Anticoagulation Timing in Acute Stroke With Atrial Fibrillation According to Chronic Kidney Disease: The OPTIMAS Trial

BACKGROUND: Patients with chronic kidney disease (CKD) are at increased risk of ischemic stroke (IS) and intracerebral hemorrhage, so the safety and efficacy of early direct oral anticoagulant (DOAC) initiation in those with CKD are of clinical relevance. METHODS: OPTIMAS (Optimal Timing of Anticoagulation After Acute Ischemic Stroke With Atrial Fibrillation) was a multicenter, randomized, parallel-group, open-label trial with blinded outcome assessment, recruiting patients with IS and atrial fibrillation from 100 UK hospitals between 2019 and 2024. Participants were randomized 1:1, stratified by stroke severity, to early (within 4 days of onset) or delayed (at days 7-14) DOAC initiation. CKD was defined as a past medical history of known CKD, collected according to trial protocol as part of the case report form. For this prespecified subgroup analysis, the trial cohorts were classified according to the presence or absence of CKD. Whether CKD modified the treatment effect of early DOAC initiation was determined by fitting mixed effects logistic regression models with interaction terms between CKD and treatment group. The primary outcome was a composite outcome of recurrent IS, symptomatic intracranial hemorrhage, and systemic arterial embolism. Key secondary outcomes included the individual components of the primary outcome and all-cause mortality. RESULTS: We included 3601 patients (mean age, 78±10 years; 45% female), 543 with CKD. There were 116 primary outcome events: 97 (3.2%) in the normal kidney function group and 19 (3.5%) in the CKD group. There was no difference between early and delayed DOAC initiation for the primary outcome in either the normal kidney function group (odds ratio, 1.01 [95% CI, 0.67-1.51]) or the CKD group (odds ratio, 0.90 [95% CI, 0.36-2.25]; Pinteraction=0.822). Similarly, for the secondary outcomes, we detected no modification of the treatment effect according to CKD (Pinteraction values of 0.637, 0.386, and 0.107 for IS, symptomatic intracranial hemorrhage, and all-cause mortality, respectively). CONCLUSIONS: Our findings suggest that CKD does not modify the effects of early versus delayed DOAC initiation after acute IS. Based on these results, early DOAC initiation should not be withheld in patients with CKD.