Real-world effectiveness of thrombectomy for basilar artery occlusion: lessons beyond the ATTENTION and BAOCHE trials

Background and Purpose: It remains controversial if endovascular treatment (EVT) can improve the outcome of patients with acute basilar artery occlusion (BAO). This study aims to compare the functional outcomes between EVT with and without intravenous thrombolysis (IVT) first in patients with acute ischemic stroke (AIS) caused by BAO. Methods: AIS patients with BAO who underwent EVT within 24 hours of onset were enrolled in this multicenter cohort study, and the efficacy and safety were compared between the IVT+EVT and direct EVT. The primary outcome was the 90-day functional independence (modified Rankin Scale of 0-2). All outcomes were assessed with adjusted odds ratio (aOR) from the multivariable logistic regression. In addition, a meta-analysis was performed on all recently published pivotal studies and incorporating these studies on functional independence after EVT in BAO patients. Results: Of 310 BAO patients enrolled, 241 (78%) were treated with direct EVT and 69 (22%) with IVT+EVT. Direct EVT was associated with a worse functional outcome (aOR, 0.46 [95% CI, 0.25-0.87]; P =0.02). IVT+EVT was associated with a lower percentage of patients who needed ≥ 3 passes of the stent retriever (10.14% vs 20.75%). The meta-analysis regression revealed a potential positive correlation between bridging with IVT first and functional independence (r, 0.14 [95% CI: 0.05-0.24]; P<0.01). Conclusions: This study showed that compared to direct EVT, EVT with standard IVT first was associated with better functional outcomes in BAO patients treated within 24 hours of onset. The meta-analysis demonstrated the similar favorable efficacy of IVT first followed by EVT in BAO patients.

To evaluate clinical outcomes of endovascular thrombectomy (EVT) for acute basilar artery occlusion (BAO) using population-level data from the United States. Weighted discharge data from the National Inpatient Sample were queried to identify adult patients with acute BAO during the period of 2015 to 2019 treated with EVT or medical management only. Complex samples statistical methods and propensity-score adjustment using inverse probability of treatment weighting (IPTW) were performed to assess clinical endpoints. Among 3,950 BAO patients identified, 1,425 (36.1%) were treated with EVT [mean age 66.7 years, median National Institute of Health Stroke Scale (NIHSS) score 22]. On unadjusted analysis, 155 (10.9%) EVT patients achieved favorable functional outcomes (discharge disposition to home without services), while 515 (36.1%) experienced in-hospital mortality, and 20 (1.4%) developed symptomatic intracranial hemorrhage (sICH). Following propensity-score adjustment by IPTW accounting for age, stroke severity, and comorbidity burden, EVT was independently associated with favorable functional outcome [adjusted odds ratio (aOR) 1.25, 95% confidence interval (CI) 1.07, 1.46; p=0.004], but not with in-hospital mortality or sICH. In an IPTW-adjusted sub-group analysis of patients with NIHSS scores >20, EVT was associated with both favorable functional outcome (discharge disposition to home or to acute rehabilitation) (aOR 1.55, 95% CI 1.24, 1.94; p < 0.001) and decreased mortality (aOR 0.78, 95% CI 0.69, 0.89; p < 0.001), but not with sICH. This retrospective population-based analysis using a large national registry provides real-world evidence of a potential benefit of EVT in acute BAO patients. ANN NEUROL 2023;94:55-60.

Introduction: Basilar artery occlusion (BAO) is a rare stroke subtype with high morbidity and mortality rates. Best reperfusion strategy is still somewhat controversial and is currently under investigation in multicenter randomized trials. We aim to describe outcomes of BAO patients submitted to mechanical thrombectomy in a comprehensive stroke center in Brazil and analyze which previous published computed tomography angiography (CTA) collateral score better predicts functional outcomes. Methods: Retrospective analysis of consecutive BAO patients from a prospective stroke registry. BAO was diagnosed through CTAs, which were also used to evaluate the Posterior Circulation Collateral Score (PC-CS), the Basilar Artery on Computed Tomography Angiography (BATMAN) scores and also for the presence of both posterior communicating arteries. A favorable outcome was defined as a mRS ≤3 at 90 days. After univariate analyses, multivariate logistic regression was used to identify if any collateral score independently predicts a favorable outcome. We also used ROC curves and C-statistics for score comparisons. Results: Between January/2011 and April/2017, 27 (85% male) BAO patients with median NIHSS of 26 (IQR:15-32) were identified. Twenty-five (93%) patients were treated with a stent-retriever or an aspiration device, and only 2 (7%) patients were treated with basilar artery angioplasty and stenting. Recanalization rate was 85% and only 1 (3.7%) patient had a symptomatic hemorrhagic transformation. Favorable outcomes were reached in 10 (37%) patients at 90-days and mortality rate was 37%. In univariate analysis, female sex, NIHSS, onset-to-groin time and PC-CS predict favorable outcomes. In multivariate analysis, only PC-CS (OR=1.69;95%CI:1.10-2.60;p=0.016) and the baseline NIHSS (OR=0.84;95%CI:0.77-0.93;p=0.001) remained as independent predictors of favorable outcomes. The PC-CS AUC for favorable outcome was 0.80 (95%CI:0.62-0.98;p=0.012). Conclusions: Mechanical thrombectomy seems to be a promising strategy for patients with acute BAO. Collateral flow assessment using the PC-CS is an independent predictor of favorable outcomes among acute BAO patients treated with mechanical thrombectomy.

Background: Tenecteplase (TNK) is a genetically modified variant of alteplase with greater fibrin specificity and longer half-life than alteplase. The recent Tenecteplase versus Alteplase before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK) trial demonstrated that increased reperfusion with TNK compared to alteplase prior to endovascular thrombectomy (EVT) in large vessel occlusion ischaemic strokes. However, only 6 patients with basilar artery occlusion (BAO) were included. We aimed to investigate the efficacy of TNK versus alteplase before EVT in patients with basilar artery occlusion (BAO). Methods: Clinical and procedural data of consecutive BAO diagnosed on CT Angiography or MR Angiography from the multisite international Basilar Artery Treatment and MANagement (BATMAN) collaboration were retrospectively analysed. The primary outcome was reperfusion of greater than 50% of the involved ischemic territory or absence of retrievable thrombus at the time of the initial angiographic assessment. Results: We included 119 BAO patients treated with intravenous thrombolysis prior to EVT; mean age 68 (SD 14), median NIHSS 16 (IQR 7-32). Eleven patients were treated with TNK (0.25mg/kg or 0.4mg/kg) and 108 with alteplase (0.9mg/kg). Overall, 113 patients had catheter angiography or early repeat imaging after thrombolysis. Reperfusion of greater than 50% of the ischemic territory or absence of retrievable thrombus occurred in 4/11 (36%) of patients treated with TNK vs 8/102 (8%) treated with alteplase (p=0.02). Onset-to-needle time did not differ between the two groups (p=0.4). Needle-to-groin-puncture time was 61 (IQR 33-100) mins in patients reperfused with TNK vs 111 (IQR 86-198) mins in patients reperfused with alteplase (p=0.048). Overall, the rate of symptomatic haemorrhage was 3/119 (2.5%). No differences were found in the rate of symptomatic intracranial haemorrhage (p=0.3) between the two thrombolytic agents. Conclusions: Despite shorter needle-to-groin-puncture times, tenecteplase was associated with an increased rate of reperfusion in comparison with alteplase before EVT in BAO. Randomized controlled trials to compare tenecteplase with alteplase in BAO patients before endovascular thrombectomy are warranted.

ObjectiveAcute basilar artery occlusion (BAO) is associated with severe neurological dysfunction and high mortality rates. The benefits of mechanical thrombectomy in BAO have not been explored in recent clinical trials. Therefore, we analyzed outcomes of stent retriever mechanical thrombectomy for BAO, and compared with anterior circulation occlusions (ACO).MethodsIn total, 161 consecutive patients (24 BAO, 137 ACO) who underwent mechanical thrombectomy with the stent retriever between January 2013 and August 2016 enrolled in our study. All patients underwent clinical assessment with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS). Radiological results were used to evaluate thrombolysis in cerebral infarction (TICI) scores and successful recanalization was defined by TICI 2b or 3.ResultsMean NIHSS scores at 24 hours and 30 days were significantly higher in the BAO group than the ACO group (p=0.021, p=0.001). mRS at 90 days was significantly higher in the BAO group (4.2) compared with the ACO group (3.0) (p=0.003). The BAO group (2.0) performed fewer stent retriever passages than the ACO group (2.7) (p=0.049). There were no significant differences between the two groups in terms of complications, but the BAO patients experienced a higher mortality (16.6%) rate than ACO patients (5.8%) (p=0.001). In subgroup analysis of BAO, patients with short procedure times achieved successful recanalization (p=0.001) and successfully recanalized patients exhibited more favorable mRS at 90 days (p=0.027).ConclusionIn our study, mechanical thrombectomy of BAO patients showed worse clinical outcome and higher mortality rate than ACO patients. However, mechanical thrombectomy with a stent retriever in BAO is an effective treatment, because successfully recanalized patients showed good clinical outcome in BAO patients.

OBJECTIVESeveral randomized trials have been focused on patients with anterior circulation stroke, whereas few data on posterior circulation stroke are available. Thus, new mechanical thrombectomy (MT) strategies, including a direct-aspiration first-pass technique (ADAPT), remain to be evaluated in basilar artery occlusion (BAO) patients. The authors here assessed the influence of reperfusion on outcome in BAO patients and examined whether ADAPT improves the reperfusion rate compared with stent retriever devices.METHODSThree comprehensive stroke centers prospectively collected individual data from BAO patients treated with MT. Baseline characteristics as well as radiographic and clinical outcomes were compared between the 2 MT strategies. The primary outcome measure was the rate of successful reperfusion, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2b-3. Favorable outcome was defined as a 90-day modified Rankin Scale score of 0-2.RESULTSAmong the 100 adult patients included in the study, 46 were treated with first-line ADAPT (median age 61 years, IQR 53-71 years; stent-retriever rescue therapy was secondarily used in 12 [26.1%]) and 54 were treated with a primary stent retriever (median age 67 years, IQR 53-78 years). There was no difference in baseline characteristics between the 2 treatment groups, except for the rate of diabetes (19.6% vs 5.7%, respectively, p = 0.035). Successful reperfusion was achieved in 79% of the overall study sample. Overall, the rate of favorable outcome was 36.8% and 90-day all-cause mortality was 44.2%. Successful reperfusion positively impacted favorable outcome (OR 4.57, 95% CI 1.24-16.87, p = 0.023). A nonsignificant trend toward a higher successful reperfusion rate (unadjusted OR 2.56, 95% CI 0.90-7.29, p = 0.071) and a significantly higher rate of complete reperfusion (mTICI grade 3; unadjusted OR 2.59, 95% CI 1.14-5.86, p = 0.021) was found in the ADAPT group. The procedure duration was also significantly lower in the ADAPT group (median 45 minutes, IQR 34 to 62 minutes vs 56 minutes, IQR 40 to 90 minutes; p = 0.05), as was the rate of periprocedural complications (4.3% vs 25.9%, p = 0.003). Symptomatic intracranial hemorrhage (0.0% vs 4.0%, p = 0.51) and 90-day all-cause mortality (46.7% vs 42.0%, p = 0.65) were similar in the 2 groups.CONCLUSIONSAmong BAO patients, successful reperfusion is a strong predictor of a 90-day favorable outcome, and the choice of ADAPT as the first-line strategy achieves a significantly higher rate of complete reperfusion with a shorter procedure duration.

IntroductionAcute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) is known to be associated with high rates of mortality and lifelong disability. In the past few years, two clinical trials (the BEST and the BASICS trials) investigated the benefits and safety of mechanical thrombectomy (MT) for BAO and did not provide evidence to support the efficacy of MT in BAO patients. Given the recent positive results from the ATTENTION and the BAOCHE clinical trials, we conducted this meta‐analysis to provide updated collective evidence regarding the benefits of MT in patients with BAO.MethodsWe searched for eligible papers till June 1st, 2021, in five databases: PubMed, Web of Science, Scopus, and Embase databases using keywords and/or medical subject (MeSH) terms. We included all randomized controlled trials (RCTs) with no restrictions on publication date, data, or language of the included studies to avoid missing any relevant papers. All data were analyzed using R software. We computed the pooled risk ratios (RRs) and their corresponding 95% confidence intervals (CI), using a random‐effect model or fixed‐effect model depending on heterogeneity among the included studies. Heterogeneity was assessed with Q statistics and the I2 test considering it significant with I2 value > 50% or P‐value < 0.05.ResultsFour trials were included in this meta‐analysis, namely the BEST, the BASICS, the BAOCHE, and the ATTENTION trials. The four trials recruited a total of 988 patients. The MT group achieved a significantly higher rate of modified Rankin scale (mRS) score of 0–3 was as compared to the best medical treatment (BMT) one (RR = 1.54; 95% CI = 1.16‐2.04; P‐value = 0.002). Similarly, the mRS 0–2 rate was significantly higher in the MT group as compared to the BMT group (RR = 1.79; 95% CI = 1.09‐2.95; P‐value = 0.022). Nevertheless, heterogeneity was noticed amongst the included studies. Moreover, there was a significant reduction in the 90‐day mortality in the MT group as compared to the BMT group (RR = 0.76; 95% CI = 0.65‐0.89; P‐value = 0.002). On the other hand, there was a significantly higher rate of symptomatic intracerebral hemorrhage (sICH) in the MT group compared to the BMT group (RR = 7.48; 95% CI = 2.27‐24.61; P‐value< 0.001). There with no heterogeneity observed in both outcomes of mortality and sICH. Noted that there were no significant differences in overall parenchymal hemorrhage (PH) and type I PH rates, yet type II PH was more prevalent in the MT group compared to the BMT one (RR = 5.53; 95% CI = 1.47‐20.84; P‐value = 0.011).ConclusionsThe current evidence favors MT for basilar artery occlusions over the conservative approach in terms of achieving higher rates of good functional outcomes and decreasing mortality rates. Further large‐scale trials of different populations are needed to corroborate these results and also to ensure generalizability.

BackgroundWhen standard endovascular thrombectomy techniques fail to achieve a successful recanalization, it is often necessary to use rescue therapies (RTs). RTs are more commonly used in basilar artery occlusions and conventionally thought to represent “a last resort option.” We sought to study the outcomes of basilar artery occlusion patients who received RT, and further hypothesize that the number of instrumental passes before initiation of RT may be associated with increased risk for poor clinical outcomes.MethodsWe performed a retrospective analysis of the ETIS (“Endovascular Treatment in Ischemic Stroke”) registry. Our primary analysis included 277 patients who underwent thrombectomy for basilar artery occlusion, of whom 74 patients (26.7%) who received RT, defined as the use of intra‐arterial drugs, angioplasty, or stenting. Primary outcome measures included successful or complete reperfusion (final modified thrombolysis in cerebral infarction ≥2b or 3), functional independence (modified Rankin scale of 0–2), and mortality at 3 months.ResultsRT patients were more likely to have an atherosclerotic cause than non‐RT patients (46/74 [62.2%] versus 38/203 [18.7%]), were more likely to die (42/74 [56.8%] versus 73/203 [36.0%]), and were less likely to achieve functional independence (12/74 [16.2%] versus 84/203 [41.4%]). In the RT cohort, 17 of 74 patients (23.0%) had 1 pass before RT initiation, and 8 of 17 (47.1%) achieved a modified Rankin scale score of 0 to 2 at 3 months, with a mortality rate of 23.5% (4/17). The chance of achieving good clinical outcome decreased with each additional pass, whereas mortality increased. The odds of mortality at 3 months were highest in the >3 passes group, with an odds ratio of 10.29 (95% CI, 2.42–43.81) compared with 1 pass. None of the 25 patients with >3 passes before RT achieved 3‐month functional independence.ConclusionsThere is a significant correlation between the number of passes before initiation of RT and 3‐month clinical outcomes in basilar artery occlusion patients.

Neurointerventional Advances in 2022

Endovascular treatment of acute basilar artery occlusion

Optimized amide proton transfer imaging of ischemic stroke

Background: Whether direct aspiration first pass technique (ADAPT) is associated with better clinical and procedural outcomes compared with stent retriever thrombectomy in basilar artery occlusion (BAO) is uncertain. We compared reperfusion and clinical outcomes between ADAPT and stent retriever thrombectomy (SR) in BAO. Methods: Clinical and procedural data of consecutive endovascular-treated stroke patients with BAO diagnosed on CT angiography from the multisite international Basilar Artery Treatment and MANagement (BATMAN) collaboration were retrospectively analysed. Good outcome was defined as modified Rankin Scale≤3 at 3 months; successful reperfusion as mTICI 2b-3 and complete reperfusion as TICI 3. Results: We included 107 BAO patients treated with mechanical thrombectomy [31 treated with first-line ADAPT and 76 with stent retriever or combined approach (“Solumbra technique”)]. An additional SR was used in 3/28 (11%) patients in the ADAPT group. Mean age was 67 (SD 14), median NIHSS 18 (IQR 7-29.5), 36% of patients received intravenous thrombolysis prior to mechanical thrombectomy. Median procedural time was 91min (IQR 49-132). Successful reperfusion was achieved in 87/107 (81%) of patients and good outcome was observed in 42/100 (42%) patients. Although a greater proportion of patients achieved successful reperfusion in the ADAPT group, this was not significant (ADAPT 87% vs SR 79%, p=0.4). Similarly, complete reperfusion occurred in 67% ADAPT vs 51% SR (p=0.2).14% of patients were treated beyond 6 hours in the ADAPT group vs 38% in the SR group (p=0.02). Procedural times were significantly shorter in the ADAPT group [52min (IQR 29-103.5) vs SR 99.5min (IQR 72-143); p&lt;0.001)]. Rates of good outcome were significantly higher in patients treated with ADAPT (64% vs 40%, p=0.04). In ordinal regression analysis adjusted for age, NIHSS and time to treatment&gt;6 hours, ADAPT remained associated with good outcome (cOR 3.4, 95%CI 1.3-8.6, p=0.01). Conclusions: ADAPT is associated with shorter procedural times and improved outcomes in comparison with stent retriever thrombectomy in BAO. Rates of successful reperfusion were similar in the two groups. Randomized controlled trials to determine the optimal endovascular technique are warranted.

Patients with basilar artery occlusion (BAO) were excluded from previous randomized controlled trials (RCTs) of endovascular treatment (ET) for acute ischemic stroke, but are commonly treated in clinical practice. This study aimed at analyzing predictors of functional outcome of ET in patients with BAO to improve patient selection for ET. Consecutive patients with BAO who received ET over a2-year time period were prospectively studied. Baseline characteristics, procedural and outcome data were evaluated. Outcome was assessed by the modified Rankin Scale (mRS) 90days after stroke. Multivariate regression analyses were performed to identify predictors of outcome across the range of the mRS, of poor outcome (mRS5-6) and independent outcome (mRS0-2). A total of 39 patients with BAO (median age: 75years, 67% male) were included. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 24. Intravenous thrombolysis therapy (IVT) was administered in 56%. Successful recanalization assessed by a modified thrombolysis in cerebral infarction (TICI) score ≥2b was achieved in 82%. Independent outcome was observed in 30% of patients with successful recanalization, but in no patient with failed recanalization. Poor outcome was observed in 47% and 86%, respectively. Successful recanalization was associated with lower scores on the mRS at 90 days (p = 0.035), and failed recanalization was associated with an odds ratio of 13.6 for poor outcome (p = 0.036). Reperfusion is the major predictor of functional outcome in BAO in clinical practice. Failed recanalization resulted in a13-fold increase of the risk of poor outcome. Successful recanalization is crucial to achieve abetter functional outcome in BAO.

This study was to investigate the admission hyperglycemia and modified effect of intravenous thrombolysis (IVT) on clinical outcomes in acute basilar artery occlusion (BAO) patients receiving endovascular treatment (EVT). We prospectively recruited acute BAO patients from 48 stroke centers across 22 Chinese provinces in the ATTENTION registry from 2017 to 2021. Hyperglycemia on admission was defined as glucose ≥7.8 ​mmol/L. We performed multivariable logistic regression analysis to evaluate the correlation of hyperglycemia on admission with the primary outcome defined as a modified Rankin scale (mRS) score of <4 ​at 90 days, and the secondary outcomes defined as successful recanalization, mRS 0–1 and 0–2 ​at 90 days. Safety outcomes were symptomatic intracranial hemorrhage (sICH) and mortality within 90 days. There were 1195 patients with acute BAO treated with EVT of whom 519 had hyperglycemia on admission. Hyperglycemia on admission was inversely associated with favorable neurological outcomes (mRS 0–3: adjusted odd ratio [aOR] 0.69, 95 ​% confidence intervals [CI] 0.54–0.89, P ​= ​0.004; mRS 0–1: aOR 0.67, 95 ​% CI 0.50–0.90, P ​= ​0.008; mRS 0–2: aOR 0.73, 95 ​% CI 0.56–0.95; P ​= ​0.02). Hyperglycemia on admission was not correlated to sICH nor successful recanalization. In the subgroup of BAO patients treated with direct EVT, those with hyperglycemia on admission had a higher mortality rate, and overall worse clinical outcomes at 90 days than patients without hyperglycemia. A significant interaction was observed between IVT and hyperglycemia on admission (Pinteraction ​= ​0.017). In patients with acute BAO treated with EVT, hyperglycemia on admission was associated with worse functional outcomes at 90 days but was not correlated with sICH nor successful recanalization. The effect of admission hyperglycemia appears to be modified by IVT allocation. Unique identifier: ChiCTR2000041117.

BackgroundPerforming mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based.ObjectiveTo compare patients’ outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between...