Infarct size does not affect treatment effect of early versus late direct oral anticoagulant initiation

For individuals with minor, moderate, or major stroke, the treatment effect of early versus late direct oral anticoagulant (DOAC) initiation does not differ, according to a study published online May 28 in JAMA Neurology.

Martina B. Goeldlin, M.D., Ph.D., from the University of Bern in Switzerland, and colleagues examined whether infarct size modifies the safety and efficacy of early versus late DOAC initiation in a post-hoc analysis of participants from the multinational randomized clinical “Early Versus Later Anticoagulation for Stroke With Atrial Fibrillation (ELAN)” trial with acute ischemic stroke, atrial fibrillation, and brain imaging available.

A composite of recurrent ischemic stroke, symptomatic intracranial hemorrhage, extracranial bleeding, systemic embolism, or vascular death within 30 days was examined as the primary outcome.

The analyses included 1,962 of the original 2,013 participants.

The researchers found that the primary outcome occurred in 2.7 versus 3.0 percent of those with early versus late DOAC initiation among those with minor stroke (odds ratio, 0.89; 95 percent confidence interval, 0.38 to 2.10); in 2.8 and 3.6 percent of those with early and late DOAC initiation, respectively, among those with moderate stroke (odds ratio, 0.80; 95 percent confidence interval, 0.35 to 1.74); and in 3.7 and 7.0 percent of those with early and late DOAC initiation, respectively, among those with major stroke (odds ratio, 0.52; 95 percent confidence interval, 0.21 to 1.18). No significant treatment interaction was seen for the primary outcome.

“While the ELAN trial was neither designed nor powered to show noninferiority or superiority, the results exclude all but a very modest harm,” the authors write.