Comparative Effectiveness of Left Atrial Appendage Occlusion Versus Oral Anticoagulation by Sex

Impact of Early Bleeding on Long-Term Mortality Following Left Atrial Appendage Occlusion

BACKGROUND

Short-term antithrombotic therapy is recommended after left atrial appendage occlusion(LAAO) to reduce the risk of device-related thrombosis(DRT). However, patients referred for LAAO have excess bleeding risk. Yet, short-term bleeding events post-LAAO are not well characterized.

OBJECTIVE

We aimed to evaluate the incidence of early bleeding post-LAAO and its association with long-term mortality risk. We also sought to identify predictors of early bleeding.

METHODS

Patients who underwent LAAO at Mayo Clinic between 2018 and 2023 were included. Early bleeding was defined as bleeding that occurred within three months of discharge. A multivariable Cox proportional hazards model was used to assess the association between early bleeding and death and to estimate the hazard ratio(HR). Multivariable regression analysis was used to identify predictors of early bleeding.

RESULTS

Among the 592 patients included, 389(66%) were male, and mean age was 75.6 years. Eighty-three patients(14.0%) experienced early bleeding, with the majority having minimal(63.4%) or minor(17.3%) bleeding. At a median follow-up of 14.4 months(IQR 4.2-27.9), early bleeding after LAAO was associated with an increased risk of all-cause mortality (adjustedHR, 2.07; 95%CI, 1.15-3.75; P=0.02). A history of intracranial bleeding, non-paroxysmal atrial fibrillation, CHA2DS2VASc score, and early DRT were independent predictors of early bleeding. Anti-thrombotic therapy on discharge was not associated with early non-procedural bleeding.

CONCLUSIONS

One in seven patients experience a non-procedural bleeding event within 90 days after LAAO. Early bleeding after LAAO is associated with a higher all-cause mortality during mid-term follow-up. Further studies are needed to optimize the management of patients undergoing LAAO.

Association between preprocedural thromboembolic and bleeding events under oral anticoagulation therapy and mid-term outcomes after percutaneous left atrial appendage closure

Currently, no consensus has been established on the most effective antithrombotic therapy to prevent thromboembolic and bleeding events in patients undergoing percutaneous left atrial appendage closure (LAAC) with preprocedural thromboembolic or bleeding events under oral anticoagulation (OAC) therapy. We retrospectively investigated the incidence of device-related thrombosis (DRT), thromboembolic events, and bleeding events in patients who underwent LAAC from September 2019 to October 2022. After categorizing patients into three groups based on preprocedural thromboembolic or bleeding events under OAC therapy, we compared the incidence of DRT and prognosis according to the postprocedural antithrombotic therapy. In patients who received the conventional antithrombotic therapy (OAC with and without single antiplatelet therapy for 45 days after LAAC and dual-antiplatelet therapy from 45 days to 6 months followed by single antiplatelet therapy), preprocedural thromboembolic events despite OAC were independently associated with DRT or postprocedural thromboembolic events at the 3 year follow-up (hazard ratio [HR] 4.55; 95% confidence interval [CI] 1.32-15.6; P = 0.016), whereas preprocedural bleeding events were independently associated with postprocedural bleeding events (HR 8.01, 95% CI 1.45-58.3; P = 0.036). Continuation of OAC for 12 months among patients who developed preprocedural thromboembolic events during OAC significantly decreased the incidence of DRT or postoperative thromboembolic events (P = 0.002) with no increase in the bleeding events (P = 0.522). Preprocedural thromboembolic and bleeding events can predict adverse events after LAAC with the conventional antiplatelet-based antithrombotic therapy. Patients who develop thromboembolic events under continuous OAC may benefit from continuous OAC for 1 year after LAAC.

The impact of sex on stroke care: From epidemiology to outcome

BACKGROUND

Carotid stenosis and atrial fibrillation are key risk factors for development of hemispheric strokes. In this review we aim to identify sex-specific differences in the pathophysiology and treatment of these risk factors and areas for future study.

KEY FINDINGS

Women are underrepresented in research studies of stroke in patients with carotid disease and atrial fibrillation. However, key differences have been found between men and women that suggest that the development of carotid disease and atrial fibrillation occur at later stages of life and are associated with higher severity of stroke. Some treatments, including surgical treatment, seem to have different rates of efficacy and women and women are at higher risk of surgical complications. This suggests that treatment recommendations may need to be sex specific.

CONCLUSION

Efforts should be made to address research and treatment gaps in women with stroke risk factors. This may lead to the development of sex-specific recommendations for stroke prevention and treatment.

Severity of Ischemic Stroke After Left Atrial Appendage Closure vs Nonwarfarin Oral Anticoagulants

BACKGROUND

Strokes after left atrial appendage closure (LAAC) prophylaxis are generally less severe than those after warfarin prophylaxis-thought to be secondary to more hemorrhagic strokes with warfarin. Hemorrhagic strokes are similarly infrequent with direct oral anticoagulant (DOAC) prophylaxis, so the primary subtype after either LAAC or DOAC prophylaxis is ischemic stroke (IS).

OBJECTIVES

The purpose of this study was to compare the severity of IS using the modified Rankin Scale in atrial fibrillation patients receiving prophylaxis with DOACs vs LAAC.

METHODS

A retrospective analysis was performed of consecutive patients undergoing LAAC at 8 centers who developed an IS (ISLAAC) compared with contemporaneous consecutive patients who developed IS during treatment with DOACs (ISDOAC). The primary outcome was disabling/fatal stroke (modified Rankin Scale 3-5) at discharge and 3 months later.

RESULTS

Compared with ISDOAC patients (n = 322), ISLAAC patients (n = 125) were older (age 77.2 ± 13.4 years vs 73.1 ± 11.9 years; P = 0.002), with higher HAS-BLED scores (3.0 vs 2.0; P = 0.004) and more frequent prior bleeding events (54.4% vs 23.6%; P < 0.001), but similar CHA2DS2-VASc scores (5.0 vs 5.0; P = 0.28). Strokes were less frequently disabling/fatal with ISLAAC than ISDOAC at both hospital discharge (38.3% vs 70.3%; P < 0.001) and 3 months later (33.3% vs 56.2%; P < 0.001). Differences in stroke severity persisted after propensity score matching. By multivariate regression analysis, ISLAAC was independently associated with fewer disabling/fatal strokes at discharge (OR: 0.22; 95% CI: 0.13-0.39; P < 0.001) and 3 months (OR: 0.25; 95% CI: 0.12-0.50; P < 0.001), and fewer deaths at 3 months (OR: 0.28; 95% CI: 0.12-0.64; P < 0.001).

CONCLUSIONS

Ischemic strokes in patients with atrial fibrillation are less often disabling or fatal with LAAC than DOAC prophylaxis.

Stroke Prevention in Atrial Fibrillation: Our Current Failures and Required Research

Nonvalvular atrial fibrillation is a common rhythm disorder of middle-aged to older adults that can cause ischemic strokes and systemic embolism. Lifelong use of oral anticoagulants reduces the risk of these ischemic events but increases the risk of major and clinically relevant hemorrhages. These medications also require strict compliance for efficacy, and they have nontrivial failure rates in higher-risk patients. Left atrial appendage closure is a nonpharmacological method to prevent ischemic strokes in atrial fibrillation without the need for lifelong anticoagulant use, but this procedure has the potential for complications and residual embolic events. This workshop of the Roundtable of Academia and Industry for Stroke Prevention discussed future research needed to further decrease the ischemic and hemorrhagic risks among patients with atrial fibrillation. A direct thrombin inhibitor, factor Xa inhibitors, and left atrial appendage closure are FDA-approved approaches whereas factor XIa inhibitors are currently being studied in phase 3 randomized controlled trials for stroke prevention. The benefits, risks, and shortcomings of these treatments and future research required in different high-risk patient populations are reviewed in this consensus statement.

Left Atrial Appendage Occlusion versus Novel Oral Anticoagulation for Stroke Prevention in Atrial Fibrillation-One-Year Survival

Aim To compare the 1-year survival rate of patients with atrial fibrillation (AF) following left atrial appendage occluder (LAAO) implantation vs. treatment with novel oral anticoagulants (NOACs).

METHODS

We have conducted an indirect, retrospective comparison between LAAO and NOAC registries. The LAAO registry is a national prospective cohort of 419 AF patients who underwent percutaneous LAAO between January 2008 and October 2015. The NOACs registry is a multicenter prospective cohort of 3138 AF patients treated with NOACs between November 2015 and August 2018. Baseline patient characteristics were retrospectively collected from coded diagnoses of hospitalization and outpatient clinic notes. Follow-up data was sorted from coded diagnoses and the national civil registry. Subjects were matched according to propensity score. Baseline characteristics were compared using Chi-Square and student's t-test. Survival analysis was performed using Kaplan-Meier survival curves, log-rank test, and multivariable Cox regression, adjusting for possible confounding variables.

RESULTS

This study included 114 subjects who underwent LAAO implantation and 342 subjects treated with NOACs. The mean age of participants was 77.9 ± 7.44 and 77.1 ± 11.2 years in the LAAO and NOAC groups, respectively (p = 0.4). The LAAO group had 70 (61%) men compared to 202 (59%) men in the NOAC group (p = 0.74). No significant differences were found in baseline comorbidities, renal function, or CHA2DS2-VASc score. One-year mortality was observed in 5 (4%) patients and 32 (9%) patients of the LAAO and NOAC groups, respectively. After adjusting for confounders, LAAO was significantly associated with a lower risk for 1-year mortality (HR 0.38, 95%CI 0.14-0.99). In patients with impaired renal function, this difference was even more prominent (HR 0.21 for creatinine clearance (CrCl) < 60 mL/min).

CONCLUSIONS

In a pooled analysis of two registries, we found a significantly lower risk for 1-year mortality in patients with AF who were implanted with LAAO than those treated with NOACs. This finding was more prominent in patients with impaired renal function. Future prospective direct studies should further investigate the efficacy and adverse effects of both treatment strategies.

Efficacy and safety of left atrial appendage closure compared with oral anticoagulation in atrial fibrillation: a meta-analysis of randomized controlled trials and propensity-matched studies

Backgrounds

Two recent randomized controlled trials (RCTs), the PROTECT-AF and the PREVAIL, showed that in atrial fibrillation (AF) patients, left atrial appendage closure (LAAC) is comparable to oral anticoagulants (OAC) in the prevention of stroke and could also possibly reduce mortality. Nevertheless, this net clinical benefit was not confirmed in the most recent RCT comparing LAAC vs. OAC, the PRAGUE-17 trial.

Aim

aim of the present study was to evaluate the efficacy and safety of LAAC compared with OAC among available high-quality studies.

Methods

A systematic search of electronic databases (Medline, Scopus, Embase and the Cochrane Library) was performed to identify eligible RCTs and observational studies with propensity score matching (PSM) analysis. PRISMA guidelines were used for abstracting data and assessing data quality and validity. Outcomes of interest were the occurrence of cardiovascular death (CVD), all-cause death, all-type stroke, and major bleedings.

Results

A total of 3 RCTs and 7 PMS studies involving 25,700 patients were identified. 12,961 patients received LAAC while 12,739 received OAC therapy. After a median follow-up of 2.6 years (IQR 2-4.4), patients who received LAAC had lower risk of CVD (RR = 0.62; 95%CI, 0.51-0.74, I2 = 0%), all-cause death (RR = 0.67; 95% CI, 0.57-0.78, I2 68%) and major bleedings (RR = 0.68; 95%CI, 0.48-0.95 I2 = 87%) compared with patients on OAC. No difference was found between the two groups regarding strokes incidence (RR = 0.94; 95% CI, 0.77-1.15, I2 = 0%).

Conclusions

According to this meta-analysis, LAAC has comparable efficacy in the prevention of stroke compared with OAC and a reduced risk of major bleedings, all-cause death and CVD that may be even larger with longer follow-up.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=269768, identifier CRD42021269768.

An Updated Meta-Analysis on the Clinical Outcomes of Percutaneous Left Atrial Appendage Closure Versus Direct Oral Anticoagulation in Patients With Atrial Fibrillation

The availability of direct oral anticoagulants (DOACs) with known lower bleeding risk compared with warfarin have raised questions about the role of left atrial appendage closure (LAAC). We aimed to perform a meta-analysis to compare the clinical outcomes for LAAC versus DOACs. All studies directly comparing LAAC with DOACs up to January 2023 were included. The outcomes studied included the combined major adverse cardiovascular (CV) events outcomes, ischemic stroke and thromboembolic events, major bleeding, CV mortality, and all-cause mortality. Hazard ratios (HRs) and their 95% confidence interval were extracted or estimated from the data and pooled together with a random-effects model. A total of 7 studies (1 randomized controlled trial, 6 propensity-matched observational studies) were finally included, with a pooled population of 4,383 patients who underwent LAAC and 4,554 patients on DOACs. There were no significant differences between patients who underwent LAAC and patients on DOACs in terms of baseline age (75.0 vs 74.7, p = 0.27), CHA2DS2-VASc score (5.1 vs 5.1, p = 0.33), or HAS-BLED score (3.3 vs 3.3, p = 0.36). After a mean weighted follow-up of 22.0 months, LAAC was associated with significantly lower rates of combined major adverse CV event outcomes (HR 0.73 [0.56 to 0.95], p = 0.02), all-cause mortality (HR 0.68 [0.54 to 0.86], p = 0.02), and CV mortality (HR 0.55 [0.41 to 0.72], p<0.01). There were no significant differences in the rates of ischemic stroke or systemic embolism (HR 1.12 [0.92 to 1.35], p = 0.25), major bleeding (HR 0.94 [0.67 to 1.32], p = 0.71), or hemorrhagic stroke (HR 1.07 [0.74 to 1.54], p = 0.74) between LAAC and DOAC. In conclusion, percutaneous LAAC was found to be as efficacious as DOACs for stroke prevention, with lower all-cause and CV mortality. The rates of major bleeding and hemorrhagic stroke were similar. LAAC has a potential role to play in stroke prevention in patients with atrial fibrillation in the era of DOACs, but further randomized data are needed.

Sex Differences in the Evaluation and Treatment of Stroke

There are differences in the prevalence and strength of risk factors in women, along with sex-specific risk factors such as pregnancy. Women have a higher lifetime risk of stroke compared to men, with worse outcomes including higher rates of death and disability. We have made strides in the identification of sex-specific risk factors but with the paucity of sex-specific end points in clinical trials, stroke treatment and research are hindered.