Early Anticoagulation in Patients with Acute Ischemic Stroke Due to Atrial Fibrillation: A Systematic Review and Meta-Analysis

Early Versus Late Initiation of Direct Oral Anticoagulants After Ischemic Stroke in People With Atrial Fibrillation and Hemorrhagic Transformation: Prespecified Subanalysis of the Randomized Controlled ELAN Trial

BACKGROUND

Whether hemorrhagic transformation (HT) modifies the treatment effect of early compared with late initiation of direct oral anticoagulation in people with ischemic stroke and atrial fibrillation is unknown.

METHODS

This is a post hoc analysis of the ELAN trial (Early Versus Late Initiation of Direct Oral Anticoagulants in Post-Ischaemic Stroke Patients With Atrial Fibrillation). The primary outcome was a composite of recurrent ischemic stroke, symptomatic intracranial hemorrhage, major extracranial bleeding, systemic embolism, or vascular death within 30 days. Secondary outcomes were the individual components, 30- and 90-day functional outcome. We estimated outcomes based on HT, subclassified as hemorrhagic infarction (HI) or parenchymal hemorrhage (PH) on prerandomization imaging (core laboratory rating) using adjusted risk differences between treatment arms.

RESULTS

Overall, 247 of 1970 participants (12.5%) had HT (114 HI 1, 77 HI 2, 34 PH 1, 22 PH 2). For the primary outcome, the estimated adjusted risk difference (early versus late) was -2.2% (95% CI, -7.8% to 3.5%) in people with HT (HI: -4.7% [95% CI, -10.8% to 1.4%]; PH: 6.1% [95% CI, -8.5% to 20.6%]) and -0.9% (95% CI, -2.6% to 0.8%) in people without HT. Numbers of symptomatic intracranial hemorrhage were identical in people with and without HT. With early treatment, the estimated adjusted risk difference for poor 90-day functional outcome (modified Rankin Scale score, 3-6) was 11.5% (95% CI, -0.8% to 23.8%) in participants with HT (HI: 7.4% [95% CI, -6.4% to 21.2%]; PH: 25.1% [95% CI, 0.2% to 50.0%]) and -2.6% (95% CI, -7.1% to 1.8%) in people without HT.

CONCLUSIONS

We found no evidence of major treatment effect heterogeneity or safety concerns with early compared with late direct oral anticoagulation initiation in people with and without HT. However, early direct oral anticoagulation initiation may worsen functional outcomes in people with PH.

REGISTRATION

URL: http://www.clinicaltrials.gov; Unique identifier: NCT03148457.

Keeping prior anticoagulation treatment in the acute phase of ischaemic stroke: the REKOALA study

INTRODUCTION

A consensus on the management of anticoagulated patients in the acute phase of ischaemic stroke has not yet been established. We aimed to evaluate clinical outcomes in such patients based on the continuation or discontinuation of anticoagulation.

METHODS

Retrospective study of patients with acute ischaemic stroke and cardioembolic source receiving anticoagulant therapy is done. Patients were classified based on the continuation or discontinuation of anticoagulation at admission. Clinical outcomes, haemorrhagic and ischaemic events were assessed. Multivariate logistic regression analysis, propensity score matching (PSM) analysis and a sub-analysis of patients with severe ischaemic stroke at admission (NIHSS score ≥ 15) were performed.

RESULTS

Anticoagulation was continued in 147 (78.8%) of 186 patients. Patients continuing anticoagulant had lower NIHSS (median 5 vs 18, p < 0.001). There were no differences in haemorrhagic or ischaemic events. In the multivariate analysis, good functional outcome at discharge was higher in the continuation group, OR (CI95%) 3.77 (1.2-11.2). PSM analysis adjusted for potential confounders such as NIHSS had higher rates of good functional outcomes at discharge (80% vs 36%, p = 0.004) and at 90 days (76% vs 44%, p = 0.042) in the continuation group. Patients with severe stroke in this group had lower 90-day mortality (34.6% vs 62.5%, p = 0.045) and higher rates of good clinical outcome at discharge (33.3% vs 8.3%, p = 0.032). No differences were observed in 90-day haemorrhagic or ischaemic events.

CONCLUSION

Continuation of anticoagulation in patients with acute ischaemic stroke and cardioembolic source did not increase the risk of intracranial haemorrhage and may be associated with better functional outcomes.

Timing of oral anticoagulants initiation for atrial fibrillation after acute ischemic stroke: A systematic review and meta-analysis

INTRODUCTION

There is a longstanding clinical uncertainty regarding the optimal timing of initiating oral anticoagulants (OAC) for non-valvular atrial fibrillation following acute ischemic stroke. Current international recommendations are based on expert opinions, while significant diversity among clinicians is noted in everyday practice.

METHODS

We conducted an updated systematic review and meta-analysis including all available randomized-controlled clinical trials (RCTs) and observational cohort studies that investigated early versus later OAC-initiation for atrial fibrillation after acute ischemic stroke. The primary outcome was defined as the composite of ischemic and hemorrhagic events and mortality at follow-up. Secondary outcomes included the components of the composite outcome (ischemic stroke recurrence, intracranial hemorrhage, major bleeding, and all-cause mortality). Pooled estimates were calculated with random-effects model.

RESULTS

Nine studies (two RCTs and seven observational) were included comprising a total of 4946 patients with early OAC-initiation versus 4573 patients with later OAC-initiation following acute ischemic stroke. Early OAC-initiation was associated with reduced risk of the composite outcome (RR = 0.74; 95% CI:0.56-0.98; I2 = 46%) and ischemic stroke recurrence (RR = 0.64; 95% CI:0.43-0.95; I2 = 60%) compared to late OAC-initiation. Regarding safety outcomes, similar rates of intracranial hemorrhage (RR = 0.98; 95% CI:0.57-1.69; I2 = 21%), major bleeding (RR = 0.78; 95% CI:0.40-1.51; I2 = 0%), and mortality (RR = 0.94; 95% CI:0.61-1.45; I2 = 0%) were observed. There were no subgroup differences, when RCTs and observational studies were separately evaluated.

CONCLUSIONS

Early OAC-initiation in acute ischemic stroke patients with non-valvular atrial fibrillation appears to have better efficacy and a similar safety profile compared to later OAC-initiation.

Update of Anticoagulation Use in Cardioembolic Stroke With a Special Reference to Endovascular Treatment

Cardioembolic stroke is a major cause of morbidity, with a high risk of recurrence, and anticoagulation represents the mainstay of secondary stroke prevention in most patients. The implementation of endovascular treatment in routine clinical practice complicates the decision to initiate anticoagulation, especially in patients with early hemorrhagic transformation who are considered at higher risk of hematoma expansion. Late hemorrhagic transformation in the days and weeks following stroke remains a potentially serious complication for which we still do not have any established clinical or radiological prediction tools. The optimal time to initiate therapy is challenging to define since delaying effective secondary prevention treatment exposes patients to the risk of recurrent embolism. Consequently, there is clinical equipoise to define and individualize the optimal timepoint to initiate anticoagulation combining the lowest risk of hemorrhagic transformation and ischemic recurrence in cardioembolic stroke patients. In this narrative review, we will highlight and critically outline recent observational and randomized relevant evidence in different subtypes of cardioembolic stroke with a special focus on anticoagulation initiation following endovascular treatment. We will refer mainly to the commonest cause of cardioembolism, non-valvular atrial fibrillation, and examine the possible risk and benefit of anticoagulation before, during, and shortly after the acute phase of stroke. Other indications of anticoagulation after ischemic stroke will be briefly discussed. We provide a synthesis of available data to help clinicians individualize the timing of initiation of oral anticoagulation based on the presence and extent of hemorrhagic transformation as well as stroke severity.