Randomised study of bailout intracranial angioplasty following thrombectomy for acute large vessel occlusion (ANGEL-REBOOT): protocol of a multicentre randomised controlled trial

Comparison of rescue intracranial stenting versus best medical treatment alone in acute refractory large vessel occlusion: study protocol for the PISTAR multicenter randomized trial

BACKGROUND

Mechanical thrombectomy (MT) has become a standard treatment for acute ischemic strokes (AIS). However, MT failure occurs in approximately 10-30% of cases, leading to severe repercussions (with mortality rates up to 40% according to observational data). Among the available rescue techniques, rescue intracranial stenting (RIS) appears as a promising option.

OBJECTIVE

This trial is poised to demonstrate the superiority of RIS in addition to the best medical treatment (BMT) in comparison with BMT alone, in improving the functional outcomes at 3 months for patients experiencing an AIS due to a large vessel occlusion refractory to MT (rLVO).

METHODS

Permanent Intracranial STenting for Acute Refractory large vessel occlusions (PISTAR) is a multicenter prospective randomized open, blinded endpoint trial conducted across 11 French University hospitals. Adult patients (≥18 years) with an acute intracranial occlusion refractory to standard MT techniques will be randomized 1:1 during the procedure to receive either RIS+BMT (intervention arm) or BMT alone (control arm).

RESULTS

The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin Scale score ≤2 and evaluated by an independent assessor blinded to the randomization arm. Secondary outcomes include hemorrhagic complications, all adverse events, and death. The number of patients to be included is 346. Two interim analyses are planned with predefined stopping rules.

CONCLUSION

The PISTAR trial is the first randomized controlled trial focusing on the benefit of RIS in rLVOs. If positive, this study will open new insights into the management of AIS.

TRIAL REGISTRATION NUMBER

NCT06071091.

Rescue Stenting for Failed Mechanical Thrombectomy in Acute Basilar Artery Occlusions: Analysis of the PC-SEARCH Registry

BACKGROUND

We aimed to investigate whether rescue stenting (RS) following failed mechanical thrombectomy (MT) for acute basilar artery occlusion results in superior functional outcomes and enhanced safety compared with the natural history of failed MT.

METHODS

This retrospective cohort study utilized data from the Posterior Circulation Ischemic Stroke Evaluation: Analyzing Radiographic and Intra-Procedural Predictors for Mechanical Thrombectomy registry, encompassing 8 high-volume centers in the United States and covering the period from 2015 to 2021. Patients with basilar artery occlusion who experienced failed MT (modified Thrombolysis in Cerebral Infarction score of 0-2a after at least 1 attempt of clot retrieval) were categorized based on whether they received additional intervention with RS. The primary outcome was a shift analysis of the 90-day modified Rankin Scale. Multivariable logistic regression was used to assess both efficacy and safety outcomes.

RESULTS

Of a total of 444 patients, 119 presented failed MT and were included in the analysis. The RS group comprised 65 (14.6%) patients, while the control group consisted of 54 (12.2%) patients. After adjusting, the RS group showed a favorable shift in the overall 90-day modified Rankin Scale distribution (adjusted common odds ratio, 4.56 [95% CI, 1.67-12.45]; P=0.003) and higher rates of 90-day 0 to 3 modified Rankin Scale score (RS: 44.6% versus control: 18.5%; adjusted odds ratio, 7.57 [95% CI, 1.91-30.12]; P=0.004) compared with the control group. RS also showed lower rates of 90-day mortality (RS: 43.1% versus control: 64.8%; adjusted odds ratio, 0.27 [95% CI, 0.09-0.80]; P=0.018) and comparable rates of symptomatic intracranial hemorrhage (RS: 3.1% versus control: 13%; adjusted odds ratio, 0.31 [95% CI, 0.05-1.95]; P=0.214).

CONCLUSIONS

Our study demonstrated that RS is associated with improved functional outcomes and reduced mortality in basilar artery occlusion patients presenting MT failure. Further randomized trials are needed to validate these findings.

Bailout intracranial angioplasty or stenting following thrombectomy for acute large vessel occlusion in China (ANGEL-REBOOT): a multicentre, open-label, blinded-endpoint, randomised controlled trial

BACKGROUND

Unsuccessful recanalisation or reocclusion after thrombectomy is associated with poor outcomes in patients with large vessel occlusion (LVO) acute ischaemic stroke (LVO-AIS). Bailout angioplasty or stenting (BAOS) could represent a promising treatment for these patients. We conducted a randomised controlled trial with the aim to investigate the safety and efficacy of BAOS following thrombectomy in patients with LVO.

METHODS

ANGEL-REBOOT was an investigator-initiated, multicentre, prospective, randomised, controlled, open-label, blinded-endpoint clinical trial conducted at 36 tertiary hospitals in 19 provinces in China. Participants with LVO-AIS 24 h after symptom onset were eligible if they had unsuccessful recanalisation (expanded Thrombolysis In Cerebral Infarction score of 0-2a) or risk of reocclusion (residual stenosis >70%) after thrombectomy. Eligible patients were randomly assigned by the minimisation method in a 1:1 ratio to undergo BAOS as the intervention treatment, or to receive standard therapy (continue or terminate the thrombectomy procedure) as a control group, both open-label. In both treatment groups, tirofiban could be recommended for use during and after the procedure. The primary outcome was the change in modified Rankin Scale score at 90 days, assessed in the intention-to-treat population. Safety outcomes were compared between groups. This trial was completed and registered at ClinicalTrials.gov (NCT05122286).

FINDINGS

From Dec 19, 2021, to March 17, 2023, 706 patients were screened, and 348 were enrolled, with 176 assigned to the intervention group and 172 to the control group. No patients withdrew from the trial or were lost to follow-up for the primary outcome. The median age of patients was 63 years (IQR 55-69), 258 patients (74%) were male, and 90 patients (26%) were female; all participants were Chinese. After random allocation, tirofiban was administered either intra-arterially, intravenously, or both in 334 [96%] of 348 participants. No between-group differences were observed in the primary outcome (common odds ratio 0·86 [95% CI 0·59-1·24], p=0·41). Mortality was similar between the two groups (19 [11%] of 176 vs 17 [10%] of 172), but the intervention group showed a higher risk of symptomatic intracranial haemorrhage (eight [5%] of 175 vs one [1%] of 169), parenchymal haemorrhage type 2 (six [3%] of 175 vs none in the control group), and procedure-related arterial dissection (24 [14%] of 176 vs five [3%] of 172).

INTERPRETATION

Among Chinese patients with unsuccessful recanalisation or who are at risk of reocclusion after thrombectomy, BAOS did not improve clinical outcome at 90 days, and incurred more complications compared with standard therapy. The off-label use of tirofiban might have affected our results and their generalisability, but our findings do not support the addition of BAOS for such patients with LVO-AIS.

FUNDING

Beijing Natural Science Foundation, National Natural Science Foundation of China, National Key R&D Program Beijing Municipal Administration of Hospitals Incubating Program, Shanghai HeartCare Medical Technology, HeMo (China) Bioengineering, Sino Medical Sciences Technology.

Endovascular Treatment for Basilar Artery Occlusion

Basilar artery occlusion (BAO) is a neurological emergency associated with a high risk for adverse outcomes. This review provides evidence on the therapeutic efficacy of intravenous thrombolysis (IVT) and endovascular therapy (EVT) in the treatment of BAO. Historically considered the primary intervention for acute ischemic stroke, IVT has been progressively combined with EVT, which has emerged from recent studies demonstrating clinical benefits, notably in patients presenting with severe stroke. Several randomised controlled trials have shown that EVT improves patient outcomes in select clinical contexts. Future research directions could address therapeutic treatment thresholds, combination strategies, and long-term outcomes.

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.