Neuroprotective effects of remote ischemic conditioning in acute ischemic stroke: a meta-analysis

Stroke is one of the leading causes of death and disability worldwide, making the search for effective neuroprotective and neurorepair strategies crucial. Remote ischemic conditioning, as an endogenous neuroprotective method, involves transient limb ischemia followed by reperfusion, potentially reducing the infarct area and improving neurological function. Although animal studies have indicated the neuroprotective effects of remote ischemic conditioning, its clinical efficacy in patients with acute ischemic stroke remains controversial. This meta-analysis aims to evaluate the efficacy and safety of remote ischemic conditioning in patients with acute ischemic stroke, focusing on its effects on neurological recovery and neuroprotection. We performed a comprehensive search of the PubMed, Web of Science, Scopus, and Cochrane databases for randomized controlled trials published from their inception to 2023. Studies were included if they met the following criteria: 1) they were randomized controlled trials; 2) they involved patients with acute ischemic stroke or transient ischemic attack; and 3) they included adult patients with a baseline National Institutes of Health Stroke Scale score of less than 24 and a modified Rankin Scale score of 2 or lower. We excluded animal studies, review articles, and studies for which full texts were not accessible. The quality of the included studies was evaluated via the Cochrane Collaboration tool, and the data were analyzed with Cochrane Review Manager 5.3, utilizing either fixed-effect or random-effects models to evaluate heterogeneity. Ultimately, 11 randomized controlled trials involving 5407 patients (2682 in the remote ischemic conditioning group and 2725 in the control group) were included. The results revealed that remote ischemic conditioning significantly reduced the National Institutes of Health Stroke Scale score at 90 days (MD = –0.75, 95% CI: –1.48, –0.01, P = 0.05) and increased the rate of good functional outcomes (modified Rankin Scale score 0–1) (RR = 1.08, 95% CI: 1.12, 1.15, P = 0.01). Additionally, remote ischemic conditioning significantly decreased the recurrence rate of acute ischemic stroke (RR = 0.79, 95% CI: 0.78, 0.93; P = 0.0003). However, remote ischemic conditioning did not significantly affect the volume of brain infarction. These results suggest that remote ischemic conditioning has significant neuroprotective effects in patients with acute ischemic stroke, improving neurological recovery and reducing stroke recurrence rates. Although the effects on the volume of brain infarction are not significant, remote ischemic conditioning is a safe and straightforward treatment method that provides an effective neuroprotective strategy for patients with acute ischemic stroke, particularly for improving long-term neurological outcomes and preventing stroke recurrence. Future research should further explore the neuroprotective mechanisms of remote ischemic conditioning and optimize treatment protocols to promote nerve repair.