No difference was found between antiplatelet agents (APs) and anticoagulant agents (ACs) in reducing recurrent ipsilateral stroke risk at 12 months in patients with cervical artery dissection, according to study results published in JAMA Neurology.
Patients with carotid and vertebral dissection who were enrolled in the Cervical Artery Dissection in Stroke Study (CADISS) were randomly assigned to receive either an AP (n=126) or an AC (n=124) in the intention-to-treat (ITT) analysis. Following a 3-month treatment period, local clinicians made the individualized choice to switch a patient to either an AP or an AC. Repeat magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging was performed at 3 months. Recurrent ipsilateral stroke or death comprised the primary outcome. Angiographic recanalization in patients with imaging-confirmed dissection was also evaluated.
The 1-year recurrent stroke rate was 2.4% in the ITT analysis vs 2.5% in the per-protocol analysis. At 12 months, there was no difference between the AP and AC groups with regard to the rate of ipsilateral stroke (3.2% vs 1.6%, respectively; odds ratio [OR] 0.56; 95% CI, 0.10-3.21), ipsilateral stroke or ipsilateral transient ischemic attack (4.0% vs 4.8%, respectively; OR 1.36; 95% CI, 0.39-4.71), any stroke or any transient ischemic attack (4.8% vs 5.65%, respectively; OR 1.29; 95% CI, 0.41-4.03), or any stroke or death (3.2% vs 1.6%, respectively; OR 0.56; 95% CI, 0.10-3.21).
In patients with confirmed dissection and complete imaging at both baseline and 3 months (n=181), no difference was observed between the AP and AC groups in terms of the presence of residual narrowing or occlusion (61% vs 60%, respectively; P =.97).
Study limitations include the lack of radiographic confirmation of dissection in 20% of the cohort, as well as the relatively small patient population.
“Analysis of outcomes by treatment arm showed no difference between AP and AC therapy,” the investigators wrote. “However, the low number of end points means that a very large sample size, of many thousands, would be required to detect a treatment difference between the 2 therapies, but the low rate of events suggests that any absolute effect on outcome, even if, for example, there was a 25% reduction in risk, would be very low.”
Markus HS, Levi C, King A, Madigan J, Norris J; Cervical Artery Dissection in Stroke Study (CADISS) Investigators. Antiplatelet therapy vs anticoagulation therapy in cervical artery dissection: the cervical artery dissection in stroke study (CADISS) randomized clinical trial final results [published online February 25, 2019]. JAMA Neurol. doi:10.1001/jamaneurol.2019.0072