Left Atrial Appendage Occlusion: Past, Present and Future

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 Anticoagulation should be promptly withdrawn and reversed.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 Occlusion versus Direct Oral Anticoagulants in the Prevention of Ischaemic Stroke in Patients with Atrial Fibrillation

INTRODUCTION

Existing randomised controlled trials assessing the safety and efficacy of left atrial appendage occlusion (LAAO) in atrial fibrillation (AF) were of relatively small sample size or included patients who could receive oral anticoagulant treatment after device implantation. We compared the outcomes of patients with newly diagnosed AF who received percutaneous LAAO or direct oral anticoagulant (DOAC) treatment, in a large population from a global federated health network (TriNetX).

METHODS

Patients with AF treated with percutaneous LAAO were matched with those treated with DOAC between December 1, 2010, and October 1, 2018. Outcomes were all-cause mortality, ischaemic stroke, and intracranial haemorrhage (ICH) at 5 years.

RESULTS

We included 200 patients with AF, who received either LAAO or DOAC. The risk of all-cause mortality, ischaemic stroke, and ICH at 5 years was not significantly different between the two groups (risk ratio [RR] for all-cause mortality: 1.52, 95% confidence interval (CI): 0.97-2.38, RR for ischaemic stroke: 1.09, 95% CI: 0.51-2.36, and RR for ICH: 1.0, 95% CI: 0.44-2.30).

CONCLUSION

Patients newly diagnosed with AF, eligible for DOAC, showed similar 5-year risk of death, ischaemic stroke, and ICH when comparing those who underwent percutaneous LAAO to those receiving DOAC. Future randomised controlled trials are needed to confirm the findings and advise changes in guidelines.

Comparison of the Efficacy and Safety of Left Atrial Appendage Closure and Direct Oral Anticoagulants for Atrial Fibrillation: A Meta-Analysis of Randomized Control Trials and Observational Studies

The aim of this study was to compare the efficacy and safety of left atrial appendage closure (LAAC) and direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF). This meta-analysis was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines. Two investigators performed an online database search on PubMed, Web of Science, and Scopus databases from inception to October 31, 2023, without any language or time restrictions. Outcomes assessed in this meta-analysis included all-cause mortality, cardiovascular mortality, stroke, and major bleeding events. Eight studies were included in this meta-analysis, enrolling 7,629 participants with AF (4,287 in the DOAC group and 3,342 in the LAAC group). The pooled analysis showed that the risk of all-cause mortality was significantly higher in patients in the DOAC group compared to LAAC (relative risk (RR): 1.87, 95% confidence interval (CI): 1.50 to 2.34). The risk of cardiovascular mortality was 1.60 times higher in patients receiving DOACs compared to those receiving LAAC (RR: 1.60, 95% CI: 1.12 to 2.28). The risk of stroke was not significantly different between the two groups (RR: 1.15, 95% CI: 0.95 to 1.41). In conclusion, LAAC for AF patients proves to be safe and effective for stroke prevention, exhibiting a superior profile in terms of all-cause mortality, cardiovascular events, and major bleeding compared to oral anticoagulation (OAC). These findings prompt consideration of LAAC as a preferred treatment for cardiovascular event prevention in high-bleeding-risk patients.

The Asymptomatic Patient with Atrial Fibrillation, previously reported in some but now found in many

Investigators in Japan evaluated echocardiographic and hemodynamic findings in patients with paroxysmal atrial fibrillation, comparing the findings of asymptomatic patients with patients who had symptomatic atrial fibrillation. Transseptal measurements of left atrial pressure were obtained. The multivariate analysis showed that patients with asymptomatic atrial fibrillation had significantly lower E/e on echo and lower rates of change of peak LA pressure in sinus rhythm or with high right atrial pacing. Patients with asymptomatic atrial fibrillation have preserved diastolic function and significantly less increase in LA pressure during atrial fibrillation. Although asymptomatic atrial fibrillation has generally been shown to be present in approximately 25% of patients with atrial fibrillation, new technologies of digital monitoring have revealed documentation of an increased number of patients with asymptomatic atrial fibrillation. This article is protected by copyright. All rights reserved.

Outcomes of left atrial appendage occlusion vs. non-vitamin K antagonist oral anticoagulants in atrial fibrillation

BACKGROUND

The effects of left atrial appendage (LAA) occlusion compared to non-vitamin K antagonist oral anticoagulant (NOAC) therapy in patients with atrial fibrillation (AF) remain unknown.

AIMS

We aimed to evaluate the outcomes in patients with AF who received LAA occlusion vs. NOAC therapy.

METHODS

We utilised data from TriNetX which is a global federated health research network currently containing data for 88.5 million patients. ICD-10 codes were employed to identify AF patients treated with either LAA occlusion or NOAC between 1st December 2010 and 17th January 2019. Clinical outcomes of interest were analysed up to 2 years.

RESULTS

108,697 patients were included. Patients who underwent LAA occlusion were younger, more likely to be white Caucasian and male, had a greater incidence of comorbidities, and were less likely to be prescribed other cardiovascular medications. Using propensity score matching, the risk of all-cause mortality was significantly lower among patients who received LAA occlusion compared to NOAC therapy [1.51% vs. 5.60%, RR 0.27 (95% CI 0.14-0.54)], but there were no statistical differences in the composite thrombotic or thromboembolic events [8.17% vs. 7.72%, RR 1.06 (95% CI 0.73-1.53)], ischaemic stroke or TIA [4.69% vs. 5.45%, RR 0.86 (95% CI 0.54-1.38)], venous thromboembolism [1.66% vs. 1.51%, RR 1.10 (95% CI 0.47-2.57)] and intracranial haemorrhage [1.51% vs. 1.51%, RR 1.00 (95% CI 0.42-2.39)].

CONCLUSION

Overall, LAA occlusion might be a suitable alternative to NOAC therapy for stroke prevention in patients with AF.

Residual Stroke Risk in Atrial Fibrillation

AF contributes to increased stroke risk via various mechanisms, including deranged blood constituents, vessel wall abnormalities and abnormal blood flow. This excess risk is frequently managed with anticoagulation therapy, aimed at preventing thromboembolic complications. Yet, a significant proportion of patients with AF remain at high residual stroke risk despite receiving appropriate dose-adjusted anticoagulation. This article explores the residual stroke risk in AF and potential therapeutic options for these patients.

Long-term outcomes of left atrial appendage occlusion in high-risk atrial fibrillation patients: 4-year follow up data

Long-term follow-up data of left atrial appendage (LAA) occlusion in patients with atrial fibrillation (AF) are sparse. To address these data gaps, we analysed the 4-year outcomes of AF patients following LAA occlusion. The was a retrospective cohort study of high-risk patients with AF who underwent successful implantation of the Amulet device at our center between 2014 and 2017. Study endpoints were the rate of stroke, major bleeding and all-cause mortality. We included 71 patients (35.2% females) with a median age of 78 (IQR 73-82) years. Over a median follow-up period of 46 (IQR 19-56) months, the annual rate of ischemic stroke was 1.06 events/100 patient-years (95% CI 0-2.35), hemorrhagic stroke was 1.06 events/100 patient-years (95% CI 0-2.35) and major extracranial bleeding that required unplanned hospital admission was 1.84 events/100 patient-years (95% CI 0.25-3.43). A total of 28 (39.4%) patients died during this period with an annual mortality rate of 10.29 events/100 patient-years (95% CI 7.25-13.32). Our experience suggests that LAA occlusion using the Amulet device appears to be associated with a low risk of ischemic stroke in high-risk AF patients who are deemed unsuitable for oral anticoagulation; however, these patients have a high rate of mortality over the medium to long-term follow-up, and an ongoing significant risk of bleeding and thrombotic events.