Large-Vessel Occlusion Stroke: Effect of Recanalization on Outcome Depends on the National Institutes of Health Stroke Scale Score

Alternative Complement Pathway in Carotid Atherosclerosis: Low Plasma Properdin Levels Associate With Long-Term Cardiovascular Mortality

BACKGROUND

Complement activation may promote atherosclerosis. Yet, data on the to which extent complement, and more specifically the alternative complement pathway, is activated in patients with carotid atherosclerosis and related to adverse outcome in these patients, are scarce.

METHODS AND RESULTS

We measured, by ELISA, plasma levels of factor D, properdin, C3bBbP (C3 convertase), and factor H in patients with advanced carotid atherosclerosis in a Discovery (n=324) and in a Validation (n=206) cohort in relation to adverse outcome (mean follow-up 7.8 and 6.6 years, respectively). Our major findings were as follows. Compared with healthy controls, patients with carotid atherosclerosis had increased plasma levels of factor D, properdin, and C3bBbP (P<0.001), but not factor H, an inhibitor of the alternative complement pathway, compared with controls. Although patients with carotid atherosclerosis had elevated levels of properdin compared with controls, within these patients, low plasma levels of properdin (ie,

CONCLUSIONS

We show a strong and independent association of low plasma properdin levels with cardiovascular mortality in 2 cohorts. Conversely, the plaque properdin levels linked to features of plaque vulnerability, potentially reflecting increased deposition at the site of inflammation or local production of properdin in the atherosclerotic lesion indicating local enhanced alternative complement pathway activation.

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Key Words

• alternative complement pathway
• carotid atherosclerosis
• complement
• plaque vulnerability
• properdin
• stroke

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MESH Headings

• Humans
• Male
• Female
• Properdin/metabolism
• Properdin/analysis
• Carotid Artery Diseases/mortality
• Carotid Artery Diseases/blood
• Carotid Artery Diseases/immunology
• Middle Aged
• Complement Pathway, Alternative
• Aged
• Biomarkers/blood
• Risk Factors
• Prognosis
• Complement Factor D/metabolism
• Complement Factor D/analysis
• Case-Control Studies
• Time Factors
• Enzyme-Linked Immunosorbent Assay
• Complement Factor H/metabolism

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Grants

• South‐Eastern Norway Regional Health Authority
• Skåne University Hospital
• Swedish Society for Medical Research
• Swedish Stroke Association
• Swedish Foundation for Strategic Research
• Region Skåne

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Affiliation(s)

Mieke C. Louwe Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Chrysostomi Gialeli Department of Clinical Sciences MalmöLund UniversityLundSweden
Annika E. Michelsen Research Institute of Internal Medicine, Oslo University HospitalOsloNorway Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway
Sverre Holm Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Andreas Edsfeldt Department of Clinical Sciences MalmöLund UniversityLundSweden Department of CardiologyMalmö, Skåne University HospitalMalmöSweden Wallenberg Center for Molecular MedicineLund UniversityLundSweden
Karolina Skagen Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway Department of NeurologyOslo University Hospital RikshospitaletOsloNorway
Tove Lekva Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Maria Belland Olsen Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Vigdis Bjerkeli Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Therese Schjørlien Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway Department of NeurologyOslo University Hospital RikshospitaletOsloNorway
Kristine Stø Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway Department of NeurologyOslo University Hospital RikshospitaletOsloNorway
Xiang Yi Kong Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Tuva B. Dahl Research Institute of Internal Medicine, Oslo University HospitalOsloNorway
Per H. Nilsson Department of ImmunologyOslo University Hospital Rikshospitalet and University of OsloNorway Linnaeus Centre for Biomaterials ChemistryLinnaeus UniversityKalmarSweden
Peter Libby Division of Cardiovascular MedicineBrigham and Women’s Hospital, Harvard Medical SchoolBostonMAUSA
Pål Aukrust Research Institute of Internal Medicine, Oslo University HospitalOsloNorway Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway Section of Clinical Immunology and Infectious DiseasesOslo University Hospital RikshospitaletOsloNorway
Tom Eirik Mollnes Department of ImmunologyOslo University Hospital Rikshospitalet and University of OsloNorway Research LaboratoryNordland HospitalBodøNorway Centre of Molecular Inflammation ResearchNorwegian University of Science and TechnologyTrondheimNorway
Thor Ueland Research Institute of Internal Medicine, Oslo University HospitalOsloNorway Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway K. G. Jebsen Thrombosis Research and Expertise CenterUniversity of TromsøNorway
Mona Skjelland Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway Department of NeurologyOslo University Hospital RikshospitaletOsloNorway
Isabel Gonçalves Department of Clinical Sciences MalmöLund UniversityLundSweden Department of CardiologyMalmö, Skåne University HospitalMalmöSweden
Bente Halvorsen Research Institute of Internal Medicine, Oslo University HospitalOsloNorway Institute of Clinical Medicine, Faculty of Medicine, University of OsloNorway

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External validation of clinical risk prediction score for elderly treated with endovascular thrombectomy

BACKGROUND AND AIM

The thrombectomy in the elderly prediction score (TERPS) for functional outcome after anterior circulation endovascular therapy (EVT) in patients ≥ 80 years was recently developed. The aim of this study was to assess predictors of functional outcome in the elderly and validate the prediction model.

METHODS

Consecutive patients treated with EVT from the Oslo Acute Reperfusion Stroke Study were evaluated for inclusion. Clinical and radiological parameters were used to calculate the TERPS, and functional outcome were assessed at 3-month follow-up.

RESULTS

Out of 1028 patients who underwent EVT for acute ischemic stroke from January 2017 to July 2022, 218 (21.2%) patients ≥ 80 years with anterior ischemic stroke were included. Fair outcome, defined as modified Rankin scale ≤ 3 (mRS), was achieved in 117 (53.7%). In bivariate analyses, male sex (p 0.035), age (p 0.025), baseline National Institute of Health Stroke Scale (NIHSS, p < 0.001), pre-stroke mRS (p 0.002) and Alberta Stroke Program Early Computed Tomography score (ASPECTS, p 0.001) were associated with fair outcome. Significant predictors for fair outcome in regression analyses were lower pre-stroke mRS, adjusted odd ratio, (aOR) 0.67 (95% CI 0.50-0.91, p 0.01), NIHSS, aOR 0.92 (95% CI 0.87-0.97, p 0.002), and higher ASPECTS, aOR 1.22 (95% CI 1.03-1.44, p 0.023). The area under the curve (AUC) using TERPS was 0.74 (95% CI 0.67-0.80).

CONCLUSIONS

The risk prediction score TERPS showed moderate performance in this external validation. Other variables may still be included to improve the model and validation using other cohorts is recommended.

TRIAL REGISTRATION

NCT06220981.

Post-ASPECTS based on hyperdensity in NCCT immediately after thrombectomy is an ultra-early predictor of hemorrhagic transformation and prognosis

Background and Purpose

Almost half of the patients exhibit futile recanalization after thrombectomy; however, the early postoperative predictors of futile recanalization remain unclear. We analyzed the relationship of post-thrombectomy ASPECTS (Post-ASPECTS) with 90-day prognosis and hemorrhagic transformation (HT).

Methods

We collected data from patients with acute ischemic stroke (AIS) with anterior-circulation large vessel occlusion (ACLVO) who were treated via thrombectomy within 10 h in 3 hospitals. Successful endovascular recanalization was achieved (modified thrombolysis in cerebral ischemia [mTICI] 2b/3). Non-contrast computed tomography (NCCT) examination was performed immediately (within 1 h) after thrombectomy. Post-ASPECTS were scored based on the brain parenchymal hyperdensity in NCCT according to the ASPECTS scoring method. HT was defined according to the ECASS II classification criteria. Linear correlation, logistic regression, and receiver operating characteristic curve analyses were used to determine the influencing factors and best predictive value of 90-day prognosis, 90-day death, and HT.

Results

A total of 231 patients were enrolled. The good prognosis rate, mortality rate, and HT rate were 57.1, 9.5, and 38.3%, respectively. The Post-ASPECTS affected poor prognosis, death, and HT. The best predictive value of Post-ASPECTS for poor prognosis, death, and HT was 7. The specificities of Post-ASPECTS for predicting HT, poor prognosis, and death were 87.6% (AUC, 0.811; P &lt; 0.001), 87.1% (AUC, 0.768; P &lt; 0.001), and 73.7% (AUC, 0.748; P &lt; 0.001), with positive predictive values of 74.2, 75.7, and 21.4%, respectively.

Conclusion

Post-ASPECTS predicted 90-day prognosis, death, and HT with high specificity and high positive predictive value in patients with AIS with ACLVO. Post-ASPECTS may be an ultra-early predictor of prognosis after thrombectomy.

Nonatrial Fibrillation was Associated With Early Neurological Improvement After Intravenous Thrombolysis With rt-PA in Patients With Acute Ischemic Stroke

BACKGROUND

Intravenous thrombolysis is the only approved pharmacological treatment for acute ischemic stroke (AIS) patients, but the immediate response to thrombolysis varies by patient.

OBJECTIVE

To investigate the factors associated with early neurological improvement (ENI) after the administration of intravenous recombinant tissue plasminogen activator (rt-PA) treatment to AIS patients within 4.5 hours of onset.

METHODS

Demographics, onset to treatment time, risk factors, and clinical and laboratory data of 209 AIS patients undergoing intravenous rt-PA therapy at a Chinese hospital between January 2013 and August 2016 were retrospectively analyzed. The National Institutes of Health Stroke Scale (NIHSS) score was recorded before thrombolytic therapy, 24 hours after the treatment, and 7 days after the treatment to evaluate the recovery of neurological function. ENI was defined as a ≥4-point decrease in NIHSS score compared with baseline or a score of 0 or 1 at 24 hours and 7 days. A multivariate logistic regression analysis was performed to assess the outcomes.

RESULTS

Of the 209 AIS patients treated by intravenous thrombolysis with rt-PA, low-density lipoprotein (LDL) levels were significantly lower (P<0.05) in patients with ENI. The multivariable analysis showed that non-atrial fibrillation (AF) was independently associated with ENI at 24 hours and 7 days after thrombolysis. An overall 40.3% non-AF patients had ENI 24 hours after thrombolysis (odds ratio=2.501, 95% confidence interval: 1.204-5.198; P=0.014), and 65.9% non-AF patients had ENI 7 days after thrombolysis (odds ratio=2.953, 95% confidence interval: 1.434-6.081; P=0.003). Onset to treatment time was an independent predictor (P<0.05) for ENI at 7 days after thrombolysis. The NIHSS score and diastolic blood pressure on admission were associated with symptomatic intracerebral hemorrhagic transformation.

CONCLUSIONS

Non-AF was independently associated with ENI after intravenous thrombolysis in AIS patients, but non-AF was not associated with the occurrence of symptomatic intracerebral hemorrhage. Onset to treatment time was an independent predictor of ENI at 7 days after thrombolysis in AIS patients.

Qualitative Posttreatment Diffusion-Weighted Imaging as a Predictor of 90-day Outcome in Stroke Intervention

PURPOSE

The aim was to assess the ability of post-treatment diffusion-weighted imaging (DWI) to predict 90-day functional outcome in patients with endovascular therapy (EVT) for large vessel occlusion in acute ischemic stroke (AIS).

METHODS

We examined a retrospective cohort from March 2016 to January 2018, of consecutive patients with AIS who received EVT. Planimetric DWI was obtained and infarct volume calculated. Four blinded readers were asked to predict modified Rankin Score (mRS) at 90 days post-thrombectomy.

RESULTS

Fifty-one patients received endovascular treatment (mean age 65.1 years, median National Institutes of Health Stroke Scale (NIHSS) 18). Mean infarct volume was 43.7 mL. The baseline NIHSS, 24-hour NIHSS, and the DWI volume were lower for the mRS 0-2 group. Also, the thrombolysis in cerebral infarction (TICI) 2b/3 rate was higher in the mRS 0-2 group. No differences were found in terms of the occlusion level, reperfusion technique, or recombinant tissue plasminogen activator use. There was a significant association noted between average infarct volume and mRS at 90 days. On multivariable analysis, higher infarct volume was significantly associated with 90-day mRS 3-5 when adjusted to TICI scores and occlusion location (OR 1.01; CI 95% 1.001-1.03; p = 0.008). Area under curve analysis showed poor performance of DWI volume reader ability to qualitatively predict 90-day mRS.

CONCLUSION

The subjective impression of DWI as a predictor of clinical outcome is poorly correlated when controlling for premorbid status and other confounders. Qualitative DWI by experienced readers both overestimated the severity of stroke for patients who achieved good recovery and underestimated the mRS for poor outcome patients. Infarct core quantitation was reliable.

Cholesterol Crystals Induce Coagulation Activation through Complement-Dependent Expression of Monocytic Tissue Factor

Cholesterol crystals (CC) are strong activators of complement and could potentially be involved in thromboinflammation through complement-coagulation cross-talk. To explore the coagulation-inducing potential of CC, we performed studies in lepirudin-based human whole blood and plasma models. In addition, immunohistological examinations of brain thrombi and vulnerable plaque material from patients with advanced carotid atherosclerosis were performed using polarization filter reflected light microscopy to identify CC. In whole blood, CC exposure induced a time- and concentration-dependent generation of prothrombin fragment 1+2 (PTF1.2), tissue factor (TF) mRNA synthesis, and monocyte TF expression. Blocking Abs against TF abolished CC-mediated coagulation, thus indicating involvement of the TF-dependent pathway. Blockade of FXII by corn trypsin inhibitor had a significant inhibitory effect on CC-induced PTF1.2 in platelet-free plasma, although the overall activation potential was low. CC exposure did not induce platelet aggregation, TF microparticle induction, or TF on granulocytes or eosinophils. Inhibition of complement C3 by CP40 (compstatin), C5 by eculizumab, or C5aR1 by PMX53 blocked CC-induced PTF1.2 by 90% and reduced TF⁺ monocytes from 18-20 to 1-2%. The physiologic relevance was supported by birefringent CC structures adjacent to monocytes (CD14), TF, and activated complement iC3b and C5b-9 in a human brain thrombus. Furthermore, monocyte influx and TF induction in close proximity to CC-rich regions with activated complement were found in a vulnerable plaque. In conclusion, CC could be active, releasable contributors to thrombosis by inducing monocyte TF secondary to complement C5aR1 signaling.

Effect of routing paradigm on patient centered outcomes in acute ischemic stroke

Background

To compare performance of routing paradigms for patients with acute ischemic stroke using clinical outcomes.

Methods

We simulated different routing paradigms in a system comprising one primary stroke center (PSC) and one comprehensive stroke center (CSC), separated by distances representative of urban, suburban, and rural environments. In the nearest center paradigm, patients are initially sent to the nearest center, while in CSC first, patients are sent to the CSC. In the Rhode Island and distributive paradigms, patients with a FAST-ED (Facial palsy, Arm weakness, Speech changes, Time, Eye deviation, and Denial/neglect) score ≥4 are sent to the CSC, while others are sent to the nearest center or PSC, respectively. Performance and efficiency were compared using rates of good clinical outcome, determined by type and timing of treatment using clinical trial data, and number needed to bypass (NNB).

Results

Good clinical outcome was achieved in 43.76% of patients in nearest center, 44.48% in CSC first, and 44.44% in Rhode Island and distributive in an urban setting; 43.38% in nearest center, 44.19% in CSC first, and 44.17% in Rhode Island in a suburban setting; and 41.10% in nearest center, 43.20% in CSC first, and 42.73% in Rhode Island in a rural setting. In all settings, NNB was generally higher for CSC first compared with Rhode Island or distributive.

Conclusion

Routing paradigms that allow bypass of nearer hospitals for thrombectomy capable centers improve population level patient outcomes. Differences are more pronounced with increasing distance between hospitals; therefore, paradigm choice may be most impactful in rural settings. Selective bypass, as implemented in the Rhode Island and distributive paradigms, improves system efficiency with minimal impact on outcomes.

Ghost Infarct Core and Admission Computed Tomography Perfusion: Redefining the Role of Neuroimaging in Acute Ischemic Stroke

Background

Determining the size of infarct extent is crucial to elect patients for reperfusion therapies. Computed tomography perfusion (CTP) based on cerebral blood volume may overestimate infarct core on admission and consequently include ghost infarct core (GIC) in a definitive lesional area.

Purpose

Our goal was to confirm and better characterize the GIC phenomenon using CTP cerebral blood flow (CBF) as the reference parameter to determine infarct core.

Methods

We performed a retrospective, single-center analysis of consecutive thrombectomies of middle cerebral or intracranial internal carotid artery occlusions considering noncontrast CT Alberta Stroke Program Early CT Score ≥6 in patients with pretreatment CTP. We used the RAPID® software to measure admission infarct core based on initial CBF. The final infarct was extracted from follow-up CT. GIC was defined as initial core minus final infarct > 10 mL.

Results

A total of 123 patients were included. The median National Institutes of Health Stroke Scale score was 18 (13-20), the median time from symptoms to CTP was 188 (67-288) min, and the recanalization rate (Thrombolysis in Cerebral Infarction score 2b, 2c, or 3) was 83%. Twenty patients (16%) presented with GIC. GIC was associated with shorter time to recanalization (150 [105-291] vs. 255 [163-367] min, p = 0.05) and larger initial CBF core volume (38 [26-59] vs. 6 [0-27] mL, p < 0.001). An adjusted logistic regression model identified time to recanalization < 302 min (OR 4.598, 95% CI 1.143-18.495, p = 0.032) and initial infarct volume (OR 1.01, 95% CI 1.001-1.019, p = 0.032) as independent predictors of GIC. At 24 h, clinical improvement was more frequent in patients with GIC (80 vs. 49%, p = 0.01).

Conclusions

CTP CBF < 30% may overestimate infarct core volume, especially in patients imaged in the very early time window and with fast complete reperfusion. Therefore, the CTP CBF technique may exclude patients who would benefit from endovascular treatment.

Effect of routing paradigm on patient-centered outcomes in acute ischemic stroke

OBJECTIVE

To compare performance of routing paradigms for patients with acute ischemic stroke using clinical outcomes.

METHODS

We simulated different routing paradigms in a system comprising one primary stroke center (PSC) and onecomprehensive stroke center (CSC), separated by distances representative of urban, suburban, and rural environments. In the Nearest Center paradigm, patients are initially sent to the nearest center, while in CSC First, patients are sent to the CSC. In Rhode Island and Distributive paradigms, patients with Field Assessment Stroke Triage for Emergency Destination (FAST-ED) score ≥4 are sent to the CSC, while others are sent to the nearest center or PSC, respectively. Performance and efficiency were compared using rates of good clinical outcome determined by type and timing of treatment using clinical trial data and number needed to bypass (NNB).

RESULTS

Good clinical outcome was achieved in 43.67% of patients in Nearest Center and 44.62% in CSC First, Rhode Island, and Distributive in an urban setting; 42.79% in Nearest Center and 43.97% in CSC First and Rhode Island in a suburban setting; and 39.76% in Nearest Center, 41.73% in CSC First, and 41.59% in Rhode Island in a rural setting. In all settings, the NNB was considerably higher for CSC First than for Rhode Island or Distributive.

CONCLUSION

Routing paradigms that allow bypass of nearer hospitals for thrombectomy-capable centers improve population-level patient outcomes. Differences are more pronounced with increasing distance between hospitals; therefore, the choice of model may have greater effect in rural settings. Selective bypass, as implemented in Rhode Island and Distributive paradigms, improves system efficiency with minimal effect on outcomes.

Leukoaraiosis Attenuates Diagnostic Accuracy of Large-Vessel Occlusion Scales

BACKGROUND AND PURPOSE

Prehospital stroke scales may help identify patients likely to have large-vessel occlusion to facilitate rapid triage to thrombectomy-capable stroke centers. Scale misclassification may result in inaccurate decisions and possible harm. Pre-existing leukoaraiosis has been shown to attenuate the association between deficit type and stroke severity. We sought to determine whether leukoaraiosis affects the predictive ability of 5 commonly used large-vessel occlusion scales.

MATERIALS AND METHODS

We retrospectively analyzed 274 consecutive patients with stroke with available brain MR imaging and vessel imaging. We used the following large-vessel occlusion scales: the 3-Item Stroke Scale; Field Assessment Stroke Triage for Emergency Destination; Rapid Arterial Occlusion Evaluation; Vision, Aphasia, Neglect score; and Cincinnati Prehospital Stroke Severity Scale. For diagnostic scale accuracy, we assessed sensitivity, specificity, positive predictive value, negative predictive value, and κ. Multivariable logistic regression was used to determine the predictive ability of the scales after adjustment for leukoaraiosis and potential confounders.

RESULTS

In unadjusted analyses, all scales predicted the presence of large-vessel occlusion (n = 46, P < .01 each), though diagnostic accuracy was attenuated among patients with moderate-to-severe leukoaraiosis. After adjustment, the Field Assessment Stroke Triage for Emergency Destination (OR = 3.2; 95% CI, 1.1-9.5; P = .033) and Rapid Arterial Occlusion Evaluation (OR = 3.7; 95% CI, 1.3-10.8; P = .015), but not the 3-Item Stroke Scale (OR = 5.4; 95% CI, 0.86-33.9; P = .073), Vision, Aphasia, Neglect score (OR = 2.5; 95% CI, 0.8-7.2), and Cincinnati Prehospital Stroke Severity Scale (OR = 2.8; 95% CI, 1.0-8.0), predicted large-vessel occlusion.

CONCLUSIONS

The diagnostic accuracy of the tested large-vessel occlusion scales was attenuated in the presence of moderate-to-severe leukoaraiosis. This information that may aid the design of future studies that require large-vessel occlusion scale screening of patients who are likely to have concomitant leukoaraiosis.

Relationship between Post-Thrombolysis Blood Pressure and Outcome in Acute Ischemic Stroke Patients Undergoing Thrombolysis Therapy

BACKGROUND

The management of blood pressure (BP) for acute ischemic stroke (AIS) patients undergoing thrombolysis is still under debate. The purpose of this study was (1) to explore the association between post-thrombolysis BP and functional outcome and (2) to examine whether post-thrombolysis BP can predict functional outcome in Chinese AIS patients undergoing thrombolysis therapy.

METHODS

From December 2012 to November 2016, AIS patients undergoing thrombolysis were reviewed retrospectively in the Department of Neurology at Xuanwu Hospital. The BP levels were measured before and immediately after thrombolysis. Clinical outcomes, which comprised favorable outcome (modified Rankin Scale score 0-2) and unfavorable outcome (modified Rankin Scale score 3-6) at 3 months, were analyzed by logistic regression model. A receiver operating characteristic curve was used to evaluate the predictive value of post-thrombolysis BP.

RESULTS

Patients with unfavorable outcome at 3 months had a higher post-thrombolysis systolic BP than those with favorable outcome (P = .015). Multivariate analysis showed that post-thrombolysis systolic BP below 159.5 mm Hg was associated with favorable outcome. According to the receiver operating characteristic curve, post-thrombolysis systolic BP was a predictor of functional outcome with an area under the curve of .573 (95% confidence interval = .504-.642).

CONCLUSIONS

Our study indicated that post-thrombolysis systolic BP is a predictor of functional outcome for Chinese AIS patients undergoing thrombolysis therapy. It is reasonable for AIS patients to keep post-thrombolysis systolic BP below 159.5 mm Hg to obtain a favorable outcome.

Unstable carotid artery plaque: new insights and controversies in diagnostics and treatment

Cardiovascular disease is estimated to be the leading cause of death, globally causing 14 million deaths each year. Stroke remains a massive public health problem and there is an increasing need for better strategies for the prevention and treatment of this disease. At least 20% of ischemic strokes are thromboembolic in nature, caused by a thromboembolism from an atherosclerotic plaque at the carotid bifurcation or the internal carotid artery. Current clinical guidelines for both primary and secondary prevention of stroke in patients with carotid stenosis caused by atherosclerotic plaques remain reliant on general patient characteristics (traditional risk factors for stroke) and static measures of the degree of artery stenosis. Patients with similar traditional risk factors, however, have been found to have different risk of stroke, and it has in recent years become increasingly clear that the degree of artery stenosis alone is not the best estimation of stroke risk. There is a need for new methods for the assessment of stroke risk to improve risk prediction for the individual patient. This review aims to give an overview of new methods available for the identification of carotid plaque instability and the assessment of stroke risk.

Thrombolysis in Real Time: Demonstration of Revascularization with Intravenous Thrombolysis Therapy in the CT Scanner

BACKGROUND AND PURPOSE

Administration of intravenous tissue plasminogen activator (tPA) in the computed tomography (CT) scanner has been recently implemented at our institution, as a means to decrease door-to-needle time. This change in protocol provided us a unique opportunity to visualize imaging signs of early recanalization.

METHODS

We evaluated patients who presented with acute ischemic stroke both before and after a change in protocol for intravenous tPA administration. We identified 10 patients who received tPA on the CT scanner and 22 patients who received tPA after CT imaging was complete. Early recanalization was defined as distal migration of thrombus or disappearance of thrombus between initial phases of imaging, large territory of diminished mean transit time on initial perfusion CT, large territory of increased cerebral blood flow on initial perfusion CT, and/or large territory of increased cerebral blood volume on initial perfusion CT. Late recanalization was defined as distal migration of thrombus or disappearance of thrombus between initial and follow-up imaging, decreased attenuation of thrombus between initial and follow-up imaging, or infarcted territory on follow-up imaging smaller than the cerebral blood volume defect on initial perfusion CT.

RESULTS

In the patients who received tPA on the CT scanner, 20% demonstrated imaging evidence of early recanalization and 30% demonstrated imaging evidence of late recanalization. In the patients who received tPA after CT imaging, 57% demonstrated imaging evidence of late recanalization.

CONCLUSION

Early recanalization of large-vessel occlusion after intravenous thrombolysis results in unique imaging findings.

Predictors of Outcome and Hemorrhage in Patients Undergoing Endovascular Therapy with Solitaire Stent for Acute Ischemic Stroke

BACKGROUND

Endovascular mechanical thrombectomy is emerging as a promising therapeutic approach for acute ischemic stroke and show some advantages. However, the data of predicting clinical outcome after thrombectomy with Solitaire retriever were limited. We attempt to identify prognostic factors of clinical outcome in patients with acute ischemic stroke undergoing thrombectomy with Solitaire retriever.

METHODS

We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between December 2010 and December2013 where the Solitaire stent retriever was used for acute ischemic stroke. We assessed the effect of selected demographic characteristics, clinical factors on poor outcome at 3 months (modified Rankin score 3-6), mortality at 3 months, and hemorrhage within 24 h (symptomatic and asymptomatic). Clinical, imaging and logistic variables were analyzed. A multivariate logistic regression analysis was used to identify variables influencing clinical outcome, based on discharge NIHSS score change and mRS at 3 months.

RESULTS

Eighty nine consecutive patients with acute ischemic stroke underwent mechanical thrombectomy. Multivariate analysis revealed that admission NIHSS score, Serum glucose and endovascular procedure duration were independently associated with clinical outcome. Sex, NIHSS score at admission, diabetes and time of operation were associated with sICH in 1 day. NIHSS score ≥20 (OR 9.38; 95% CI 2.41-36.50), onset to reperfusion >5 hours (OR 5.23; 95% CI1.34,20.41) and symptomatic intracranial hemorrhage (OR 10.19; 95% CI1.80,57.83) were potential predictive factors of mortality at 3 months.

CONCLUSION

Multiple pre- and intra-procedural factors can be used to predict clinical outcome, symptomatic intracranial hemorrhage and mortality in acute ischemic stroke patients undergoing endovascular therapy. This knowledge is helpful for patients selection for endovascular mechanical thrombectomy.