A substantial body of basic and clinical research has demonstrated the protective effects of remote ischemic conditioning (RIC) in ischemic stroke. While these clinical studies support the safety of RIC, the neuroprotective benefits of RIC in acute ischemic stroke (AIS) patients lack robust evidence due to small sample sizes, heterogeneous RIC protocols, and variability in the severity of neurological deficits among study populations. Our recent multicenter randomized clinical trial, the RICAMIS study, investigated the efficacy of RIC in patients with acute moderate ischemic stroke. The results showed that RIC administered within 48 hours of onset significantly improved 90-day neurological outcomes in patients with moderate stroke severity. It is well established that anterior circulation stroke (ACS) and posterior circulation stroke (PCS) differ in multiple aspects, including anatomical structure, collateral circulation, blood supply, clinical manifestations, prognosis, ischemic tolerance time, and treatment response. For instance, compared to the anterior circulation, the posterior circulation has poorer collateral circulation, a higher proportion of stroke etiologies attributed to atherosclerosis, and longer ischemic tolerance time. Consequently, intravenous thrombolysis and endovascular therapy may offer a more extended therapeutic time window for PCS patients. A prespecified subgroup analysis of the RICAMIS study revealed that patients with PCS derived greater benefit from RIC than those with ACS. However, this finding requires further validation through prospective studies, as prior research has never specifically examined the efficacy of RIC in PCS patients.

Based on the above discussion, this study aims to investigate the efficacy and safety of RIC in patients with acute moderate PCS.

Inclusion Criteria:

• Age ≥18 years;
• Time from onset to treatment: ≤48 hours;
• Posterior circulation ischemic stroke confirmed by CT or MRI, including patients who have received intravenous thrombolysis or endovascular therapy;
• NIHSS score at randomization: 6-16, with an item 1a (level of consciousness) score of 0-1;
• First-ever stroke or prior stroke without significant residual disability (modified Rankin Scale score ≤1);
• Signed informed consent.

Exclusion Criteria:

• intracerebral hemorrhage or subarachnoid hemorrhage；
• Uncontrolled severe hypertension (systolic blood pressure >180 mmHg or diastolic blood pressure >110 mmHg despite antihypertensive therapy)；
• Subclavian artery stenosis ≥ 50% or subclavian steal syndrome;
• Intracranial tumor, arteriovenous malformation or aneurysm;
• Severe abnormalities in coagulation;
• Any contraindication for remote ischemic adaptation: the upper limb has serious soft tissue injury, fracture or vascular injury, distal upper limb perivascular lesions, etc.;
• Participating in other clinical trials within 3 months;
• Comorbidity with any serious diseases and life expectancy is less than half a year;
• Patients not suitable for this clinical studies considered by researcher;