S-nitrosylation of AMPKγ impairs coronary collateral circulation and disrupts VSMC reprogramming.

Collateral circulation is essential for blood resupply to the ischemic heart, which is dictated by the contractile phenotypic restoration of vascular smooth muscle cells (VSMC). Here we investigate whether S-nitrosylation of AMP-activated protein kinase (AMPK), a key regulator of the VSMC phenotype, impairs collateral circulation. In rats with collateral growth and development, nitroglycerin decreases coronary collateral blood flow (CCBF), inhibits vascular contractile phenotypic restoration, and increases myocardial infarct size, accompanied by reduced AMPK activity in the collateral zone. Nitric oxide (NO) S-nitrosylates human recombinant AMPKγ1 at cysteine 131 and decreases AMP sensitivity of AMPK. In VSMCs, exogenous expression of S-nitrosylation-resistant AMPKγ1 or deficient NO synthase (iNOS) prevents the disruption of VSMC reprogramming. Finally, hyperhomocysteinemia or hyperglycemia increases AMPKγ1 S-nitrosylation, prevents vascular contractile phenotypic restoration, reduces CCBF, and increases the infarct size of the heart in Apoe-/- mice, all of which is rescued in Apoe-/-/iNOSsm-/- mice or Apoe-/- mice with enforced expression of the AMPKγ1-C130A mutant following RI/MI. We conclude that nitrosative stress disrupts coronary collateral circulation during hyperhomocysteinemia or hyperglycemia through AMPK S-nitrosylation.

Introducing the Concept of Sanctuary Sites in Ischemic Stroke.

BACKGROUND: The topography of arterial territories has been defined using digital maps of supratentorial infarcts. Regions with a high probability of infarction (Pi) exist in the deep compartment due to a paucity of collaterals. However, less attention has been given to regions with a low Pi. METHODS: Using published digital maps, patients with cortical stroke and documented vessel occlusion were included. Infarcts from T2-weighted magnetic resonance images were segmented and registered onto a standard brain template (Montreal Neurological Institute 152). Segmented magnetic resonance images were averaged to yield the Pi at a voxel level. The overall Pi for the combined arterial territories was calculated to ensure that Pi was in the range of 0 to 1. Sanctuary sites were identified as regions with Pi <0.1. RESULTS: There were 154 patients (63% men; median age, 69 years; and interquartile range, 57-78 years). The magnetic resonance imaging scan used for segmentation was performed at a median interval of 35 (interquartile range, 3-66) days after stroke onset. Sanctuary sites were present in the frontal (gyrus rectus, the paracentral lobule, and orbitofrontal and precentral gyrus), parietal (postcentral, supramarginal, and angular gyrus, superior and inferior parietal lobule, and precuneus and posterior cingulate), and occipital cortex (cuneus, middle, and superior occipital gyrus). CONCLUSIONS: We propose that following vessel occlusion, there are cortical regions with a low Pi, which we termed sanctuary sites. The anatomic basis for this observation is the compensatory capacity of leptomeningeal collaterals.

Screening of Moyamoya Disease From Retinal Photographs: Development and Validation of Deep Learning Algorithms.

BACKGROUND: Moyamoya disease (MMD) is a rare and complex pathological condition characterized by an abnormal collateral circulation network in the basal brain. The diagnosis of MMD and its progression is unpredictable and influenced by many factors. MMD can affect the blood vessels supplying the eyes, resulting in a range of ocular symptoms. In this study, we developed a deep learning model using real-world data to assist a diagnosis and determine the stage of the disease using retinal photographs. METHODS: This retrospective observational study conducted from August 2006 to March 2022 included 498 retinal photographs from 78 patients with MMD and 3835 photographs from 1649 healthy participants. Photographs were preprocessed, and an ResNeXt50 model was developed. Model performance was measured using receiver operating curves and their area under the receiver operating characteristic curve, accuracy, sensitivity, and F1-score. Heatmaps and progressive erasing plus progressive restoration were performed to validate the faithfulness. RESULTS: Overall, 322 retinal photographs from 67 patients with MMD and 3752 retinal photographs from 1616 healthy participants were used to develop a screening and stage prediction model for MMD. The average age of the patients with MMD was 44.1 years, and the average follow-up time was 115 months. Stage 3 photographs were the most prevalent, followed by stages 4, 5, 2, 1, and 6 and healthy. The MMD screening model had an average area under the receiver operating characteristic curve of 94.6%, with 89.8% sensitivity and 90.4% specificity at the best cutoff point. MMD stage prediction models had an area under the receiver operating characteristic curve of 78% or higher, with stage 3 performing the best at 93.6%. Heatmap identified the vascular region of the fundus as important for prediction, and progressive erasing plus progressive restoration result shows an area under the receiver operating characteristic curve of 70% only with 50% of the important regions. CONCLUSIONS: This study demonstrated that retinal photographs could be used as potential biomarkers for screening and staging of MMD and the disease stage could be classified by a deep learning algorithm.

A Minimalist Iron Oxide Nanoprobe for the High-Resolution Depiction of Stroke by Susceptibility-Weighted Imaging.

The precise mapping of collateral circulation and ischemic penumbra is crucial for diagnosing and treating acute ischemic stroke (AIS). Unfortunately, there exists a significant shortage of high-sensitivity and high-resolution in vivo imaging techniques to fulfill this requirement. Herein, a contrast enhanced susceptibility-weighted imaging (CE-SWI) using the minimalist dextran-modified Fe3O4 nanoparticles (Fe3O4@Dextran NPs) are introduced for the highly sensitive and high-resolution AIS depiction under 9.4 T for the first time. The Fe3O4@Dextran NPs are synthesized via a simple one-pot coprecipitation method using commercial reagents under room temperature. It shows merits of small size (hydrodynamic size 25.8 nm), good solubility, high transverse relaxivity (r2) of 51.3 mM-1s-1 at 9.4 T, and superior biocompatibility. The Fe3O4@Dextran NPs-enhanced SWI can highlight the cerebral vessels readily with significantly improved contrast and ultrahigh resolution of 0.1 mm under 9.4 T MR scanner, enabling the clear spatial identification of collateral circulation in the middle cerebral artery occlusion (MCAO) rat model. Furthermore, Fe3O4@Dextran NPs-enhanced SWI facilitates the precise depiction of ischemia core, collaterals, and ischemic penumbra post AIS through matching analysis with other multimodal MR sequences. The proposed Fe3O4@Dextran NPs-enhanced SWI offers a high-sensitivity and high-resolution imaging tool for individualized characterization and personally precise theranostics of stroke patients.

Correlation between triglyceride glucose index and collateral circulation formation in patients with chronic total occlusion of coronary arteries in different glucose metabolic states.

BACKGROUND: To investigate the correlation between triglyceride glucose index (TyG) and collateral circulation in patients with chronic total occlusion (CTO) of coronary arteries in different glucose metabolic states. METHODS: A total of 681 patients who underwent coronary angiography between January 2020 and December 2021 to determine the presence of CTO lesions in at least one major coronary artery were retrospectively included in this study. Patients were categorized into a group with poor collateral circulation formation (Rentrop grade 0-1, n = 205) and a group with good collateral circulation formation (Rentrop grade 2-3, n = 476) according to the Rentrop scale. They were also categorized according to their glucose metabolism status: normal glucose regulation (NGR) (n = 139), prediabetes mellitus (Pre-DM) (n = 218), and diabetes mellitus (DM) (n = 324). Correlation between TyG index and collateral circulation formation was analyzed by logistic regression analysis and receiver operating characteristic (ROC) curves. RESULTS: Among patients with CTO, TyG index was significantly higher in the group with poor collateral circulation formation than in the group with good collateral circulation formation. Logistic regression analysis showed that TyG index was an independent risk factor for poor collateral circulation formation (OR 5.104, 95% CI 3.323-7.839, P < 0.001). The accuracy of TyG index in predicting collateral circulation formation was evaluated by the ROC curve, which had an area under the curve of 0.779 (95% CI 0.738-0.820, P < 0.001). The restrictive cubic spline curves showed that the risk of poor collateral circulation formation in the Pre-DM and DM groups was initially flat and finally increased rapidly, except for the NGR group. TyG index was significantly associated with an increased risk of poor collateral circulation formation in the Pre-DM and DM groups. CONCLUSIONS: TyG index was significantly associated with the risk of poor collateral circulation formation in patients with CTO, especially those with Pre-DM and DM.

Assessment of Myocardial Viability and Risk Stratification in Coronary Chronic Total Occlusion: A Qualitative and Quantitative Stress Cardiac MRI Study.

BACKGROUND: Indicators for assessing myocardial viability and risk stratification in patients with coronary chronic total occlusion (CTO) are still in the research stage. PURPOSE: To use stress-MRI to assess myocardial function, blood perfusion, and viability and to explore their relationship with collateral circulation. STUDY TYPE: Prospective. SUBJECTS: Fifty-one patients with CTO in at least one major artery confirmed by X-ray coronary angiography (male: 46; age 55.2 ± 10.8 years). FIELD STRENGTH/SEQUENCE: 3.0T; TurboFlash, balanced steady-state free precession cine, and phase-sensitive inversion recovery sequences. ASSESSMENT: Stress-MRI was used to obtain qualitative and quantitative parameters of segmental myocardium. Myocardial segments supplied by CTO target vessels were grouped according to the degree of collateral circulation assessed by radiographic coronary angiography (no/mild, moderate, or good). Depending on qualitative stress perfusion assessment and late gadolinium enhancement (LGE) extent, segments were also categorized as negative, viable, or trans-infarcted. STATISTICAL TESTS: Independent sample Student's t-test, one-way analysis of variance (ANOVA) test, Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient (r). P < 0.05 was considered statistically significant. RESULTS: A total of 334 segments were supplied by CTO target vessels. The radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of the negative, viable, and trans-infarcted regions showed a significant and stepwise impairment. Myocardial blood flow at rest was positively correlated with RS, CS, and LS (r = 0.42, 0.43, 0.38, respectively). Among the different collateral circulation, there were no significant differences in RS, CS, LS, and LGE volume (P = 0.788, 0.562, 0.122, 0.170, respectively), and there were also no statistically significant differences in the proportions of negative, viable, and trans-infarcted regions (P = 0.372). DATA CONCLUSION: Myocardial perfusion obtained by stress-MRI combined with strain and LGE may comprehensively evaluate myocardial function and viability, and has potential to facilitate risk stratification of CTO. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke.

OBJECTIVES: This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes. METHODS: This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed. RESULTS: Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively. CONCLUSION: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study. CLINICAL RELEVANCE STATEMENT: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. KEY POINTS: • Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.

Thrombectomy improves functional independence in severe basilar artery occlusion with favorable collateral circulation.

BACKGROUND AND PURPOSE: This study aimed to investigate the effect of collateral circulation on the outcomes of thrombectomy versus medical management alone in basilar artery occlusion (BAO) patients with varying stroke severities. METHODS: Data from the ATTENTION cohort were used to perform a post-hoc analysis comparing the outcomes of thrombectomy with medical management in BAO patients with varying degrees of collateral circulation and stroke severity. Basilar Artery on Computed Tomography Angiography (BATMAN) scores were used to quantify the collateral circulation, and the effect was estimated through a primary outcome of 90-day functional independence (modified Rankin Scale score, mRS ≤2). Favorable versus unfavorable BATMAN scores were analyzed as both continuous and categorical variables, and an adjusted multivariate regression model was applied. RESULTS: Among 221 BAO patients, thrombectomy significantly improved functional independence compared to medical management in patients with favorable BATMAN scores (aOR 7.75, 95% CI 2.78-26.1), but not in those with unfavorable BATMAN scores (aOR 1.33, 95% CI 0.28-6.92; pinteraction = 0.028). When treated as a continuous variable, increased BATMAN score was found to be associated with a higher likelihood of functional independence in the thrombectomy group (aOR 1.97, 95% CI 1.44-2.81; pinteraction = 0.053). In severe stroke patients with higher BATMAN scores (National Institutes of Health Stroke Scale (NIHSS) ≥21), we identified a significant interaction for treatment effect with thrombectomy compared to medical management (pinteraction = 0.042). CONCLUSION: An increased BATMAN score was significantly associated with a higher probability of functional independence after thrombectomy than after medical management, particularly in patients with severe BAO.

Hypoxia-Preconditioned Bone Marrow Mesenchymal Stem Cells Improved Cerebral Collateral Circulation and Stroke Outcome in Mice.

BACKGROUND: Adequate collateral circulation can remarkably improve patient prognoses for patients experiencing ischemic stroke. Hypoxic preconditioning enhances the regenerative properties of bone marrow mesenchymal stem cells (BMSCs). Rabep2 (RAB GTPase binding effector protein 2) is a key protein in collateral remodeling. We investigated whether BMSCs and hypoxia-preconditioned BMSCs (H-BMSCs) augment collateral circulation poststroke, particularly through Rabep2 regulation. METHODS: BMSCs or H-BMSCs (1×106) were delivered intranasally in ischemic mice with distal middle cerebral artery occlusion at 6 hours poststroke. Two-photon microscopic imaging and vessel painting methods were used to analyze collateral remodeling. Blood flow, vascular density, infarct volume, and gait analysis were assessed to evaluate poststroke outcomes. Expressions of proangiogenic marker VEGF (vascular endothelial growth factor) and Rabep2 were determined by Western blotting. Western blot, EdU (5-ethynyl-2'-deoxyuridine) incorporation, and tube formation assays were conducted on cultured endothelial cells treated with BMSCs. RESULTS: BMSCs were more effectively transplanted in the ischemic brain after hypoxic preconditioning. The ipsilateral collateral diameter was increased by BMSCs and strengthened by H-BMSCs (P<0.05). BMSCs increased peri-infarct blood flow and vascular density and reduced infarct volume, gait deficits (P<0.05), and furthermore by H-BMSCs (P<0.05). VEGF and Rabep2 protein expression was increased by BMSCs (P<0.05), which was enhanced by preconditioning (P<0.01). Additionally, BMSCs increased Rabep2 expression, proliferation, and tube formation of endothelial cells in vitro (P<0.05). H-BMSCs enhanced these effects (P<0.05), which were annulled by Rabep2 knockdown. CONCLUSIONS: BMSCs increased collateral circulation and improved poststroke outcomes, through the upregulation of Rabep2. These effects were enhanced by hypoxic preconditioning.

White matter hyperintensity burden and collateral circulation in acute ischemic stroke with large artery occlusion.

OBJECTIVE: This study aimed to investigate the association between white matter hyperintensity (WMH) burden and pial collaterals in acute strokes caused by intracranial large artery occlusion treated with mechanical thrombectomy in the anterior circulation, focusing on stroke subtypes. METHODS: Consecutive patients undergoing mechanical thrombectomy between December 2019 and June 2022 were retrospectively screened. The Fazekas scale assessed WMH burden. Pial collaterals were categorized as either poor (0-2) or good (3-4) based on the Higashida score. A multivariable analysis was used to determine the relationship between WMH burden and pial collaterals. Subgroup analyses delved into associations stratified by stroke subtypes, namely cardioembolism (CE), tandem lesions (TLs), and intracranial atherosclerosis (ICAS). RESULTS: Of the 573 patients included, 274 (47.8%) demonstrated poor pial collaterals. Multivariable regression indicated a strong association between extensive WMH burden (Fazekas score of 3-6) and poor collaterals [adjusted OR 3.04, 95% CI 1.70-5.46, P < 0.001]. Additional independent predictors of poor collaterals encompassed ICAS-related occlusion (aOR 0.26, 95% CI 0.09-0.76, P = 0.014), female sex (aOR 0.63, 95% CI 0.41-0.96, P = 0.031), and baseline Alberta Stroke Program Early Computed Tomography scores (aOR 0.80, 95% CI 0.74-0.88, P < 0.001). Notably, an interaction between extensive WMH burden and stroke subtypes was observed in predicting poor collaterals (P = 0.001), being pronounced for CE (adjusted OR 2.30, 95% CI 1.21-4.37) and TLs (adjusted OR 5.09, 95% CI 2.32-11.16), but was absent in ICAS (adjusted OR 1.24, 95% CI 0.65-2.36). CONCLUSIONS: Among patients treated with mechanical thrombectomy for anterior circulation large artery occlusion, extensive WMH burden correlates with poor pial collaterals in embolic occlusion cases (CE and TLs), but not in ICAS-related occlusion.

Evaluation of collateral circulation in patients with internal carotid artery occlusion: A clinical and ultrasonographic multicenter study.

BACKGROUND: Internal carotid artery (ICA) occlusion is the major cause of ischemic stroke. The effect of collateral vessels on cerebral hemodynamics in ICA occlusion remains unclear. This study investigated the correlation between collateral vessels and the peak systolic velocity of the middle cerebral artery (MCA) in patients with ICA occlusion. METHODS: The relevant collateral vessels included the anterior communicating (ACoA), posterior communicating (PCoA), and internal-external carotid (IECCA) arteries, respectively. Patients with unilateral ICA occlusion (n = 251) underwent transcranial Doppler imaging to detect the peak systolic velocity (PSV) of the MCA and other intracranial arteries. The clinical symptoms were assessed using the National Institutes of Health Stroke Scale (NIHSS). RESULTS: Patients with ACoA collaterals had significantly higher PSVMCA scores and significantly lower NIHSS scores than those without ACoA collaterals (p < 0.001). Patients without any notable collaterals and those with only IECCA had the lowest PSVMCA and highest NIHSS scores. The PSVMCA and NIHSS scores were negatively correlated (r = -0.566, p < 0.001). CONCLUSION: Collateral circulation patency in unilateral ICA occlusion was closely associated with clinical symptoms, and patients with ACoA collaterals may have favorable outcomes. (ClinicalTrials.gov Identifier: NCT02397655).

Association between the pan-immune-inflammation value and coronary collateral circulation in chronic total coronary occlusive patients.

BACKGROUND: Inflammation and immunity play important roles in the formation of coronary collateral circulation (CCC). The pan-immune-inflammation value (PIV) is a novel marker for evaluating systemic inflammation and immunity. The study aimed to investigate the association between the PIV and CCC formation in patients with chronic total occlusion (CTO). METHODS: This retrospective study enrolled 1150 patients who were diagnosed with CTO through coronary angiographic (CAG) examinations from January 2013 to December 2021 in China. The Cohen-Rentrop criteria were used to catagorize CCC formation: good CCC formation (Rentrop grade 2-3) and poor CCC formation group (Rentrop grade 0-1). Based on the tertiles of the PIV, all patients were classified into three groups as follows: P1 group, PIV ≤ 237.56; P2 group, 237.56< PIV ≤ 575.18; and P3 group, PIV > 575.18. RESULTS: A significant relationship between the PIV and the formation of CCC was observed in our study. Utilizing multivariate logistic regression and adjusting for confounding factors, the PIV emerged as an independent risk factor for poor CCC formation. Notably, the restricted cubic splines revealed a dose-response relationship between the PIV and risk of poor CCC formation. In terms of predictive accuracy, the area under the ROC curve (AUC) for PIV in anticipating poor CCC formation was 0.618 (95% CI: 0.584-0.651, P < 0.001). Furthermore, the net reclassification index (NRI) and integrated discrimination index (IDI) for PIV, concerning the prediction of poor CCC formation, were found to be 0.272 (95% CI: 0.142-0.352, P < 0.001) and 0.051 (95% CI: 0.037-0.065, P < 0.001), respectively. It's noteworthy that both the NRI and IDI values were higher for PIV compared to other inflammatory biomarkers, suggesting its superiority in predictive capacity. CONCLUSIONS: PIV was associated with the formation of CCC. Notably, PIV exhibited potential as a predictor for poor CCC formation and showcased superior predictive performance compared to other complete blood count-based inflammatory biomarkers.

Association between the atherogenic index of plasma and coronary collateral circulation in patients with chronic total occlusion.

BACKGROUND: The atherogenic index of plasma (AIP) is considered an independent risk factor for coronary artery disease (CAD). The present study investigated whether AIP correlates with the formation of coronary collateral circulation (CCC) in CAD patients with chronic total occlusion (CTO). METHODS: This retrospective study included 1093 CAD patients with CTO confirmed by coronary angiography from January 2020 to December 2020 at Beijing Anzhen Hospital. Based on the Rentrop scoring system, the patients were divided into the good CCC group and the poor CCC group. AIP was calculated by log (triglyceride/high-density lipoprotein cholesterol). Meanwhile, the study population was further divided into four groups according to the quartiles of AIP. RESULTS: Patients in the poor CCC group exhibited significantly higher AIP compared to those in the good CCC group (0.31 ± 0.27 vs. 0.14 ± 0.24, p < 0.001). Multivariate logistic regression analysis revealed an independent association between AIP and poor CCC, regardless of whether AIP was treated as a continuous or categorical variable (p < 0.001), after adjusting for confounding factors. Besides, this association remained consistent across most subgroups. The incorporation of AIP into the baseline model significantly enhanced the accuracy of identifying poor CCC [area under the curve (AUC): baseline model, 0.661 vs. baseline model + AIP, 0.721, p for comparison < 0.001]. CONCLUSIONS: Elevated AIP is independently associated with an increased risk of poor CCC in CAD patients with CTO, and AIP may improve the ability to identify poor CCC in clinical practice.

Challenging the angiosome concept: Delineating peripheral arterial disease patterns in diabetic foot ulcers.

OBJECTIVES: The angiosome concept has significantly impacted diabetic foot ulcer management by highlighting the vascular anatomy's role in wound healing. However, its clinical applicability and validity remain debated due to complexities in foot blood supply and ulcer location determination. METHODS: A cross-sectional study was conducted on 84 individuals with diabetic foot ulcers undergoing lower limb angiography. Demographics, ulcer characteristics, and angiographic data were collected and analyzed using descriptive statistics and relevant tests. RESULTS: Digital subtraction angiography assessed 89 limbs with diabetic foot ulcers; males comprised 54.8%, primarily type 2 diabetes (96.4%), averaging 64.36 ± 10.09 years. Of 129 angiosomes, angiosome 2 (40.3%) had the highest ulcer incidence. Posterior tibial artery (PTA) involvement was predominant (72.9%), while external iliac artery (EIA) and profunda femoris artery (PFA) were least affected (2.4% each). Posterior tibial artery showed 46.5% complete occlusion. Angiosome 2 correlated notably with anterior tibial artery (ATA), peroneal artery (CPA), and PTA, but categorizing angiosomes by supply patterns showed no significant artery correlation (p > .05). CONCLUSIONS: The research indicates inconsistent support for below-the-knee artery involvement correlating with foot ulcer locations in angiosomes. While aiding vascular comprehension, the angiosome concept may not fully elucidate lower limb vascular complexities and ulcer genesis. Factors like collateral circulation should be noticed to understanding ulcer localization and severity, extending beyond angiosomal arterial supply.

Coronary steal: how many thieves are out there?

The colorful term "coronary steal" arose in 1967 to parallel "subclavian steal" coined in an anonymous 1961 editorial. In both instances, the word "steal" described flow reversal in the setting of an interconnected but abnormal vascular network-in one case a left subclavian stenosis proximal to the origin of the vertebral artery and in the other case a coronary fistula. Over time, the term has morphed to include a larger set of pathophysiology without explicit flow reversal but rather with a decrease in stress flow due to other mechanisms. This review aims to shed light on this phenomenon from a clinical and a pathophysiological perspective, detailing the anatomical and physiological conditions that allow so-called steal to appear and offering treatment options for six distinct scenarios.

Automated evaluation of collateral circulation for outcome prediction in acute ischemic stroke.

INTRODUCTION: The assessment of collateral circulation in acute ischemic stroke management is essential. Modern tools, such as Brainomix's e-CTA, powered by artificial intelligence, provide detailed insights into collateral assessment. This retrospective study aims to identify factors contributing to favorable collateral status and compare outcomes between patients with good collaterals (grade 3) and fair collaterals (grade 0-2). METHOD: This retrospective study included 97 patients admitted to the Stroke Unit at the Hospital de Clínicas of the Federal University of Paraná, Brazil, from September 2021 to January 2023. Comparative analyses involved demographic factors, cardiovascular risk factors, and the combined outcome of mortality and moderate to severe disability at discharge, 30-day, and 90-day follow-ups. RESULTS: Among the 97 cases, 58.8 % showed 'good collaterals' with a grade 3 status. Variables affecting collateral status included age (p = 0.042), neutrophil-lymphocyte ratio (p = 0.005), and initial NIHSS scores (p<0.001). The presence of good collaterals according to e-CTA reduced the odds of death and moderate-severe disability at discharge (p = 0.003; OR 0.27) and at 30 days (p = 0.015; OR 0.33), although this effect diminished at the 90-day mark after multivariate analysis. DISCUSSION: Automated collateral assessment through e-CTA is a valuable tool in acute ischemic stroke evaluation. Good e-CTA collateral score serve as a promising imaging biomarker, guiding informed clinical decisions during Stroke Unit hospitalizations. This study highlights the relationship between collaterals and stroke outcomes and underscores the potential for AI-driven tools to enhance stroke care management.

Development and validation of a novel nomogram model predicting the unfavorable outcome based on NAR and collaterals status for patients with AIS.

INTRODUCTION: Stroke is a leading cause of disability and mortality globally. This study aimed to develop a prognostic nomogram based on neutrophil-to-albumin ratio (NAR) and collateral status in acute ischemic stroke (AIS) patients with anterior large vessel occlusion (LVO). MATERIAL & METHOD: 590 AIS patients with LVO assessed for regional leptomeningeal collateral (rLMC) were retrospectively enrolled, and randomly divided into a training set (n = 414) and a testing set (n = 176). Unfavorable functional outcome was defined as a modified Rankin scale (mRS) score of 3 to 6 at 3 months. We assessed the accuracy and clinical utility of the nomogram using calibration plots, area under the curve (AUC), decision curve analysis (DCA), net reclassification index (NRI), and integrated discrimination improvement (IDI). RESULTS: Both NAR and rLMC were independently associated with unfavorable outcome at 3 months (OR=8.96, p=0.0341; OR=0.89, p=0.0002, respectively). The developed nomogram (akaike information criterion (AIC)=398.77), which included NAR, rLMC and other factors, showed good performance (the AUC for the development and validation cohorts was 0.848 and 0.840 respectively) and improved the predictive value compared to a model without NAR and rLMC, according to an overall NRI of 3.27% (p=0.2401), overall IDI of 3.27% (p=0.2414), and a higher AUC (0.848 vs 0.831). CONCLUSIONS: NAR can serve as an independent predictor in AIS patients with anterior LVO, and the nomogram incorporating NAR and rLMC is reliable in predicting unfavorable outcome. Further studies with larger sample sizes are needed to validate and extend these findings.

A thyroidea ima artery variation providing collateral circulation to the mediastinum.

The thyroidea ima artery (TIA) is a highly variable arterial deviation of the blood supply to the thyroid gland with critical implications for surgical neck procedures such as tracheostomy. Though relatively common in the population at large (~ 4%), most TIA variations are related to the origin of the artery and whether it emerges from the common sites of the brachiocephalic trunk, aortic arch, and right common carotid artery, or another more unique vessel-as opposed to its dispersion pattern. TIA variants generally supply the thyroid gland, occasionally co-occurring with absent thyroid arteries. Here, we report on a unique case of a four-pronged variation of the TIA discovered during an anatomy laboratory dissection of first-year medical students. This variant originated from the brachiocephalic trunk and had three branches terminating in the thyroid gland and a fourth branch traveling into the thorax to provide accessory circulation in the mediastinum. Specifically, small arterial branches from the inferior TIA branch supplied the anterior pericardium and surrounding adipose tissue, in addition to normal pericardiacophrenic circulation. We discuss the potential embryological and clinical relevance of this unique variation and voice further support for imaging as a requirement before surgical neck procedures to prevent catastrophic bleeding in the event of a TIA variant.

The clinical and imaging data fusion model for single-period cerebral CTA collateral circulation assessment.

BACKGROUND: The Chinese population ranks among the highest globally in terms of stroke prevalence. In the clinical diagnostic process, radiologists utilize computed tomography angiography (CTA) images for diagnosis, enabling a precise assessment of collateral circulation in the brains of stroke patients. Recent studies frequently combine imaging and machine learning methods to develop computer-aided diagnostic algorithms. However, in studies concerning collateral circulation assessment, the extracted imaging features are primarily composed of manually designed statistical features, which exhibit significant limitations in their representational capacity. Accurately assessing collateral circulation using image features in brain CTA images still presents challenges. METHODS: To tackle this issue, considering the scarcity of publicly accessible medical datasets, we combined clinical data with imaging data to establish a dataset named RadiomicsClinicCTA. Moreover, we devised two collateral circulation assessment models to exploit the synergistic potential of patients' clinical information and imaging data for a more accurate assessment of collateral circulation: data-level fusion and feature-level fusion. To remove redundant features from the dataset, we employed Levene's test and T-test methods for feature pre-screening. Subsequently, we performed feature dimensionality reduction using the LASSO and random forest algorithms and trained classification models with various machine learning algorithms on the data-level fusion dataset after feature engineering. RESULTS: Experimental results on the RadiomicsClinicCTA dataset demonstrate that the optimized data-level fusion model achieves an accuracy and AUC value exceeding 86%. Subsequently, we trained and assessed the performance of the feature-level fusion classification model. The results indicate the feature-level fusion classification model outperforms the optimized data-level fusion model. Comparative experiments show that the fused dataset better differentiates between good and bad side branch features relative to the pure radiomics dataset. CONCLUSIONS: Our study underscores the efficacy of integrating clinical and imaging data through fusion models, significantly enhancing the accuracy of collateral circulation assessment in stroke patients.

The Atherogenic Index of Plasma is a Predictor for Chronic Total Occlusion and Coronary Collateral Circulation Formation in CTOs Patients.

Background: The atherogenic index of plasma (AIP), determined by the logarithmic transformation of the ratio of triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C), was found to be a marker of cardiovascular disease. We sought to investigate the correlation between the atherogenic AIP and coronary collateral circulation (CCC) formation in chronic total occlusive (CTOs) patients. Methods: This retrospective cohort study included 665 non-CTOs and 345 CTOs patients. CTOs were divided into 206 CCC poor formation patients and 139 CCC good formation patients according to the Cohen-Rentrop grade. Spearman correlation analysis was carried out to obtain the relationship between AIP and the Rentrop grade. We used multivariate logistic regression analysis to assess CTOs and CCC poor formation risk factors. Receiver operating characteristic (ROC) curves were used to determine the optimal threshold for AIP to predict CTOs and CCC poor formation. The predicted increment of AIP on CTOs and CCC poor formation was evaluated by calculating the Net Reclassification Index (NRI) and the Integrated Discriminant Index (IDI). Results: AIP in CTOs was significantly elevated compared to non-CTOs patients [(1.55 (1.02, 2.59)) vs (1.26 (0.82, 1.90)), p < 0.001] AIP in the CCC poor formation group was significantly higher than that in the CCC good formation group [(1.73 (1.12, 2.90)) vs (1.37 (0.84, 2.13)), p = 0.002]. There was a negative correlation between AIP and the Rentrop grade (r = -0.145, p = 0.007). The results of multivariate logistic regression revealed that AIP was an independent predictor of CTOs (OR = 4.371, 95% CI: 2.436-7.844, p < 0.001) and CCC poor formation (OR = 3.749, 95% CI: 1.628-8.635, p = 0.002). In the ROC analysis, the area under the curve of AIP for identifying CTOs and CCC poor formation was 0.596 (OR = 3.680, 95% CI: 1.490-9.090, p = 0.005) and 0.597 (95% CI: 0.535-0.658, p = 0.002), respectively. Conclusions: Contrary to previous research, we found that AIP is a moderate but not powerful indicator for detecting both CTO patients and poor CCC formation.