Anticoagulation in patients with cerebral amyloid angiopathy

Advances in the medical treatment and diagnosis of intracranial hemorrhage associated with oral anticoagulation

INTRODUCTION

With the increasing prevalence of atrial fibrillation (AF), it entails expanding oral anticoagulants (OACs) use, carrying a higher risk of associated hemorrhagic events, including intracranial hemorrhage (ICH). Despite advances in OACs development with a better safety profile and reversal agent for these anticoagulants, there is still no consensus on the optimal management of patients with OACs-associated ICH.

AREAS COVERED

In this review, the authors have carried out an exhaustive search on the advances in recent years. The authors provide an update on the management of ICH in anticoagulated patients, as well as an update on the latest evidence on anticoagulation resumption, recent therapeutic strategies, and investigational drugs that could play a role in the future.

EXPERT OPINION

Following an ICH event in an anticoagulated patient, a comprehensive clinical evaluation is imperative. Anticoagulation should be promptly withdrawn and reversed. Once the patient is stabilized, a reintroduction of anticoagulation should be considered, typically within a timeframe of 4-8 weeks, if feasible. If re-anticoagulation is not possible, alternative options such as Left Atrial Appendage Occlusion are available.

Left atrial appendage closure for patients with atrial fibrillation at high intracranial haemorrhagic risk

BACKGROUND AND OBJECTIVES

Although left atrial appendage closure (LAAC) is performed in patients with non-valvular atrial fibrillation (NVAF) at increased risk of intracranial haemorrhage (ICH), outcome data are scarce. We assessed the detailed neurological indications for LAAC and outcomes after LAAC in high ICH risk patients.

METHODS

Study population included consecutive patients with NVAF who underwent LAAC in a single hospital network between January 2015 and October 2021 because of prior ICH or the presence of high ICH risk imaging markers on brain MRI (cerebral microbleeds (CMBs)). Primary safety and efficacy outcome measures were the occurrence of ICH and thromboembolic events, respectively, after LAAC.

RESULTS

Among 146 patients with NVAF who underwent LAAC for high ICH risk, 122 had a history of ICH, while 24 presented with high ICH risk imaging markers only. Mean age was 75.7±7.61, 42 (28.8%) were women. Mean CHA2DS2-VASc score was 5.23±1.52. Of 122 patients with ICH history, 58 (47.5%) had intraparenchymal haemorrhage (IPH), 40 (32.8%) had traumatic ICH (T-ICH) and 18 (14.7%) had non-traumatic subdural haemorrhage. Of 85 patients with brain MRIs including necessary sequences, 43 (50.6%) were related to cerebral amyloid angiopathy and 37 (43.5%) to hypertensive microangiopathy. While 70% of patients were discharged on oral anticoagulants (OAC), 92% were not taking OAC at 1 year. Over 2.12 years mean follow-up, one patient had recurrent non-traumatic IPH (incidence rate (IR) 0.32 per 100 patient-years), five had T-ICH (IR 1.61 per 100 patient-years) and six had an ischaemic stroke (IR 1.94 per 100 patient-years).

CONCLUSIONS

Among patients with NVAF at high ICH risk, LAAC demonstrated a low risk of recurrent ICH or ischaemic stroke compared with previously published data. LAAC in high ICH risk populations should be considered in clinical practice per FDA approval and recent guidelines.

Cerebral haemorrhage in the patient with atrial fibrillation: do we employ the direct oral anticoagulants without waiting too long?

Intracranial haemorrhage (ICH) is the most feared haemorrhagic complication of oral anticoagulant therapy (OAT), although the risk is significantly lower with direct oral anticoagulants (DOACs) compared with warfarin. Intracranial haemorrhage is generally considered, by clinicians, to be an absolute contraindication to starting or resuming OAT in patients with atrial fibrillation (AF). On the other hand, the pivotal trials with DOACs excluded patients with previous ICH. Observational studies actually indicate a net clinical benefit in favour of DOAC in patients with AF and previous ICH. This benefit is confirmed by randomized clinical trials which, however, have the limitation of the small number of cases, but larger clinical trials comparing DOACs vs. aspirin or no therapy are underway. While OAT is certainly contraindicated in patients with lobar ICH and cerebral amyloid angiopathy, in other cases, the decision must be made in the individual patient through an accurate balance between thromboembolic risk and haemorrhagic risk and a multidisciplinary cardio-neurological evaluation.

Secondary stroke prevention in people with atrial fibrillation: treatments and trials

Atrial fibrillation is one of the most common cardiac arrhythmias and is a major cause of ischaemic stroke. Recent findings indicate the importance of atrial fibrillation burden (device-detected, subclinical, or paroxysmal and persistent or permanent) and whether atrial fibrillation was known before stroke onset or diagnosed after stroke for the risk of recurrence. Secondary prevention in patients with atrial fibrillation and stroke aims to reduce the risk of recurrent ischaemic stroke. Findings from randomised controlled trials assessing the optimal timing to introduce direct oral anticoagulant therapy after a stroke show that early start (ie, within 48 h for minor to moderate strokes and within 4-5 days for large strokes) seems safe and could reduce the risk of early recurrence. Other promising developments regarding early rhythm control, left atrial appendage occlusion, and novel factor XI inhibitor oral anticoagulants suggest that these therapies have the potential to further reduce the risk of stroke. Secondary prevention strategies in patients with atrial fibrillation who have a stroke despite oral anticoagulation therapy is an unmet medical need. Research advances suggest a heterogeneous spectrum of causes, and ongoing trials are investigating new approaches for secondary prevention in this vulnerable patient group. In patients with atrial fibrillation and a history of intracerebral haemorrhage, the latest data from randomised controlled trials on stroke prevention shows that oral anticoagulation reduces the risk of ischaemic stroke but more data are needed to define the safety profile.

The Impact of Anti-Amyloid Immunotherapies on Stroke Care

Anti-amyloid immunotherapies have recently emerged as treatments for Alzheimer's disease. While these therapies have demonstrated efficacy in clearing amyloid-β and slowing cognitive decline, they have also been associated with amyloid-related imaging abnormalities (ARIA) which include both edema (ARIA-E) and hemorrhage (ARIA-H). Given that ARIA have been associated with significant morbidity in cases of antithrombotic or thrombolytic therapy, an understanding of mechanisms of and risk factors for ARIA is of critical importance for stroke care. We discuss the latest data regarding mechanisms of ARIA, including the role of underlying cerebral amyloid angiopathy, and implications for ischemic stroke prevention and management.