Endovascular thrombectomy alone versus intravenous thrombolysis plus endovascular thrombectomy on acute basilar artery occlusion (ATTENTION IV): study protocol for a multicentre randomised controlled trial.

introductionThe DEVT and DIRECT-MT trials showed that endovascular thrombectomy (EVT) alone is non-inferior to intravenous thrombolysis (IVT) followed by EVT in achieving 90-day functional independence for stroke patients with large-vessel occlusion (LVO). However, it is unclear whether EVT alone is non-inferior to IVT followed by EVT among patients with acute basilar artery occlusion (BAO). Therefore, additional studies are needed to explore the potential benefits of EVT alone in these patients. METHODS AND ANALYSIS: The ATTENTION IV trial is a prospective, multicentre, non-inferiority, blinded endpoint assessment, randomised controlled clinical trial to assess the effect of EVT alone compared with IVT plus EVT in acute BAO patients within 4.5 hours of symptom onset. Patients will be randomised in a 1:1 ratio to either the EVT-alone group or the IVT-plus-EVT group. A score of 0-2 on the 90-day modified Rankin Scale (mRS) was designated as the primary outcome for this study. Primary analysis will follow the intention-to-treat principle with a 15% non-inferiority margin. Secondary outcomes encompass functional status (mRS shift, excellent/good/fair outcomes), quality of life, early neurological recovery and radiological outcomes alongside safety endpoints of intracerebral haemorrhage and mortality. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of the First Affiliated Hospital of the University of Science and Technology of China (2023KY-055) and will be conducted following the Declaration of Helsinki. Study results will be published in peer-reviewed academic journals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT05827042).