Modified Thrombolysis in Cerebral Infarction 2C/Thrombolysis in Cerebral Infarction 3 Reperfusion Should Be the Aim of Mechanical Thrombectomy

Complete Recanalization in Mechanical Thrombectomy Is Associated with Favorable Functional Outcome for M2 Occlusions

Objective

There are insufficient coherent reports on mechanical thrombectomy (MT) for occlusion of the second segment of the middle cerebral artery (M2 occlusion) in a real-world clinical setting. We evaluated the efficacy and safety of MT for M2 occlusions and compared the primary thrombectomy strategies (stent retriever, aspiration catheter, and combined technique) to analyze factors predicting good functional outcomes.

Methods

We evaluated background factors, preprocedural factors, procedural factors, and procedural time for patients who underwent MT for M2 occlusions from our retrospective cohort. According to the modified Rankin Scale (mRS) score three months after MT, patients were divided into good (mRS ≤2) and poor (mRS ≥3) prognosis groups.

Results

A total of 29 patients (median age, 78 years; 11 [37.9%] females) were included in the study. In this cohort, rates of successful reperfusion, thrombolysis in cerebral infarction (TICI) 3, postprocedural hemorrhage (PPH), and symptomatic PPH were 82.8, 34.5, 31.0, and 0%, respectively. Good prognoses were achieved in 13 (45%) cases. A prognostic factor of MT for M2 occlusions is TICI 3 from multivariate analysis (OR, 11.7; 95% CI, 1.003-136; p = 0.0497). There was no statistically significant difference in the functional outcome three months after MT based on the choice of the primary thrombectomy strategy.

Conclusion

MT for M2 occlusions is a reliable and relatively safe procedure. The presence of TICI 3 was a prognostic factor in this cohort. Future studies are warranted to investigate the optimal thrombectomy strategy for medium vessel occlusion.

A Simple Grading Scale for Predicting Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy

INTRODUCTION

Hemorrhagic transformation, especially symptomatic intracranial hemorrhage (sICH), is a common complication after mechanical embolectomy. This study explored a grading scale based on clinical and radiological parameters to predict sICH after mechanical embolectomy.

METHODS

Demographic and clinical data were retrospectively collected from patients with acute ischemic stroke treated with mechanical embolectomy at West China Hospital. Clinical and radiological factors associated with sICH were identified and used to develop the "STBA" grading scale. This score was then validated using data from an independent sample at the First Affiliated Hospital of Kunming Medical University.

RESULTS

We analyzed 268 patients with acute ischemic stroke who were treated with mechanical embolectomy at West China Hospital, of whom 30 (11.2%) had sICH. Patients were rated on an "STBA" score ranging from 0 to 6 based on whether systolic blood pressure was ≥145 mm Hg at admission (yes = 2 points; no = 0 points), time from acute ischemic stroke until groin puncture was ≥300 min (yes = 1; no = 0), blood glucose was ≥8.8 mmol/L (yes = 1; no = 0), and the Alberta Stroke Program Early Computed Tomography score at admission was 0-5 (2 points), 6-7 (1 point), or 8-10 (0 points). The STBA score showed good discrimination in the derivation sample (area under the receiver operating characteristic curve = 0.858) and in the validation sample (area = 0.814).

CONCLUSIONS

The STBA score may be a reliable clinical scoring system to predict sICH in acute ischemic stroke patients treated with mechanical embolectomy.

Successful Reperfusion is Associated with Favorable Functional Outcome despite Vessel Perforation during Thrombectomy: A Case Series and Systematic Review

BACKGROUND

Arterial perforation is a potentially serious complication during endovascular thrombectomy.

PURPOSE

Our aim was to describe interventional approaches after arterial perforation during endovascular thrombectomy and to determine whether reperfusion remains associated with favorable outcome despite this complication.

DATA SOURCES

Data from consecutive patients with acute stroke undergoing endovascular thrombectomy were retrospectively collected between 2015 to 2020 from a single-center cohort, and a systematic review was performed using PubMed, EMBASE, and Ovid MEDLINE up to June 2020.

STUDY SELECTION

Articles reporting functional outcome after arterial perforation during endovascular thrombectomy were selected.

DATA ANALYSIS

Functional outcomes of patients achieving successful reperfusion (TICI 2b/3) were compared with outcomes of those with unsuccessful reperfusion in our single-center cohort. We then summarized the literature review to describe interventional approaches and outcomes after arterial perforation during endovascular thrombectomy.

DATA SYNTHESIS

In our single-center cohort, 1419 patients underwent endovascular thrombectomy, among whom 32 (2.3%) had vessel perforation and were included in the analysis. The most common hemostatic strategy was watchful waiting (71% of cases). Patients with successful reperfusion had a higher proportion of favorable 90-day mRS scores (60% versus 12.5%; P = .006) and a lower mortality rate (13.3% versus 56.3%, P = .01) than patients without successful reperfusion. Thirteen articles were included in the systematic review. Successful reperfusion also appeared to be associated with better outcomes.

LIMITATIONS

Given the low number of published reports, we performed only a descriptive analysis.

CONCLUSIONS

Arterial perforation during endovascular thrombectomy is rare but is associated with high mortality rates and poor outcome. However, successful reperfusion remains correlated with favorable outcome in these patients.

Continuing early mTICI 2b recanalization may improve functional outcome but is associated with a higher risk of intracranial hemorrhage

Background

Successful reperfusion (mTICI 2c/3) and low number of passes are key determinants for good clinical outcome in acute large vessel occlusion. While final mTICI 2c/3 reperfusion is superior to partial reperfusion (mTICI 2b) it remains unclear if this is also true for the subgroup of patients with early mTICI 2b (achieved in ≤2 retrieval attempts) reperfusion who are secondarily improved to mTICI 2c/3. This study was designed to examine if early mTICI2b should be continued or stopped during mechanical thrombectomy (MT).

Methods

Nine hundred and thirteen ischemic stroke patients who received MT were retrospectively analyzed. Angiography runs following each recanalization attempt were scored for mTICI. The patients with early mTICI 2b reperfusions were dichotomized in “TICI2b-stopped” (MT withdrawal after mTICI 2b was achieved with first or second retrieval) and “TICI2b-continued” (MT was continued after mTICI 2b was achieved with first or second retrieval). Functional outcome was obtained after 90 days using the modified Rankin scale (mRS90).

Results

Of 362 Patients with a M1-occlusion, 100 patients fulfilled the inclusion criteria with an early mTICI 2b. 78/100 patients were included in the “TICI2b-stopped” group and 22/100 patients were in the “TICI2b-continued” group. Of these 22 patients, none had a final mTICI score lower than 2b and 11 patients had a final mTICI score of 2c/3. Regarding good functional outcome at mRS90, “TICI2b-continued” showed by trend a slight advantage of 40.1 vs. 35.6% in “TICI2b-stopped” but in multivariate logistic regression analysis adjusted for confounders, no significant difference was found between the two groups (OR 0.75, 95% CI 0.19–2.87, p = 0.67). Symptomatic intracranial hemorrhage was significantly higher in “TICI2b-continued” compared to “TICI2b-stopped” (31.8 vs. 10.3%, p = 0.031).

Conclusion

Successfully improving an early mTICI 2b to mTICI 2c/3 reperfusion is possible in a substantial number of patients and might improve functional outcome. However, an increase in symptomatic intracranial hemorrhage (SICH) due to further retrieval attempts may diminish the potential functional benefit to continue early mTICI 2b. To support this finding, further investigation with more power is needed to account for the low number of events regarding SICH.

The stress hyperglycemia ratio is associated with the development of cerebral edema and poor functional outcome in patients with acute cerebral infarction

Background and purpose

Absolute hyperglycemia at admission has been shown to be associated with the development of cerebral edema (CED) after acute cerebral infarction. Stress hyperglycemia is a more objective reflection of hyperglycemic state than absolute hyperglycemia. However, studies on the associations between stress hyperglycemia and CED are limited. We aimed to explore the associations of stress hyperglycemia, measured by stress hyperglycemia ratio (SHR), with the development of CED and poor functional outcome of acute cerebral infarction.

Methods

Patients with acute middle artery cerebral infarction admitted to the Department of Neurology, West China Hospital of Sichuan University, within 24 h of symptom onset from January 2017 to March 2021 were included. Stress hyperglycemia was assessed by the SHR: admission fasting plasma glucose (FPG)/hemoglobin A1c (HbA1c). The primary outcome was the degree of CED evaluated on brain image. The secondary outcomes were moderate-to-severe CED, poor functional outcome (modified Rankin Scale score > 2), and death at 90 days. The associations between the SHR and outcomes were assessed with multivariate logistic regression analyses. We further compared the predictive value of the SHR, admission random plasma glucose (RPG), and admission FPG for outcomes in the training dataset and validation dataset.

Results

638 patients were enrolled. Each 0.1-point increase in the SHR was independently associated with a 1.31-fold increased risk of a higher degree of CED [odds ratio (OR): 1.31 (95% confidence interval (CI): 1.20–1.42), P < 0.001]. The SHR was independently associated with moderate-to-severe CED [per 0.1-point increase: OR: 1.39 (95% CI: 1.24–1.57), P < 0.001], poor functional outcome [per 0.1-point increase: OR: 1.25 (95% CI: 1.12–1.40), P < 0.001], and death [per 0.1-point increase: OR: 1.13 (95% CI: 1.03–1.25), P < 0.05]. The predictive value of the SHR (as a continuous variable), exhibited by the area under the curve in receiver operating characteristic analysis, was higher than that of the RPG and FPG for moderate-to-severe CED and poor functional outcome (P < 0.05).

Conclusion

The SHR is independently associated with the severity of CED, poor functional outcome, and death after acute cerebral infarction, and the SHR (as a continuous variable) has a better predictive value for moderate-to-severe CED and poor functional outcome than the RPG and FPG.

Shortening door-to-puncture time and improving patient outcome with workflow optimization in patients with acute ischemic stroke associated with large vessel occlusion

OBJECTIVE

We aimed to evaluate door-to-puncture time (DPT) and door-to-recanalization time (DRT) without directing healthcare by neuro-interventionalist support in the emergency department (ED) by workflow optimization and improving patients' outcomes.

METHODS

Records of 98 consecutive ischemic stroke patients who had undergone endovascular therapy (EVT) between 2018 to 2021 were retrospectively reviewed in a single-center study. Patients were divided into three groups: pre-intervention (2018-2019), interim-intervention (2020), and post-intervention (January 1st 2021 to August 16th, 2021). We compared door-to-puncture time, door-to-recanalization time (DRT), puncture-to-recanalization time (PRT), last known normal time to-puncture time (LKNPT), and patient outcomes (measured by 3 months modified Rankin Scale) between three groups using descriptive statistics.

RESULTS

Our findings indicate that process optimization measures could shorten DPT, DRT, PRT, and LKNPT. Median LKNPT was shortened by 70 min from 325 to 255 min(P < 0.05), and DPT was shortened by 119 min from 237 to 118 min. DRT shortened by 132 min from 338 to 206 min, and PRT shortened by 33 min from 92 to 59 min from the pre-intervention to post-intervention groups (all P < 0.05). Only 21.4% of patients had a favorable outcome in the pre-intervention group as compared to 55.6% in the interventional group (P= 0.026).

CONCLUSION

This study demonstrated that multidisciplinary cooperation was associated with shortened DPT, DRT, PRT, and LKNPT despite challenges posed to the healthcare system such as the COVID-19 pandemic. These practice paradigms may be transported to other stroke centers and healthcare providers to improve endovascular time metrics and patient outcomes.

Predictors of malignant middle cerebral artery infarction after endovascular thrombectomy: results of DIRECT-MT trial

OBJECTIVES

Predictors of malignant middle cerebral artery infarction (mMCAi) in patients after intravenous thrombolysis were well documented, but the risk factors of mMCAi after endovascular thrombectomy (EVT) were not fully explored. Therefore, the present study aimed to investigate the predictors of mMCAi after EVT in stroke patients.

METHODS

This was a secondary analysis of the DIRECT-MT trial. Patients who underwent EVT for the occlusions of MCA and/or intracranial internal carotid artery were analyzed. Primary outcome was the occurrence of mMCAi after EVT. Demographic, clinical, imaging, and treatment data were recorded, and multivariate logistic regression analysis was used to identify independent predictors. All of the candidate predictors were included, and forward elimination was applied to establish the most effective predictive model. Predictive ability and calibration of the model were assessed using the area under the receiver operating characteristic curve (AUC) and Hosmer-Lemeshow test, respectively.

RESULTS

Of 559 enrolled patients, 74 (13.2%) patients developed mMCAi. Predictors of mMCAi included unsuccessful reperfusion, higher serum glucose, lower Alberta Stroke Project Early Computed Tomography Change Score (ASPECTS), higher clot burden score (CBS), lower collateral score, and higher pass number of thrombectomy device. AUC of predictive model integrating all independent variables was 0.836. The Hosmer-Lemeshow test showed appropriate calibration (p = 0.859).

CONCLUSIONS

Reperfusion, serum glucose, ASPECTS, CBS, collateral, and pass number of thrombectomy device were associated with the occurrence of mMCAi in stroke patients after EVT, while alteplase treatment was not. Our findings might facilitate the early identification and management of stroke patients at a high risk of mMCAi.

KEY POINTS

• A total of 13.2% of stroke patients with large vessel occlusion of anterior circulation developed mMCAi after EVT. • The occurrence of mMCAi had a definite negative impact on the outcome for stroke patients. • Reperfusion, serum glucose, ASPECTS, CBS, collateral score, and the pass number of thrombectomy device were associated with the occurrence of mMCAi after EVT in stroke patients.

Safety and effectiveness of mechanical thrombectomy for acute ischemic stroke using single plane angiography

OBJECTIVES

Nearly all data on mechanical thrombectomy for acute ischemic stroke is based on procedures performed on biplane angiography systems. However, thrombectomy may be performed on single-plane systems in situations of triage or limited resources. We present the first US study comparing the safety and effectiveness of mechanical thrombectomy performed on single-plane vs. biplane systems.

METHODS AND METHODS

A retrospective review of a prospectively maintained database identified all patients treated with thrombectomy between July 2020 and July 2021 by a high-volume practice. Patients were dichotomized into those treated on single plane and biplane systems. Demographic, procedural, clinical and follow-up characteristics were compared.

RESULTS

Of the 246 patients treated with mechanical thrombectomy, 70 (33%) and 141 (66%) patients were treated on SP and BP systems, respectively. No significant differences were detected in follow-up 'good functional outcome' (mRS ≤ 2; SP 51% vs BP 43%, p = 0.14), successful recanalization (SP 87% vs BP 88%, p = 0.72), intra-procedural vascular injury (SP 3% vs BP 2%, p = 0.96), or time from groin puncture to reperfusion (SP 24 min vs BP 26 min, p = 0.58). Additionally, no significant differences were detected in peri-procedural complications, fluoroscopy times or total radiation. Patients treated on single plane systems required significantly more contrast.

CONCLUSIONS

Mechanical thrombectomy for acute ischemic stroke performed on single plane angiography systems is as safe and efficacious as when performed on biplane systems. Our results may have implications for increasing stroke care access, both domestically in underserved/rural areas and internationally when considering requirements for stroke care in lower-income countries.

Digital subtraction angiography in cerebrovascular disease: current practice and perspectives on diagnosis, acute treatment and prognosis

Digital Subtraction Angiography (DSA) is the gold-standard imaging modality in acute cerebrovascular diagnosis. The role of DSA has become increasingly prominent since the incorporation of endovascular therapy in standards of care for acute ischemic stroke. It is used in the assessment of cerebral vessel patency; however, the therapeutic role of DSA from a prognostic standpoint merits further investigation. The current paper provides an update on current practice on diagnostic, therapeutic and prognostic use of DSA in acute cerebrovascular diseases and various indications and perspectives that may apply, or limit its use, in ongoing surveillance or prognosis. Pre-clinical and clinical studies on the aspects, including but not limited to the morphology of cerebrovasculature in acute ischaemic stroke, are required to delineate and inform its prognostic role.

CT angiographic radiomics signature for risk stratification in anterior large vessel occlusion stroke

BACKGROUND AND PURPOSE

As "time is brain" in acute stroke triage, the need for automated prognostication tools continues to increase, particularly in rapidly expanding tele-stroke settings. We aimed to create an automated prognostication tool for anterior circulation large vessel occlusion (LVO) stroke based on admission CTA radiomics.

METHODS

We automatically extracted 1116 radiomics features from the anterior circulation territory on admission CTAs of 829 acute LVO stroke patients who underwent mechanical thrombectomy in two academic centers. We trained, optimized, validated, and compared different machine-learning models to predict favorable outcome (modified Rankin Scale ≤ 2) at discharge and 3-month follow-up using four different input sets: "Radiomics", "Radiomics + Treatment" (radiomics, post-thrombectomy reperfusion grade, and intravenous thrombolysis), "Clinical + Treatment" (baseline clinical variables and treatment), and "Combined" (radiomics, treatment, and baseline clinical variables).

RESULTS

For discharge outcome prediction, models were optimized/trained on n = 494 and tested on an independent cohort of n = 100 patients from Yale. Receiver operating characteristic analysis of the independent cohort showed no significant difference between best-performing Combined input models (area under the curve, AUC = 0.77) versus Radiomics + Treatment (AUC = 0.78, p = 0.78), Radiomics (AUC = 0.78, p = 0.55), or Clinical + Treatment (AUC = 0.77, p = 0.87) models. For 3-month outcome prediction, models were optimized/trained on n = 373 and tested on an independent cohort from Yale (n = 72), and an external cohort from Geisinger Medical Center (n = 232). In the independent cohort, there was no significant difference between Combined input models (AUC = 0.76) versus Radiomics + Treatment (AUC = 0.72, p = 0.39), Radiomics (AUC = 0.72, p = 0.39), or Clinical + Treatment (AUC = 76, p = 0.90) models; however, in the external cohort, the Combined model (AUC = 0.74) outperformed Radiomics + Treatment (AUC = 0.66, p < 0.001) and Radiomics (AUC = 0.68, p = 0.005) models for 3-month prediction.

CONCLUSION

Machine-learning signatures of admission CTA radiomics can provide prognostic information in acute LVO stroke candidates for mechanical thrombectomy. Such objective and time-sensitive risk stratification can guide treatment decisions and facilitate tele-stroke assessment of patients. Particularly in the absence of reliable clinical information at the time of admission, models solely using radiomics features can provide a useful prognostication tool.

Predictors of Symptomatic Hemorrhage After Endovascular Treatment for Anterior Circulation Occlusions: Turkish Endovascular Stroke Registry

We evaluated the predictive factors of symptomatic intracranial hemorrhage (SICH) in endovascular treatment of stroke. We included 975 ischemic stroke patients with anterior circulation occlusion. Patients that had hemorrhage and an increase of ≥4 points in their National Institutes of Health Stroke Scale (NIHSS) after the treatment were considered as SICH. The mean age of patients was 65.2±13.1 years and 469 (48.1%) were women. The median NIHSS was 16 (13-18) and Alberta Stroke Program Early CT 9 (8-10). In 420 patients (43.1%), modified Rankin Scale was favorable (0-2) and mortality was observed in 234 (24%) patients at the end of the third month. Patients with high diastolic blood pressure (P<.05) had significantly higher SICH. SICH was significantly higher in those with high NIHSS scores (P<.001), high blood glucose (P<.001), and leukocyte count at admission (P<.05). Diabetes mellitus (DM) (OR 1.90; P<.001), NIHSS (OR 1.07; P<.05), adjuvant intra-arterial thrombolytic therapy (IA-rtPA) (OR, 1.60; P<.05), and puncture-recanalization time (OR 1.01; P<.05) were independent factors of SICH. Higher baseline NIHSS score, longer procedure time, multiple thrombectomy maneuvers, administration of IA-rtPA, and the history of DM are independent predictors of SICH in anterior circulation occlusion.

The claw sign predicts first-pass effect in mechanical thrombectomy for cerebral large vessel occlusion in the anterior circulation

Background:

Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE.

Methods:

We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE.

Results:

FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047).

Conclusion:

The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke.

Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) study protocol: a stepped wedge randomised trial of stroke screening using the National Institutes of Health Stroke Scale in the ambulance

Background

Less than 50% of stroke patients in Norway reach hospital within 4 h of symptom onset. Early prehospital identification of stroke and triage to the right level of care may result in more patients receiving acute treatment. Quality of communication between paramedics and the stroke centre directly affects prehospital on-scene time, emphasising this as a key factor to reduce prehospital delay. Prehospital stroke scales are developed for quick and easy identification of stroke, but have poor sensitivity and specificity compared to an in-hospital assessment with the National Institutes of Health Stroke Scale (NIHSS). The aim of the Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) is to assess whether a structured learning program, prehospital NIHSS and a mobile application facilitating communication with the stroke physician may improve triage of acute stroke patients.

Methods

A stepped wedge cluster randomised controlled intervention design will be used in this trial in Oslo, Norway. Paramedics at five ambulance stations will enrol adult patients with suspected stroke within 24 h of symptom onset. All paramedics will begin in a control phase with standard procedures. Through an e-learning program and practical training, a random and sequential switch to the intervention phase takes place. A mobile application for NIHSS scoring, including vital patient information for treatment decisions, transferring data from paramedics to the on-call stroke physician at the Stroke Unit at Oslo University Hospital, will be provided for the intervention.

The primary outcome measure is positive predictive value (PPV) for prehospital identification of patients with acute stroke defined as the proportion of patients accepted for stroke evaluation and discharged with a final stroke diagnosis. One thousand three hundred patients provide a 50% surplus to the 808 patients needed for 80% power to detect a 10% increase in PPV.

Discussion

Structured and digital communication using a common scale like NIHSS may result in increased probability for better identification of stroke patients and less stroke mimics delivered to a stroke team for acute diagnostics and treatment in our population.

Trial registration

ClinicalTrials.govNCT04137874. Registered on October 24, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06006-4.

Clinical protocol of the ischemic stroke patients treatment

Today in Ukraine there is no single standardized protocol for the treatment of patients in the acute period of ischemic stroke using modern methods of diagnosis and treatment, which include thrombolytic therapy and endovascular treatment. This protocol was created and implemented in Scientific-practical Center of endovascular neuroradiology, NAMS of Ukraine and is based on the latest recommendations of AHA/ASA and ESO, as well as registers of patients with ischemic stroke. The main purpose of this publication is the creation and implementation of «instructions» for the diagnosis and selection of objective tactics for treating patients in the acute period of ischemic stroke.

Is a picture-perfect thrombectomy necessary in acute ischemic stroke?

BACKGROUND

The benefit of complete reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 3) over near-complete reperfusion (≥90%, mTICI 2c) remains unclear. The goal of this study is to compare clinical outcomes between mechanical thrombectomy (MT)-treated stroke patients with mTICI 2c versus 3.

METHODS

This is a retrospective study from the Stroke Thrombectomy and Aneurysm Registry (STAR) comprising 33 centers. Adults with anterior circulation arterial vessel occlusion who underwent MT yielding mTICI 2c or mTICI 3 reperfusion were included. Patients were categorized based on reperfusion grade achieved. Primary outcome was modified Rankin Scale (mRS) 0-2 at 90 days. Secondary outcomes were mRS scores at discharge and 90 days, National Institutes of Health Stroke Scale score at discharge, procedure-related complications, and symptomatic intracerebral hemorrhage.

RESULTS

The unmatched mTICI 2c and mTICI 3 cohorts comprised 519 and 1923 patients, respectively. There was no difference in primary (42.4% vs 45.1%; p=0.264) or secondary outcomes between the unmatched cohorts. Reperfusion status (mTICI 2c vs 3) was also not predictive of the primary outcome in non-imputed and imputed multivariable models. The matched cohorts each comprised 191 patients. Primary (39.8% vs 47.6%; p=0.122) and secondary outcomes were also similar between the matched cohorts, except the 90-day mRS which was lower in the matched mTICI 3 cohort (p=0.049). There were increased odds of the primary outcome with mTICI 3 in patients with baseline mRS ≥2 (36% vs 7.7%; p=0.011; pinteraction=0.014) and a history of stroke (42.3% vs 15.4%; p=0.027; pinteraction=0.041).

CONCLUSIONS

Complete and near-complete reperfusion after MT appear to confer comparable outcomes in patients with acute stroke.

Bridging Thrombolysis versus Direct Mechanical Thrombectomy in Stroke Due to Basilar Artery Occlusion

Background and Purpose

Mechanical thrombectomy (MT) is an effective treatment for patients with basilar artery occlusion (BAO) acute ischemic stroke. It remains unclear whether bridging intravenous thrombolysis (IVT) prior to MT confers any benefit. This study compared the outcomes of acute BAO patients who were treated with direct MT versus combined IVT plus MT.

Methods

This multicenter retrospective cohort study included patients who were treated for acute BAO from eight comprehensive stroke centers between January 2015 and December 2019. Patients received direct MT or combined bridging IVT plus MT. Primary outcome was favorable functional outcome defined as modified Rankin Scale 0–3 measured at 90 days. Secondary outcome measures included mortality and symptomatic intracranial hemorrhage (sICH).

Results

Among 322 patients, 127 (39.4%) patients underwent bridging IVT followed by MT and 195 (60.6%) underwent direct MT. The mean±standard deviation age was 67.5±14.1 years, 64.0% were male and median National Institutes of Health Stroke Scale was 16 (interquartile range, 8 to 25). At 90-day, the rate of favorable functional outcome was similar between the bridging IVT and direct MT groups (39.4% vs. 34.4%, P=0.361). On multivariable analyses, bridging IVT was not as Comorbidisociated with favorable functional outcome, mortality or sICH. In subgroup analyses, patients with underlying atherosclerosis treated with bridging IVT compared to direct MT had a higher rate of favorable functional outcome at 90 days (37.2% vs. 15.5%, P=0.013).

Conclusions

Functional outcomes were similar in BAO patients treated with bridging IVT versus direct MT. In the subgroup of patients with underlying large-artery atherosclerosis stroke mechanism, bridging IVT may potentially confer benefit and this warrants further investigation.

Successful mechanical thrombectomy in acute ischemic stroke: revascularization grade and functional independence

Most studies define the technical success of endovascular thrombectomy (EVT) as a Thrombolysis in Cerebral Infarction (TICI) revascularization grade of 2b or higher. However, growing evidence suggests that TICI 3 is the best angiographic predictor of improved functional outcomes. To assess the association between successful TICI revascularization grades and functional independence at 90 days, we performed a systematic review and network meta-analysis of thrombectomy studies that reported TICI scores and functional outcomes, measured by the modified Rankin Scale, using the semi-automated AutoLit software platform. Forty studies with 8691 patients were included in the quantitative synthesis. Across TICI, modified TICI (mTICI), and expanded TICI (eTICI), the highest rate of good functional outcomes was observed in patients with TICI 3 recanalization, followed by those with TICI 2c and TICI 2b recanalization, respectively. Rates of good functional outcomes were similar among patients with either TICI 2c or TICI 3 grades. On further sensitivity analysis of the eTICI scale, the rates of good functional outcomes were equivalent between eTICI 2b50 and eTICI 2b67 (OR 0.81, 95% CI 0.52 to 1.25). We conclude that near complete or complete revascularization (TICI 2c/3) is associated with higher rates of functional outcomes after EVT.

High glycemic albumin representing prestroke glycemic variability is associated with hemorrhagic transformation in patients receiving intravenous thrombolysis

We evaluated the impact of prestroke glycemic variability estimated by glycated albumin (GA) on symptomatic hemorrhagic transformation (SHT) in patients with intravenous thrombolysis (IVT). Using a multicenter database, we consecutively enrolled acute ischemic stroke patients receiving IVT. A total of 378 patients were included in this study. Higher GA was defined as GA ≥ 16.0%. The primary outcome measure was SHT. Multivariate regression analysis and a receiver operating characteristic curve were used to assess risks and predictive ability for SHT. Among the 378 patients who were enrolled in this study, 27 patients (7.1%) had SHT as defined by the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SHT_SITS). The rate of SHT_SITS was higher in the higher GA group than in the lower GA group (18.0% vs. 1.6%, p < 0.001). A higher GA level (GA ≥ 16.0%) significantly increased the risk of SHT_SITS (adjusted odds ratio [OR], [95% confidence interval, CI], 12.57 [3.08–41.54]) in the logistic regression analysis. The predictive ability of the GA level for SHT_SITS was good (AUC [95% CI]: 0.83 [0.77–0.90], p < 0.001), and the cutoff value of GA in SHT was 16.3%. GA was a reliable predictor of SHT after IVT in acute ischemic stroke in this study.

Endogenous Deoxyribonuclease Activity and Cell-Free Deoxyribonucleic Acid in Acute Ischemic Stroke: A Cohort Study

BACKGROUND AND PURPOSE

Cell-free DNA (cfDNA) and endogenous deoxyribonuclease activity are opposing mediators and might influence the inflammatory response following acute ischemic stroke. In this cohort study, we investigated the relation between these markers, circulating inflammatory mediators and clinical course including occurrence of stroke-associated infections (SAI) in patients with acute stroke.

METHODS

Ninety-two patients with stroke due to large vessel occlusion undergoing mechanical thrombectomy were prospectively recruited at Hannover Medical School from March 2018 to August 2019. Deoxyribonuclease activity, cfDNA, damage-associated molecular patterns, and circulating cytokines were measured in venous blood collected immediately before mechanical thrombectomy and 7 days later. Reperfusion status was categorized (sufficient/insufficient). Clinical outcome was evaluated using the modified Rankin Scale after 90 days, where a score of 3 to 6 was considered unfavorable. To validate findings regarding SAI, another stroke cohort (n=92) was considered with blood taken within 24 hours after stroke onset.

RESULTS

Patients with unfavorable clinical outcome had higher cfDNA concentrations. After adjustment for confounders (Essen Stroke Risk Score, National Institutes of Health Stroke Scale, and sex), 7-day cfDNA was independently associated with clinical outcome and especially mortality (adjusted odds ratio: 3.485 [95% CI, 1.001-12.134] and adjusted odds ratio: 9.585 [95% CI, 2.006-45.790]). No association was found between reperfusion status and cfDNA or deoxyribonuclease activity. While cfDNA concentrations correlated positively, deoxyribonuclease activity inversely correlated with distinct biomarkers. Baseline deoxyribonuclease activity was lower in patients who developed SAI compared with patients without SAI. This association was confirmed after adjustment for confounding factors (adjusted odds ratio: 0.447 [95% CI, 0.237-0.844]). In cohort 2, differences of deoxyribonuclease activity between patients with and without SAI tended to be higher with higher stroke severity.

CONCLUSIONS

The interplay of endogenous deoxyribonuclease activity and cfDNA in acute stroke entails interesting novel diagnostic and potential therapeutic approaches. We confirm an independent association of cfDNA with a detrimental clinical course after stroke due to large vessel occlusion. This study provides first evidence for lower endogenous deoxyribonuclease activity as risk factor for SAI after severe stroke.

Heterogeneity of the Relative Benefits of TICI 2c/3 over TICI 2b50/2b67 : Are there Patients who are less Likely to Benefit?

PURPOSE

Incomplete reperfusion after mechanical thrombectomy (MT) is associated with a poor outcome. Rescue therapy would potentially benefit some patients with an expanded treatment in cerebral ischemia score (eTICI) 2b50/2b67 reperfusion but also harbors increased risks. The relative benefits of eTICI 2c/3 over eTICI 2b50/67 in clinically important subpopulations were analyzed.

METHODS

Retrospective analysis of our institutional database for all patients with occlusion of the intracranial internal carotid artery (ICA) or the M1/M2 segment undergoing MT and final reperfusion of ≥eTICI 2b50 (903 patients). The heterogeneity in subgroups of different time metrics, age, National Institutes of Health Stroke Scale (NIHSS), number of retrieval attempts, Alberta Stroke Programme Early CT Score (ASPECTS) and site of occlusion using interaction terms (p_i) was analyzed.

RESULTS

The presence of eTICI 2c/3 was associated with better outcomes in most subgroups. Time metrics showed no interaction of eTICI 2c/3 over eTICI 2b50/2b67 and clinical outcomes (onset to reperfusion p_i = 0.77, puncture to reperfusion p_i = 0.65, onset to puncture p_i = 0.63). An eTICI 2c/3 had less consistent association with mRS ≤2 in older patients (>82 years, p_i = 0.038) and patients with either lower NIHSS (≤9) or very high NIHSS (>19, p_i = 0.01). Regarding occlusion sites, the beneficial effect of eTICI 2c/3 was absent for occlusions in the M2 segments (aOR 0.73, 95% confidence interval [CI] 0.33-1.59, p_i = 0.018).

CONCLUSION

Beneficial effect of eTICI 2c/3 over eTICI 2b50/2b67 only decreased in older patients, M2-occlusions and patients with either low or very high NIHSS. Improving eTICI 2b50/2b67 to eTICI 2c/3 in those subgroups may be more often futile.

Dose-Response Relationship and Threshold Drug Dosage Identification for a Novel Hybrid Mechanical-Thrombolytic System with an Ultra-Low Dose Patch

Introduction

Ischemic stroke treatment has advanced in the last two decades and intravenous thrombolysis is now considered the standard of care for selected patients. Recanalization can also be achieved by mechanical endovascular treatment for patients with large vessel occlusions. Complicating treatment-related symptomatic intracerebral hemorrhage and prolonged needle-to-recanalization times have been identified as major determinants of poor three-month functional outcomes. A hybrid mechanical-thrombolytic system with a patch imbued with an ultra-low dose of thrombolytic agents loaded onto a stent-retriever has been developed.

Methods

In this study, the in situ dose-response relationship of the thrombolytic patch imbued with up to 1000 IU of urokinase plasminogen activator (uPA) was quantified using Raman spectroscopy.

Results

Thrombi of up to 400 μm thickness dissolved within 15 min when patches imbued with < 1% of the conventional thrombolysis therapy dosage were applied. The results demonstrated that low-dose thrombolytic patches can dissolve normal clots compressed in the blood vessel in a short time. 500 IU is the threshold uPA dosage in the thrombolytic patch that most effectively dissolves the clots.

Conclusion

This study suggests that a novel endovascular stent-retriever loaded with an ultra-low drug dose fibrinolytic patch may be a suitable treatment for patients who are ineligible for conventional thrombolytic therapy.

A regional strategy to decrease the time to thrombectomy in patients with low probability of treatment by thrombolysis

BACKGROUND AND PURPOSE

The best transportation strategy for patients with suspected large vessel occlusion (LVO) is unknown. Here, we evaluated a new regional strategy of direct transportation to a Comprehensive Stroke Center (CSC) for patients with suspected LVO and low probability of receiving intravenous thrombolysis (IVT) at the nearest Primary Stroke Center (PSC).

METHODS

Patients could be directly transported to the CSC (bypass group) if they met our pre-hospital bypass criteria: high LVO probability (i.e., severe hemiplegia) with low IVT probability (contraindications) and/or travel time difference between CSC and PSC<15 minutes. The other patients were transported to the PSC according to a "drip-and-ship" strategy. Treatment time metrics were compared in patients with pre-hospital bypass criteria and confirmed LVO in the bypass and drip-and-ship groups.

RESULTS

In the bypass group (n=79), 54/79 (68.3%) patients met the bypass criteria and 29 (36.7%) had confirmed LVO. The positive predictive value of the hemiplegia criterion for LVO detection was 0.49. In the drip-and-ship group (n=457), 92/457 (20.1%) patients with confirmed LVO met our bypass criteria. Among the 121 patients with bypass criteria and confirmed LVO, direct routing decreased the time between symptom discovery and groin puncture by 55 minutes compared with the drip-and-ship strategy (325 vs. 229 minutes, P<0.001), without significantly increasing the time to IVT (P=0.19).

CONCLUSIONS

Our regional strategy led to the correct identification of LVO and a significant decrease of the time to mechanical thrombectomy, without increasing the time to IVT, and could be easily implemented in other territories.

Clinical outcomes of first-pass effect after mechanical thrombectomy for acute ischemic stroke: A systematic review and meta-analysis

OBJECTIVE

The first-pass effect (FPE) during a mechanical thrombectomy for ischemic stroke results in favorable clinical outcomes and low symptomatic intracranial hemorrhage (sICH) rates according to individual observational studies. We performed an integrated study-level meta-analysis to compare the clinical outcomes and safety profiles of single (FPE group) and multiple passages (non-FPE group) of devices in patients who achieved successful recanalizations.

METHODS

A literature search of the PubMed, Embase, and Cochrane databases for FPE was conducted. We included studies comparing outcomes between patients with and without FPE for 90-day favorable outcome, mortality, and sICH. The results from the pooled analysis using the random-effects model were presented as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Of the 8 selected studies comprising 2308 patients, the overall rates of the FPE were 40.3% (930/2308). The FPE was significantly associated with more 90-day favorable outcomes (OR: 1.31, 95% CI: 1.13-1.51) and lower mortality (OR: 0.53, 95% CI: 0.34-0.81), but there were no significant differences in sICH rates (OR: 0.80, 95% CI: 0.50-1.30). The results of the meta-regression analysis showed that there was no confounding effect of intravenous thrombolysis prior to thrombectomy.

CONCLUSION

Our findings indicated that patients who achieved the FPE would have more 90-day favorable outcomes and lower mortality compared with non-FPE patients. However, there was a limited association between the FPE and reduced sICH rates.

Global Epidemiology of Stroke and Access to Acute Ischemic Stroke Interventions

PURPOSE OF THE REVIEW

To provide an up-to-date review of the incidence of stroke and large vessel occlusion (LVO) around the globe, as well as the eligibility and access to IV thrombolysis (IVT) and mechanical thrombectomy (MT) worldwide.

RECENT FINDINGS

Randomized clinical trials have established MT with or without IVT as the usual care for patients with LVO stroke for up to 24 hours from symptom onset. Eligibility for IVT has extended beyond 4.5 hours based on permissible imaging criteria. With these advances in the last 5 years, there has been a notable increase in the population of patients eligible for acute stroke interventions. However, access to acute stroke care and utilization of MT or IVT is lagging in these patients.

SUMMARY

Stroke is the second leading cause of both disability and death worldwide, with the highest burden of the disease shared by low- and middle-income countries. In 2016, there were 13.7 million new incident strokes globally; ≈87% of these were ischemic strokes and by conservative estimation about 10%-20% of these account for LVO. Fewer than 5% of patients with acute ischemic stroke received IVT globally in the eligible therapeutic time window and fewer than 100,000 MTs were performed worldwide in 2016. This highlights the large gap among eligible patients and the low utilization rates of these advances across the globe. Multiple global initiatives are underway to investigate interventions to improve systems of care and bridge this gap.

Biomarkers of Technical Success After Embolectomy for Acute Stroke

PURPOSE OF THE REVIEW

Stent retrievers and large-bore aspiration catheters have doubled substantial reperfusion rates compared to first-generation devices. This has been accompanied by a 3-fold reduction in procedural time to revascularization. To measure future thrombectomy improvements, new benchmarks for technical efficacy are needed. This review summarizes the recent literature concerning biomarkers of procedural success and harm and highlights future directions.

RECENT FINDINGS

Expanded Treatment in Cerebral Ischemia (eTICI), which incorporates scores for greater levels of reperfusion, improves outcome prediction. Core laboratory-adjudicated studies show that outcomes following eTICI 2c (90%-99% reperfusion) are superior to eTICI 2b50 and nearly equivalent to eTICI 3. Moreover, eTICI 2c improves scale reliability. Studies also confirm the importance of rapid revascularization, whether measured as first pass effect or procedural duration under 30 minutes. Distal embolization is a complication that impedes the extent and speed of revascularization, but few studies have reported its per-pass occurrence. Distal embolization and emboli to new territory should be measured after each thrombectomy maneuver. Collaterals have been shown to be an important modifier of thrombectomy benefit. A drawback of the currently accepted collateral grading scale is that it does not discriminate among the broad spectrum of partial collateralization. Important questions that require investigation include reasons for failed revascularization, the utility of a global Treatment in Cerebral Ischemia scale, and the optimal grading system for vertebrobasilar occlusions.

SUMMARY

Emerging data support a lead technical efficacy endpoint that combines the extent and speed of reperfusion. Efforts are needed to better characterize angiographic measures of treatment harm and of collateralization.

Predictors of favorable outcome after endovascular thrombectomy for acute ischemic stroke due to large vessel occlusion in young patients

BACKGROUND

Mechanical thrombectomy (MT) became a standard of care for patients with acute ischemic stroke (AIS) with its efficacy demonstrated by meta-analysis and randomized studies. Although ischemic stroke is associated more with older patients, it may also have devastating neurological effects on young patients.

PURPOSE

To present our experience with stroke patients aged <50 years treated with endovascular means and to evaluate clinical and procedural factors associated with outcome and mortality.

MATERIAL AND METHODS

This study was conducted on 34 young stroke patients treated with MT. Clinical features including baseline results, radiological imaging, procedural details, and outcome results were documented and evaluated. Recanalization was assessed according to the TICI score. The clinical condition was evaluated after three months using mRS. Mortality rate was calculated.

RESULTS

The rate of successful recanalization (TICI ≥2c) was 79% (27/34). Symptomatic intracranial hemorrhage (sICH) was observed in 5 (15%) patients. After 90 days, the mortality rate was 12%. Favorable clinical outcome (mRs 0-2) was regained in 65% of the patients whereas satisfactory clinical outcome was seen in 85%. Poor clinical outcome (mRs >2) was observed in 9 (23.7%) patients.

CONCLUSION

In conclusion, the results of this study demonstrate that MT for AIS in young patients is feasible and provides an excellent rate of arterial recanalization and high rate of favorable outcomes. Statistical analysis showed that shorter time from onset to arrival and reperfusion, successful recanalization and absence of hemorrhagic transformation are the predictors of favorable clinical outcome and overall survival rate.

Impact of Prior Statin Use on Reperfusion Rate and Stroke Outcomes in Patients Receiving Endovascular Treatment

Background: We evaluated the impact of prior statin use on successful reperfusion and stroke outcomes after endovascular treatment (EVT). Method: Using consecutive multicenter databases, we enrolled acute ischemic stroke patients receiving EVT between 2015 and 2021. Patients were classified into prior statin users and no prior statin users after a review of premorbid medications. The primary outcome measure was successful reperfusion defined as modified TICI grade 2b or 3 after EVT. Secondary outcome measures were early neurologic deterioration (END) and a 3-month modified Rankin Scale (mRS) score of 0 to 2. Results: Among 385 patients receiving EVT, 74 (19.2%) were prior statin users, who had a significantly higher successful reperfusion rate compared with no prior statin users (94.6% versus 78.8%, p = 0.002). Successful reperfusion and END occurrence were improved according to statin intensity with a dose–response relationship. In multivariate analysis, prior statin was associated with successful reperfusion after EVT (adjusted odds ratio (95% confidence interval) 5.31 (1.67–16.86)). In addition, prior statin was associated with a lower occurrence of END and good functional status. Conclusion: Our study showed that prior statin use before ischemic stroke might improve successful reperfusion and stroke outcomes after EVT.

Optimal Tissue Reperfusion Estimation by Computed Tomography Perfusion Post-Thrombectomy in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Modified Thrombolysis in Cerebral Infarction score (mTICI) ≥2b is defined as successful reperfusion. However, mTICI has rarely been correlated with dynamic perfusion imaging postendovascular therapy for acute stroke. We aimed to study the proportion of tissue optimal reperfusion (TOR) postendovascular therapy across different grades of mTICI.

METHODS

We conducted a single-center retrospective analysis of patients with acute ischemic strokes who had endovascular therapy between 2018 and 2019. Computer tomography perfusion or magnetic resonance perfusion was performed before and after endovascular therapy. Tmax+6 volume reduction of >90% was defined as TOR. Comparisons of proportions of TOR in different grades of mTICI were performed. In the present study, the requirement for informed consents was waived.

RESULTS

Eighty-two patients were included. The difference in the proportion of TOR for TICI categories was statistically significant (mTICI score 0, 0%, mTICI score 2A, 0%, mTICI score 2b, 50.0%, mTICI score 2c, 80.0%, mTICI score 3, 81.3%, χ²=14.035, P=0.003). Multivariable logistic regression showed that lower age (odds ratio, 0.932, P=0.017), onset-to-tissue-type plasminogen activator time (odds ratio, 0.980, P=0.005) and TOR (odds ratio, 8.764, P=0.031) were associated with favorable functional outcome.

CONCLUSIONS

The proportion of TOR achieved by mTICI score of 2b was significantly lower than mTICI score of 2c and mTICI score of 3. TOR was associated with favorable functional outcome, and the degree of reperfusion was more strongly correlated with outcomes than the mTICI scores.

The Tigertriever 13 for mechanical thrombectomy in distal and medium intracranial vessel occlusions

PURPOSE

To report our two-center initial experience using the Tigertriever 13 in the treatment of acute stroke of distal, medium vessel occlusions (DMVO).

METHODS

We performed a retrospective analysis of all patients treated by mechanical thrombectomy using the Tigertriever 13 device (a manually expandable low profile stent retriever) due to an acute DMVO. Locations included the anterior, middle, and posterior cerebral artery in the A2 and A3, the M3 and M4, and the P2 or P3 segment and the superior cerebellar artery.

RESULTS

Forty-three patients with 45 DMVOs underwent MTE using the Tigertriever 13 with the intention-to-treat approach between May 2019 and December 2020. After a median of two thrombectomy maneuvers, the successful recanalization rate (mTICI 2b-3) was 84.4% (38/45) with a first pass effect of 26.7% (12/45). The rate of symptomatic intracranial hemorrhages (sICH) and subarachnoid hemorrhages (SAH) was 7.0% (3/43) and 14.0% (6/43), respectively. At discharge, 53.5% (23/43) of the patients had a favorable clinical outcome (mRS 0-2).

CONCLUSION

Mechanical thrombectomy in DMVOs using the Tigertriever 13 leads to high recanalization rates. The incidence of mostly asymptomatic hemorrhagic events appears higher compared to MTE procedures in LVOs. Further studies will help to identify anatomic and clinical criteria to define a guideline for MTE in DMVOs.

Effect of Thrombectomy With Combined Contact Aspiration and Stent Retriever vs Stent Retriever Alone on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion: The ASTER2 Randomized Clinical Trial

IMPORTANCE

Mechanical thrombectomy using a stent retriever or contact aspiration is widely used for treatment of patients with acute ischemic stroke due to anterior circulation large vessel occlusion, but the additional benefit of combining contact aspiration with stent retriever is uncertain.

OBJECTIVE

To determine whether mechanical thrombectomy for treatment of anterior circulation large vessel occlusion stroke with initial contact aspiration and stent retriever combined results in better final angiographic outcome than with standard stent retriever alone.

DESIGN, SETTING, AND PARTICIPANTS

This trial was a multicenter randomized, open-label, blinded end point evaluation that enrolled 408 patients from October 16, 2017, to May 29, 2018, in 11 French comprehensive stroke centers, with a 12-month outcome follow-up. Patients with a large vessel occlusion in the anterior circulation were included up to 8 hours after symptom onset. The final date of follow-up was June, 19, 2019.

INTERVENTIONS

Patients were randomly assigned (1:1 allocation) to receive initial thrombectomy with contact aspiration and stent retriever combined (205) or stent retriever alone (203).

MAIN OUTCOMES AND MEASURES

The primary outcome was the rate of expanded Thrombolysis In Cerebral Infarction score of 2c or 3 (eTICI 2c/3; ie, scores indicate near-total and total reperfusion grades) at the end of the procedure.

RESULTS

Among the 408 patients who were randomized, 3 were excluded, and 405 (99.3%) patients (mean age, 73 years; 220 [54%] women and 185 [46%] men) were included in the primary analysis. The rate of eTICI 2c/3 at the end of the endovascular procedure was not significantly different between the 2 thrombectomy groups (64.5% [131 of 203 patients] for contact aspiration and stent retriever combined vs 57.9% [117 of 202 patients] for stent retriever alone; risk difference, 6.6% [95% CI, -3.0% to 16.2%]; adjusted odds ratio [OR], 1.33 [95% CI, 0.88 to 1.99]; P = .17). Of 14 prespecified secondary efficacy end points, 12 showed no significant difference. A higher rate of successful reperfusion was achieved in the contact aspiration combined with stent retriever group vs the stent retriever alone group (eTICI 2b50/2c/3, 86.2% vs 72.3%; adjusted OR, 2.54 [95% CI, 1.51 to 4.28]; P < .001) and of near-total or total reperfusion (eTICI 2c/3, 59.6% vs 49.5%; adjusted OR, 1.52 [95% CI, 1.02 to 2.27]; P = .04) after the assigned initial intervention alone.

CONCLUSIONS AND RELEVANCE

Among patients with acute ischemic stroke due to large vessel occlusion, an initial thrombectomy technique consisting of contact aspiration and stent retriever combined, compared with stent retriever alone, did not significantly improve the rate of near-total or total reperfusion (eTICI 2c/3) at the end of the endovascular procedure, although the trial may have been underpowered to detect smaller differences between groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03290885.

Cortical Venous Changes on Susceptibility-Weighted Imaging Predict the Cerebral Collateral Circulation as Confirmed by Digital Subtraction Angiography

Objective: Asymmetrical cortical vein sign (ACVS) shown on susceptibility-weighted imaging (SWI) can reflect regional hypoperfusion. We investigated if ACVS could predict the cerebral collateral circulation (CC) as assessed by digital subtraction angiography (DSA) in acute ischemic stroke patients with ipsilateral severe stenosis/occlusion of the anterior circulation.

Methods: Clinical data and imaging data of 62 acute ischemic stroke patients with ipsilateral severe stenosis or occlusion of the anterior circulation confirmed by DSA were collected retrospectively. Participants underwent magnetic resonance imaging, including an SWI sequence. ACVS was defined as more and/or larger venous signals in the cerebral cortex of one side of SWI than that in the contralateral side. ACVS was measured using the Alberta Stroke Program Early Computed Tomography score based on SWI. The grading of the cerebral CC was judged using DSA.

Results: Of the 62 patients, 30 patients (48.4%) had moderate-to-severe ACVS. According to DSA assessment, 19 patients (30.6%) had a good CC (grade 3–4), and 43 (69.4%) patients had a poor-to-moderate CC (grade 0–2). Among the 30 patients with moderate-to-severe ACVS, only three (10%) patients had a good CC, and 27 (90%) patients had a poor-to-moderate CC; among the 32 patients with none or mild ACVS, 16 (50%) of them had a good CC, and the other 50% had a moderate-to-severe CC. We constructed two logistic regression models with ACVS grading and none or mild ACVS entered into the models, respectively, together with age and large-artery occlusion. In model 1, no ACVS (compared with severe ACVS; OR = 40.329, 95%CI = 2.817–577.422, P = 0.006), mild ACVS (compared with severe ACVS; OR = 17.186, 1.735–170.224, 0.015) and large-artery occlusion (OR = 45.645, 4.603–452.592, 0.001) correlated with a good CC. In model 2, none or mild ACVS (OR = 36.848, 95%CI = 5.516–246.171, P < 0.001) was significantly associated with a good CC as judged by DSA, adjusted by age and large-artery occlusion.

Conclusions: Cortical venous changes in SWI may be a useful indicator for the cerebral CC as confirmed by DSA.

Use of quantitative angiographic methods with a data-driven model to evaluate reperfusion status (mTICI) during thrombectomy

PURPOSE

Intra-procedural assessment of reperfusion during mechanical thrombectomy (MT) for emergent large vessel occlusion (LVO) stroke is traditionally based on subjective evaluation of digital subtraction angiography (DSA). However, semi-quantitative diagnostic tools which encode hemodynamic properties in DSAs, such as angiographic parametric imaging (API), exist and may be used for evaluation of reperfusion during MT. The objective of this study was to use data-driven approaches, such as convolutional neural networks (CNNs) with API maps, to automatically assess reperfusion in the neuro-vasculature during MT procedures based on the modified thrombolysis in cerebral infarction (mTICI) scale.

METHODS

DSAs from patients undergoing MTs of anterior circulation LVOs were collected, temporally cropped to isolate late arterial and capillary phases, and quantified using API peak height (PH) maps. PH maps were normalized to reduce injection variability. A CNN was developed, trained, and tested to classify PH maps into 2 outcomes (mTICI 0,1,2a/mTICI 2b,2c,3) or 3 outcomes (mTICI 0,1,2a/mTICI 2b/mTICI 2c,3), respectively. Ensembled networks were used to combine information from multiple views (anteroposterior and lateral).

RESULTS

The study included 383 DSAs. For the 2-outcome classification, average accuracy was 81.0% (95% CI, 79.0-82.9%), and the area under the receiver operating characteristic curve (AUROC) was 0.86 (0.84-0.88). For the 3-outcome classification, average accuracy was 64.0% (62.0-66.0), and AUROC values were 0.85 (0.83-0.87), 0.74 (0.71-0.77), and 0.78 (0.76-0.81) for the mTICI 0,1,2a, mTICI 2b, and mTICI 2c,3 classes, respectively.

CONCLUSION

This study demonstrated the feasibility of using hemodynamic information in API maps with data-driven models to autonomously assess intra-procedural reperfusion during MT.

CE: Acute Ischemic Stroke

ABSTRACT

Stroke, the most common form of cerebrovascular disease, is a leading cause of death and disability throughout the world. There have been no significant advances in the development of effective therapeutics for hemorrhagic stroke, and for ischemic stroke highly effective, evidence-based therapies such as alteplase and mechanical thrombectomy are widely underutilized. Improving outcomes for patients experiencing ischemic stroke requires faster recognition and appropriate intervention within the treatment window (the first 24 hours after symptom onset). This article discusses the pathophysiology underlying the various types of ischemic stroke; the risk factors for ischemic stroke; stroke presentation; and the evidence-based treatments, nursing assessments, and monitoring protocols that are critical to patient recovery.

Mechanical Thrombectomy in Acute Terminal Internal Carotid Artery Occlusions Using a Large Manually Expandable Stentretriever (Tiger XL Device): Multicenter Initial Experience

Background: The recently introduced Tigertriever XL Device for treatment of cerebral vessel occlusions combines manual adjustability and maximum length in one device. In this study, we report our initial experience with the Tigertriever XL in terminal ICA occlusions. Methods: Retrospective multicenter analysis of acute terminal ICA occlusions treated by mechanical thrombectomy using the Tigertriever XL Device. Results: 23 patients were treated using the Tigetriever XL due to an acute occlusion of the terminal ICA. The overall successful reperfusion rate after a median of two maneuvers using the Tigertriever XL Device was 78.3% (mTICI 2b-3). In 43.5% (10/23) additional smaller devices were applied to treat remaining occlusions in downstream territories, which resulted in a final successful reperfusion rate of 95.7%. Device related complications did not occur. Two symptomatic intracerebral hemorrhages (sICH) were observed. Conclusions: The Tigertriever XL Device might be a helpful tool in the treatment of ICA terminus occlusions with large clot burden resulting in high reperfusion rates. This is mainly related to the manual adjustability of the device combined with the maximum length.

First-Pass Effect in Basilar Artery Occlusions: Insights From the Endovascular Treatment of Ischemic Stroke Registry

BACKGROUND AND PURPOSE

In the settings of thrombectomy, the first-pass effect (FPE), defined by a complete recanalization after one pass with no rescue therapy, has been shown to be associated with an improved outcome. As this phenomenon has been predominantly described in anterior circulation strokes, we aimed to study the prevalence, outcomes, and predictors of FPE in patients with a basilar artery occlusion.

METHODS

From a prospective multicentric registry, we collected the data of all consecutive basilar artery occlusion patients who underwent thrombectomy and compared the outcomes of patients who achieved FPE and those who did not. We also compared FPE patients with those who achieved a complete recanalization with >1 pass. Finally, a multivariate analysis was performed to determine the predictors of FPE.

RESULTS

Data from 280 patients were analyzed in our study, including 84 of 280 patients (30%) with an atheromatous etiology. An FPE was achieved in 93 patients (33.2%), with a significantly higher proportion of good outcomes (modified Rankin Scale score 0-2 at 3 months) and lower mortality than non-FPE patients. An FPE was also associated with improved outcomes compared with patients who went on to have full recanalization with >1 pass. Contact aspiration as first-line strategy was a strong predictor of FPE, whereas baseline antiplatelets and atheromatous etiology were negative predictors.

CONCLUSIONS

In our study, an FPE was achieved in approximately one-third of patients with a basilar artery occlusion and was associated with improved outcomes. More research is needed to improve devices and techniques to increase the incidence of FPE. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03776877.

The Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Predict Reperfusion and Prognosis after Endovascular Treatment of Acute Ischemic Stroke

Background: Studies assessing the prognostic effect of inflammatory markers of blood cells on the outcomes of patients with acute ischemic stroke treated with endovascular treatment (EVT) are sparse. We evaluated whether the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) affect reperfusion status in patients receiving EVT. Methods: Using a multicenter registry database, 282 patients treated with EVT were enrolled in this study. The primary outcome measure was unsuccessful reperfusion rate after EVT defined by thrombolysis in cerebral infarction grades 0–2a. Logistic regression analysis was performed to analyze the association between NLR/PLR and unsuccessful reperfusion rate after EVT. Results: Both NLR and PLR were higher in the unsuccessful reperfusion group than in the successful reperfusion group (p < 0.001). Multivariate analysis showed that both NLR and PLR were significantly associated with unsuccessful reperfusion (adjusted odds ratio (95% confidence interval): 1.11 (1.04–1.19), PLR: 1.004 (1.001–1.01)). The receiver operating characteristic curve showed that the predictive ability of both NLR and PLR was close to good (area under the curve (AUC) of NLR: 0.63, 95% CI (0.54–0.72), p < 0.001; AUC of PLR: 0.65, 95% CI (0.57–0.73), p < 0.001). The cutoff values of NLR and PLR were 6.2 and 103.6 for unsuccessful reperfusion, respectively. Conclusion: Higher NLR and PLR were associated with unsuccessful reperfusion after EVT. The combined application of both biomarkers could be useful for predicting outcomes after EVT.

Combined Approach to Stroke Thrombectomy Using a Novel Short Flexible Aspiration Catheter with a Stent Retriever : Preliminary Clinical Experience

BACKGROUND

Large-bore aspiration catheters enabling greater flow rates and suction force for mechanical thrombectomy might improve outcomes in patients with stroke secondary to large-vessel occlusion. Complete or near-complete reperfusion after a single thrombectomy pass (first-pass effect) is associated with improved clinical outcomes. We assessed the efficacy and safety of novel MIVI Q™ aspiration catheters in combination with stent-retriever devices.

METHODS

We retrospectively analyzed demographics, procedure characteristics, and clinical data from consecutive patients with acute anterior large-vessel occlusion treated with a combined approach using MIVI Q™ aspiration catheters and stent retrievers. Reperfusion was defined according to the modified thrombolysis in cerebral infarction (mTICI) score. Clinical outcomes were measured by the National Institute of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores.

RESULTS

We included 52 patients (median age, 75 y IQR: 64-83); 31 (59.6%) women; 14 (26.9%) with terminal internal carotid artery occlusions, 26 (50%) middle cerebral artery (MCA) segment M1 occlusions, and 12 (23.1%) MCA segment M2 occlusions; median NIHSS score at admission was 19 (IQR: 13-22). After the first pass, 25 (48%) patients had mTICI ≥ 2c. At the end of the procedure, 47 (90.4%) had mTICI ≥ 2b and 35 (67.3%) had mTICI ≥ 2c. No serious device-related adverse events were observed. Symptomatic intracranial hemorrhage developed in 1 patient. Mean NIHSS score was 13 at 24 h and 5 at discharge. At 90 days, 24 (46.2%) patients were functionally independent (mRS 0-2).

CONCLUSION

This preliminary study found good efficacy and safety for MIVI Q™ aspiration catheters used in combination with stent-retriever devices.

Circulating Cytokines and Growth Factors in Acute Cerebral Large Vessel Occlusion-Association with Success of Endovascular Treatment

Mechanical thrombectomy (MT) is a highly efficient treatment in patients with acute ischemic stroke due to large vessel occlusion (LVO). However, in a relevant proportion of LVO, no sufficient recanalization can be achieved. The composition of cerebral thrombi is highly heterogeneous and may constitute a relevant factor for insufficient reperfusion. We hypothesized that circulating cytokines and growth factors involved in thromboinflammation and platelet activation may be associated with reperfusion status and thrombus composition in patients undergoing MT. An according biomarker panel was measured in plasma specimens taken prior to MT and at a 7-day follow-up. The reperfusion status was categorized into sufficient or insufficient. The composition of retrieved thrombi was histologically analyzed. Differences of baseline biomarker concentrations between insufficient and sufficient reperfusions were highest for interferon (IFN)-γ, epidermal growth factor, platelet-derived growth factor (PDGF)-AB/BB, and IFN-γ-induced protein 10 (IP-10/CXCL10). After applying correction for multiple comparisons and logistic regression analysis adjusting for stroke etiology, intravenous thrombolysis, and vascular risk factors, PDGF-AB/BB was identified as an independent predictor of reperfusion status (odds ratio: 0.403; 95% confidence interval: 0.199-0.819). Histological analysis revealed that the majority of thrombi had a mixed composition. In conclusion, this study provides the first evidence that cytokines and growth factors are potential effectors in patients undergoing MT for the treatment of acute ischemic stroke.

Thrombolytic strategies for ischemic stroke in the thrombectomy era

Twenty-five years ago, intravenous thrombolysis has revolutionized the care of patients with acute ischemic stroke. Since 2015, randomized clinical trials have demonstrated that mechanical thrombectomy improves functional outcome in stroke patients over intravenous thrombolysis alone. More recently, three randomized clinical trials have suggested that mechanical thrombectomy alone is noninferior to a combined strategy with both intravenous thrombolysis and mechanical thrombectomy. In the present review, we will present the last clinical and preclinical studies on the use of thrombolysis in stroke patients in the modern thrombectomy era. At the cost of a potential increased risk of hemorrhagic transformation, thrombolysis may promote arterial recanalization before thrombectomy, improve the rate of successful recanalization after thrombectomy, and restore microcirculation patency downstream of the main thrombus. Besides, new thrombolytic strategies targeting tissue-type plasminogen activator resistant thrombi are being developed, which could strengthen the beneficial effects of thrombolysis without carrying additional pro-hemorrhagic effects. For instance, tenecteplase has shown improved rate of recanalization compared with tissue-type plasminogen activator (alteplase). Beyond fibrinolysis, DNA- and von Willebrand factor-targeted thrombolytic strategies have shown promising results in experimental models of ischemic stroke. New combined strategies, improved thrombolytics, and dedicated clinical trials in selected patients are eagerly awaited to further improve functional outcome in stroke.

Early TICI 2b or Late TICI 3-Is Perfect the Enemy of Good?

Background and Purpose

A Thrombolysis in Cerebral Infarction (TICI) score of 3 has been established as therapeutic goal in endovascular therapy (EVT) for acute ischemic stroke; however, in the case of early TICI2b reperfusion, the question remains whether to stop the procedure or to continue in the pursuit of perfection (i.e., TICI 2c/3).

Methods

A total of 6635 patients were screened from the German Stroke Registry. Patients who underwent EVT for occlusion of the middle cerebral artery (M1 segment), with final TICI score of 2b/3 were included. Multivariable logistic regression was performed with functional independence (modified Rankin Scale, mRS at day 90 of 0–2) as the dependent variable.

Results

Of 1497 patients, 586 (39.1%) met inclusion criteria with a final TICI score of 2b and 911 (60.9%) with a TICI score of 3. Patients who achieved first-pass TICI3 showed highest odds of functional independence (Odds ratio [OR] 1.71, 95% confidence interval [95% CI] 1.18–2.47). Patients who achieved TICI2b with the second pass (OR 0.53, 95% CI 0.31–0.89) or with three or more passes (OR 0.44, 95% CI 0.27–0.70) had significantly worse clinical outcomes compared to first-pass TICI2b. TICI3 at the second pass was by trend better than first-pass TICI2b (OR 1.55, 95% CI 0.98–2.45), but TICI3 after 3 or more passes (OR 0.93, 95% CI 0.57–1.50) was not significantly different from first-pass TICI2b.

Conclusion

First-pass TICI2b was superior to TICI2b after ≥ 2 retrievals and comparable to TICI3 at ≥ 3 retrievals. The potential benefit in outcome after achieving TICI3 following further retrieval attempts after first-pass TICI2b need to be weighed against the risks.

Supplementary Information

The online version of this article (10.1007/s00062-021-01048-8) contains supplementary material, which is available to authorized users.

First-Pass Reperfusion by Mechanical Thrombectomy in Acute M1 Occlusion: The Size of Retriever Matters

Introduction: Single-pass complete reperfusion using stent retrievers has been shown to improve functional outcome in patients with large vessel occlusion strokes. The aim of this study was to investigate the optimal size of stent retrievers to achieve one-pass complete reperfusion by mechanical thrombectomy. Methods: The study evaluated the results of aspiration-assisted mechanical thrombectomy of acute isolated occlusion of the middle cerebral artery in the M1 segment with a novel 5 × 40-mm stent retriever compared to the usual 4 × 20-mm device. Reperfusion status was quantified using the Thrombolysis In Cerebral Infarction (TICI) scale. We hypothesized that thrombectomy of M1 occlusions with 5 × 40-mm stent retriever yields higher rates of complete first-pass reperfusion (FP) (TICI ≥2c after one pass) and successful or modified FP (mFP) (TICI ≥2b after one pass) than thrombectomy with 4 × 20. We included isolated M1 occlusions treated with pRESET 5 × 40 (phenox) as first-choice device for thrombectomy and compared with M1 occlusions treated with pRESET 4 × 20. We excluded patients with additional occlusions or tandem stenosis or who received an intracranial stent or angioplasty as a part of the endovascular treatment. Results: One hundred thirteen patients were included in the 4 × 20 group and 57 patients in the 5 × 40 group. The 5 × 40 group achieved higher FP compared to 4 × 20 group [61.4% (35 of 57 patients) vs. 40.7% (46 of 113), respectively; adjusted odds ratio (OR) and 95% confidence interval (95% CI) = 2.20 (1.08-4.48), p = 0.030] and a higher mFP [68.4%, 39 of 57 patients vs. 48.7%, 55 of 113; adjusted OR (95% CI) = 2.11 (1.04-4.28), p = 0.037]. Frequency of successful reperfusion (TICI ≥2b) was similar in both groups (100 vs. 97.3%), but frequency of complete reperfusion (TICI ≥2c) was higher in the 5 × 40 group [82.5 vs. 61.9%, adjusted OR (95% CI) = 2.47 (1.01-6.04), p = 0.047]. Number of passes to achieve reperfusion was lower in the 5 × 40 group than in the 4 × 20 group [1.6 ± 1.1 vs. 2 ± 1.4, p = 0.033; adjusted incidence rate ratio (95% CI) = 0.84 (0.69-1.03), p = 0.096]. Modified Rankin scale at 90 days was similar in 5 × 40 and 4 × 20 groups. Conclusions: The size of stent retriever matters in acute M1 occlusions treated with aspiration-assisted mechanical thrombectomy. A longer stent retriever with a larger nominal diameter achieves a higher complete and successful FP and higher successful reperfusion compared to a shorter stent retriever.

On the Sensitivity Analysis of Porous Finite Element Models for Cerebral Perfusion Estimation

Computational physiological models are promising tools to enhance the design of clinical trials and to assist in decision making. Organ-scale haemodynamic models are gaining popularity to evaluate perfusion in a virtual environment both in healthy and diseased patients. Recently, the principles of verification, validation, and uncertainty quantification of such physiological models have been laid down to ensure safe applications of engineering software in the medical device industry. The present study sets out to establish guidelines for the usage of a three-dimensional steady state porous cerebral perfusion model of the human brain following principles detailed in the verification and validation (V&V 40) standard of the American Society of Mechanical Engineers. The model relies on the finite element method and has been developed specifically to estimate how brain perfusion is altered in ischaemic stroke patients before, during, and after treatments. Simulations are compared with exact analytical solutions and a thorough sensitivity analysis is presented covering every numerical and physiological model parameter. The results suggest that such porous models can approximate blood pressure and perfusion distributions reliably even on a coarse grid with first order elements. On the other hand, higher order elements are essential to mitigate errors in volumetric blood flow rate estimation through cortical surface regions. Matching the volumetric flow rate corresponding to major cerebral arteries is identified as a validation milestone. It is found that inlet velocity boundary conditions are hard to obtain and that constant pressure inlet boundary conditions are feasible alternatives. A one-dimensional model is presented which can serve as a computationally inexpensive replacement of the three-dimensional brain model to ease parameter optimisation, sensitivity analyses and uncertainty quantification. The findings of the present study can be generalised to organ-scale porous perfusion models. The results increase the applicability of computational tools regarding treatment development for stroke and other cerebrovascular conditions.

Interobserver Agreement in Scoring Angiographic Results of Basilar Artery Occlusion Stroke Therapy

BACKGROUND AND PURPOSE

The modified TICI Infarction grading system is a metric currently used to evaluate angiographic results of thrombectomy for large-vessel occlusion in ischemic stroke. Originally designed for evaluating MCA territories, it is currently used for other vessel occlusions, including the posterior circulation. We postulate that the modified TICI use for the posterior circulation is not accurate due to the different vascular territories supplied by vertebrobasilar vasculature, making grading more complex.

MATERIALS AND METHODS

We collected angiographic results from 30 patients who presented with acute posterior circulation occlusions between 2015 and 2018 and underwent thrombectomy in our institution. Eight observers were asked to evaluate the TICI scores before and after thrombectomy. The multirater statistics were computed using Fleiss κ analysis. Further data were collected regarding the potential brain territories at risk and the existence of atherosclerotic disease in the basilar artery.

RESULTS

The overall agreement κ reached 0.277 (SD, 0.013), which suggests a "fair" agreement among the raters. On average, 45% of observers achieved a high accuracy in predicting brain areas at risk of ischemia. As for the existence of basilar atherosclerotic disease, a high agreement (defined as at least 5 of 6 observers) was seen in 20 of the 30 patients.

CONCLUSIONS

Despite TICI being ubiquitous in stroke diagnostics, the high variability of posterior circulation TICI scores calls into question its use in these strokes. Other methods should be developed to assess recanalization in the posterior circulation.

Usefulness of combination usage of balloon guide catheter with contact aspiration thrombectomy

BACKGROUND

Angiographic outcomes of contact aspiration thrombectomy (CAT), a frontline thrombectomy strategy, can vary depending on balloon guide catheter (BGC) usage, stroke etiology, and occlusion location. The purpose of this study was to analyze conditional outcomes of CAT to determine which result in maximum angiographic benefits.

METHODS

Patients who received CAT for anterior circulation occlusive stroke between January 2017 and December 2018 were included. Angiographic and clinical outcomes were compared relative to BGC use, stroke etiology, and occlusion location. Multivariable analyses for first-pass reperfusion (FPR) and favorable clinical outcome were performed.

RESULTS

Of 160 included patients, the rates of FPR, successful reperfusion after CAT, final successful reperfusion, and favorable clinical outcome were 43.1%, 58.1%, 81.9%, and 60.6%, respectively. BGC use was associated with a higher rate of FPR, successful reperfusion after CAT, a lower rate of distal embolization, and faster reperfusion. Based on subgroup analysis, BGC usage in ICA, MCA M1 occlusion, and cardioembolism were associated with higher FPR, successful reperfusion after CAT, and lower distal embolization. Faster reperfusion was achieved in ICA occlusions and cardioembolisms. BGC usage was an independent predictor of FPR. Favorable clinical outcome was associated with male gender, low initial NIHSS score, fast onset to reperfusion, and FPR.

CONCLUSIONS

In CAT, BGC usage was associated with better angiographic outcomes, including higher FPR, successful reperfusion after CAT, prevention of distal embolization, and faster reperfusion, especially in proximal occlusions and cardioembolisms. These conditions may play a role in maximizing the benefits of CAT.

Benchmarking the Extent and Speed of Reperfusion: First Pass TICI 2c-3 Is a Preferred Endovascular Reperfusion Endpoint

Background and Purpose: End-of-procedure substantial reperfusion [modified Treatment in Cerebral Ischemia (mTICI) 2b-3], the leading endpoint for thrombectomy studies, has several limitations including a ceiling effect, with recent achieved rates of ~90%. We aimed to identify a more optimal definition of angiographic success along two dimensions: (1) the extent of tissue reperfusion, and (2) the speed of revascularization.

Methods: Core-lab adjudicated TICI scores for the first three passes of EmboTrap and the final all-procedures result were analyzed in the ARISE II multicenter study. The clinical impact of extent of reperfusion and speed of reperfusion (first-pass vs. later-pass) were evaluated. Clinical outcomes included 90-day functional independence [modified Rankin Scale (mRS) 0–2], 90-day freedom-from-disability (mRS 0–1), and dramatic early improvement [24-h National Institutes of Health Stroke Scale (NIHSS) improvement ≥ 8 points].

Results: Among 161 ARISE II subjects with ICA or MCA M1 occlusions, reperfusion results at procedure end showed substantial reperfusion in 149 (92.5%), excellent reperfusion in 121 (75.2%), and complete reperfusion in 79 (49.1%). Reperfusion rates on first pass were substantial in 81 (50.3%), excellent reperfusion in 62 (38.5%), and complete reperfusion in 44 (27.3%). First-pass excellent reperfusion (first-pass TICI 2c-3) had the greatest nominal predictive value for 90-day mRS 0–2 (sensitivity 58.5%, specificity 68.6%). There was a progressive worsening of outcomes with each additional pass required to achieve TICI 2c-3.

Conclusions: First-pass excellent reperfusion (TICI 2c-3), reflecting rapid achievement of extensive reperfusion, is the technical revascularization endpoint that best predicted functional independence in this international multicenter trial and is an attractive candidate for a lead angiographic endpoint for future trials.

Clinical Trial Registration:http://www.clinicaltrials.gov, identifier NCT02488915.