ATTENTION Trial: Basilar Artery EVT
In acute basilar artery occlusion with NIHSS ≥10 within 12 hours of estimated onset, does endovascular thrombectomy improve mRS 0–3 at 90 days compared with best medical care alone?
Tao et al. (NEJM 2022) · doi:10.1056/NEJMoa2206317 · 340 patients
Population
Included
- Age ≥18 (≥80 with pre-stroke mRS 0 only)
- Acute basilar artery occlusion confirmed on CTA/MRA/DSA
- NIHSS ≥10 at randomization
- Within 12 hours of estimated onset
- PC-ASPECTS ≥6 (<80y) or ≥8 (≥80y); pre-stroke mRS ≤2
- Symptoms and signs compatible with ischemia in the basilar artery territory
- Basilar artery occlusion confirmed by CTA/MRA/DSA
- Age of 18 years or older
- Time from stroke onset to randomization within 12 hours of estimated time of basilar artery occlusion (for unwitnessed/wake-up strokes, the time last known to be without major neurological deficits is used as the time of onset)
- Written informed consent
- NIHSS score ≥10 at the time of neuroimaging
Excluded
- Anterior circulation LVO (use HERMES-era evidence)
- Complete bilateral thalamic/brainstem infarction
- Spontaneous recanalization before randomization
- Excessive vascular tortuosity; bilateral mydriasis
- Advanced cancer, severe anemia, bleeding diathesis
- Pre-existing dependency with mRS ≥3 for patients <80 years; premorbid mRS ≥1 for patients ≥80 years
- Bilateral mydriasis
- Pregnancy; if a woman is of childbearing potential a urine or serum beta HCG test is positive
- Severe contrast allergy or absolute contraindication to iodinated contrast
- Participation in other clinical trials
- Systolic pressure >185 mmHg or diastolic pressure >110 mmHg, and cannot be controlled by antihypertensive drugs
- Known genetic or acquired bleeding constitution, lack of anticoagulant factors, or oral anticoagulant drugs and INR > 1.7
- Blood glucose < 2.7 or >22.2 mmol/L; platelet count < 50×10⁹/L, or hematocrit < 25%
- Life expectancy < 1 year
- Patients that cannot complete 90-day follow-up
- Acute ischemic cerebral infarction within 48 hours after major surgery (can enroll if more than 48 hours)
- Premorbid cerebrovascular inflammation
- Premorbid nervous system disease or mental disorders hindering assessment
Imaging exclusion
- CT/MR shows intracranial hemorrhage (microbleeds ≤5mm allowed)
- CTA/MRA/DSA shows the artery is seriously tortuous, variable or dissected, and thrombectomy device cannot reach the target vessel
- PC-ASPECTS on CT/CTA-SI/MRI-DWI <6 for patients <80 years (<8 for patients ≥80 years)
- CT or MR shows cerebellar infarction with obvious space-occupying effect and compression of the fourth ventricle
- Complete bilateral thalami or bilateral brainstem infarction on CT/MR
- Occlusion of both anterior and posterior circulation on CTA/MRA/DSA
- Intracranial tumors (except small meningiomas)
Source: ClinicalTrials.gov NCT04751708· Retrieved 2026-06-08
Primary Outcome
mRS 0–3 at 90 Days
Study Arms
- Agent
- Endovascular thrombectomy (operator-choice technique) added to best medical care
- Route
- Endovascular
- Frequency
- Single index procedure
- Duration
- Within 12 h of estimated basilar-artery occlusion onset
- Co-interventions
- Best medical care per Chinese national/institutional guidelines (IV thrombolytics, antiplatelets, anticoagulation, or combinations); IV thrombolysis used in 31% of thrombectomy-group patients (Tao NEJM 2022 p.1361,1365)
EVT at operator discretion: stent retrievers, thromboaspiration, balloon angioplasty, stenting, intraarterial thrombolysis (alteplase or urokinase), or combinations. 221/228 underwent EVT; GA 56%; additional intracranial angioplasty/stenting 40% (p.1364-65). 2:1 randomization.
- Agent
- Best medical care alone
- Route
- Medical
- Duration
- 90-day follow-up
- Co-interventions
- Best medical care per Chinese national/institutional guidelines; IV thrombolysis used in 34% of control-group patients (patients within 4.5 h received IV thrombolysis per Chinese standard of care) (Tao NEJM 2022 p.1361,1364-65)
Control = best medical care without EVT. 6 patients total (3 per group) crossed over. Rescue EVT not part of control protocol (p.1365).
Safety
Symptomatic ICH (SITS-MOST, 24–72h)
5%
0%
12/226 EVT vs 0/114 control. Periprocedural risk, but mortality reduction outweighs.
90-day mortality
37%
55%
83/226 EVT vs 63/114 control (adjusted RR 0.66, 95% CI 0.52–0.82). One of the few stroke interventions shown to significantly reduce mortality.
Trial Design
Type
- Multicenter randomized open-label trial
- Conducted in China
- 1:1 allocation (EVT vs. BMT)
Timeline
Enrolled 2020-2021
N
340
Enrollment
340 patients (226 EVT / 114 control, 2:1 ITT) at 36 centers in China. Enrolled Feb 2021 – Jan 2022. Published NEJM 2022.
ClinicalTrials.gov
NCT04751708Bedside Pearl
In acute basilar artery occlusion with NIHSS ≥10, PC-ASPECTS ≥6, and pre-stroke mRS ≤2, EVT within 12 hours roughly halves mortality (37% vs 55%) and doubles the chance of mRS 0–3 at 90 days. mRS 0–3 (not 0–2) is used because BAO carries up to 80% untreated mortality.
See also
Trial lineage
Endovascular therapy for basilar artery occlusion
BEST and BASICS were the first two RCTs in basilar-artery occlusion and both failed their primary frame — driven by substantial crossover in BEST and a control arm in BASICS that frequently received alteplase. ATTENTION and BAOCHE, both in Chinese populations, established benefit in 0-12 h and 6-24 h windows respectively and shifted guideline support toward EVT for basilar LVO.
- 2020BEST TrialNEUTRAL
First RCT of EVT for basilar artery occlusion. ITT primary (mRS 0-3 at 90 days): 42% vs 32% (OR 1.74, CI 0.81–3.74, p=0.23). Terminated early for crossover and low enrollment. Preceded ATTENTION (2022).
- 2021BASICS TrialNEUTRAL
Multinational RCT of EVT for basilar artery occlusion within 6 hours. Primary (mRS 0-3 at 90 days): 44.2% EVT vs 37.7% medical (RR 1.18, CI 0.92–1.50, P=0.19). Statistically negative; CI did not rule out meaningful benefit. Preceded ATTENTION (2022).
- 2022ATTENTION Trial· this pagePOSITIVE
Basilar artery thrombectomy within 12 hours; China trial.
- 2022BAOCHE TrialPOSITIVE
Basilar EVT 6–24 hours with imaging selection.