Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging

A systematic review of the socioeconomic impact of mechanical thrombectomy for acute ischemic stroke

BACKGROUND

Mechanical Thrombectomy (MT) is an efficacious treatment for severe acute ischemic stroke patients. However, access to MT is limited in many parts of the world, partly due to economic barriers. The purpose of this systematic review is to provide an updated frame about the socioeconomic impact of MT.

METHODS

To carry out this systematic review we used the PRISMA guidelines. We included scientific articles analyzing the socioeconomic impact of MT for acute ischemic stroke, in which MT was compared to best medical therapy (BMT). The online databases of Pubmed, Scopus and Web of Science were used as main sources of information. To carry out the comparative analysis, the incremental cost-effectiveness ratio (ICER) was used, relating the cost to quality-adjusted life-year (QALY). Risk of bias was assessed with the Consensus Health Economic Criteria (CHEC) and the Consolidated Health Economic Evaluation Reporting Standards (CHEERS).

RESULTS

Eight hundred thirty-two studies were identified in this systematic review. As a result, studies that used cost-effectiveness analysis show that MT saves costs in the long term and cost-utility analysis show that the cost per QALY is reasonable with a mean ICER value of $14242.36/QALY.

CONCLUSIONS

MT has a favorable socioeconomic impact, as derived from cost-effectiveness and cost-utility analyses. Therefore, public policies should encourage the implementation of MT for stroke patients around the world.

Ischemic core volumes and collateral status have diurnal fluctuations - A retrospective cohort study of 18,137 patients

INTRODUCTION

Recent observations suggest that circadian rhythms are implicated in the timing of stroke onset and the speed of infarct progression. We aimed to replicate these observations in a large, multi-center, automated imaging database.

METHODS

The RAPID Insights database was queried from 02/01/2016 to 01/31/2022 for patients with perfusion imaging and automated detection of an ischemic stroke due to a presumed large vessel occlusion. Exclusion criteria included: patient age ≤25, mismatch volume of <0 cc, and failure to register a positive value on either relative cerebral blood flow (rCBF) reduction of 38% less than normal or total mismatch volume. Imaging time was subdivided into three epochs: Night: 23:00h-06:59h and Day: 07:00h-14:59h, and Evening: 15:00h-22:59h. Perfusion parameters were defined using standard conventions for core volume, penumbra, and collateral circulation (measured via the Hypoperfusion Intensity Ratio, HIR). Statistical significance was tested using a sinusoidal regression analysis.

RESULTS

A total of 18,137 cases were analyzed. The peak incidence of stroke imaging of patients with LVOs occurred around noon. A sinusoidal pattern was present, with larger ischemic core volumes and higher HIR during the night compared to the day: peak ischemic core volume of 23.4 cc occurred with imaging performed at 3:56 AM (p<0.001) and peak HIR of 0.35 at 3:40 AM (p<0.001).

CONCLUSION

We found that ischemic core volumes were larger and collateral status worse at nighttime compared to daytime in this large national database. These findings support prior data suggesting that poor collateral recruitment with subsequent larger ischemic stroke volumes may occur at night.

Clinical outcome and cost effectiveness of acute ischemic stroke transfers for endovascular reperfusion therapy from geographically distant counties: Stroke transfer outcomes

OBJECTIVES

Endovascular reperfusion therapy (EVT) for acute ischemic stroke (AIS) with large vessel occlusion (LVO) has resulted in increased patient transfers to comprehensive stroke centers (CSCs). Clinical outcomes including the financial impact of these transfers from geographically dispersed population are lacking. Hence, we studied outcomes and cost-effectiveness of stroke transfers from remote areas.

MATERIALS AND METHODS

We used a 3-year cohort of AIS patients transferred from geographically dispersed counties (<100 mi., 101-200 mi., and >200 mi.). A 3-month modified Rankin scale (mRS) score of 0-2 defined a favorable clinical outcome. Cost-effectiveness is studied by calculating the incremental cost effectiveness ratio, using hospital costs reimbursed data and utility-weighted (UW)-mRS.

RESULTS

Among 172 patients transferred for EVT, patients transferred from nearby counties were more likely to undergo intervention compared to other counties (56.9 % vs. 36.7 % vs. 49.2 % p = .11). Irrespective of proximity (in mi.) to CSC [21.5 (14-56.3)] vs. 185 (137-185) vs. 349 (325-355)], there was a similar delay (in min.) to arrival from all locations [321.5 (244-490), 366 (298-432), and 460 (385-554.5) respectively], but no statistically significant differences in favorable outcomes (18.0 %, 34.1 %, and 22.2 %, respectively, p = .41). Patients undergoing EVT had higher hospital costs reimbursed compared to non-EVT patients [$37,303 (25,745-40,658) vs. $14,008 (8,640-21,273) respectively, p < .001] and no statistically significant difference in UW-mRS [0.32 (0.06-0.56) vs. 0.06 (0-0.56), p = .30].

CONCLUSIONS

Our study identifies a need for targeted interventions to improve community awareness and optimize systems of care to improve outcomes and cost-effectiveness of EVT.

Ischemic core volume is associated with hemorrhagic transformation post endovascular thrombectomy

INTRODUCTION

Symtomatic hemorrhagic transformation(sHT) was defined as any intracerebral hemorrhage that combined with clinical deterioration. While recent studies showed low rates of sHT in large core ischemic strokes treated with endovascular thrombectomy (EVT), the specific impact of core size on overall hemorrhagic transformation (HT) remains unclear. We aim to investigate the relationship between ischemic core size and development of HT post thrombectomy.

METHODS

This prospective study enrolled acute ischemic stroke (AIS) patients with anterior large vessel occlusion undergoing EVT who had baseline MRI from 2017 to 2019. Pre-EVT Arterial Spin Labeling (ASL) and Diffusion-Weighted Imaging (DWI) scans were performed for volume calculations. Primary outcome was HT assessed within 72 h post EVT. Multivariable logistic regression was used to analyze the associations between baseline DWI and ASL volumes and HT occurrence. Discriminative ability for HT was compared using receiver operating curve analysis (c-statistic).

RESULTS

We included 101 patients (median age: 64 [IQR 56-74] years, baseline NIHSS 13 [IQR 9-16]). Median DWI and ASL volume were 21.0 ml [IQR 8.3-47.2] and 105 ml [59.5-172.9], respectively. 16.8 % recieved intravenous thrombolysis before EVT. HT occurred in 36.6 % of patients, including 16.8 % with sHT. Baseline DWI volume was independently associated with HT (OR = 1.030, 95 % CI 1.008 to 1.053, P = 0.009), while ASL volume wasn't statistically significant(P = 0.330). The DWI model was superior to ASL model in predicting HT within 72 h (c-statistic, 0.787).Neither DWI (P = 0.149) nor ASL volume (P = 0.834) effectively indicated sHT.

CONCLUSIONS

DWI-based ischemic core volume correlates significantly with HT within 72 h post successful thrombectomy. This highlights the potential clinical utility of DWI in guiding treatment decisions for this population.

The role of neutrophil and LDL-C levels in predicting intracranial hemorrhage following endovascular thrombectomy in patients with acute ischemic stroke

OBJECTIVES

To investigate the association between intracranial hemorrhage (ICH) and preoperative levels of neutrophils and low-density lipoprotein-cholesterol (LDL-C) in acute ischemic stroke (AIS) patients following endovascular thrombectomy (EVT), and to assess the predictive value of preoperative levels of neutrophils and LDL-C.

METHODS

A retrospective analysis was performed on the clinical records of patients diagnosed with AIS who underwent EVT at Nanchong Central Hospital between 2019 and 2023. Multivariate regression analysis was employed to examine the association of preoperative levels of neutrophils and LDL-C with the occurrence of ICH. Furthermore, a receiver operating characteristic curve was constructed to assess the predictive efficacy of these parameters.

RESULTS

A total of 300 patients with a mean age of 68.0 years (standard deviation, 11.1 years) and a median baseline National Institutes of Health Stroke scale (NIHSS) score of 15.5 (interquartile range, 12.0-19.75) were identified in this cohort. Of these, 28 (9.3%) patients experienced ICH. Multivariate regression analysis revealed that elevated preoperative neutrophil (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.10-1.38, P < 0.001) and LDL-C (OR 2.64, 95% CI 1.52-4.58, P < 0.001) levels were independently associated with ICH. The combined indicator demonstrated a higher area under the curve (AUC 0.759, 95% CI 0.654-0.865) compared with preoperative neutrophil (AUC 0.647, 95% CI 0.532-0.763) and LDL-C (AUC 0.711, 95% CI 0.607-0.814) levels individually.The specificity and sensitivity of the combined indicator were 67.9% and 83.1%, respectively.

CONCLUSIONS

Preoperative levels of neutrophils and LDL-C may serve as predictive indicators for ICH in patients with AIS who have undergone EVT; moreover, the combination of preoperative neutrophil and LDL-C levels demonstrates enhanced predictive efficacy.

Stroke Prevention and Treatment for Youth with Sickle Cell Anemia: Current Practice and Challenges and Promises for the Future

PURPOSE OF REVIEW

Sickle cell anemia (SCA) is an autosomal recessive inherited hemoglobinopathy that results in a high risk of stroke. SCA primarily affects an underserved minority population of children who are frequently not receiving effective, multi-disciplinary, preventative care. This article reviews primary and secondary stroke prevention and treatment for children with SCA for the general adult and pediatric neurologist, who may play an important role in providing critical neurologic evaluation and care to these children.

RECENT FINDINGS

Primary stroke prevention is efficacious at reducing ischemic stroke risk, but it is not consistently implemented into clinical practice in the United States, resulting in these children remaining at high risk. Acute symptomatic stroke management requires neurology involvement and emergent transfusion to limit ischemia. Furthermore, while chronic transfusion therapy is a proven secondary preventative modality for those with prior symptomatic or silent cerebral infarcts, it carries significant burden. Newer therapies (e.g., stem cell therapies and voxelotor) deserve further study as they may hold promise in reducing stroke risk and treatment burden. Effective primary and secondary stroke prevention and treatment remain a challenge. Informing and engaging neurology providers to recognize and provide critical neurologic evaluation and treatment has potential to close care gaps.

Ensemble machine learning to predict futile recanalization after mechanical thrombectomy based on non-contrast CT imaging

OBJECTIVES

Despite successful recanalization after Mechanical Thrombectomy (MT), approximately 25 % of patients with Acute Ischemic Stroke (AIS) due to Large Vessel Occlusion (LVO) show unfavorable clinical outcomes, namely Futile Recanalization (FR). We aimed to use a Machine Learning (ML) Non-Contrast brain CT (NCCT) imaging predictive model to identify FR in patients undergoing MT.

MATERIALS & METHODS

Between July 2022 and December 2022, 70 consecutive patients with LVO undergoing a complete recanalization (eTICI 3) with MT within 8 h from onset at our Centre were analyzed. Two NCCT images per patient of middle cerebral artery vascular territory and patients' clinical characteristics were classified by the presence of ischemic features on 24 h NCCT after MT. Each slice was segmented with "Mazda" software ver.4.6 by placing a Region Of Interest (ROI) on the whole brain by two radiologists in consensus. A total of 381 features were extracted for each slice. The dataset was split into train and test set with a 70:30 ratio.

RESULTS

Eleven classification models were trained. An Ensemble Machine Learning (EML) model was obtained by averaging the predictions of models with accuracy on a test set >70 %, with and without patients' clinical characteristics. The EML model combined with clinical data showed an accuracy of 0.76, a sensitivity of 0.88, a specificity of 0.69 with a NPV of 0.90, a PPV of 0.64, with AUC of 0.84.

CONCLUSION

NCCT and ML analysis shows promise in predicting FR after complete recanalization following MT in AIS patients. Larger studies are required to confirm these preliminary results.

Endovascular thrombectomy vs best medical management for late presentation acute ischaemic stroke with large vessel occlusion without CT perfusion or MR imaging selection: A systematic review and meta-analysis

BACKGROUND

The efficacy and safety of endovascular thrombectomy (EVT) beyond 6 hours from stroke onset for patients with large vessel occlusion (LVO) selected without CT perfusion(CTP) or MR imaging(MRI) is undetermined. We conducted a systematic review and meta-analysis of the current literature comparing outcomes for late presenting patients with LVO treated by best medical management (BMM) with those selected for EVT based only on non-contrast CT(NCCT)/CT angiography(CTA) (without CTP or MRI).

METHODS

PRISMA guidelines were employed. The primary outcome was functional independence (modified Rankin Scale 0-2) at 3 months. Secondary outcomes were symptomatic intracranial haemorrhage (sICH) and mortality at 3 months. Data were analysed using the random-effects model.

RESULTS

Six studies of 2083 patients, including three randomised controlled trials, were included; 1271 patients were treated with EVT and 812 patients with BMM. Compared to BMM, patients treated with EVT demonstrated higher odds of achieving functional independence (39.0 % EVT vs 22.0 % BMM; OR = 2.55, 95 %CI 1.61-4.05,p < 0.0001, I2 = 74 %). The rates of sICH (OR = 2.09, 95 %CI 0.86-5.04,p = 0.10) and mortality (OR = 0.62, 95 %CI 0.35-1.10,p = 0.10) were not significantly different between each cohort.

CONCLUSION

Compared to BMM, late presenting stroke patients selected for EVT eligibility with NCCT/CTA only and treated with EVT achieved significantly higher rates of functional independence at 90 days, without increasing the incidence of sICH or mortality. Whilst these findings indicate that NCCT/CTA only may be used for EVT eligibility selection for patients who present beyond 6 hours from stroke onset, the results should be interpreted with caution due to the substantial heterogeneity between studies.

Success with incrementally faster times to endovascular therapy (SWIFT-EVT): A systematic review and meta-analysis

BACKGROUND

A major systematic review and meta-analysis assessing trial data through 2014 (the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials, HERMES) demonstrated that particularly over the initial six hours of acute ischemic stroke (AIS), rapid performance of endovascular therapy (EVT) markedly improves outcomes. The current analysis, Success with Incrementally Faster Times to EVT (SWIFT-EVT), aimed to provide an updated metric summarizing latest estimates for modified Rankin Scale (mRS) improvements accrued by streamlining time to EVT.

METHODS

A systematic review and meta-analysis was conducted using electronic databases. Eligible studies reported a time-benefit slope with times from AIS onset (or time last known normal) to EVT commencement; the predictor was onset-to-groin (OTG) time. Primary and secondary outcomes were 90-day functional independence (mRS 0-2) and 90-day excellent function (mRS 0-1), respectively.

RESULTS

Five studies were included. Results showed increased change of good outcome with each hour of pre-EVT time savings for mRS 0-2 for 0-270' (OR 1.25, 95 % CI 1.16-1.35, I2 40 %) and 271-360' time frame (1.22, 95 % CI 1.12-1.33, I2 58 %). For the studies assessing mRS 0-1, estimates were found appropriate for both the 0-270' time frame (OR 1.34, 95 % CI 1.19-1.51, I2 27 %) and the 271-360' time frame (OR 1.20, 95 % CI 1.03-1.38, I2 60 %).

CONCLUSIONS

Each hour saved from AIS onset to EVT start is associated with a 22-25 % increased odds of achieving functional independence, a useful metric to inform patient-specific and systems planning decisions.

Adaptive Trials in Stroke: Current Use and Future Directions

Inclusion of adaptive design features in a clinical trial provides preplanned flexibility to dynamically modify a trial during its conduct while preserving validity and integrity. Adaptive trials are needed to accelerate the conduct of more efficient, informative, and ethical clinical research in the field of neurology. Stroke is a natural candidate for adoption of these innovative approaches to trial design. This Research Methods in Neurology article is informed by a scoping review that identified 45 completed or ongoing adaptive clinical trials in stroke that were appraised: 15 trials had published results with or without a published protocol and 30 ongoing trials (14 trials had a published protocol, and 16 trials were registered only). Interventions spanned acute (n = 28), rehabilitation (n = 8), prevention (n = 8), and rehabilitation and prevention (n = 1). A subsample of these trials was selected to illustrate the utility of adaptive design features and discuss why each adaptive feature was incorporated in the design to best achieve the aim; whether each individual feature was used and whether it resulted in expected efficiencies; and any learnings during preparation, conduct, or reporting. We then discuss the operational, ethical, and regulatory considerations that warrant careful consideration during adaptive trial planning and reflect on the workforce readiness to deliver adaptive trials in practice. We conclude that adaptive trials can be designed, funded, conducted, and published for a wide range of research questions and offer future directions to support adoption of adaptive trial designs in stroke and neurologic research more broadly.

Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study

BACKGROUND

Intracranial hemorrhage (ICH) is a potentially severe complication of endovascular thrombectomy (EVT). However, the relationship between the incidence and severity of ICH and vascular occlusion location is not well described.

OBJECTIVE

To present a comprehensive analysis of subtypes of ICHs and their relationship to the occlusion site following EVT in the anterior circulation.

METHODS

All patients with anterior circulation vessel occlusion stroke (internal carotid (ICA) and middle cerebral artery's first (M1) and later segments (M2 and beyond)) registered in the two Swedish national quality registers for stroke care and endovascular therapy during 2015-2020 were included. Hemorrhagic complications identified on imaging within 36 hours post-EVT were classified according to Heidelberg Bleeding Classification and further divided into symptomatic (sICH) or non-symptomatic (non-sICH).

RESULTS

Of the 3077 patients, ICH frequency was 24.2%, which included 4.5% sICH. Subarachnoid hemorrhage (SAH) was the most frequent subtype of hemorrhage (10.9%). The hemorrhagic subtypes differed significantly by occlusion site, but the frequency of any bleed did not. EVT performed in and beyond the M2 more often resulted in SAH, frequently classified as non-sICH. EVT performed in the ICA was associated with more severe hemorrhages, such as intraventricular and large parenchymal hematomas, that were more often classified as sICH.

CONCLUSION

In this nationwide unselected EVT cohort we found that ICH severity significantly differed between different vessel occlusion sites.

Effects of reperfusion grade and reperfusion strategy on the clinical outcome: Insights from ESCAPE-NA1 trial

BACKGROUND

We evaluated the association of reperfusion quality and different patterns of achieved reperfusion with clinical and radiological outcomes in the ESCAPE NA1 trial.

METHODS

Data are from the ESCAPE-NA1 trial. Good clinical outcome [90-day modified Rankin Scale (mRS) 0-2], excellent outcome (90-day mRS0-1), isolated subarachnoid hemorrhage, symptomatic hemorrhage (sICH) on follow-up imaging, and death were compared across different levels of reperfusion defined by expanded Treatment in Cerebral Infarction (eTICI) Scale. Comparisons were also made between patients with (a) first-pass eTICI 2c3 reperfusion vs multiple-pass eTICI 2c3; (b) final eTICI 2b reperfusion vs eTICI 2b converted-to-eTICI 2c3; (c) sudden reperfusion vs gradual reperfusion if >1 pass was required. Multivariable logistic regression was used to test associations of reperfusion grade and clinical outcomes.

RESULTS

Of 1037 included patients, final eTICI 0-1 was achieved in 46 (4.4%), eTICI 2a in 76 (7.3%), eTICI 2b in 424 (40.9%), eTICI 2c in 284 (27.4%), and eTICI 3 in 207 (20%) patients. The odds for good and excellent clinical outcome gradually increased with improved reperfusion grades (adjOR ranging from 5.7-29.3 and 4.3-17.6) and decreased for sICH and death. No differences in outcomes between first-pass versus multiple-pass eTICI 2c3, eTICI 2b converted-to-eTICI 2c3 versus unchanged eTICI 2b and between sudden versus gradual eTICI 2c3 reperfusion were observed.

CONCLUSION

Better reperfusion degrees significantly improved clinical outcomes and reduced mortality, independent of the number of passes and whether eTICI 2c3 was achieved suddenly or gradually.

Comprehensive analysis of the impact of procedure time and the 'golden hour' in subpopulations of stroke thrombectomy patients

OBJECTIVE

To evaluate the effect of procedure time on thrombectomy outcomes in different subpopulations of patients undergoing endovascular thrombectomy (EVT), given the recently expanded indications for EVT.

METHODS

This multicenter study included patients undergoing EVT for acute ischemic stroke at 35 centers globally. Procedure time was defined as time from groin puncture to successful recanalization (Thrombolysis in Cerebral Infarction score ≥2b) or abortion of procedure. Patients were stratified based on stroke location, use of IV tissue plasminogen activator (tPA), Alberta Stroke Program Early CT score, age group, and onset-to-groin time. Primary outcome was the 90-day modified Rankin Scale (mRS) score, with scores 0-2 designating good outcome. Secondary outcome was postprocedural symptomatic intracranial hemorrhage (sICH). Multivariate analyses were performed using generalized linear models to study the impact of procedure time on outcomes in each subpopulation.

RESULTS

Among 8961 patients included in the study, a longer procedure time was associated with higher odds of poor outcome (mRS score 3-6), with 10% increase in odds for each 10 min increment. When procedure time exceeded the 'golden hour', poor outcome was twice as likely. The golden hour effect was consistent in patients with anterior and posterior circulation strokes, proximal or distal occlusions, in patients with large core infarcts, with or without IV tPA treatment, and across age groups. Procedures exceeding 1 hour were associated with a 40% higher sICH rate. Posterior circulation strokes, delayed presentation, and old age were the variables most sensitive to procedure time.

CONCLUSIONS

In this work we demonstrate the universality of the golden hour effect, in which procedures lasting more than 1 hour are associated with worse clinical outcomes and higher rates of sICH across different subpopulations of patients undergoing EVT.

The presence of a ghost infarct core is associated with fast core growth in acute ischemic stroke

INTRODUCTION

The overestimation of ischemic core volume by CT perfusion (CTP) is a critical concern in the selection of candidates for reperfusion therapy. This phenomenon is termed a ghost infarct core (GIC). Core growth rate (CGR) is an indicator of ischemic severity. We aimed to elucidate the association between GIC and CGR.

PATIENTS AND METHODS

Consecutive patients with acute ischemic stroke who underwent mechanical thrombectomy in our institute from March 2017 to July 2022 were enrolled. The initial ischemic core volume (IICV) was measured by pretreatment CTP, and the final infarct volume (FIV) was measured by diffusion-weighted imaging. A GIC was defined by IICV minus FIV > 10 ml. The CGR was calculated by dividing the IICV by the time from onset to CTP. Univariable analysis and a multivariable logistic regression model were used to evaluate the association between GIC-positive and CGR.

RESULTS

Of all 91 patients, 21 (23.1%) were GIC-positive. The GIC-positive group had higher CGR (14.2 [2.6-46.7] vs 4.8 [1.6-17.1] ml/h, p = 0.02) and complete recanalization (n = 15 (71.4%) vs 29 (41.4%), p = 0.02) compared to the GIC-negative group. On receiver-operating characteristic curve analysis, the optimal cutoff point of CGR to predict GIC-positive was 22 ml/h (sensitivity, 0.48; specificity, 0.85; AUC, 0.67). Multivariable logistic regression analysis showed that CGR ⩾ 22 ml/h (OR 6.44, 95% CI [1.59-26.10], p = 0.01) and complete recanalization (OR 3.72, 95% CI [1.14-12.08], p = 0.02) were independent predictors of GIC-positive.

CONCLUSIONS

A GIC was associated with fast CGR in acute ischemic stroke. Overestimation of the initial ischemic core may be determined by core growth speed.

Endovascular thrombectomy after anterior circulation large vessel ischemic stroke: an updated meta-analysis

BACKGROUND

Endovascular thrombectomy (EVT) has emerged as the established standard of care for the treatment of anterior circulation large-vessel occlusion (LVO). However, its benefits remain unclear in specific patient populations. Herein, we present an updated systematic review and meta-analysis aimed at thoroughly assessing the effectiveness and safety of combining EVT with medical treatment (MT) compared with MT alone.

METHODS

This systematic review was performed in accordance with the PRISMA guideline. The MEDLINE, Embase, and Cochrane databases were systematically searched to identify relevant articles published until December 30, 2023. The inclusion criteria restricted articles to randomized clinical trials (RCTs). We pooled odds ratios (OR) and their respective 95% confidence intervals (CIs).

RESULTS

Fifteen RCTs involving 3897 patients were included in the study. EVT plus MT was associated with a significant reduction in disability at 90 days (OR = 1.91, [1.61-2.26]), improved functional independence (modified Rankin Scale [mRS] 0-2) (OR = 2.19 [1.81-2.64]), excellent functional outcomes (mRS 0-1) (OR = 2.37, [1.45-3.87]), improved independent ambulation (mRS 0-3) (OR = 2.17, [1.75-2.69]), and higher rates of partial/complete recanalization (OR = 2.18, [1.66-2.87] compared with EVT. Efficacy outcomes for both large and small infarct cores were statistically favorable following EVT. Safety outcomes showed comparable rates, except for intracerebral and subarachnoid hemorrhage, which favored MT alone.

CONCLUSION

This meta-analysis supports the use of EVT plus MT as the standard of care for acute ischemic stroke patients with LVO of any infarct core size, as it offers substantial improvements in functional outcomes and recanalization. Safety considerations, particularly the risk of hemorrhage, warrant careful patient selection. These findings provide valuable insights for optimizing stroke management protocols and enhancing patient outcomes.

Multicenter clinical trial evaluating the safety and efficacy of mechanical thrombectomy using the Versi Retriever

BACKGROUND

This study aimed to elucidate the safety and efficacy of mechanical thrombectomy using the Versi Retriever in patients with acute ischemic stroke (AIS).

METHODS

This was a prospective, multicenter, single-arm study conducted at 10 institutes in Japan from December 2018 to March 2021 on mechanical thrombectomy using the Versi Retriever in patients with AIS. The primary efficacy outcome was the modified Rankin scale (mRS) 0-2 at 90 days after the procedure. The primary safety outcome was mortality within 90 days after the procedure.

RESULTS

Fifty-eight patients with a mean age of 72.7 years were enrolled in the study. The primary efficacy outcome of mRS 0-2 at 90 days was 62.0% (95% CI 47.2-75.3%) in patients within 8 hours of stroke onset. The rate of immediate reperfusion of Thrombolysis in Cerebral Infarction (TICI) grade 2b-3 using the Versi Retriever in three passes was 78.0% (64.0-88.5%). The rate of final reperfusion of TICI 2b-3 was 100% (92.9-100%). The primary safety outcome of mortality within 90 days was 8.0% (2.2-19.2%) in patients within 8 hours of AIS onset. The incidence of intracranial hemorrhage within 24 hours was 12.0% (4.5-24.3%) for symptomatic cases and 32.0% (19.5-46.7%) for asymptomatic cases.

CONCLUSION

The Versi Retriever proved to be a safe and effective option for mechanical thrombectomy in patients with AIS.

CT Perfusion imaging as prognostic factor for outcome of lacunar stroke

BACKGROUND

Early neurological deterioration (END) affects 20-30% of patients with lacunar stroke within 48 h despite optimal treatment. Previously established markers included infection and infarct location on imaging. We studied the utility of measuring global cerebral blood flow (gCBF) measured by CT-Perfusion (CTP) as an early predictor of END in patients with lacunar strokes.

METHODS

162 patients with lacunar stroke were measured for gCBF including both cerebral hemispheres and cerebellum. We stratified patients by normal gCBF (> 40 ml/100 mg/min) vs. low gCBF (< 40 ml/100 mg/min). Stroke location, vascular risk factors, age and gender were assessed. The primary outcome was the change in the NIHSS score after 48 h from index stroke.

RESULTS

Mean gCBF of the overall cohort was 37.72 ml/100 mg/min. Both groups had a baseline NIHSS score of 4.2 with similar standard deviations. The NIHSS score decreased by 1.3 points in normal gCBF group and increased by 1.1 points in the low gCBF group. All stroke sites deteriorated in the low gCBF group, particularly the capsula interna, corona radiata, and lateral pontine area. END occurred in 37.8% in low gCBF compared to 3.1% in the normal gCBF patients. In contrast, clinical improvement after 48 h occurred in 64.2% of patients with normal gCBF but only 6.1% with low gCBF.

CONCLUSION

Our study supports measurement of gCBF by CTP as a potential imaging biomarker for END. Additionally, it adds evidence to the body of supporting the vulnerability of capsula interna and pontine infarctions to END.

The move to 24/7 mechanical thrombectomy provision for ischaemic stroke: an observational study of the impact on referrals, activity, procedural efficacy, and safety at a supra-regional centre

BACKGROUND

Health systems are striving to improve delivery of mechanical thrombectomy (MT) for ischaemic stroke. With the move to 24/7 provision, we aimed to assess (1) the change in referral and procedural frequency and timing, (2) reasons referrals did not proceed to MT, and (3) nocturnal procedural efficacy and safety.

METHODS

This was an observational study comparing 12-month data for an extended daytime service (2021/2022, hours, 0800-2000) to that for a 12-month period delivering 24/7 cover (2023-2024). Nocturnal and daytime outcomes (rate of recanalisation using modified TICI scoring), extent of postprocedural infarction (using ASPECTS grading), rate of early neurological improvement (using 24-h NIHSS change), 90-day mortality, and complicating symptomatic intracranial haemorrhage (SICH) in the latter period were compared.

RESULTS

Both referrals (432 to 851) and procedural caseload (191 to 403) approximately doubled with the move to 24/7 cover; 36% of procedures occurred overnight (n = 145). The dominant reasons for referrals not proceeding to MT were a large core infarct (n = 144) or absence of a large vessel occlusion on baseline imaging (n = 140). There were no significant differences in successful recanalisation (TICI 2B/3: 85.5% vs 87.1%, P = .233), rates of postprocedural ASPECTS≥7 (74.9% vs 75.8%, P = .987), early neurological improvement (NIHSS reduction ≥30%: 43.4% vs 42.4%, P = .917), 90-day mortality (19.6% vs 18.6%, P = .896), or SICH (1.9% vs 4.1%, P = .214) obtained for daytime vs nighttime hours.

CONCLUSION

24/7 MT provision has resulted in a rapid rise in the number of patients who may benefit from MT. This service can be provided with an acceptable safety profile during nighttime hours in a high-volume comprehensive UK centre.

Dual Energy CT for Deep Learning-Based Segmentation and Volumetric Estimation of Early Ischemic Infarcts

Ischemic changes are not visible on non-contrast head CT until several hours after infarction, though deep convolutional neural networks have shown promise in the detection of subtle imaging findings. This study aims to assess if dual-energy CT (DECT) acquisition can improve early infarct visibility for machine learning. The retrospective dataset consisted of 330 DECTs acquired up to 48 h prior to confirmation of a DWI positive infarct on MRI between 2016 and 2022. Infarct segmentation maps were generated from the MRI and co-registered to the CT to serve as ground truth for segmentation. A self-configuring 3D nnU-Net was trained for segmentation on (1) standard 120 kV mixed-images (2) 190 keV virtual monochromatic images and (3) 120 kV + 190 keV images as dual channel inputs. Algorithm performance was assessed with Dice scores with paired t-tests on a test set. Global aggregate Dice scores were 0.616, 0.645, and 0.665 for standard 120 kV images, 190 keV, and combined channel inputs respectively. Differences in overall Dice scores were statistically significant with highest performance for combined channel inputs (p < 0.01). Small but statistically significant differences were observed for infarcts between 6 and 12 h from last-known-well with higher performance for larger infarcts. Volumetric accuracy trended higher with combined inputs but differences were not statistically significant (p = 0.07). Supplementation of standard head CT images with dual-energy data provides earlier and more accurate segmentation of infarcts for machine learning particularly between 6 and 12 h after last-known-well.

Thrombectomy for patients with a large infarct core: a study-level meta-analysis with trial sequential analysis

Background

The effectiveness and safety of endovascular treatment compared with medical management alone regarding outcomes for patients with a large infarct core remain uncertain.

Objectives

To juxtapose the clinical outcomes of thrombectomy versus the best medical care in patients with a large infarct core.

Design

Systematic review and meta-analysis.

Data sources and methods

We conducted searches in PubMed, Cochrane, and Embase for articles published up until November 8, 2023. Randomized trials were selected for inclusion if they encompassed patients with large vessel occlusion and sizable strokes receiving thrombectomy. The primary outcome was functional outcomes at 3 months after pooling data using random-effects modeling. Safety outcomes included mortality at 3 months, symptomatic intracranial hemorrhage (SICH), and decompressive craniectomy. We performed a trial sequential analysis to balance type I and II errors.

Results

From 904 citations, we identified six randomized trials, involving a cohort of 1897 patients with a large ischemic region. Of these, 953 individuals underwent endovascular thrombectomy. At 3 months, thrombectomy was significantly correlated with better neurological prognosis, as evidenced by the increased odds of good functional outcomes (odds ratio (OR), 2.90; 95% confidence interval (CI), 2.08-4.05) and favorable functional outcomes (OR, 2.40; 95% CI, 1.86-3.09). Mortality rates did not demonstrably diminish as a consequence of the endovascular management (OR, 0.78; 95% CI, 0.58-1.06). However, the incidence of SICH was greater in the thrombectomy group compared to those with only medical treatment (5.5% vs 3.2%; OR, 1.77; 95% CI, 1.11-2.83). The application of trial sequential analysis yielded definitive evidence regarding favorable function outcomes and a shift in the distribution of modified Rankin scale scores at 3 months; however, others remained inconclusive.

Conclusion

The results from most of the included trials display consistency. Meta-analysis of these six randomized trials offers high-quality evidence that thrombectomy significantly mitigates disability in patients with a large infarction, while also increasing the risk of SICH.

Trial registration

PROSPERO, CRD42023480359.

Utility of automated CT perfusion software in acute ischemic stroke with large and medium vessel occlusion

BACKGROUND

Early diagnosis of large vessel occlusion (LVO) in acute stroke often requires CT angiography (CTA). Automated CT perfusion (CTP) software, which identifies blood flow abnormalities, enhances LVO diagnosis and patient selection for endovascular thrombectomy (EVT). This study evaluates the sensitivity of automated CTP images in detecting perfusion abnormalities in patients with acute ischemic stroke (AIS) and LVO or medium vessel occlusion (MeVO), compared to CTA.

METHODS

We screened acute ischemic stroke patients presenting within 24 h who underwent CT, CTA, and CTP as per institutional protocol. RAPID AI software processed CTP images, while neuroradiologists reviewed CTA for intracranial arterial occlusions. Sensitivity, specificity, and accuracy of automated CTP maps in detecting occlusions were assessed.

RESULTS

Of 790 screened patients, 31 were excluded due to lack of RAPID CTP data or poor-quality scans, leaving 759 for analysis. The median age was 71 years (IQR: 61-81), with 47% female. Among them, 678 had AIS, and 81 had AIS ruled out. CTA identified arterial occlusion in 562 patients (74%), with corresponding CTP abnormalities in 537 patients (Tmax > 6 sec). In the 197 without occlusion, CTP was negative in 161. Automated CTP maps had a sensitivity of 95.55% (CI 95: 93.50-97.10%), specificity of 81.73% (CI 95: 75.61-86.86%), negative predictive value of 98.22% (CI 95: 97.39-98.79%), positive predictive value of 63.54% (CI 95: 56.46-70.09%), and overall accuracy of 85.18% (CI 95: 82.45-87.64%).

CONCLUSIONS

Automated CTP maps demonstrated high sensitivity and negative predictive value for LVOs and MeVOs, suggesting their usefulness as a rapid diagnostic tool, especially in settings without expert neuroradiologists.

Stroke: Evolution of newer treatment modalities for acute ischemic stroke

Acute ischemic stroke is one of the leading causes of morbidity and mortality worldwide. Restoration of cerebral blood flow to affected ischemic areas has been the cornerstone of therapy for patients for eligible patients as early diagnosis and treatment have shown improved outcomes. However, there has been a paradigm shift in the management approach over the last decade, and with the emphasis currently directed toward including newer modalities such as neuroprotection, stem cell treatment, magnetic stimulation, anti-apoptotic drugs, delayed recanalization, and utilization of artificial intelligence for early diagnosis and suggesting algorithm-based management protocols.

Evaluating post-thrombectomy effective connectivity changes in anterior circulation stroke

OBJECTIVE

Granger causal analysis (GCA) and amplitude of low-frequency fluctuation (ALFF) are commonly used to evaluate functional alterations in brain disorders. By combining the GCA and ALFF, this study aimed to investigate the effective connectivity (EC) changes in patients with acute ischemic stroke (AIS) and anterior circulation occlusion after mechanical thrombectomy (MT).

METHODS

Resting-state functional magnetic resonance imaging (rs-fMRI) data were collected from 43 AIS patients with anterior circulation occlusion within 1 week post-MT and 37 healthy controls. ALFF and GCA were calculated for each participant. Patients were further divided into groups based on prognosis and perfusion levels. The differences in ALFF and EC were compared between AIS patients and healthy controls and between subgroups of patients. Pearson correlations between EC, ALFF values, and clinical characteristics of patients were calculated.

RESULTS

Compared to healthy controls, post-MT, AIS patients exhibited significant ALFF increases in the left precuneus and decreases in the left fusiform gyrus and right caudate. Increased EC from the contralesional lingual gyrus, contralesional putamen, ipsilesional thalamus, and contralesional thalamus to the contralesional caudate was obsrved, while decrease in EC were found for contralesional caudate to the ipsilesional thalamus and medial superior frontal gyrus. EC differences were particularly notable between perfusion groups, with significantly lower EC in the poorly perfused group. EC values were also positively correlated with National Institutes of Health Stroke Scale (NIHSS) scores pre-MT.

INTERPRETATION

In AIS patients, the caudate nucleus was central to the observed EC changes post-MT, characterized by decreased outputs and increased inputs. These changes indicate functional remodeling within the cortico-basal ganglia-thalamic-cortical pathway.

Deep Learning Denoising Improves CT Perfusion Image Quality in the Setting of Lower Contrast Dosing: A Feasibility Study

BACKGROUND AND PURPOSE

Considering recent iodinated contrast shortages and a focus on reducing waste, developing protocols with lower contrast dosing while maintaining image quality through artificial intelligence is needed. This study compared reduced iodinated contrast media and standard dose CTP acquisitions, and the impact of deep learning denoising on CTP image quality in preclinical and clinical studies. The effect of reduced X-ray mAs dose was also investigated in preclinical studies.

MATERIALS AND METHODS

Twelve swine underwent 9 CTP examinations each, performed at combinations of 3 different x-ray (37, 67, and 127 mAs) and iodinated contrast media doses (10, 15, and 20 mL). Clinical CTP acquisitions performed before and during the iodinated contrast media shortage and protocol change (from 40 to 30 mL) were retrospectively included. Eleven patients with reduced iodinated contrast media dosages and 11 propensity-score-matched controls with the standard iodinated contrast media dosages were included. A residual encoder-decoder convolutional neural network (RED-CNN) was trained for CTP denoising using k-space-weighted image average filtered CTP images as the target. The standard, RED-CNN-denoised, and k-space-weighted image average noise-filtered images for animal and human studies were compared for quantitative SNR and qualitative image evaluation.

RESULTS

The SNR of animal CTP images decreased with reductions in iodinated contrast media and milliampere-second doses. Contrast dose reduction had a greater effect on SNR than milliampere-second reduction. Noise-filtering by k-space-weighted image average and RED-CNN denoising progressively improved the SNR of CTP maps, with RED-CNN resulting in the highest SNR. The SNR of clinical CTP images was generally lower with a reduced iodinated contrast media dose, which was improved by the k-space-weighted image average and RED-CNN denoising (P < .05). Qualitative readings consistently rated RED-CNN denoised CTP as the best quality, followed by k-space-weighted image average and then standard CTP images.

CONCLUSIONS

Deep learning-denoising can improve image quality for low iodinated contrast media CTP protocols, and could approximate standard iodinated contrast media dose CTP, in addition to potentially improving image quality for low milliampere-second acquisitions.

Quantification of Infarct Core Volume in Patients with Acute Ischemic Stroke Using Cerebral Metabolic Rate of Oxygen in CT Perfusion

BACKGROUND AND PURPOSE

The cerebral metabolic rate of oxygen (CMRO2) is considered a robust marker of the infarct core in 15O-tracer-based PET. We aimed to delineate the infarct core in patients with acute ischemic stroke by using commonly used relative CBF (rCBF) < 30% and oxygen metabolism parameter of CMRO2 on CT perfusion in comparison with pretreatment DWI-derived infarct core volume.

MATERIALS AND METHODS

Patients with acute ischemic stroke who met the inclusion criteria were recruited. The CMRO2 and CBF maps in CT perfusion were automatically generated by using postprocessing software. The infarct core volume was quantified with relative cerebral metabolic rate of oxygen (rCMRO2) <20% -30% and rCBF <30%. The optimal threshold was defined as those that demonstrated the smallest mean absolute error, lowest mean infarct core volume difference, narrowest 95% limit of agreement, and largest intraclass correlation coefficient (ICC) against the DWI.

RESULTS

This study included 76 patients (mean age ± standard deviation, 69.97 ± 12.15 years, 43 men). The optimal thresholds of rCMRO2 <26% resulted in the lowest mean infarct core volume difference, narrowest 95% limit of agreement, and largest ICC among different thresholds. Bland-Altman analysis demonstrated a volumetric bias of 1.96 mL between DWI and rCMRO2 <26%, whereas in cases of DWI and rCBF <30%, the bias was notably larger at 14.10 mL. The highest correlation was observed for rCMRO2 <26% (ICC = 0.936), whereas rCBF <30% showed a slightly lower ICC of 0.934.

CONCLUSIONS

CT perfusion-derived CMRO2 is a promising parameter for estimating the infarct core volume in patients with acute ischemic stroke.

Decreased Quantitative Cerebral Blood Volume Is Associated With Poor Outcomes in Large Core Patients

BACKGROUND

Recent large core trials have highlighted the effectiveness of mechanical thrombectomy (MT) in acute ischemic stroke with large vessel occlusion. Variable perfusion-imaging thresholds and poor Alberta Stroke Program Early Computed Tomography Score reliability underline the need for more standardized, quantitative ischemia measures for MT patient selection. We aimed to identify the computed tomography perfusion parameter most strongly associated with poor outcomes in patients with acute ischemic stroke-large vessel occlusion with significant ischemic cores.

METHODS

In this study from 2 comprehensive stroke centers from 2 comprehensive stroke centers within the Johns Hopkins Medical Enterprise (Johns Hopkins Hospita-East Baltimore and Bayview Medical Campus) from July 29, 2019 to January 29, 2023 in a continuously maintained database, we included patients with acute ischemic stroke-large vessel occlusion with ischemic core volumes defined as relative cerebral blood flow <30% and ≥50 mL on computed tomography perfusion or Alberta Stroke Program Early Computed Tomography Score <6. We used receiver operating characteristics to find the optimal cutoff for parameters like cerebral blood volume (CBV) <34%, 38%, 42%, and relative cerebral blood flow >20%, 30%, 34%, 38%, and time-to-maximum >4, 6, 8, and 10 seconds. The primary outcome was unfavorable outcomes (90-day modified Rankin Scale score 4-6). Multivariable models were adjusted for age, sex, diabetes, baseline National Institutes of Health Stroke Scale, intravenous thrombolysis, and MT.

RESULTS

We identified 59 patients with large ischemic cores. A receiver operating characteristic curve analysis showed that CBV<42% ≥68 mL is associated with unfavorable outcomes (90-day modified Rankin Scale score 4-6) with an area under the curve of 0.90 (95% CI, 0.82-0.99) in the total and MT-only cohorts. Dichotomizing at this CBV threshold, patients in the ≥68 mL group exhibited significantly higher relative cerebral blood flow, time-to-maximum >8 and 10 seconds volumes, higher CBV volumes, higher HIR, and lower CBV index. The multivariable model incorporating CBV<42% ≥68 mL predicted poor outcomes robustly in both cohorts (area under the curve for MT-only subgroup was 0.87 [95% CI, 0.75-1.00]).

CONCLUSIONS

CBV<42% ≥68 mL most effectively forecasts poor outcomes in patients with large-core stroke, confirming its value alongside other parameters like time-to-maximum in managing acute ischemic stroke-large vessel occlusion.

Hypoperfusion index ratio and pretreatment with intravenous thrombolysis are independent predictors of good functional outcome in acute ischemic stroke patients with large vessel occlusion treated with acute reperfusion therapies

INTRODUCTION

We aimed to investigate the performance of several neuroimaging markers provided by perfusion imaging of Acute Ischemic Stroke (AIS) patients with large vessel occlusion (LVO) in order to predict clinical outcomes following reperfusion treatments.

METHODS

We prospectively evaluated consecutive AIS patients with LVO who were treated with reperfusion therapies, during a six-year period. In order to compare patients with good (mRS scores 0-2) and poor (mRS scores 3-6) functional outcomes, data regarding clinical characteristics, the Alberta Stroke Programme Early Computed Tomography Score (ASPECTS) based on unenhanced computed tomography (CT), CT angiography collateral status and perfusion parameters including ischemic core, hypoperfusion volume, mismatch volume between core and penumbra, Tmax > 10 s volume, CBV index and the Hypoperfusion Index Ratio (HIR) were assessed.

RESULTS

A total of 84 acute stroke patients with LVO who met all the inclusion criteria were enrolled. In multivariable logistic regression models increasing age (odds ratio [OR]: 0.93; 95%CI: 0.88-0.96, p = 0.001), lower admission National Institute of Health Stroke Scale (NIHSS)-score (OR: 0.88; 95%CI: 0.80-0.95, p = 0.004), pretreatment with intravenous thrombolysis (OR: 3.83; 95%CI: 1.29-12.49, p = 0.019) and HIR (OR:0.36; 95%CI: 0.10-0.95, p = 0.042) were independent predictors of good functional outcome at 3 months. The initial univariable associations between HIR and higher likelihood for symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2 (PH2) were attenuated in multivariable analyses failing to reach statistical significance.

DISCUSSION

Our pilot observational study of unselected AIS patients with LVO treated with reperfusion therapies demonstrated that pre-treatment low HIR in perfusion imaging and IVT were associated with better functional outcomes.

Sex differences in Wake-Up Stroke patients characteristics and outcomes

OBJECTIVES

Wake-up Stroke (WUS) accounts for about 25% of all ischemic strokes. Differences according to sex in the WUS subgroup has been poorly investigated so far, so we aimed to assess these differences by differentiating the enrolled population based on treatment administered.

MATERIALS & METHODS

We retrospectively analysed clinical and imaging data of WUS patients admitted to our hospital between November 2013 and December 2018 dividing them in two groups: rTPA-treated and non-rTPA treated group. To point out outcome differences we evaluated: NIHSS at 7 days or at discharge, mRS at discharge and ΔNIHSS.

RESULTS

We enrolled 149 WUS patients, 74 rTPA treated and 75 non-rTPA treated. Among rTPA treated patients, time from last known well (LKW) to Emergency Department (ED) admission was longer in females than males (610 vs 454 min), while females had a higher ΔNIHSS than males (5 vs 3). Finally, among non-rTPA treated patients, females were older than males (85 vs 79 years), had a higher pre-admission mRS (although very low in both cases), had a longer length of stay (17 vs 13 days) and shown a higher NIHSS at discharge (4 vs 2) compared to males.

CONCLUSIONS

Females not receiving thrombolytic treatment had worse functional outcome than males, showing a higher NIHSS at discharge but, in contrast, when treated with rTPA they showed better neurological recovery as measured by a greater ΔNIHSS. We emphasize the importance of a prompt recognition of WUS in females since they seem to benefit more from rTPA treatment.

Longitudinal changes in the US emergency department use of advanced neuroimaging in the mechanical thrombectomy era

PURPOSE

To describe ED neuroimaging trends across the time-period spanning the early adoption of endovascular therapy for acute stroke (2013-2018).

MATERIALS AND METHODS

We performed a retrospective, cross-sectional study of ED visits using the 2013-2018 National Emergency Department Sample, a 20% sample of ED encounters in the United States. Neuroimaging use was determined by Common Procedural Terminology (CPT) code for non-contrast head CT (NCCT), CT angiography head (CTA), CT perfusion (CTP), and MRI brain (MRI) in non-admitted ED patients. Data was analyzed according to sampling weights and imaging rates were calculated per 100,000 ED visits. Multivariate logistic regression analysis was performed to identify hospital-level factors associated with imaging utilization.

RESULTS

Study population comprised 571,935,906 weighted adult ED encounters. Image utilization increased between 2013 and 2018 for all modalities studied, although more pronounced in CTA (80.24/100,000 ED visits to 448.26/100,000 ED visits (p < 0.001)) and CTP (1.75/100,000 ED visits to 28.04/100,000 ED visits p < 0.001)). Regression analysis revealed that teaching hospitals were associated with higher odds of high CTA utilization (OR 1.88 for 2018, p < 0.05), while low-volume EDs and public hospitals showed the reverse (OR 0.39 in 2018, p < 0.05).

CONCLUSIONS

We identified substantial increases in overall neuroimaging use in a national sample of non-admitted emergency department encounters between 2013 and 2018 with variability in utilization according to both patient and hospital properties. Further investigation into the appropriateness of this imaging is required to ensure that access to acute stroke treatment is balanced against the timing and cost of over-imaging.

Effect of coastal and island geographic environments on patients with acute ischemic stroke in southeastern China

OBJECTIVE

To analyze the geographic variation in characteristics and treatment processes of patients with acute ischemic stroke (AIS) in coastal, island, and inland regions.

METHODS

We conducted a retrospective, cross-sectional analysis of data from patients with AIS in southeastern China. We collected demographic and clinical information, including the time from stroke onset to treatment for those receiving reperfusion therapy, using a time-tracking table.

RESULTS

Among 8069 patients with AIS, 26.6% received reperfusion therapy, with a higher proportion undergoing endovascular therapy in maritime hospitals than in inland hospitals (14.2% vs. 6.7%). Maritime hospitals had a higher prevalence of atrial fibrillation (15.1% vs. 11.9%) and cardioembolism (17.2% vs. 13.6%) than inland hospitals. Patients in maritime hospitals had shorter in-hospital processing times than those in inland hospitals (39 vs. 46 minutes). Island hospitals showed different patterns, with a shorter time from stroke onset to emergency room arrival (80 vs. 120 minutes) but a longer in-hospital process time (51 vs. 36 minutes), than coastline hospitals.

CONCLUSIONS

Our study suggests geographic variation in AIS characteristics and treatment processes across southeastern China, emphasizing the need for region-specific strategies. These findings are essential for tailoring public health policies and guidelines to improve stroke outcomes in various regions.

Outcomes of Mechanical Thrombectomy for Patients With Stroke Presenting With Low Alberta Stroke Program Early Computed Tomography Score in Early and Late Time Windows

BACKGROUND AND OBJECTIVES

This study aimed to compare outcomes of low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) patients with stroke who underwent mechanical thrombectomy (MT) within 6 hours or 6 to 24 hours after stroke onset.

METHODS

A retrospective cohort study was conducted using data from a large multicenter international registry from 2013 to 2023. Patients with low ASPECTS (2-5) who underwent MT for anterior circulation intracranial large vessel occlusion were included. A propensity matching analysis was conducted for patients presented in the early (<6 hours) vs late (6-24 hours) time window after symptom onset or last known normal.

RESULTS

Among the 10 229 patients who underwent MT, 274 met the inclusion criteria. 122 (44.5%) patients were treated in the late window. Early window patients were older (median age, 74 years [IQR, 63-80] vs 66.5 years [IQR, 54-77]; P < .001), had lower proportion of female patients (40.1% vs 54.1%; P = .029), higher median admission National Institutes of Health Stroke Scale score (20 [IQR, 16-24] vs 19 [IQR, 14-22]; P = .004), and a higher prevalence of atrial fibrillation (46.1% vs 27.3; P = .002). Propensity matching yielded a well-matched cohort of 84 patients in each group. Comparing the matched cohorts showed there was no significant difference in acceptable outcomes at 90 days between the 2 groups (odds ratio = 0.90 [95% CI = 0.47-1.71]; P = .70). However, the rate of symptomatic ICH was significantly higher in the early window group compared with the late window group (odds ratio = 2.44 [95% CI = 1.06-6.02]; P = .04).

CONCLUSION

Among patients with anterior circulation large vessel occlusion and low ASPECTS, MT seems to provide a similar benefit to functional outcome for patients presenting <6 hours or 6 to 24 hours after onset.

Neuroserpin and Extracellular Vesicles in Ischemic Stroke: Partners in Neuroprotection?

Ischemic stroke represents a significant global health challenge, often resulting in death or long-term disability, particularly among the elderly, where advancing age stands as the most unmodifiable risk factor. Arising from the blockage of a brain-feeding artery, the only therapies available to date aim at removing the blood clot to restore cerebral blood flow and rescue neuronal cells from death. The prevailing treatment approach involves thrombolysis by administration of recombinant tissue plasminogen activator (tPA), albeit with a critical time constraint. Timely intervention is imperative, given that delayed thrombolysis increases tPA leakage into the brain parenchyma, causing harmful effects. Strategies to preserve tPA's vascular benefits while shielding brain cells from its toxicity have been explored. Notably, administering neuroserpin (Ns), a brain-specific tPA inhibitor, represents one such approach. Following ischemic stroke, Ns levels rise and correlate with favorable post-stroke outcomes. Studies in rodent models of focal cerebral ischemia have demonstrated the beneficial effects of Ns administration. Ns treatment maintains blood-brain barrier (BBB) integrity, reducing stroke volume. Conversely, Ns-deficient animals exhibit larger stroke injury, increased BBB permeability and enhanced microglia activation. Furthermore, Ns administration extends the therapeutic window for tPA intervention, underscoring its potential in stroke management. Remarkably, our investigation reveals the presence of Ns within extracellular vesicles (EVs), small membrane-surrounded particles released by all cells and critical for intercellular communication. EVs influence disease outcome following stroke through cargo transfer between cells. Clarifying the role of EVs containing NS could open up urgently needed novel therapeutic approaches to improve post-ischemic stroke outcome.

Ischemic core detection threshold of computed tomography perfusion (CTP) in acute stroke

PURPOSE

This study aimed to determine the accuracy of detecting ischemic core volume using computed tomography perfusion (CTP) in patients with suspected acute ischemic stroke compared to diffusion-weighted magnetic resonance imaging (DW-MRI) as the reference standard.

METHODS

This retrospective monocentric study included patients who underwent CTP and DW-MRI for suspected acute ischemic stroke. The ischemic core size was measured at DW-MRI. The detectability threshold volume was defined as the lowest volume detected by each method. Clinical data on revascularization therapy, along with the clinical decision that influenced the choice, were collected. Volumes of the ischemic cores were compared using the Mann-Whitney U test.

RESULTS

Of 83 patients who underwent CTP, 52 patients (median age 73 years, IQR 63-80, 36 men) also had DW-MRI and were included, with a total of 70 ischemic cores. Regarding ischemic cores, only 18/70 (26%) were detected by both CTP and DW-MRI, while 52/70 (74%) were detected only by DW-MRI. The median volume of the 52 ischemic cores undetected on CTP (0.6 mL, IQR 0.2-1.3 mL) was significantly lower (p < 0.001) than that of the 18 ischemic cores detected on CTP (14.2 mL, IQR 7.0-18.4 mL). The smallest ischemic core detected on CTP had a volume of 5.0 mL. Among the 20 patients with undetected ischemic core on CTP, only 10% (2/20) received thrombolysis treatment.

CONCLUSIONS

CTP maps failed in detecting ischemic cores smaller than 5 mL. DW-MRI remains essential for suspected small ischemic brain lesions to guide a correct treatment decision-making.

Comparison of Telemedicine-Administered Thrombolytic Therapy for Acute Ischemic Stroke by Neurology Subspecialty: A Cross-Sectional Study

Background and Purpose

To determine if any difference exists in safety and outcomes of thrombolytic therapy for acute ischemic stroke administered via telemedicine, based on the subspeciality of the treating neurologist.

Methods

We performed a retrospective cross-sectional study using data from our local stroke registry of thrombolytic therapy administered via telemedicine at our rural stroke network over 5 years. The cohort was divided in 2 groups based on the subspecialty of the treating neurologist: vascular neurology (VN) and neurocritical care (NCC). Demographics, clinical characteristics, stroke metrics, thrombolytic complications, and final diagnosis were reviewed. In-hospital mortality and mRS and 30 days were noted.

Results

Among 142 patients who received thrombolytic therapy via telemedicine, 44 (31%) were treated by VN specialists; 98 (69%) by NCC specialist. There was no difference in baseline characteristics and stroke metrics between the 2 groups. Compared to NCC, VN had a trend toward higher, but non-significant, sICH (6% vs 1%, P = 0.05). In a logistic regression analysis, correcting for NIHSS, SBP, door-to-needle time, and use of antiplatelet therapy, the type of neurology subspecialty was not independently associated with development of sICH (OR: 0.141, SE: 0.188, P = 0.141). The rate of in-hospital mortality was also similar between VN and NCC (7% vs 5%, P = 0.8). In a model that accounted for stroke severity, no association was established between the type of neurology subspecialty and mRS at 30 days (OR: 1.589, SE: 0.662, P = 0.266).

Conclusions

Safety and outcome of thrombolytic therapy via telemedicine was not influenced by the subspecialty of treating neurologist. Our study supports the expansion of telemedicine for acute stroke patients in rural and underserved areas.

Association of Systemic Inflammatory Response Index and Neutrophil-to-Lymphocyte Ratio on Unfavorable Functional Outcomes in Acute Ischemic Stroke Patients After Endovascular Therapy

BACKGROUND

Inflammatory markers for the prognosis of acute ischemic stroke (AIS) with endovascular therapy remain unclear. The purpose of this study was to investigate the association between the systemic inflammatory response index (SIRI) and neutrophil-to-lymphocyte ratio (NLR) with unfavorable functional outcomes at 90-day in individuals of AIS who underwent endovascular therapy.

METHODS

A total of 128 AIS patients who had endovascular therapy were enrolled from the Nanjing Stroke Registry between September 2019 and November 2022. Peripheral venous blood was collected from patients within 24 h of admission for information on the following parameters: neutrophil count, lymphocyte count, and monocyte count. Then, the SIRI and NLR values were calculated and the association among SIRI, NLR, and modifled Rankin Scale scores 90 days after endovascular therapy was examined via univariate and multivariate logistic analyses. Receiver operating characteristic curves were utilized to determine the best threshold for SIRI and NLR in predicting negative neurological outcomes following endovascular treatment for patients with AIS.

RESULTS

A total of 128 participants were evaluated, among which 50% had unfavorable outcomes. Linear regression analysis showed that the best threshold for SIRI was >1.407 (odds ratio = 1.265; 95% confidence interval, 1.071-1.493; P = 0.006), and for NLR it was >5.347 (odds ratio = 1.088; 95% confidence interval, 1.007-1.175; P = 0.033). These results revealed NLR and SIRI as significant predictors of unfavorable outcomes at 90 days. The area under the curve for SIRI and NLR in predicting 90-day adverse outcomes was 0.643 and 0.609, respectively.

CONCLUSIONS

Higher SIRI and NLR levels at admission may lead to unfavorable outcomes at 90 days for AIS patients with endovascular therapy.

Ten-year trends, disparities, and clinical impact of stroke thrombectomy and thrombolysis: A single center experience 2012-2021

OBJECTIVES

As indications for acute ischemic stroke treatment expand, it is unclear whether disparities in treatment utilization and outcome still exist. The main objective of this study was to investigate disparities in acute ischemic stroke treatment and determine impact on outcome.

MATERIALS AND METHODS

Retrospective observational cohort study of consecutive ischemic stroke admissions to a comprehensive stroke center from 2012-2021 was performed. Primary exposure was intravenous thrombolysis and/or endovascular thrombectomy. Primary end points were discharge modified Rankin Scale, home disposition, and expired/hospice. Multivariable logistic regression analyses were conducted to elucidate disparities in treatment utilization and determine impact on outcome.

RESULTS

Of 517,615 inpatient visits, there were 7,540 (1.46 %) ischemic stroke admissions, increasing from 1.14 % to 1.79 % from 2012-2021. Intravenous thrombolysis significantly decreased from 14.4 % to 9.8 % while endovascular thrombectomy significantly increased from 0.8 % to 10.5 %. Both intravenous thrombolysis and endovascular thrombectomy increased odds of discharge home and modified Rankin Scale 0-2, and thrombectomy decreased odds of expired/hospice. After adjusting for covariates, decreased odds of thrombectomy was associated with Medicaid insurance (Odds Ratio [95 % Confidence Interval] 0.55 [0.32-0.93]), age 80+ (0.49 [0.35-0.69]), prior stroke (0.49 [0.31-0.77]), and diabetes mellitus (0.55 [0.39-0.79]), while low median household income (<$80,000/year) increased odds of no acute treatment (1.34 [1.16-1.56]). No sex or racial disparities were observed. Medicaid and low-income were not associated with worse clinical outcomes.

CONCLUSIONS

Less endovascular thrombectomy occurred in Medicaid, older, prior stroke, and diabetic patients, while low-income was associated with no treatment. The observed socioeconomic disparities did not impact discharge outcome.

Safety and efficacy of endovascular recanalization in patients with mild anterior stroke due to large-vessel occlusion exceeding 24 hours

BACKGROUND

Endovascular recanalization (ER) has demonstrated efficacy as a treatment modality for patients presenting with acute ischemic stroke (AIS) caused by large-vessel occlusion (LVO) within a 24-hour timeframe. Nevertheless, the safety and effectiveness of ER in patients with a time of onset exceeding 24 h remain uncertain.

OBJECTIVE

To evaluate the safety and efficacy of ER treatment for mild ischemic stroke beyond 24-h from symptom onset.

METHODS

A retrospectively maintained database of mild AIS due to LVO from March2018 to September 2022 at a comprehensive stroke center was screened.Patients received ER or standard medical therapies (SMT) for anterior circulation AIS due to LVO > 24-h were selected.

RESULTS

We included 47 LVO patients with mild AIS beyond 24-h who suffered neurological deterioration (ND). 34 of these patients underwent ER, the other 13 received SMT. The technical success rate of recanalization was 82.4% (28/34). Patients received ER had significantly lower NIHSS score at discharge and 90-day mRS score (p = 0.028, p = 0.037, respectively) compared to SMT. In addition, they had significantly lower 90-day recurrence of ischemic stroke and lower incidence of moderate-severe stroke (with a NIHSS score at least 5) (p = 0.037, p = 0.033). There were 4 patients (11.7%) had perioperative complications, and no symptomatic intracranial hemorrhage occurred.

CONCLUSION

ER treatment for mild AIS due to LVO encountered ND was generally safe and effective, even beyond 24-h, and resulted in a good prognosis and lower 90-day recurrence compared to SMT.

Big data analysis of endovascular treatment for acute ischemic stroke: a study based on bibliometric analysis

BACKGROUND

 While bibliometric analyses are prevalent in the medical field, few have focused on ther endovascular treatment for acute ischemic stroke (AIS).

OBJECTIVE

 To employ big data analysis to examine the research status, trends, and hotspots in endovascular treatment for AIS.

METHODS

 We conducted a comprehensive search using the Web of Science (WOS) database to identify relevant articles on the endovascular treatment for AIS from 1980 to the present. We used various tools for data analysis, including an online platform (https://bibliometric.com/app), the Citespace software, the Vosviewer software, and the ArcMap software, version 10.8. A number of bibliometric indicators were collected and analyzed, such as publication date, country where the studies were conducted, institutions to which the authors were affiliated, authors, high-frequency keywords, cooperative relationship etc. RESULTS:  A total of 5,576 articles were retrieved. A substantial increase in the number of articles occurred after 2010. High-frequency keywords included terms such as large vessel occlusion, reperfusion, outcome, and basilar artery occlusion. Among the top 10 most productive authors, Raul G. Nogueira ranked first, with 136 published articles. Among the journals, The New England Journal of Medicine ranked first, with 5,631 citations. The United States has the closest collaborative ties with other nations.

CONCLUSION

 In the present study, we found that the reports of endovascular treatment for AIS gradually increased after 2010. Among them, Raul G. Nogueira was the most productive author in this field. The New England Journal of Medicine was the most cited, and it had the greatest impact. The Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) trial study was the most cited, and it was a landmark study. There are many interesting studies on endovascular treatment for AIS, such as ischemic penumbra, collateral circulation, bridging therapy etc.

Infarct density defined by ADC threshold is associated with long-term functional outcome after endovascular thrombectomy

OBJECTIVES

Endovascular thrombectomy (EVT) dramatically improves clinical outcomes, but the reduction in final infarct volume only accounts for 10-15 % of the treatment benefit. We aimed to develop a novel MRI-ADC-based metric that quantify the degree of tissue injury to test the hypothesis that it outperforms infarct volume in predicting long-term outcome.

MATERIALS AND METHODS

A single-center cohort consisted of consecutive acute stroke patients with anterior circulation large vessel occlusion, successful recanalization via EVT (mTICI ≥2b), and MRI of the brain between 12 h and 7 days post-EVT. Imaging was processed via RAPID software. Final infarct volume was based on the traditional ADC <620 threshold. Logistic regression quantified the association of lesion volumes and good outcome (90-day modified Rankin Scale ≤2) at a range of lower ADC thresholds (<570, <520, and <470). Infarct density was calculated as the percentage of the final infarct volume below the ADC threshold with the greatest effect size. Univariate and multivariate logistic regression quantified the association between imaging/clinical metrics and functional outcome.

RESULTS

120 patients underwent MRI after successful EVT. Lesion volume based on the ADC threshold <470 had the strongest association with good outcome (OR: 0.81 per 10 mL; 95 % CI: 0.66-0.99). In a multivariate model, infarct density (<470/<620 * 100) was independently associated with good outcome (aOR 0.68 per 10 %; 95 % CI: 0.49-0.95), but final infarct volume was not (aOR 0.98 per 10 mL; 95 % CI: 0.85-1.14).

CONCLUSIONS

Infarct density after EVT is more strongly associated with long-term clinical outcome than infarct volume.

Prevalence and Distribution of Intracranial Vessel Occlusion on Angiography and Its Association with Functional Outcome in Patients with Atrial Fibrillation Presenting with Ischemic Stroke

OBJECTIVES

To determine the prevalence and distribution of intracranial vessel occlusion identified on computed tomography (CT) or magnet resonance (MR) angiography and to explore its association with functional outcome in patients with atrial fibrillation (AF) and ischemic stroke.

METHODS

Multicenter cohort study enrolling consecutive patients with AF with imaging-confirmed ischemic stroke who underwent CT- or MR-angiography on admission (2014-2022). Multivariable regression was used to explore the association between intracranial vessel occlusion and poor functional outcome (modified Rankin Scale score 3-6) at 90 days.

RESULTS

The analysis included 10,164 patients (median age 81.5 years, 47.8% female, median National Institutes of Health Stroke Scale score on admission 6; 14.7% on a vitamin K antagonist [VKA], 27.5% on a direct oral anticoagulant [DOAC], 57.8% not receiving oral anticoagulation). Angiography showed intracranial vessel occlusion in 5,190 patients (51.1%), affecting the anterior cerebral circulation in 87.4%. Overall, 29.2% and 29.4% of patients received thrombolysis and mechanical thrombectomy, respectively. The proportion of patients with poor functional outcome at 90 days was 60.6% and 42.7% in those with and without vessel occlusion, respectively. In multivariable analyses, vessel occlusion was associated with poor functional outcome (adjusted odds ratio [aOR]: 1.95, 95% confidence interval [CI]: 1.71-2.22) with consistent results in subgroups according to oral anticoagulation use (VKA, aOR: 1.98, 95% CI: 1.40-2.80; DOAC, aOR: 2.35, 95% CI: 1.83-3.03; none, aOR: 1.76, 95% CI: 1.49-2.09).

INTERPRETATION

Intracranial vessel occlusion is common in patients with AF with ischemic stroke, mainly affects the anterior circulation and is associated with poor functional outcome. ANN NEUROL 2024.

Delayed door to puncture time during off-duty hours is associated with unfavorable outcomes after mechanical thrombectomy in the early window of acute ischemic stroke

BACKGROUNDS

The impact of off-duty hours mechanical thrombectomy on outcomes remains a subject of controversy. The impacts of off-duty hours on procedures are influenced by various factors, but the most critical one is the time delay in initiating the procedure after the patient's arrival at the emergency room. Recently, a report suggested that the impact of time delay on post-procedural outcomes is evident in patients who arrive at the emergency room within 6 h of symptom onset, referred to as the "early window." We hypothesized that the impact of procedure delays on outcomes during off duty-hours would be most significant within this early window. This study aimed to investigate the impact of door-to-puncture time (DTPT) delays in patients who underwent mechanical thrombectomy for acute ischemic stroke (AIS) during off-duty hours in both the early and late time windows.

METHODS

We investigated patients who presented to the emergency center between 2014 and 2022. Among a total of 6,496 AIS patients, we selected those who underwent mechanical thrombectomy within 24 h of the onset of acute anterior circulation occlusion. The eligible patients were divided into two groups: those who arrived within 6 h of symptom onset and received the procedure within 8 h (early window), and those who received the procedure between 8 h and 24 h after symptom onset (late window). The study assessed the association between the onset to puncture time in each group and poor outcomes, measured by the modified Rankin scores(mRs) at 90 days. Furthermore, the study analyzed the impact of receiving the procedure during off-hours in both the early and late windows on outcomes. Specifically, the analysis focused on the impact of delayed DTPT in patients during off-duty hours on outcomes measured by the 90-days mRS.

RESULTS

Among the eligible patients, a total of 501 AIS patients underwent mechanical thrombectomy for acute anterior circulation occlusion within 24 h. Of these, 395 patients (78.8%) fell into the early window category, and 320 patients (63.9%) underwent the procedure during off-duty hours. In the early window, for every 60-minute increase in OTPT, the probability of occurrence a poor outcome at 90 days significantly increased in the fully adjusted model (OR = 1.21; 95% CI, 1.02 to 1.43; p = 0.03). In the early window, delayed procedures during off-duty hours (exceeding 103 min of DTPT) were identified as an independent predictor of poor outcomes (OR = 1.85; 95% CI, 1.05 to 3.24; p = 0.03). However, in the late window, there was no association between DTPT and outcomes at 90 days, and the impact of DTPT delays during off-hours was not observed.

CONCLUSIONS

Through this study, it became evident that the impacts of off-duty hours in mechanical thrombectomy were most pronounced in the early window, where the impact of time delay was clear. Therefore, it is believed that improvements in the treatment system are necessary to address this issue.

Endovascular management of acute stroke

Stroke related to large vessel occlusion is a leading cause of disability and death worldwide. Advances in endovascular therapy to reopen occluded arteries have been shown to reduce patient disability and mortality. Expanded indications to treat patients with large vessel occlusion in the late window (>6 h from symptom onset), with basilar artery occlusion, and with large ischaemic core at presentation have enabled treatment of more patients with simplified imaging methods. Ongoing knowledge gaps include an understanding of which patients with large ischaemic infarct are more likely to benefit from endovascular therapy, the role of endovascular therapy in patients who present with low National Institutes of Health Stroke Scale scores or medium or distal vessel occlusion, and optimal management of patients with underlying intracranial atherosclerotic disease. As reperfusion can now be facilitated by intravenous thrombolysis, mechanical thrombectomy, or both, the development of cytoprotective or adjunctive drugs to slow infarct growth, enhance reperfusion, or decrease haemorrhagic risk has gained renewed interest with the hope to improve patient outcomes.

StentRetriever- aspiration (SRa) vs direct aspiration (DA) in the treatment of acute M2 segment occlusion of middle cerebral artery: A single center randomized prospective study

Decision making and patient selection for isolated occlusion of the M2 segment of the middle cerebral artery is challenging, with the efficacy of treatment for such distal occlusions still controversial in recent studies, as occlusion in such small and thin vessels tends to manifest with less severe symptoms initially and hold higher surgical risks. It is even less clear which endovascular technique is more effective for this type of occlusion, with the choice usually left to the radiologist's preference. We conducted a controlled prospective study of consecutive patients presenting to Novara Hospital with an acute M2 occlusion diagnosed at the AngioCt and, following a predetermined randomization, we divided them into two treatment arms with either stent retriever aspiration (SRa) or direct aspiration (DA). All patients were examined on admission, at discharge and after 3 months, and clinical data as well as mRS and NIHSS scale scores were recorded. Our primary aim was to evaluate the difference in recanalization rate in the two groups by comparing the angiographic eTICI obtained with the two techniques. We then investigated whether there were differences in clinical outcomes and complications. Our data confirm a good recanalization rate with an eTICI ≥ 2b in 76.19% of patients in the cohort. An overall good outcome was achieved in 57% of patients as ∆NIHSS and in 50.79% of patients considering mRS. We found no statistically significant difference in recanalization rate nor higher complication rate in either the SRa or DA group. Both techniques are safe, effective and can be considered equally.

Trans-Clot MAP gradient: A novel innovative technique during thrombectomy for acute ischemic stroke with potential applications for assessing collateral circulation, determining clot etiology, informing device selection, and predicting first-pass success

Endovascular mechanical thrombectomy has significantly improved recovery in acute ischemic stroke (AIS). While traditional patient selection has relied on factors such as last known well and penumbra volume, emerging research highlights the importance of collateral circulation in influencing thrombectomy success. However, current methods to assess collateral circulation are often unreliable and lack standardization, limiting their integration into clinical decision-making and prompting the need for innovative approaches. This study introduces trans-clot manometry as a promising approach for quantitatively assessing collateral blood flow before thrombectomy. Two patients were included in this study: a 64-year-old female with a left M1 near-complete occlusion and an 81-year-old male with a left P1 occlusion. After receiving intravenous tenecteplase, each patient underwent emergent thrombectomy where intraoperative trans-clot manometry revealed significant trans-clot mean arterial pressure (MAP) gradients (66.7% for Patient 1 and 96.9% for Patient 2). Both patients had successful first-pass thrombectomy (Patient 1: TICI 3; Patient 2: TICI 3), with substantial clinical improvement (Patient 1: NIHSS 11 to 1; Patient 2: NIHSS 19 to 8). Intraoperative trans-clot manometry offers a simple yet powerful, objective, and generalizable measure of collateral circulation, applicable to a wide range of AIS cases regardless of clot location or vessel size. In addition, real-time correlations with heart-rate variability and radial artery pressures provide an intrinsic quality control, ensuring proper execution of the technique and accuracy of the resulting MAP gradient. Future research will focus on validating this approach, determining its generalizability, and establishing MAP gradient thresholds to enhance device selection and predict first-pass success.

Spontaneous recanalization in acute large core ischemic stroke due to large vessel occlusion: a post-hoc analysis of the ANGEL-ASPECT trial

BACKGROUND

Previous studies have indicated that a subset of patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) experience spontaneous recanalization (SR), but the prognosis and factors associated with SR in these individuals are not well characterized.

METHODS

We conducted a post hoc secondary analysis of the Study of Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients with a Large Infarct Core (ANGEL-ASPECT) trial. SR in the medical management group was defined as a modified arterial occlusive lesion (AOL) grade of 2 or 3 on computed tomography angiography (CTA) or magnetic resonance angiography (MRA) at 36 hours (±12 hours).

RESULTS

SR was detected in 67 out of 184 patients (36.4%) in the medical management (MM) group. The median age of patients was 67 years (interquartile range (IQR) 58-72), and 48 (71.6%) were male. The adjusted odds ratio (aOR) for 90-day modified Rankin Scale (mRS) score shift toward better outcomes of the MM with SR group vs the MM without SR group was 1.83, with marginally significant difference (95% confidence interval (CI) 0.992 to 3.36; P=0.053). No significant difference was found between the MM with SR group and EVT recanalization group (aOR 1.45; 95% CI 0.86 to 2.43; P=0.16) with similar findings in the inverse probability treatment weighting analysis (OR 0.85; 95% CI 0.49 to 1.48; P=0.57). Multivariable regression analysis showed that hypertension, atherothrombotic stroke and higher clot burden score were factors associated with SR.

CONCLUSIONS

SR in medically managed patients with acute large ischemic stroke caused by LVO was associated with good functional outcome. An improved understanding of SR patients may be helpful to develop therapeutic strategy in patients with large infarct due to LVO in anterior circulation.

TRIAL REGISTRATION NUMBER

NCT04551664.

Prevalence and Determinants of Prehospital Impression of Stroke in Ischemic Stroke Patients

BACKGROUND

Emergency Medical Services (EMS) clinicians are front-line in evaluating patients with stroke in the community. Their ability to correctly identify stroke influences downstream management decisions. We sought to use a large national database of prehospital clinical data to determine risk factors associated with missed EMS stroke identification.

METHODS

Retrospective study examining EMS evaluation of adults with Emergency Department (ED) stroke diagnosis. We leveraged the ESO Data Collaborative research dataset containing EHR data from 2019-2022 that has a subset of encounters with linked hospital diagnostic codes. Our primary outcome was the presence of an EMS diagnosis of stroke. We evaluated the association between demographic and clinical variables with EMS stroke identification using Pearson χ2 test for demographic variables and multivariable GLM for clinical variables with adjustment for demographic variables.

RESULTS

We identified 34,504 EMS encounters for patients with ED stroke diagnosis. Of these, 11,077 (32.1%) strokes had missed EMS stroke identification and instead had an EMS impression of "Generalized Weakness" (25.9%), "Altered Level of Consciousness" (24.9%), and "Dizziness" (7.2%). Patients more likely to have missed prehospital stroke identification were of Black race (p=0.0001) and Hispanic ethnicity (p=0.0001). Clinical variables associated with higher risk of missed EMS stroke identification were suspected alcohol or drug use (RR 1.48, 95% CI 1.37-1.59), low GCS (RR 1.17, 95% CI 1.10-1.24), tachycardia (RR 1.05, 95% CI 1.01-1.09), and hypotension (RR 1.47, 95% CI 1.34-1.61).

CONCLUSIONS

Approximately 1-in-3 patients transported by EMS did not have their stroke identified in the prehospital setting. Factors associated with lower odds of missed EMS stroke identification provide a starting point for future performance improvement initiatives.

Determinants of infarct progression and perfusion core growth in transferred LVO patients from remote regions

Introduction

Repeat imaging when regional and remote stroke patients arrive at a comprehensive stroke center (CSC) can delay endovascular thrombectomy (EVT). We examined which clinical and imaging parameters predict infarct progression and perfusion core growth during transport.

Methods

We included patients recruited from 2017 to 2023 in a prospective database who were transferred from remote sites with large vessel occlusion, had CT perfusion imaging at the primary stroke center (PSC), and had repeat CT on arrival at the CSC demonstrating persistent occlusion. The key imaging characteristics were perfusion core change (rCBF < 30%) and ASPECTS change. Multiple and ordinal logistic regression analyses were used to assess the relationship between background clinical and imaging variables and the CT-perfusion core and ASPECTS on arrival. DEFUSE 3 criteria (ASPECTS ≥ 6, perfusion core < 70 mL) were used to define "favorable imaging."

Results

In 90 patients with CT perfusion at both PSC and CSC and persistent occlusion, the median time from onset to PSC presentation was 279 min (IQR 143-702). The median time from PSC presentation to CSC arrival was 243.5 min (IQR 186-335), and the median distance traveled was 186.5 km (IQR 101-258). Lower baseline ASPECTS (per point) was associated with a 7 mL increase (95%CI 2-11 mL) in perfusion core between scans (p = 0.004). The time from onset, the time between PSC and CSC, and the distance traveled were not significantly associated with either ASPECTS or perfusion core growth during transport. In total, 11 out of 78 patients (14%) had deterioration of initially favorable imaging profiles during transport.

Conclusion

Perfusion core growth during transport was uncommon and most strongly associated with lower ASPECTS at the PSC. Initially, favorable PSC imaging May predict whether repeat imaging is necessary at the CSC.

Automated detection of large vessel occlusion using deep learning: a pivotal multicenter study and reader performance study

BACKGROUND

To evaluate the stand-alone efficacy and improvements in diagnostic accuracy of early-career physicians of the artificial intelligence (AI) software to detect large vessel occlusion (LVO) in CT angiography (CTA).

METHODS

This multicenter study included 595 ischemic stroke patients from January 2021 to September 2023. Standard references and LVO locations were determined by consensus among three experts. The efficacy of the AI software was benchmarked against standard references, and its impact on the diagnostic accuracy of four residents involved in stroke care was assessed. The area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity of the software and readers with versus without AI assistance were calculated.

RESULTS

Among the 595 patients (mean age 68.5±13.4 years, 56% male), 275 (46.2%) had LVO. The median time interval from the last known well time to the CTA was 46.0 hours (IQR 11.8-64.4). For LVO detection, the software demonstrated a sensitivity of 0.858 (95% CI 0.811 to 0.897) and a specificity of 0.969 (95% CI 0.943 to 0.985). In subjects whose symptom onset to imaging was within 24 hours (n=195), the software exhibited an AUROC of 0.973 (95% CI 0.939 to 0.991), a sensitivity of 0.890 (95% CI 0.817 to 0.936), and a specificity of 0.965 (95% CI 0.902 to 0.991). Reading with AI assistance improved sensitivity by 4.0% (2.17 to 5.84%) and AUROC by 0.024 (0.015 to 0.033) (all P<0.001) compared with readings without AI assistance.

CONCLUSIONS

The AI software demonstrated a high detection rate for LVO. In addition, the software improved diagnostic accuracy of early-career physicians in detecting LVO, streamlining stroke workflow in the emergency room.

The time threshold to reperfusion for DWI reversal in acute ischemic stroke depends on pre-interventional ADC value

PURPOSE

The aims of this study are to explore the apparent diffusion coefficient (ADC)-dependent thresholds for time to reperfusion in reversible lesions following mechanical thrombectomy for acute ischemic stroke, and to investigate the associated risks of hemorrhagic transformation.

METHODS

We conducted a retrospective case-control study, enrolling patients with large-vessel occlusion who underwent mechanical thrombectomy in Otaru General Hospital from 2016 to 2021. Reversible lesions were identified using volumetric ADC data, and the mean time from image to reperfusion (TIR) in each ADC range was compared between groups with and without reversible lesions, as well as those with and without parenchymal hematoma. The Wilcoxon rank sum test and chi-square test were used for comparison between two groups, and receiver operating characteristic curves were created to determine optimal thresholds.

RESULTS

Seventy-five patients were included and 581 volumetric data were obtained. The mean TIR in the group with reversible lesions was shorter than in that without, and time thresholds were 131, 123 and 112 min for ADC values > 540 × 10-6, 500-540 × 10-6 and 440-500 × 10-6 mm2/s, respectively. Furthermore, in patients with parenchymal hematoma, the mean TIR was significantly longer, and the average ADC value was significantly lower than those without hematoma.

CONCLUSION

The time thresholds for the irreversible ischemic core may vary depending on the ADC value, and they may be shorter when the ADC value is lower. Moreover, both the low ADC value and the late reperfusion might be associated with an increased risk of parenchymal hematoma.