Antiplatelet Therapy vs Anticoagulation Therapy in Cervical Artery Dissection: The Cervical Artery Dissection in Stroke Study (CADISS) Randomized Clinical Trial Final Results

Importance Extracranial carotid and vertebral artery dissection is an important cause of stroke, particularly in younger individuals. In some but not all observational studies, it has been associated with a high risk of recurrent stroke. Both antiplatelet agents (APs) and anticoagulants (ACs) are used to reduce stroke risk, but whether 1 treatment strategy is more effective is unknown. Objective To determine whether AP or AC therapy is more effective in preventing stroke in cervical dissection and the risk of recurrent stroke in a randomized clinical trial setting. A secondary outcome was to determine the effect on arterial imaging outcomes. Design, Setting and Participants Randomized, prospective, open-label international multicenter parallel design study with central blinded review of both clinical and imaging end points. Recruitment was conducted in 39 stroke and neurology secondary care centers in the United Kingdom and 7 centers in Australia between February 24, 2006, and June 17, 2013. One-year follow-up and analysis was conducted in 2018. Two hundred fifty participants with extracranial carotid and vertebral dissection with symptom onset within the last 7 days were recruited. Follow-up data at 1 year were available for all participants. Interventions Randomization to AP or AC (heparin followed by warfarin) for 3 months, after which the choice of AP and AC agents was decided by the local clinician. Main Outcomes and Measures The primary end point was ipsilateral stroke and death. A planned per protocol (PP) analysis was performed in patients meeting the inclusion criteria following central review of imaging to confirm the diagnosis of dissection. A secondary end point was angiographic recanalization in those with imaging confirmed dissection. Results Two hundred fifty patients were randomized (118 carotid and 132 vertebral), 126 to AP and 124 to AC. Mean (SD) age was 49 (12) years. Mean (SD) time to randomization was 3.65 (1.91) days. The recurrent stroke rate at 1 year was 6 of 250 (2.4%) on ITT analysis and 5 of 197 (2.5%) on PP analysis. There were no significant differences between treatment groups for any outcome. Of the 181 patients with confirmed dissection and complete imaging at baseline and 3 months, there was no difference in the presence of residual narrowing or occlusion between those receiving AP (n = 56 of 92) vs those receiving AC (n = 53 of 89) ( P  = .97). Conclusions and Relevance During 12 months of follow-up, the number of recurrent strokes was low. There was no difference between treatment groups in outcome events or the rate of recanalization. Trial Registration ISRCTN.com Identifier:CTN44555237