Outcomes after reperfusion therapies in patients with ACA stroke: A multicenter cohort study from the EVATRISP collaboration

Endovascular thrombectomy versus medical management for moderate-to-severe anterior cerebral artery occlusion stroke

BACKGROUND

There are no established patient selection criteria for endovascular thrombectomy (EVT) for anterior cerebral artery (ACA) stroke.

METHODS

This was a retrospective cohort study of the 2016-2020 National Inpatient Sample in the United States. Isolated ACA-occlusion stroke patients with moderate-to-severe stroke symptoms (NIH stroke scale [NIHSS] ≥ 6) were included. Primary outcome was hospital discharge to home with self-care. Secondary outcomes include in-hospital mortality and intracranial hemorrhage (ICH). Confounders were accounted for by multivariable logistic regression.

RESULTS

6685 patients were included; 335 received EVT. Compared to medical management (MM), EVT patients were younger (mean 67.2 versus 72.2 years; p = 0.014) and had higher NIHSS (mean 16.0 versus 12.5; p < 0.001). EVT was numerically but not statistically significantly associated with higher odds of home discharge compared to MM (aOR 2.26 [95%CI 0.99-5.17], p = 0.053). EVT was significantly associated with higher odds of home discharge among patients with NIHSS 10 or greater (aOR 3.35 [95%CI 1.06-10.58], p = 0.039), those who did not receive prior thrombolysis (aOR 3.96 [95%CI 1.53-10.23], p = 0.005), and those with embolic stroke etiology (aOR 4.03 [95%CI 1.21-13.47], p = 0.024). EVT was not significantly associated with higher rates of mortality (aOR 1.93 [95%CI 0.80-4.63], p = 0.14); however, it was significantly associated with higher rates of ICH (22.4% vs. 8.5%, p < 0.001).

CONCLUSION

EVT was associated with higher odds of favorable short-term outcomes for moderate-to-severe ACA-occlusion stroke in select patients. Future studies are needed to confirm the efficacy of EVT in terms of longer term neurological outcomes.

Endovascular thrombectomy versus intravenous thrombolysis for primary distal, medium vessel occlusion in acute ischemic stroke

Introduction

In the absence of clinical trials, the benefit of endovascular therapy (EVT) on the treatment of acute ischemic stroke (AIS) with primary distal and medium vessel occlusions (DMVO) is still not well defined. The aim of the study is to evaluate EVT with or without intravenous thrombolysis (EVT ± IVT) in primary DMVO stroke in comparison with a control cohort treated with IVT alone.

Methods

We analysed all consecutive AIS with proven primary DMVO. Primary endpoints were excellent outcome, functional independence at 3 months follow-up, and early neurologic improvement at 1 day after treatment.

Results

One hundred and fourteen patients with DMVO strokes were included between 2019 and 2023. Propensity-weighted analysis showed no significant differences in EVT ± IVT vs IVT for the excellent outcome (adjusted OR [aOR], 1.575; 95% CI, 0.706-3.513), functional independence (aOR, 2.024; 95% CI, 0.845-4.848), early neurological improvement (aOR, 2.218; 95% CI, 0.937-5.247), mortality (aOR, 0.498; 95% CI, 0.177-1.406), symptomatic intracranial haemorrhage (aOR, 0.493; 95% CI, 0.102-2.385), and subarachnoid haemorrhage (aOR, 0.560; 95% CI, 0.143-2.187). The type of revascularization did not influence the percentage of cerebral volume lost (adjusted linear regression estimate, -19.171, t value, 11.562; p = 0.104).

Conclusions

This study supports the hypothesis that patients with primary DMVO stroke treated with EVT (±IVT) or IVT alone have comparable outcomes.

EnDovascular Therapy Plus Best Medical Treatment (BMT) Versus BMT Alone for MedIum distal VeSsel Occlusion sTroke (DISTAL): An international, multicentre, randomized-controlled, two-arm, assessor-blinded trial

RATIONALE

Whether endovascular therapy (EVT) in addition to best medical treatment (BMT) in people with acute ischemic stroke (AIS) due to a medium distal vessel occlusion (MDVO) is beneficial remains unclear.

AIM

To determine if people experiencing an AIS due to an isolated MDVO (defined as the co- or non-dominant M2 segment, the M3 or M4 segment of the middle cerebral artery, the A1, A2, or A3 segment of the anterior cerebral artery or the P1, P2 or P3 segment of the posterior cerebral artery) will have superior outcome if treated with EVT in addition to BMT compared to BMT alone.

SAMPLE SIZE

To randomize 526 participants 1:1 to EVT plus BMT or BMT alone.

METHODS AND DESIGN

A multicentre, international, prospective, randomized, open-label, blinded-endpoint (PROBE) superiority trial.

OUTCOMES

The primary efficacy endpoint is the distribution of disability levels on the modified Rankin Scale at 90 days. Secondary clinical efficacy outcomes include normalized change in National Institutes of Health Stroke Scale score from baseline to day 1, cognitive outcome at 90 days, and health-related quality of life at 90 days. Safety outcomes include all serious adverse events, symptomatic intracranial hemorrhage within 24 h, and all-cause mortality up to 90 days. Secondary imaging outcomes include successful reperfusion at end of EVT procedure and recanalization of target artery at 24 h.

DISCUSSION

DISTAL will inform physicians whether EVT in addition to BMT in people with AIS due to a MDVO is more efficacious than BMT alone.

Distal Medium Vessel Occlusion Strokes: Understanding the Present and Paving the Way for a Better Future

Distal medium vessel occlusions (DMVOs) are thought to cause as many as 25% to 40% of all acute ischemic strokes and may result in substantial disability amongst survivors. Although intravenous thrombolysis (IVT) is more effective for distal than proximal vessel occlusions, the overall efficacy of IVT remains limited in DMVO with less than 50% of patients achieving reperfusion and about 1/3 to 1/4 of the patients failing to achieve functional independence. Data regarding mechanical thrombectomy (MT) among these patients remains limited. The smaller, thinner, and more tortuous vessels involved in DMVO are presumably associated with higher procedural risks whereas a lower benefit might be expected given the smaller amount of tissue territory at risk. Recent advances in technology have shown promising results in endovascular treatment of DMVOs with room for future improvement. In this review, we discuss some of the key technical and clinical considerations in DMVO treatment including the anatomical and clinical terminology, diagnostic modalities, the role of IVT and MT, existing technology, and technical challenges as well as the contemporary evidence and future treatment directions.

Mechanical thrombectomy for the treatment of primary and secondary distal medium-vessel occlusion stroke: systematic review and meta-analysis

BACKGROUND

There is limited evidence on the indication and role of mechanical thrombectomy (MT) in patients with distal medium-vessel occlusions (DMVOs). The aim of this systematic review and meta-analysis was to evaluate all the evidence available on the efficacy and safety of MT techniques (stent retriever, aspiration) in primary and secondary DMVOs.

METHODS

Five databases were searched from inception to January 2023 for studies of MT in primary and secondary DMVOs. Outcomes of interest included favorable functional outcome (90-day modified Rankin scale (mRS) 0-2), successful reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3), symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. Prespecified subgroup meta-analyses according to the specific MT technique and to the vascular territory (distal M2-M5, A2-A5, P2-P5) were also performed.

RESULTS

A total of 29 studies with 1262 patients were included. For primary DMVOs (n=971 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 84% (95% confidence interval (CI) 76 to 90%), 64% (95% CI 54 to 72%), 12% (95% CI 8 to 18%), and 6% (95% CI 4 to 10%), respectively. For secondary DMVOs (n=291 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 82% (95% CI 73 to 88%), 54% (95% CI 39 to 69%), 11% (95% CI 5 to 20%), and 3% (95% CI 1 to 9%), respectively. Subgroup analyses by MT technique and by vascular territory showed no differences in primary and secondary DMVOs.

CONCLUSION

Our findings suggest that MT using aspiration or stent retriever techniques appears to be effective and safe in primary and secondary DMVOs. However, given the level of evidence of our results, further confirmation in well-designed randomized controlled trials is needed.

Endovascular therapy for acute ischemic stroke with distal medium vessel occlusion: a systematic review and meta-analysis

AIMS

Endovascular therapy (EVT) for distal medium vessel occlusions (DMVOs) is a potential frontier of acute ischemic stroke (AIS) treatment, but its efficacy against best medical therapy (BMT) remains unknown. We performed a systematic review and meta-analysis evaluating the efficacy and safety of EVT versus BMT in primary DMVO.

METHODS

We systematically searched PubMed, Cochrane Library and Embase, from inception to August 14, 2022, for studies comparing EVT with BMT in DMVO-AIS. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Efficacy outcomes were functional independence (90-day modified Rankin Scale (mRS) 0-2) and excellent functional outcomes (90-day mRS 0-1). Safety outcomes were symptomatic intracranial hemorrhage (sICH) and 90-day mortality.

RESULTS

Fourteen observational and two randomized-controlled studies were included, with 1202 patients receiving EVT and 1267 receiving BMT. After trim-and-fill correction, EVT achieved significantly better odds of functional independence than BMT (adjusted OR 1.61, 95% CI 1.06 to 2.43). There were no significant differences in overall excellent functional outcomes (OR 1.23, 95% CI 0.88 to 1.71), sICH (OR 1.44, 95% CI 0.78 to 2.66), and mortality (OR 1.03, 95% CI 0.73 to 1.45). Stratified by EVT method, mechanical thrombectomy±intra-arterial thrombolysis achieved more excellent functional outcomes than BMT (OR 1.59, 95% CI 1.13 to 2.23). In mild strokes (National Institutes of Health Stroke Scale score <6), EVT caused significantly more sICH (OR 6.30, 95% CI 1.55 to 25.64).

CONCLUSIONS

EVT shows promising efficacy benefit over BMT for primary DMVO-AIS. Further randomized controlled trials are necessary to evaluate the efficacy and safety of EVT in DMVO-AIS.

Mechanical thrombectomy for the treatment of primary and secondary anterior cerebral artery occlusions: insights from STAR

BACKGROUND

The safety and efficacy of mechanical thrombectomy (MT) for the treatment of acute anterior cerebral artery (ACA) occlusions have not clearly been delineated. Outcomes may be impacted based on whether the occlusion is isolated to the ACA (primary ACA occlusion) or occurs in conjunction with other cerebral arteries (secondary).

METHODS

We performed a retrospective review of the multicenter Stroke Thrombectomy and Aneurysm (STAR) database. All patients with MT-treated primary or secondary ACA occlusions were included. Baseline characteristics, procedural outcomes, complications, and clinical outcomes were collected. Primary and secondary ACA occlusions were compared using the Mann-Whitney U test and Kruskal-Willis test for continuous variables and the χ2 test for categorical variables.

RESULTS

The study cohort comprised 238 patients with ACA occlusions (49.2% female, median (SD) age 65.6 (16.7) years). The overall rate of successful recanalization was 75%, 90-day good functional outcome was 23%, and 90-day mortality was 35%. There were 44 patients with a primary ACA occlusion and 194 patients with a secondary ACA occlusion. When adjusted for baseline variables, the rates of successful recanalization (68% vs 76%, P=0.27), 90-day good functional outcome (41% vs 19%, P=0.38), and mortality at 90 days (25% vs 38%, P=0.12) did not differ between primary and secondary ACA occlusion groups.

CONCLUSION

Clinical and procedural outcomes are similar between MT-treated primary and secondary ACA occlusions for select patients. Our findings demonstrate the need for established criteria to determine ideal patient and ACA stroke characteristics amenable to MT treatment.

Endovascular Therapy for Acute Stroke: New Evidence and Indications

Endovascular therapy (EVT) has revolutionized the treatment of acute ischemic stroke. In the past few years, endovascular treatment indications have expanded to include patients being treated in the extended window, with large ischemic core infarction, basilar artery occlusion (BAO) thrombectomy, as demonstrated by several randomized clinical trials. Intravenous thrombolysis (IVT) bridging to mechanical thrombectomy has also been studied via several randomized clinical trials, with the overall results indicating that IVT should not be skipped in patients who are candidates for both IVT and EVT. Simplification of neuroimaging protocols in the extended window to permit non-contrast CT, CTA collaterals have also expanded access to mechanical thrombectomy, particularly in regions across the world where access to advanced imaging may not be available. Ongoing study of areas to develop include rescue stenting in patients with failed thrombectomy, medium vessel occlusion thrombectomy, and carotid tandem occlusions. In this narrative review, we summarize recent trials and key data in the treatment of patients with large ischemic core infarct, simplification of neuroimaging protocols for the treatment of patients presenting in the late window, bridging thrombolysis, and BAO EVT evidence. We also summarize areas of ongoing study including medium and distal vessel occlusion.

Thrombectomy versus Medical Management for Isolated Anterior Cerebral Artery Stroke: An International Multicenter Registry Study

Background Evidence supporting a potential benefit of thrombectomy for distal medium vessel occlusions (DMVOs) of the anterior cerebral artery (ACA) is, to the knowledge of the authors, unknown. Purpose To compare the clinical and safety outcomes between mechanical thrombectomy (MT) and best medical treatment (BMT) with or without intravenous thrombolysis for primary isolated ACA DMVOs. Materials and Methods Treatment for Primary Medium Vessel Occlusion Stroke, or TOPMOST, is an international, retrospective, multicenter, observational registry of patients treated for DMVO in daily practice. Patients treated with thrombectomy or BMT alone for primary ACA DMVO distal to the A1 segment between January 2013 and October 2021 were analyzed and compared by one-to-one propensity score matching (PSM). Early outcome was measured by the median improvement of National Institutes of Health Stroke Scale (NIHSS) scores at 24 hours. Favorable functional outcome was defined as modified Rankin scale scores of 0-2 at 90 days. Safety was assessed by the occurrence of symptomatic intracerebral hemorrhage and mortality. Results Of 154 patients (median age, 77 years; quartile 1 [Q1] to quartile 3 [Q3], 66-84 years; 80 men; 94 patients with MT; 60 patients with BMT) who met the inclusion criteria, 110 patients (median age, 76 years; Q1-Q3, 67-83 years; 50 men; 55 patients with MT; 55 patients with BMT) were matched. DMVOs were in A2 (82 patients; 53%), A3 (69 patients; 45%), and A3 (three patients; 2%). After PSM, the median 24-hour NIHSS point decrease was -2 (Q1-Q3, -4 to 0) in the thrombectomy and -1 (Q1-Q3, -4 to 1.25) in the BMT cohort (P = .52). Favorable functional outcome (MT vs BMT, 18 of 37 [49%] vs 19 of 39 [49%], respectively; P = .99) and mortality (MT vs BMT, eight of 37 [22%] vs 12 of 39 [31%], respectively; P = .36) were similar in both groups. Symptomatic intracranial hemorrhage occurred in three (2%) of 154 patients. Conclusion Thrombectomy appears to be a safe and technically feasible treatment option for primary isolated anterior cerebral artery occlusions in the A2 and A3 segment with clinical outcomes similar to best medical treatment with and without intravenous thrombolysis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhu and Wang in this issue.

Tandem occlusions involving the internal carotid and anterior cerebral arteries-A rare form of stroke: Results from the multicenter EVATRISP collaboration study

Background

Patients with stroke secondary to isolated anterior cerebral artery (ACA) occlusions have poor outcomes. Whether tandem occlusions (TO) of the extracranial internal carotid (ICA) and the ACA carry even worse outcomes that remain unknown.

Methods

Patients with TO involving ICA and ACA occlusions were identified from 14 participating centers from the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) project which is a multicenter, observational, cohort study with prospective accrual of data followed by retrospective data analysis. Patients with isolated ACA stroke served as controls.

Results

Included were 92 patients with isolated ACA and 16 patients with ICA-ACA TO stroke. On univariate analyses, patients with TO had more severe strokes on admission [median NIHSS (IQR) 13.5 (9-21) vs. 8 (5-12), p = 0.003] and were more often treated with thrombectomy (81 vs. 40%, p = 0.002). Mortality rates were higher among TO patients (31 vs. 11%, p = 0.03). Rates of favorable functional outcomes were numerically lower among TO patients (38 vs. 60%) but the difference was not statistically significant (p = 0.09). On multivariate analyses, the presence of TO did not modify the chances for favorable outcomes.

Conclusion

TO stroke with ICA and isolated ACA involvement is rare and results in more severe initial neurological deficits and higher mortality compared to those seen in patients with isolated ACA stroke.

Mechanical Thrombectomy for the Treatment of Anterior Cerebral Artery Occlusion: A Systematic Review of the Literature

BACKGROUND

The overall safety and efficacy of mechanical thrombectomy for anterior cerebral artery strokes remain unclear.

PURPOSE

Our aim was to summarize procedural and clinical outcomes in patients who underwent mechanical thrombectomy for treatment of anterior cerebral artery ischemic stroke.

DATA SOURCES

A systematic literature review was performed using PubMed, Ovid MEDLINE, and the Web of Science from inception until March 4, 2022.

STUDY SELECTION

We identified 9 studies with a total of 168 patients with mechanical thrombectomy-treated anterior cerebral artery occlusions.

DATA ANALYSIS

Recanalization, procedural data, and clinical outcome at last follow-up were collected and summarized. Categoric variables were reported as proportions. The χ² test of independence or the Kruskal-Wallis test was performed to assess the relationship between selected variables and the anterior cerebral artery embolus type (ie, primary isolated anterior cerebral artery, primary combined anterior cerebral artery, and secondary anterior cerebral artery occlusion) or the mechanical thrombectomy technique.

DATA SYNTHESIS

For mechanical thrombectomy-treated anterior cerebral artery occlusions, recanalization modified TICI 2b/3 was achieved in 80%, postprocedural complications occurred in 17% of patients, and the 90-day mortality rate was 19%. The rate of symptomatic intracranial hemorrhage varied depending on the anterior cerebral artery embolus type (χ² = 8.45, P = .01).

LIMITATIONS

This analysis did not consider factors such as small-study effects that affect reliability and limit interpretation.

CONCLUSIONS

Mechanical thrombectomy for the treatment of anterior cerebral artery occlusions is safe and efficacious, offering a favorable rate of recanalization and procedural complications. Mechanical thrombectomy-treated anterior cerebral artery occlusions appear to have lower rates of short-term good functional outcomes and an increased risk of symptomatic intracerebral hemorrhage compared with mechanical thrombectomy-treated MCA/ICA occlusions. Single and multicenter studies are needed to further examine the safety and efficacy of mechanical thrombectomy-treated anterior cerebral artery occlusions.