Reversal of ophthalmic artery flow as a predictor of intracranial hemodynamic compromise: implication for prognosis of severe carotid stenosis

A Nomogram Based on Ocular Hemodynamics for Predicting Ischemic Stroke

PURPOSE

Ischemic stroke is a cerebrovascular disease with high mortality and disability. Due to similar physiological characteristics, ocular vascular characteristics are important indicators for monitoring cerebrovascular diseases. This study aimed to develop a nomogram prediction model for ischemic stroke based on ocular hemodynamic characteristics.

DESIGN

Retrospective clinical cohort study.

METHODS

A total of 337 patients were included in this study and randomly divided into 235 training and 102 validation cohorts. The general data were collected, and the hemodynamic parameters of ophthalmic artery, central retinal artery and posterior ciliary artery were detected by ultrasound. The retinal vascular diameter was extracted from the color fundus image, and the relevant laboratory indexes of the patients were collected. Logistic regression analysis was used to determine the risk factors of ischemic stroke. A nomogram was constructed based on the identified risk factors, and the accuracy and clinical applicability of the model were analyzed using the receiver operating curve (ROC), Hosmer-Lemeshow test, and decision curve analysis (DCA).

RESULTS

Independent risk factors for ischemic stroke including hypertension (OR 2.17, 95% confidence interval [CI] 1.16 to 4.08; P = .016), hyperlipidemia (OR 2.21, 95% CI 1.18 to 4.14; P = .013), and resistance index of ophthalmic artery (OR 5.98, 95% CI 3.27 to 10.93; P < .001) were identified by multivariate regression analysis. The area under the ROC curve of the training cohort was 0.790 (95% CI 0.733 to 0.847) and that of the validation cohort was 0.773 (95% CI 0.679 to 0.866), revealing the consistent ability of the nomogram to predict ischemic stroke. The mean absolute error of the training and validation cohorts were 0.020 and 0.013, respectively. In addition, the DCA curve showed good clinical benefit.

CONCLUSIONS

The nomogram combining traditional factors and ophthalmic artery resistance index has a preferable predictive performance for ischemic stroke. This suggests that the model combined with ocular hemodynamics can effectively promote the early diagnosis and intervention of ischemic stroke.

Decreased Ocular Perfusion Pressure Associated With Reverse Ophthalmic Artery Flow on Transcranial Doppler Ultrasonography

Innovative applications of clinical ocular diagnostic tools are emerging to help identify systemic disorders that extend beyond ocular diseases. Ophthalmodynamometry (ODM) is a screening tool that non-invasively determines mean central retinal artery pressure (MCRAP) and ocular perfusion pressure (OPP). Decreased OPP and MCRAP on Falck Medical Multifunctional Device (FMD, Falck Medical, Inc., Mystic, CT), along with reverse ophthalmic artery flow (ROAF) on transcranial Doppler ultrasonography (TCD), indicate increased collateral brain perfusion and possible stenosis of the ophthalmic artery or internal carotid artery (ICA). In this case report, we describe the case of a 78-year-old female with ROAF, reduced MCRAP, and OPP in the right eye, confirmed by carotid duplex of 50-79% right ICA stenosis. Early application of ODM and TCD allowed for prompt diagnosis and management with a vascular specialist.

Optical Coherence Tomography Angiography: Revolutionizing Clinical Diagnostics and Treatment in Central Nervous System Disease

Optical coherence tomography angiography (OCTA), as a new generation of non-invasive and efficient fundus imaging technology, can provide non-invasive assessment of vascular lesions in the retina and choroid. In terms of anatomy and development, the retina is referred to as an extension of the central nervous system (CNS). CNS diseases are closely related to changes in fundus structure and blood vessels, and direct visualization of fundus structure and blood vessels provides an effective "window" for CNS research. This has important practical significance for identifying the characteristic changes of various CNS diseases on OCTA in the future, and plays a key role in promoting early screening, diagnosis, and monitoring of disease progression in CNS diseases. This article reviews relevant fundus studies by comparing and summarizing the unique advantages and existing limitations of OCTA in various CNS disease patients, in order to demonstrate the clinical significance of OCTA in the diagnosis and treatment of CNS diseases.

Impact of cerebral collateral flow on stroke outcomes after carotid stenting

OBJECTIVE

Internal carotid artery stenosis is a main contributor to recurrent ischemic stroke. This study aimed to evaluate associations between recurrent stroke and changes in prestenting flow direction in the primary collaterals or both primary and secondary collaterals, and the potential interaction between extra- and intracranial arteries.

METHODS

This longitudinal study recruited stroke patients without intracranial stenosis who underwent right-side carotid stenting between 2011 and 2019. The main study outcome was recurrent stroke. Predictive factors were anterior circulation flow direction change (ACFDC), posterior circulation flow direction change, and reversal of ophthalmic artery/leptomeningeal anastomosis (ROALA) detected by transcranial color-coded duplex (TCCD) before carotid stenting. Patient follow-up was 9 years. Risk factors for recurrent stroke were identified by Kaplan-Meier plot and Cox regression analyses.

RESULTS

A total of 234 patients (mean age 70.88 ± 10.3 years, 86.32% male) were included, and 115 had recurrent stroke. Kaplan-Meier plot showed that patients with left ACFDC and ROALA had worse outcomes than those with ACFDC only, while patients with left ACFDC had worse outcome than those with right ACFDC (both p < 0.001). Cox regression analysis showed that recurrent stoke was associated with ACFDC at right (hazard ratio [95% CI]: 20.988 [2.549-172.790], p < 0.01), left (151.441 [20.100-1140.993], p < 0.001), and both sides (144.889 [19.089-1099.710], p < 0.001).

INTERPRETATION

Anterior circulation flow direction change is significantly associated with recurrent stroke in patients with unilateral carotid stenosis. Patients with ACFDC and ROALA together have worse outcomes compared to those with ACFDC only. Prestenting TCCD images help provide definitive information to predict outcomes after carotid stenting.

Ophthalmic artery flow direction change predicts recurrence of ischemic stroke after carotid stenting: a longitudinal observational study

BACKGROUND AND PURPOSE

The implantation of carotid artery stents prevents recurrent ischemic stroke in patients with carotid stenosis. This study aimed to investigate associations between change of ophthalmic artery flow (COAF) post carotid stenting and recurrent ischemic stroke, as well as the link toward the anterior and posterior circulations and patients' prognosis after carotid stenting.

METHODS

This retrospective, longitudinal cohort study recruited 87 left side carotid stenosed ischemic stroke patients undergoing left side carotid stenting between year of 2009 and 2013, and patients were followed up to 9 years after carotid procedures. Clinical data were derived from medical records. The primary outcome was stroke recurrence. Predictive factors were stenosis  > 50% in one intracranial artery and ROAF. Kaplan-Meier and Cox regression analyses were used to identify risk factors associated with stroke recurrence.

RESULTS

Among 87 included patients undergone left side carotid stent treatment, 44 had stroke recurrence within 3 years after carotid stenting. The recurrence group had significantly greater proportions of COAF after stenting (p = 0.001), and middle cerebral artery (MCA) and basilar artery or vertebral artery (BA/VA) stenosis > 50% (all p < 0.001) than the no-recurrence group. Survival was significantly shorter in patients with COAF than in those without (p < 0.01). Regression analysis showed that COAF was associated with stroke recurrence (HR: 3.638, 95% CI 1.54-8.62, p = 0.003). The recurrence rate was highest in patients with bilateral MCA stenosis  > 50% (100%), followed by left MCA stenosis  > 50% plus BA/VA stenosis  > 50% (83.33%) or COAF (82.14%). Patients with bilateral MCA stenosis  < 50% had no recurrence within 3-year follow-up.

CONCLUSIONS

Prognosis after carotid stenting is poorer for patients with MCA stenosis  > 50%, BA/VA stenosis  > 50% and/or COAF. Carotid duplex and magnetic resonance angiography provide definitive information for prognosis prediction.

Adhesion molecules and cerebral microvascular hemodynamic abnormalities in sickle cell disease

Cerebrovascular abnormalities are a common feature of sickle cell disease that may be associated with risk of vaso-occlusive pain crises, microinfarcts, and cognitive impairment. An activated endothelium and adhesion factors, VCAM-1 and P-selectin, are implicated in sickle cell vasculopathy, including abnormal hemodynamics and leukocyte adherence. This study examined the association between cerebral expression of these adhesion factors and cortical microvascular blood flow dynamics by using in-vivo two-photon microscopy. We also examined the impact of blood transfusion treatment on these markers of vasculopathy. Results showed that sickle cell mice had significantly higher maximum red blood cell (RBC) velocity (6.80 ± 0.25 mm/sec, p ≤ 0.01 vs. 5.35 ± 0.35 mm/sec) and more frequent blood flow reversals (18.04 ± 0.95 /min, p ≤ 0.01 vs. 13.59 ± 1.40 /min) in the cortical microvasculature compared to controls. In addition, sickle cell mice had a 2.6-fold (RFU/mm2) increase in expression of VCAM-1 and 17-fold (RFU/mm2) increase in expression of P-selectin compared to controls. This was accompanied by an increased frequency in leukocyte adherence (4.83 ± 0.57 /100 μm/min vs. 2.26 ± 0.37 /100 μm/min, p ≤ 0.001). We also found that microinfarcts identified in sickle cell mice were 50% larger than in controls. After blood transfusion, many of these parameters improved, as results demonstrated that sickle cell mice had a lower post-transfusion maximum RBC velocity (8.30 ± 0.98 mm/sec vs. 11.29 ± 0.95 mm/sec), lower frequency of blood flow reversals (12.80 ± 2.76 /min vs. 27.75 ± 2.09 /min), and fewer instances of leukocyte adherence compared to their pre-transfusion imaging time point (1.35 ± 0.32 /100 μm/min vs. 3.46 ± 0.58 /100 μm/min). Additionally, we found that blood transfusion was associated with lower expression of adhesion factors. Our results suggest that blood transfusion and adhesion factors, VCAM-1 and P-selectin, are potential therapeutic targets for addressing cerebrovascular pathology, such as vaso-occlusion, in sickle cell disease.

The age factor influencing long-term physical functionality in stroke patients undergoing intra-arterial thrombectomy treatment

The treatment of acute ischemic stroke is heavily time-dependent, and even though, with the most efficient treatment, the long-term functional outcome is still highly variable. In this current study, the authors selected acute ischemic stroke patients who were qualified for intravenous thrombolysis with recombinant tissue plasminogen activator and followed by intra-arterial thrombectomy. With primary outcome defined by the functional level in a 1-year follow-up, we hypothesize that patients with older age are at a disadvantage in post-stroke recovery. However, an age-threshold should be determined to help clinicians in selection of patients to undergo such therapy. This is a retrospective chart review study that include 92 stroke patients in Changhua Christian hospital with a total of 68 evaluation indexes recorded. The current study utilized the forward stepwise regression model whose Adj-R2 and P value in search of important variables for outcome prediction. The chngpt package in R indicated the threshold point of the age factor directing the better future functionality of the stroke patients. Datasets revealed the threshold of the age set at 79 the most appropriate. Admission Barthel Index, Age, ipsilateral internal carotid artery resistance index (ICA RI), ipsilateral vertebral artery (VA) PI, contralateral middle cerebral artery (MCA) stenosis, contralateral external carotid artery (ECA) RI, and in-hospital pneumonia are the significant predicting variables. The higher the age, in-hospital pneumonia, contralateral MCA stenosis, ipsilateral ICA RI and ipsilateral VA PI, the less likely patient to recover from functional deficits as the result of acute ischemic stroke; the higher the value of contralateral ECA RI and admission Barthel Index, the better chance to full functional recovery at 1-year follow up. Parameters of pre-intervention datasets could provide important information to aid first-line clinicians in decision making. Especially, in patients whose age is above 79 receives diminish return in the benefit to undergo such intervention and should be considered seriously by both the patients and the physicians.

Evolution of the Flow Patterns After Endovascular Treatment in Patients with High-Grade Carotid Artery Stenosis - the Clinical Value of Insonation of the Supratrochlear Artery and Alternating Flow

AIM

We aimed to describe the evolution of flow pattern in the ophthalmic artery (OA) and supratrochlear artery (SA) by transcranial Doppler (TCD) ipsilateral to a severe proximal carotid artery stenosis before and after staged endovascular treatment (EVT).

METHODS

We insonated and recorded the flow patterns of OA and SA in 63 patients with ≥ 80% carotid artery stenosis before and after staged carotid angioplasty and stenting at 2-4 weeks apart. Based on the direction of OA and SA blood flow, we categorized patients into (1) reversed, (2) alternating, or (3) forward flow, groups. We evaluated the evolving sonographic flow patterns in OA and SA at the 3-time points and correlated them with the stenotic and flow velocity change.

RESULTS

Despite the disconcordance between OA and SA, the evolution of flow direction were evoluted from reversed to alternating or from alternating to forward in both OA and SA. OA and SA's disagreement rate at three-time points was 19.1%, 49.2%, and 28.6%, respectively. After angioplasty alone, we detected an alternating flow in 21 (33.3%) and 46 (73.0%) patients in OA and SA, respectively. Alternating flow patterns in SA persisted in 20 patients (31.7%) after stenting. The post-angioplasty residual stenosis did not differ between the three flow pattern groups (p>0.05).

CONCLUSIONS

An alternating flow in OA or SA might mark the hemodynamic recovery after EVT. Insonation of SA may provide supporting evidence for hemodynamic change in patients with carotid artery stenosis undergoing EVT.

Reversed ophthalmic artery flow in patients with acute ischemic stroke and ipsilateral significant extracranial carotid artery stenosis, and its effect in functional outcome

Background

Cerebral hemodynamics and collateral circulation have an important role in determining stroke outcome, while the role of primary collateral is well known, the role of secondary collaterals including ophthalmic artery flow is still controversial. Our aim was to evaluate the flow of ophthalmic artery in patients with acute ischemic stroke and significant extracranial carotid stenosis and assess its role on the functional outcome. Thirty patients with acute ischemic stroke and extracranial carotid stenosis were included from Ain Shams University hospitals, color coded duplex was used to assess extracranial carotid arteries, ophthalmic artery was assessed by transcranial color-coded duplex. According to ophthalmic artery flow patients were divided into two groups, one with forward and other with reversed flow. Modified Rankin Scale (MRS) after 3 months was compared between the two groups

Results

Reversed ophthalmic artery flow (ROAF) was seen among 10 (33.33%) patients. After 3 month MRS was better in ROAF group (1.5 ± 1.958) than forward ophthalmic artery flow (FOAF) group (2.1 ± 1.954) but with no statistical difference (p value 0.398); furthermore, the difference between MRS after 3 months and discharge was significant in ROAF group (p value 0.042).

Conclusions

Transcranial duplex is a noninvasive, safe method in determining ophthalmic artery flow; furthermore, ROAF could help in better stroke outcome.

Diagnosis of extracranial carotid stenosis by MRA of the brain

Severe extracranial carotid stenosis (SECS) patients may present with nonspecific neurological symptoms that require intracranial magnetic resonance imaging (MRI) and time-of-flight (TOF)-MR angiography (MRA) to exclude intracranial pathology. Recognition of SECS on intracranial TOF-MRA findings is beneficial to provide a prompt carotid imaging study and aggressive stroke prevention. Patients with SECS (January 2016 to May 2019) undergoing percutaneous transluminal angioplasty and stenting (PTAS) were included. Differences in normalized signal intensities (SR_ICA) and diameters (D_ICA) between bilateral petrous internal carotid arteries (ICAs) were calculated 1 cm from the orifice. A hypothesized criterion describing the opacification grades (G_OPH) of bilateral ophthalmic arteries was proposed. We correlated SR_ICA (p = 0.041), D_ICA (p = 0.001) and G_OPH (p = 0.012), with the severity of extracranial carotid stenosis on digital subtractive angiography (DSA) in the examined group (n = 113), and all showed statistical significance in predicting percentages of ICA stenosis. The results were further validated in another patient group with SECS after radiation therapy (n = 20; p = 0.704 between the actual and predicted stenosis grades). Our findings support the evaluation of the signal ratio and diameter of intracranial ICA on TOF-MRA to achieve early diagnosis and provide appropriate management of SECS.

Relationship between ophthalmic artery flow direction and visual deterioration after carotid angioplasty and stenting

OBJECTIVE

Visual deterioration is one of the disabling complications that can occur after carotid angioplasty and stenting (CAS). The purpose of this study was to evaluate the risk factors for newly developed visual symptoms after CAS, focusing on ophthalmic artery (OA) flow pattern and etiology of visual loss.

METHODS

A retrospective review of 127 patients with 138 internal carotid artery (ICA) stenosis lesions that were treated with CAS from February 2009 to October 2017 in a single institution was performed. The flow pattern of the OA was evaluated with digital subtraction angiography and classified into 3 types: type I, antegrade OA flow before and after CAS; type II, antegrade OA flow reversal after CAS; and type III, retained nonantegrade OA flow after CAS.

RESULTS

The degree of ipsilateral ICA stenosis was significantly higher in the nonantegrade group than that in the antegrade group (81.73% ± 9.87% vs 75.74% ± 10.27%, p = 0.001). Independent risk factors for newly developed visual symptoms after CAS were visual symptoms before CAS (OR 65.29, 95% CI 5.14-827.2; p = 0.001) and type III OA flow pattern (OR 55.98, 95% CI 2.88-1088.0; p = 0.008). The post-CAS visual symptoms in 10 patients were related to acute elevation of intraocular pressure in 6 patients and retinal artery occlusion in 3 patients.

CONCLUSIONS

Maintained retrograde or undetected OA flow after CAS and initial visual symptoms before CAS were related to post-CAS visual symptoms. Thus, careful attention is needed for these patients during the perioperative period, and immediate evaluation and management are required for patients with post-CAS visual loss.

Reversed ophthalmic artery flow following ischemic stroke: a possible predictor of outcomes following carotid artery stenting

Stroke is the leading cause of death worldwide and stenosis of the carotid artery accounts for more than half of all cases. Carotid duplex is an effective non-invasive ultrasound test which identifies stroke patients with moderate to severe carotid stenosis who are candidates for preventative intervention to reduce the risk of recurrence. In patients with moderate to severe carotid stenosis, reversed ophthalmic artery flow (ROAF) is often observed at the time of the carotid duplex scan. In this study, we investigated whether ROAF, denoting exhaustion of cerebral collateral flow in ischemic stroke patients affected mid-term functional outcomes following carotid artery stenting (CAS) procedures. In total, 144 consecutive patients with a first episode of ischemic stroke and subsequent CAS procedure conducted between January 2010 and November 2014 at Changhua Christian Hospital, Taiwan were included. Clinical data were obtained by medical record review. Disability was assessed at two time points by utilising the Barthel Index (BI) and modified Rankin Scale (mRS) before CAS and 12 months post-CAS. Among 85 patients presenting without ROAF, 48/85 (56.4%) had improved mRS scores following stenting. The condition remained unchanged (stationary) in 36/85 (43.5%) patients after stenting and one patient exhibited deteriorated condition 1/85(1.1%). In contrast, among the 59 patients presenting with ROAF, 24/59 (40.6%) had improved mRS score following stenting. The condition remained unchanged (stationary) in the remaining 35/59 (59.3%) patients after stenting, and no patient exhibited deteriorated condition 0/59 (0 %). This study provides evidence that CAS is a valid and effective treatment option regardless of whether patients exhibited ROAF or not. Patients without ROAF were significantly more likely to have improved mid-term functional outcomes compared to those with ROAF. In the group without ROAF admission, CRP may play a role in predicting subsequent functional outcomes, whereas admission Barthel Index was a predictor of outcome in the ROAF group.

Compensatory Vasodilator Mechanisms in the Ophthalmic Artery of Endothelial Nitric Oxide Synthase Gene Knockout Mice

Nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) plays an important role in the maintenance of ocular vascular homeostasis. Therefore, perturbations in vascular NO synthesis have been implicated in the pathogenesis of several ocular diseases. We recently reported that eNOS contributes significantly to vasodilation of the mouse ophthalmic artery. Interestingly, dilatory responses were also retained in eNOS gene-deficient mice (eNOS-/-), indicating inherent endothelial adaptive mechanism(s) that act as back-up systems in chronic absence of eNOS to preserve vasorelaxation. Thus, this study endeavoured to identify the compensatory mechanism(s) in the ophthalmic artery of eNOS-/- mice employing isolated arterial segments and pharmacological inhibitors in vitro. Endothelium removal virtually abolished acetylcholine (ACh)-induced vasodilation, suggesting an obligatory involvement of the endothelium in cholinergic control of vascular tone. However, non-NOS and non-cyclooxygenase components compensate for eNOS deficiency via endothelium-derived hyperpolarizing factors (EDHFs). Notably, arachidonic acid-derived metabolites of the 12-lipoxygenase pathway were key mediators in activating the inwardly rectifying potassium channels to compensate for chronic lack of eNOS. Conclusively, endothelium-dependent cholinergic responses of the ophthalmic artery in the eNOS-/- mice are largely preserved and, this vascular bed has the ability to compensate for the loss of normal vasodilator responses solely via EDHFs.

4D Flow MR Imaging of Ophthalmic Artery Flow in Patients with Internal Carotid Artery Stenosis

Background and Purpose:

To assess the clinical feasibility of time-resolved 3D phase contrast (4D Flow) MRI assessment of the ophthalmic artery (OphA) flow in patients with internal carotid artery stenosis (ICS).

Materials and Methods:

Twenty-one consecutive patients with unilateral ICS were recruited. 4D Flow MRI and acetazolamide-stress brain perfusion single photon emission computed tomography (SPECT) were performed. The flow direction on the affected-side OphA was categorized into native flow (anterograde or unclear) and non-native flow (retrograde flow) based on 4D Flow MRI. In the affected-side middle cerebral artery (MCA) territory, the ratio of rest cerebral blood flow to normal control (RCBF_MCA) and cerebral vascular reserve (CVR_MCA) were calculated from SPECT dataset. High-risk patients were defined based on the previous large cohort study (RCBF_MCA < 80% and CVR_MCA < 10%).

Results:

Eleven patients had native OphA flow (4 anterograde, 7 unclear) and the remaining 10 had non-native OphA flow. RCBF_MCA and CVR_MCA each were significantly lower in non-native flow group (84.9 ± 18.9% vs. 69.8 ± 7.3%, P < 0.05; 36.4 ± 20.6% vs. 17.0 ± 15.0%, P < 0.05). Four patients in the non-native flow group and none in the native flow group were confirmed as high-risk (Sensitivity/Specificity, 1.00/0.65).

Conclusion:

The 6 min standard 4D Flow MRI assessment of OphA in patients with ICS can predict intracranial hemodynamic impairment.

Is carotid sonography a useful tool for predicting functional capabilities in ischemic stroke patients following carotid artery stenting?

Carotid stenosis is a major cause of stroke and timely intervention with stenting manipulation can significantly reduce the risk of secondary stroke. The impact of stenting procedures on patient functional capabilities has not yet been explored. The primary aim of this study was to examine associations between periprocedural carotid sonography parameters and post-treatment functional capabilities in stroke patients.Sixty-seven patients who received carotid stenting at 1 angiography laboratory were included. Prestenting and poststenting carotid duplex data were recorded and resistance index (RI) differences at various carotid system locations were compared. The modified Rankin Scale (mRS) was used to assess functional capability. All of the studied parameters were analyzed by SPSS (version 16.0, SPSS Inc, Chicago, IL).Following stenting, mRS scores improved (n = 44) or remained stationary (n = 23). Net contralateral internal carotid artery (ICA) RI for patients with improved mRS was lower compared to that for patients with stationary mRS (median = 0.040 vs 0.11; P = 0.003). The contralateral common carotid artery RI before and after stenting differed significantly (P < 0.050) in both. The ipsilateral ICA RI differed (P < 0.050) only in patients with improved mRS. The difference in mean transit time, Barthel index, net ipsilateral ICA RI, net contralateral external carotid artery RI, postipsilateral common carotid artery RI, and postipsilateral ICA RI differed significantly between different baseline stroke severity groups (P < 0.050).Carotid artery stenting improved physical function in a proportion of ischemic stroke patients with carotid stenosis. Carotid ultrasound is a useful assessment tool to predict likely functional outcomes following carotid artery stenting.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS (P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow (P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Collateral Assessment by CT Angiography as a Predictor of Outcome in Symptomatic Cervical Internal Carotid Artery Occlusion

BACKGROUND AND PURPOSE

Cervical internal carotid artery occlusion can present with varied clinical manifestations such as transient ischemic attack, stroke, and chronic ocular ischemia, or can be asymptomatic. The outcome in these patients is considerably influenced by cerebral hemodynamic compensatory adaptation of the intracranial collateral pathways. Our aim was to study whether collateral circulation as assessed by CT angiography can predict 3-month outcome and initial stroke severity in patients with symptomatic cervical ICA occlusion.

MATERIALS AND METHODS

This was a retrospective study of 65 patients with symptomatic cervical ICA occlusion from January 2011 to December 2013. The collateral vessels (anterior and posterior communicating arteries, ophthalmic artery, and leptomeningeal arteries) were assessed by CTA. The outcome at 3 months was defined as poor if the modified Rankin Scale score was ≥3.

RESULTS

The mean age of subjects was 57 ± 11.6 years (range, 32-80 years), and 92% were men. Thirty-three (50.8%) patients had poor outcome. Absence of the ipsilateral ophthalmic artery, poor leptomeningeal collaterals, and <2 collaterals were predictors of stroke severity at onset and poor 3-month outcome in univariate analysis. In the multiple logistic regression analysis, inadequate flow through the secondary collaterals (ipsilateral ophthalmic artery or leptomeningeal collaterals; OR, 4.5; 95% CI, 1.4-14.9; P = .01) and higher NIHSS score at stroke onset (OR, 19.2; 95% CI, 2.2-166.2; P = .007) independently predicted poor outcome at 3 months.

CONCLUSIONS

Assessment of collateral circulation with CTA can be a useful predictor of 3-month outcome in patients with symptomatic cervical ICA occlusion.

Homozygous ALDH2*2 Is an Independent Risk Factor for Ischemic Stroke in Taiwanese Men

Background and Purpose—

The * 2 allele of the aldehyde dehydrogenase 2 gene (ALDH2 ) is the most common variant in Asian populations. The variant resulting in enzyme dysfunction was highly related to coronary artery disease. Recently, genome-wide association studies also discovered that the 12q24 locus near ALDH2 gene was associated with hypertension and ischemic stroke. This study intended to further investigate whether the above variant of ALDH2 increases the risk for ischemic stroke in Taiwanese.

Methods—

A case–control study was conducted on 914 patients with acute ischemic stroke and 746 nonstroke controls. Polymerase chain reaction and sequencing were used to identify the ALDH2 genotype. Vascular risk factors, stroke subtypes, vascular stenosis, and stroke outcomes were analyzed.

Results—

ALDH2 genotypes differed significantly between male controls (* 1/*1 versus * 1/*2 versus * 2/*2 =53.8% versus 39.9% versus 6.4%) and male patients with ischemic stroke (* 1/*1 versus * 1/*2 versus * 2/*2 =51.5% versus 37.3% versus 11.2%; P =0.048). No significant difference was found between groups for female patients ( P =0.228). Multivariate logistic regression analysis revealed that the ALDH2*2/*2 genotype was an independent risk factor for ischemic stroke in male patients (odds ratio, 1.93 [95% confidence interval, 1.07–3.46]; P =0.028). Further analysis of men with ischemic stroke demonstrated that the polymorphism of ALDH2 was not related to vascular risk factors, severity of vascular atherosclerosis, stroke subtypes, and stroke functional outcomes.

Conclusions—

The study demonstrated that ALDH2*2/*2 may be an independent risk factor for ischemic stroke in Taiwanese men, but not in Taiwanese women.

First-ever ischemic stroke in elderly patients: predictors of functional outcome following carotid artery stenting

Age is an important risk factor for stroke, and carotid artery stenosis is the primary cause of first-ever ischemic stroke. Timely intervention with stenting procedures can effectively prevent secondary stroke; however, the impact of stenting on various periprocedural physical functionalities has never been thoroughly investigated. The primary aim of this study was to investigate whether prestenting characteristics were associated with long-term functional outcomes in patients presenting with first-ever ischemic stroke. The secondary aim was to investigate whether patient age was an important factor in outcomes following stenting, measured by the modified Rankin scale (mRS). In total, 144 consecutive patients with first-ever ischemic stroke who underwent carotid artery stenting from January 2010 to November 2014 were included. Clinical data were obtained by review of medical records. The Barthel index (BI) and mRS were used to assess disability before stenting and at 12-month follow-up. In total, 72/144 patients showed improvement (mRS[+]), 71 showed stationary and one showed deterioration in condition (mRS[-]). The prestenting parameters, ratio of cerebral blood volume (1.41 vs 1.2 for mRS[-] vs mRS[+]), BI (75 vs 85), and high-sensitivity C-reactive protein (hsCRP 5.0 vs 3.99), differed significantly between the two outcome groups (P<0.05). The internal carotid artery/common carotid artery ratio (P=0.011), BI (P=0.019), ipsilateral internal carotid artery resistance index (P=0.003), and HbA1c (P=0.039) were all factors significantly associated with patient age group. There was no significant association between age and poststenting outcome measured by mRS with 57% of patients in the ≥75 years age group showing mRS(-) and 43% showing mRS(+) (P=0.371). Our findings indicate that in our elderly patient series, carotid artery stenting may benefit a significant proportion of carotid stenotic patients regardless of age. Ratio of cerebral blood volume, BI, and admission hsCRP could serve as important predictors of mRS improvement and may facilitate differentiation of patients at baseline.

Risk Factor Stratification for Intracranial Stenosis in Taiwanese Patients With Cervicocerebral Stenosis

BACKGROUND

Intracranial stenosis (ICS) is a major determinant of ischemic stroke in Asians. We determined the clinical significance of different risk factors and the role of ICS in Taiwanese patients with varied distributions of cervicocerebral stenosis.

METHODS AND RESULTS

Presence of extracranial carotid stenosis (ECS, ≥70%) and ICS (>50%) was examined in 13 539 patients using ultrasonography and magnetic resonance angiography, respectively. Seven hundred thirty-three patients with non-ECS/ICS (n=372), isolated ICS (n=112), isolated ECS (n=121), or combined ECS/ICS (CEIS, n=128) were selected. Prevalence of ischemic stroke in each group was compared, and risk factors for stenosis were determined. The area under the receiver operating characteristic curve for each risk factor was calculated. Prevalence of ischemic stroke was highest in patients with CEIS (odds ratio 15.86; P<0.001), followed in decreasing order by those with isolated ICS (odds ratio 7.16; P<0.001), isolated ECS (odds ratio 1.77; P=0.011), and non-ECS/ICS. Multivariate logistic regression analysis revealed that hypertension, coronary artery disease, and smoking were risk factors for isolated ECS; hypertension, diabetes mellitus, coronary artery disease, and smoking were risk factors for isolated ICS; and diabetes mellitus, coronary artery disease, and smoking were risk factors for CEIS. Smoking, diabetes mellitus, and coronary artery disease were the greatest contributors to CEIS, isolated ICS, and isolated ECS, respectively.

CONCLUSIONS

CEIS was associated with higher odds of ischemic stroke compared with isolated ICS and isolated ECS. Smoking and diabetes mellitus, major determinants of CEIS and isolated ICS, should be targeted in therapeutic strategies to reduce the risk of ischemic stroke.

Reversal of ophthalmic artery flow and stroke outcomes in Asian patients with acute ischemic stroke and unilateral severe cervical carotid stenosis

Background

The aim of this study was to assess the clinical implications of reversed ophthalmic artery flow (ROAF) for stroke risk and outcomes in subjects with unilateral severe cervical carotid stenosis/occlusion.

Methods

We investigated 128 subjects (101 with acute stroke and 27 without), selected from a large hospital patients base (n  =  14,701), identified with unilateral high-grade cervical carotid stenosis/occlusion by using duplex ultrasonography and brain magnetic resonance imaging. All clinical characteristics were compared for stroke risk between acute stroke and nonstroke groups. Patients with acute stroke were divided into 4 subgroups according to ophthalmic artery flow direction and intracranial stenosis severity, and stroke outcomes were evaluated.

Results

The acute stroke group had significantly higher percentages of ROAF (52.5%, p  =  0.003), carotid occlusion (33.7%, p  =  0.046), and severe intracranial stenosis (74.3%, p<0.001). However, multivariate analysis demonstrated that intracranial stenosis was the only significant risk factor (odds ratio  =  10.38; 95% confidence interval  =  3.64–29.65; p<0.001). Analysis of functional outcomes among the 4 subgroups of patients with stroke showed significant trends (p  =  0.018 to 0.001) for better stroke outcomes from ROAF and mild or no intracranial stenosis. ROAF improved 10–20% stroke outcomes, as compared to forward ophthalmic artery flow, among the patients with stroke and the same degree of severities of intracranial stenosis.

Conclusions

Patients with acute stroke and severe unilateral cervical carotid stenosis/occlusion significantly have high incidence of intracranial stenosis and ROAF. Intracranial stenosis is a major stroke risk indicator as well as a predictor for worse stroke outcomes, and ROAF may provide partial compensation for improving stroke outcomes.