with respect to subsequent infarct growth over 24 hours, with and without revascularization. Methods: The independent RESILIENT imaging and angiography core lab scored baseline CTA Tan collateral grade (0-3) and CT ASPECTS scores at baseline and 24 hours in both arms. ASITN collateral grade (0-4) was adjudicated prior to revascularization in the interventional arm. Descriptive statistics, univariate, multivariate and ANOVA related CTA collateral grade with 24-hour infarct growth. Results: 210/221 (95%) subjects (median age 67 (53-76) years; 48% women) in RESILIENT had baseline single-phase CTA available to the core lab evaluation. CTA collateral grade was complete (grade 3) in 106 (50.5%), grade 2 (50-99%) in 68 (32.4%), grade 1 (1-49%) in 36 (17.1%), with no collaterals in 0. The extent of collaterals was more robust in the medical arm (55.0% grade 3, 31.4% grade 2, 13.3% grade 1) compared to the interventional arm (45.7% grade 3, 33.3% grade 2, 21.0% grade 1), although this finding was not statistically significant (p=0.11). In the interventional arm, the extent of CTA collaterals had a strong correlation with ASITN grade (ρ=0.59, p&lt;0.001). Overall, the median baseline ASPECTS (n=210) was 8 (range 6-10) with CTA grade 3 collaterals, 8 (5-9) with grade 2 and 7 (2-10) with grade 1. For 24-hour ASPECTS (n=202) the median was 6 (range 0-10) with CTA grade 3 collaterals, 4 (0-8) with grade 2 and 3 (0-7) with grade 1. 24-hour infarct growth (n=200) was greater in those with worse collateral grade, p&lt;0.001. 24-hour infarct growth was more pronounced in the medical arm compared with subjects treated with revascularization in the interventional arm, p&lt;0.01. Multivariate analysis showed that 24-hour infarct growth was worse in the medical arm, despite more extensive collaterals at baseline p=0.001. Conclusions: In RESILIENT, CTA collateral grade was linked with higher ASPECTS and less infarct growth over 24 hours. Despite more robust collaterals in the medical arm, greater infarct growth occurred without revascularization or endovascular therapy.

Abstract WP66: Impaired Collaterals Are Associated With Intracranial Thrombus Extension: Evidence From MRI, Catheter Angiography, and Retrieved Thrombus Composition

Background: Clot propagation after initial occlusion may increase target thrombus burden and its pathophysiologic basis has not been extensively studied in acute human ischemic stroke. We investigated whether clot characteristics on MRI, catheter angiography, and thrombus histopathology indicated that impaired collaterals may be associated with extension of acute intracranial occlusions via stasis clotting in slow flow arterial segments. Methods: Analysis of consecutive AIS-LVO endovascular thrombectomy patients at 2 academic medical centers with: 1) pretreatment MRI, and 2) retrieved thrombi. GRE MR susceptibility vessel sign presence and extent of ASITN collateral scores were rated by blinded assessors. Extracted clots were fixed in formalin, stained by hematoxylin and eosin, and RBC, WBC and fibrin percent composition quantified by a neuropathologist blinded to clinical details. We evaluated the correlation of collateral grade with clot size by susceptibility vessel sign (SVS) and clot composition by RBC%. Non-parametric values were computed via Spearman correlation. Results: Among the 48 patients, mean age was 71.4 (SD 17.7), 56.3% female, and mean presenting NIHSS was 15.5 (SD 7.41). A susceptibility vessel sign was present in 65%, with mean SVS length 15.6 mm (SD 8.3). Collateral scores were mean 2.3 (SD 1.2). The number of passes per procedure was mean 1.98 (SD 1.30) The presence of a susceptibility vessel sign correlated with higher RBC% in retrieved thrombi (r s =0.36 p=0.011). Worse collateral grades correlated with longer SVS length (r s =-0.50 p=0.004) and greater SVS width (r s =-0.54 p=0.002). Worse collateral grade also trended toward correlation with higher RBC% in retrieved clots (r s =-0.19 p=0.18). Conclusion: Impaired angiographic collaterals are associated with longer RBC-rich thrombi on susceptibility imaging and trend toward association with higher RBC% in retrieved thrombi. These findings support that, in LVO acute ischemic stroke, clot propagation after initial occlusion occurs by stasis clotting accelerated by impaired collaterals.

Abstract TP175: To Study the Correlation of Environmental and Physical Factors With Cerebral Collateral Circulation

Introduction: Presence of functional leptomeningeal collaterals has been found to be one of the key determinants of good outcomes. We evaluated the effects of certain environmental and physical factors in cerebral collateral circulation. Methods: After IRB approval, data was collected from prospective institutional Neurocritical Care and Stroke Registry. Stroke patients presenting with acute anterior circulation large vessel occlusion between May 2013 and August 2018 were included. Collaterals were graded based on CT-Angiogram and CT-Perfusion images obtained on presentation, by a blinded Neuroradiologist as good (grade 3-4) and poor (grades 0-2). Ohio air pollution data (2013-2018) were obtained from the US EPA and summarized as a single mean concentration by monitor. Strokes were geocoded and linked with the closest monitor. Odds of good (vs. poor) collateral grade were compared using BMI (linear), smoking status, antiplatelet medication use, and mean PM 2.5 concentration (cubic). Sensitivity analyses assessed additional adjustment by sex and change in NIHSS (admission to discharge). Results: A total of 73 strokes were analyzed with 48% male, mean BMI of 30.4 (SD=7.2), and 22% with good collateral grade. For each kg/m 2 greater BMI, the odds of having good collaterals (vs. poor) were 11% higher (OR: 1.11; 95%CI:1.01-1.22; p =0.029). Higher PM 2.5 concentrations were suggestive of lower odds of good collaterals ( p =0.124). Antiplatelet medication use (OR: 2.10; 95%CI:0.59-7.45) and smoking status (OR: 1.35; 95%CI:0.73-13.9) were not associated with the odds of having good collateral grade. After controlling for change in NIHSS and sex, higher BMI remained associated with good collateral grade (fig.1). Conclusions: Higher BMI was independently associated with higher odds of good collateral grade; this association needs to be explored in larger population taking other factors like age and medical comorbidities into account.

Abstract TMP11: Endovascular Treatment for Acute Ischemic Stroke in the Within 6-Hour versus 6-24-Hour Window: Simple Imaging Protocol

Introduction: DAWN and DEFUSE 3 trials utilized advanced imaging to prove the benefit of endovascular treatment (EVT) in patients within 6-24 hours. There is increasing evidence to suggest the limitations of advanced imaging in real-world practice. Non-contrast-enhanced computed tomography (NCCT) has proved with good sensitivity and specificity in the definition of infarct core. It is still unknown if a simpler and faster protocol may adequately select patients within 6-24 hours for EVT. Hypothesis: To compare outcomes of patients submitted to EVT presenting within 6 hours or 6-24 hours, selected using simple imaging protocol. Methods: An observational study was performed, which included consecutive patients with anterior circulation ischemic stroke eligible for EVT within 6 hours or 6-24 hours. Patients within early window received routine treatment, while patients presenting within late window were treated if they had a mismatch between the clinical deficit, the infarct volume, and collateral blood blow: (NIHSS score was ≥10 and ASPECTS was ≥7) or (ASPECTS was =6, and the collateral score was ≥2). ASPECTS of NCCT/DWI-MRI and collateral status on CTA/DSA were assessed by a blinded neuroradiologist. The collateral grading system was scored on a scale of 0-3 as in the ESCAPE trial. Results: Of the 184 patients were included, 77 (41,8%) received thrombectomy in late window, 107 (58,2%) received acute treatment in early window. Baseline characteristics were similar between groups, except for longer onset to groin puncture time (median, 300 vs 705 min; P&lt;0,0001), higher admission NIHSS (median, 13 vs 16; P&lt;0,0001), lower in ASPECTS (median, 9 vs 8; P&lt;0,0001), and large artery atherosclerosis etiology (61,7 vs 72,7%, P=0,002) in the late window group. No significant differences in successful reperfusion rate and rates of parenchymal hematoma type 2 (81,3 vs 83,1%, P=0,75; 4/107 vs 4/77, P=0,63, respectively). Functional independence (mRS 0-2) and mortality at 90 days did not differ significantly (65,4 vs 57,1%, P=0,25; 10,3 vs 6,5%, P=0,43; respectively). Conclusions: This real-world observational study suggests that EVT may be safe and effective in patients presenting within 6-24 hours selected using clinical-core mismatch and collateral blood blow.

The Relationship Between Circulating Neuregulin-1 and Coronary Collateral Circulation in Patients with Coronary Artery Disease.

Coronary collateral circulation (CCC) plays a crucial role in myocardial blood supply, especially for ischemic myocardium. Previous study has shown that neuregulin-1 is a prominent angiogenic factor in diabetic cardiomyopathy, whereas the relationship between neuregulin-1 and CCC has not been investigated. Thus, we aimed to investigate relationship between circulating neuregulin-1 levels and CCC in stable coronary artery disease patients.Coronary artery disease patients with a stenosis of ≥ 90% as evidenced by coronary angiography were included in our study. According to the Rentrop-Cohen classification, coronary collateral degree was graded as 1 to 4. Patients with collateral degree grade 0 or 1 were enrolled in poor CCC group, whereas patients with grade 2 or 3 were enrolled in good CCC group.Plasma neuregulin-1 level was significantly increased in good collateral group and positively related to Rentrop grade (P < 0.01). Multivariate regression analysis and ROC (receiver operating characteristic curve) revealed that plasma neuregulin-1 could predict CCC status effectively.Increased plasma neuregulin-1 level was related to better CCC in patients with coronary artery disease. Neuregulin-1 was an independent and reliable predictor for good coronary collateral development and provided a potential therapeutic strategy to reduce myocardial ischemia injury.

Cerebral vessel anatomy as a predictor of first-pass effect in mechanical thrombectomy for emergent large-vessel occlusion.

Mechanical thrombectomy is effective in acute ischemic stroke secondary to emergent large-vessel occlusion, but optimal efficacy is contingent on fast and complete recanalization. First-pass recanalization does not occur in the majority of patients. The authors undertook this study to determine if anatomical parameters of the intracranial vessels impact the likelihood of first-pass complete recanalization. The authors retrospectively evaluated data obtained in 230 patients who underwent mechanical thrombectomy for acute ischemic stroke secondary to large-vessel occlusion at their institution from 2016 to 2018. Eighty-six patients were identified as having pure M1 occlusions, and 76 were included in the final analysis. The authors recorded and measured clinical and anatomical parameters and evaluated their relationships to the first-pass effect. The first-pass effect was achieved in 46% of the patients. When a single device was employed, aspiration thrombectomy was more effective than stent retriever thrombectomy. A larger M1 diameter (p = 0.001), decreased vessel diameter tapering between the petrous segment of the internal carotid artery (ICA) and M1 (p < 0.001), and distal collateral grading (p = 0.044) were associated with first-pass recanalization. LASSO (least absolute shrinkage and selection operator) was used to generate a predictive model for recanalization using anatomical variables. The authors demonstrated that a larger M1 vessel diameter, low rate of vessel diameter tapering along the course of the intracranial ICA, and distal collateral status are associated with first-pass recanalization for patients with M1 occlusions.

Leukoaraiosis and collateral blood flow in stroke patients with anterior circulation large vessel occlusion

BackgroundLeukoaraiosis and collateral blood flow are processes that involve small vessels, the former related to flow within the deep perforating arterioles and the latter involving the small, cortical pial-pial connections,...

Clinical and Imaging Determinants of Collateral Status in Patients With Acute Ischemic Stroke in MR CLEAN Trial and Registry.

Background and Purpose- Collateral circulation status at baseline is associated with functional outcome after ischemic stroke and effect of endovascular treatment. We aimed to identify clinical and imaging determinants that are associated with collateral grade on baseline computed tomography angiography in patients with acute ischemic stroke due to an anterior circulation large vessel occlusion. Methods- Patients included in the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands; n=500) and MR CLEAN Registry (n=1488) were studied. Collateral status on baseline computed tomography angiography was scored from 0 (absent) to 3 (good). Multivariable ordinal logistic regression analyses were used to test the association of selected determinants with collateral status. Results- In total, 1988 patients were analyzed. Distribution of the collateral status was as follows: absent (7%, n=123), poor (32%, n=596), moderate (39%, n=735), and good (23%, n=422). Associations for a poor collateral status in a multivariable model existed for age (adjusted common odds ratio, 0.92 per 10 years [95% CI, 0.886-0.98]), male (adjusted common odds ratio, 0.64 [95% CI, 0.53-0.76]), blood glucose level (adjusted common odds ratio, 0.97 [95% CI, 0.95-1.00]), and occlusion of the intracranial segment of the internal carotid artery with occlusion of the terminus (adjusted common odds ratio 0.50 [95% CI, 0.41-0.61]). In contrast to previous studies, we did not find an association between cardiovascular risk factors and collateral status. Conclusions- Older age, male sex, high glucose levels, and intracranial internal carotid artery with occlusion of the terminus occlusions are associated with poor computed tomography angiography collateral grades in patients with acute ischemic stroke eligible for endovascular treatment.

Automatic Collateral Scoring From 3D CTA Images.

The collateral score is an important biomarker in decision making for endovascular treatment (EVT) of patients with ischemic stroke. The existing collateral grading systems are based on visual inspection and prone to subjective interpretation and interobserver variation. The purpose of our work is the development of an automatic collateral scoring method. In this work, we present a method that is inspired by human collateral scoring. Firstly, we define an anatomical region by atlas-based registration and extract vessel structures using a deep convolutional neural network. From this, high-level features based on the ratios of vessel length and volume of the occluded and the contralateral side are defined. Multi-class classification models are used to map the feature space to a four-grade collateral score and a quantitative score. The dataset used for training, validation and testing is from a registry of images acquired in clinical routine at multiple medical centers. The model performance is tested on 269 subjects, achieving an accuracy of 0.8. The dichotomized collateral score accuracy is 0.9. The error is comparable to the interobserver variation, the results are comparable to the performance of two radiologists with 10 to 30 years of experience.

Collateral score on CT angiography in patients with acute ischemic stroke - A retrospective study

Objective: Clinically assessing the status of cerebral collaterals is thought to provide invaluable diagnostic and prognostic data in managing acute ischemic stroke (AIS) patients. In this study we present a report, based on commonly used collateral grading system, assessing the correlation between the collateral status seen on CT angiography and patients’ functional outcome at Day 90 in our institution. Method: Patients presenting to the Emergency Department within 6 hours of onset of stroke from January 2010 until December 2014 were chosen for the study. CT angiography source images were retrospectively reviewed and given a “collateral score” (CS) by a radiologist who was blinded to the patient’s clinical information on presentation, as well as the clinical outcomes at 90 days. Patients’ mRS score at 90 days was obtained retrospectively and compared against the “collateral score”. Results: 87 patients were enrolled into this study, of which 60 (69%) were male and 27 (31%) were female with a mean age of 60.3 years. In this study, 56 (64.4%) patients had a collateral score (CS) &gt; 2 and 31 (35.6%) patients had a CS &lt; 2. Out of 56 patients who had a CS &gt; 2, 51 of them (91%) had good clinical outcome with a mRS &lt; 2. All the patients who had CS &lt; 2 showed poor clinical outcome with a mRS &gt; 2. The collateral score predicts accurately the clinical outcome with an area under the curve (ROC) of 0.75 (95% CI, 0.675-0.871, P=0.001). There is significant Spearman correlation between CS and the clinical outcome at Day 90, in patients with AIS during CTA analysis. Conclusion: Our data supports the potential use of CS analysis in predicting clinical outcome of patients with AIS. Nevertheless, further study on a larger scale is strongly suggested to verify the reliability and reproducibility of CS assessment in CTA analysis prior to reperfusion in AIS patients.

Collateral score on CT angiography in patients with acute ischemic stroke - A retrospective study.

Objective: Clinically assessing the status of cerebral collaterals is thought to provide invaluable diagnostic and prognostic data in managing acute ischemic stroke (AIS) patients. In this study we present a report, based on commonly used collateral grading system, assessing the correlation between the collateral status seen on CT angiography and patients’ functional outcome at Day 90 in our institution. Method: Patients presenting to the Emergency Department within 6 hours of onset of stroke from January 2010 until December 2014 were chosen for the study. CT angiography source images were retrospectively reviewed and given a “collateral score” (CS) by a radiologist who was blinded to the patient’s clinical information on presentation, as well as the clinical outcomes at 90 days. Patients’ mRS score at 90 days was obtained retrospectively and compared against the “collateral score”. Results: 87 patients were enrolled into this study, of which 60 (69%) were male and 27 (31%) were female with a mean age of 60.3 years. In this study, 56 (64.4%) patients had a collateral score (CS) ? 2 and 31 (35.6%) patients had a CS &lt; 2. Out of 56 patients who had a CS ? 2, 51 of them (91%) had good clinical outcome with a mRS ? 2. All the patients who had CS &lt; 2 showed poor clinical outcome with a mRS &gt; 2. The collateral score predicts accurately the clinical outcome with an area under the curve (ROC) of 0.75 (95% CI, 0.675-0.871, P=0.001). There is significant Spearman correlation between CS and the clinical outcome at Day 90, in patients with AIS during CTA analysis. Conclusion: Our data supports the potential use of CS analysis in predicting clinical outcome of patients with AIS. Nevertheless, further study on a larger scale is strongly suggested to verify the reliability and reproducibility of CS assessment in CTA analysis prior to reperfusion in AIS patients.

Collateral grade of the Willis' circle predicts outcomes of acute intracranial internal carotid artery occlusion before thrombectomy.

Background and PurposeEndovascular mechanical thrombectomy (EVMT) shows significant promise in improving acute ischemic stroke (AIS) with proximal artery occlusion, but outcomes have been variable. We explored the patients treated by thrombectomy to investigate the association between a favorable clinical outcome of EVMT in intracranial internal carotid artery occlusion (iICAO) and a set of predictors.MethodsA total of 38 iICAO patients treated by EVMTs were analyzed. Primary collateral grades (PCG) at baseline based on the integrity of Willis' circle were categorized into three degrees. The favorable outcomes, measured by modified Rankin scale (mRS), were defined as ≤2 at 90 days. The reperfusion was one of the most important confounders, defined as modified thrombolysis in cerebral infarction (mTICI) ≥ 2b. The other risk factors included demographic characteristics, vascular risk factors, stroke severity, procedural EVMT, and PCG at baseline was adjusted to reveal the association with favorable outcomes.ResultsOf 38 iICAO patients, 65.8% (25 in 38) achieved reperfusion. However, only 31.6% (12/38) achieved favorable outcomes at 90 days. With a PCG3, 61.5% of them achieved favorable outcomes, while only 37.5% of those with PCG2 and PCG1 achieved favorable outcomes (p = .003). In multivariable logistic regression, PCG was revealed as a predictor for favorable outcomes (OR 5.278, p = .019) after adjusting the reperfusion and other factors.ConclusionsThe PCG based on the integrity of Willis' circle might be an underlying predictor of the prognosis of AIS in patients with iICAO after EVMT. The function of intact anterior communicating artery (AcoA) and ipsilateral posterior communicating artery (PcoA) in favoring prognosis of the iICAO patients might need to be validation in future study.

Dynamic CT but Not Optimized Multiphase CT Angiography Accurately Identifies CT Perfusion Target Mismatch Ischemic Stroke Patients.

Imaging protocols for acute ischemic stroke varies significantly from center to center leading to challenges in research translation. We aimed to assess the inter-rater reliability of collateral grading systems derived from dynamic computed tomography angiography (CTA) and an optimized multiphase CTA and, to analyze the association of the two CTA modalities with CT perfusion (CTP) compartments by comparing the accuracy of dynamic CTA (dCTA) and optimized multiphase CTA (omCTA) in identifying CT perfusion (CTP) target mismatch patients. Acute ischemic stroke patients with a proximal large vessel occlusion who underwent whole brain CTP were included in the study. Collateral status were assessed using ASPECTS collaterals (Alberta Stroke Program Early CT Score on Collaterals) and ASITN/SIR collateral system (the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology) on dCTA and omCTA. Eighty-one patients were assessed, with a median ischemic core volume of 29 mL. The collateral assessment with ASPECTS collaterals using dCTA have a similar inter-rater agreement (K-alpha: 0.71) compared to omCTA (K-alpha: 0.69). However, the agreement between dCTA and CTP in classifying patients with target mismatch was higher compared to omCTA (Kappa, dCTA: 0.81; omCTA: 0.64). We found dCTA was more accurate than omCTA in identifying target mismatch patients with proximal large vessel occlusion.

Is There Any Correlation Between The Grade of Coronary Collaterals and Vitamin D Levels In Patients with Coronary Chronic Total Occlusion?

Objective: There have been studies which revealed a possible relation with the grade of coronary collateral circulation (CCC) and the level of Vitamin D in the literature. The objective of this study was to assess whether there is a correlation between the grade of CCC and the level of Vitamin D according to both Rentrop and Werner classifications in patients with coronary chronic total occlusion (CTO) who underwent percutaneous coronary intervention. Material-Method: The present study is a single-centre, retrospective cohort study. A total of 101 consecutive patients, who were hospitalized to undergo coronary CTO procedure, were enrolled in the study. The patients were classified into 3 groups with regard to the grade of CCC according to both Rentrop and Werner classifications. These groups were compared with each other according to the 25(OH)VitD3 levels. Results: There was no significant difference among 3 groups with regard to 25(OH)VitD3 levels when the patients were classified according to the Rentrop classification [Rentrop 1: 15.7 ng/ml (7.0-77.0 ng/ml), Rentrop 2: 16.9 ng/ml (7.0-71.3), Rentrop 3: 16.6 ng/ml (7.0-28.7), p=0.925]. Moreover, there was no significant difference among 3 groups with regard to 25(OH)VitD3 levels when the patients were classified according to the Werner classification. [Werner 0: 19.6 ng/ml (7.0-77.0 ng/ml), Werner 1: 16.6 ng/ml (7.0-71.3), Werner 2: 17.0 ng/ml (7.0-28.3), p=0.411]. Conclusion: We deem that there may not be a direct correlation (one-to-one relationship) between the level of 25(OH)VitD3 and the grade of CCC in clinical practice.

Relationship between CT angiography-derived collateral status and CT perfusion-derived tissue viability

To explore the relationship between computed tomography (CT) angiography (CTA)-derived collateral status and CT perfusion (CTP)-derived tissue viability. Patients having middle cerebral artery (MCA) M1/M2 segment and/or internal carotid artery (ICA) occlusion and within 12 hours of onset were included. Collateral was graded from 0 to 3 on maximum intensity projection (MIP) images of CTA. The area with relative cerebral blood flow (rCBF) <30% or time-to-maximum (Tmax) >10 or >12 or >14 seconds was defined as the infarct core, and Tmax >6 seconds as the penumbra. Kruskal-Wallis and Spearman's correlation tests were performed to assess the correlation between collateral grade and infarct size or mismatch ratio. Eighty-three patients were enrolled and 52 of them met the inclusion criteria. Infarct size defined by rCBF <30% or Tmax >10 or >12 or >14 seconds and mismatch ratios were significantly different among the four groups. The correlation between collateral grades and infarct core using rCBF <30% (ρ=-0.814, p<0.01) was better than that defined by Tmax >10s, >12s or >14s. Mismatch ratio for the infarct core defined by rCBF <30% (ρ=0.945, p<0.01) had the best correlation with collateral grades. Patients with good collaterals show a smaller infarct core and higher mismatch ratio. Infarct size defined by rCBF <30% and mismatch ratio defined by rCBF <30% and Tmax >6 seconds appear to be more correlated with collaterals in AIS patients.

Optimizing Outcome Prediction Scores in Patients Undergoing Endovascular Thrombectomy for Large Vessel Occlusions Using Collateral Grade on Computed Tomography Angiography.

Although several outcome prediction scores incorporated with pretreatment variables have been developed for acute ischemic stroke (AIS) patients, there is not currently a prediction score that includes pretreatment imaging that can show salvageable brain tissue. To evaluate whether addition of the collateral grade on computed tomography angiography to previously published prediction scores could increase accuracy of clinical outcome prediction in endovascular thrombectomy (EVT) for AIS. This study used a retrospective multicenter registry for patients undergoing EVT for anterior circulation large vessel occlusion. Three previously published outcome prediction scores (Houston intra-arterial therapy 2, HIAT2; totaled health risks in vascular events, THRIVE; and Pittsburgh response to endovascular therapy, PRE scores) were tested in this study. Using 482 deprivation cohorts, areas under the receiver operating characteristic curves (AUC-ROCs) were compared between prediction scores with/without collateral grades in predicting the poor outcomes (modified Rankin Scale 4-6 at 3-mo follow-up) after EVT. We developed modified prediction scores by adding the collateral grade, and their advancement of outcome prediction was validated using 208 independent validation cohorts. AUC-ROCs of HIAT2, THRIVE, and PRE scores that incorporated with collateral grade were superior in predicting poor outcomes when compared to that of the unmodified scores (P<0.001). In modified prediction models, 3, 3, and 10 points were added for poor collateral grade to HIAT2, THRIVE, and PRE score. Modified models outperformed unmodified models in testing of the validation cohorts (P<0.001). The addition of the collateral grade to outcome prediction scores resulted in better prediction of poor outcome after EVT for AIS compared to the prediction scores alone.

Does Sex Modify the Effect of Endovascular Treatment for Ischemic Stroke?

Background and Purpose- Previous studies have reported less favorable outcome and less effect of endovascular treatment (EVT) after ischemic stroke in women than in men. Our aim was to study the influence of sex on outcome and on the effect of EVT for ischemic stroke in recent randomized trials on EVT. Methods- We used data from 7 randomized controlled trials on EVT within the HERMES collaboration. The primary outcome was 90-day functional outcome (modified Rankin Scale). We compared baseline characteristics and outcomes between men and women. With ordinal logistic regression, we evaluated the association between EVT and 90-day functional outcome for men and women separately, adjusted for potential confounders. We tested for interaction between sex and EVT. Results- We included 1762 patients in the analyses, of whom 833 (47%) were women. Women were older (median, 70 versus 66 years; P<0.001), were smoking less often (30% versus 44%; P<0.001), and had higher collateral grades (grade 3: 46% versus 35%; P<0.001) than men. Functional independence (modified Rankin Scale score, 0-2) at 90 days was reached by 318 women (39%) and 364 men (39%). The effect of EVT on the ordinal modified Rankin Scale was similar in women (adjusted common odds ratio [acOR], 2.13; 95% CI, 1.47-3.07) and men (acOR, 2.16; 95% CI, 1.59-2.96), with a P for interaction of 0.926. Conclusions- Sex does not influence clinical outcome after EVT and does not modify treatment effect of EVT. Therefore, sex should not be a consideration in the selection of patients for EVT.

Collateral Circulation in Moyamoya Disease: A New Grading System.

Background and Purpose- Predicting the risk of stroke and determining intervention indications are highly important for patients with Moyamoya disease (MMD). Here, we evaluated a novel MMD grading system based on collateral circulation and Suzuki stage to evaluate symptoms and predict prognosis. Methods- In total, 301 idiopathic MMD patients were retrospectively analyzed between 2014 and 2016. A collateral circulation grading system with scores ranging from 1 to 12 was established: the anatomic extent of pial collateral blood flow from posterior cerebral artery to middle cerebral artery and anterior cerebral artery was scored from 1 to 6; perforator collateral and internal cerebral artery flow were scored as 6 to 1, which corresponded to Suzuki stages 1 to 6. Dynamic susceptibility contrast-magnetic resonance imaging was used to evaluate hemodynamic status. We assessed the association between the grading system and clinical characteristics. Results- We analyzed 364 symptomatic hemispheres of 301 patients (146 males, 28±16 years). Ischemic patients who presented with infarction were more likely to score <8 points (P<0.001), whereas those with ischemia symptoms (transient ischemic attack and headache) were more likely to score >8 points. Hemorrhagic patients who presented with intraparenchymal hemorrhage were more likely to score <8 points, whereas those who presented with intraventricular hemorrhage were more likely to score >8 points (P<0.001). According to dynamic susceptibility contrast-magnetic resonance imaging, lower scores were correlated with more severe time to peak delay (P<0.001) and worse relative cerebral blood volume ratio (P=0.016) and cerebral flow ratio (P=0.002). Encephaloduroarteriosynangiosis was performed in 348 symptomatic hemispheres. Patients who had collateral scores <4 points were more likely to have a postoperative stroke and a worse prognosis during the follow-up. Conclusions- This new MMD collateral grading system correlated well with clinical symptoms, hemodynamic status, and therapeutic prognosis and may facilitate risk stratification and prognosis predictions in patients with MMD.