Importance Cervical artery dissection is the most common cause of stroke in younger adults. To date, there is no conclusive evidence on which antithrombotic therapy should be used to treat patients.

Objective To perform an individual patient data meta-analysis of randomized clinical trials comparing anticoagulants and antiplatelets in prevention of stroke after cervical artery dissection.

Data Sources PubMed.gov, Cochrane database, Embase, and ClinicalTrials.gov were searched from inception to August 1, 2023.

Study Selection Randomized clinical trials that investigated the effectiveness and safety of antithrombotic treatment (antiplatelets vs anticoagulation) in patients with cervical artery dissection were included in the meta-analysis. The primary end point was required to include a composite of (1) any stroke, (2) death, or (3) major bleeding (extracranial or intracranial) at 90 days of follow-up.

Data Extraction/Synthesis Two independent investigators performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and inconsistencies were resolved by a principal investigator.

Main Outcomes and Measures The primary outcome was a composite of (1) ischemic stroke, (2) death, or (3) major bleeding (extracranial or intracranial) at 90 days of follow-up. The components of the composite outcome were also secondary outcomes. Subgroup analyses based on baseline characteristics with a putative association with the outcome were performed. Logistic regression was performed using the maximum penalized likelihood method including interaction in the subgroup analyses.

Results Two randomized clinical trials, Cervical Artery Dissection in Stroke Study and Cervical Artery Dissection in Stroke Study and the Biomarkers and Antithrombotic Treatment in Cervical Artery Dissection, were identified, of which all participants were eligible. A total of 444 patients were included in the intention-to-treat population and 370 patients were included in the per-protocol population. Baseline characteristics were balanced. There were fewer primary end points in those randomized to anticoagulation vs antiplatelet therapy (3 of 218 [1.4%] vs 10 of 226 [4.4%]; odds ratio [OR], 0.33 [95% CI, 0.08-1.05]; P = .06), but the finding was not statistically significant. In comparison with aspirin, anticoagulation was associated with fewer strokes (1 of 218 [0.5%] vs 10 of 226 [4.0%]; OR, 0.14 [95% CI, 0.02-0.61]; P = .01) and more bleeding events (2 vs 0).

Conclusions and Relevance This individual patient data meta-analysis of 2 currently available randomized clinical trial data found no significant difference between anticoagulants and antiplatelets in preventing early recurrent events.