Use of Direct Oral Anticoagulation Therapy Following Implantation of the Watchman Left Atrial Appendage Occlusion Device

Effectiveness and safety of short-term anticoagulant regimens after left atrial appendage occlusion: A systematic review and meta-analysis

INTRODUCTION

Left atrial appendage occlusion (LAAO) provides an alternative for poor candidates of long-term oral anticoagulant (OAC) therapy; however, anticoagulant therapy after surgical procedures has limited use due to associated uncertainties. We aimed to evaluate the effectiveness and safety of the short-term use of direct oral anticoagulant (DOAC) and warfarin after LAAO.

METHOD

Electronic databases such as PubMed, Embase, Medline, and Cochrane Library databases were searched up to November 11, 2022. Our study compared DOAC therapy and warfarin in patients after LAAO. A meta-analysis was conducted with the Review Manager software (version 5.4).

RESULTS

The meta-analysis included 13 cohort studies with a total of 32,607 patients. Our findings indicated that the incidence of stroke/TIA/SE, peri-device leaks>5 mm, device-related thrombosis, and all-cause mortality were not significantly different between the two groups after LAAO (P > 0.05). The DOAC group had a significantly lower incidence of major bleeding (OR = 0.83, 95 % CI: 0.74-0.94, P = 0.003), any bleeding (OR = 0.34, 95 % CI: 0.23-0.51, P < 0.001), stroke/TIA/SE and major bleeding (OR = 0.57, 95 % CI: 0.34-0.95, P = 0.03), and any major adverse event (OR = 0.89, 95 % CI:0.82-0.97, P = 0.010) than the warfarin group. The subgroup analysis revealed that the rate of stroke/TIA/SE was similar in the two groups in terms of the different regions, follow-up time, study type, anticoagulant strategy, and bleeding risk. The incidence of major bleeding in the DOAC group was significantly lower than that in the warfarin group in North America, as well as at follow-up period ≤6 months, retrospective cohort, HAS-BLED average score ≥ 3. In addition, the risk of major bleeding was higher with the combination of OAC and single antiplatelet therapy (SAPT) than with OAC alone. Finally, in the North American region, retrospective cohort, and HAS-BLED average score ≥ 3, the incidence of any serious adverse event in the DOAC group was still significantly lower than that in the warfarin group.

CONCLUSION

Compared to warfarin, DOAC reduced the risk of major bleeding and any serious adverse event in patients after LAAO. This advantage was particularly notable in North America and high-risk populations for bleeding. In addition, the incidence of device-related thrombosis, peri-device leaks, stroke/TIA/SE and all-cause mortality were similar in both groups. The risk of major bleeding was lower in patients taking OAC alone compared with those taking OAC plus SAPT, without increasing the risk of thrombosis.

Treatment of Persistent Left Atrial Appendage Thrombus in Patients with Atrial Fibrillation on Adequate Oral Anticoagulation: Pathways of Care for All-comers and Heart Failure Patients

In patients with AF, the presence of left atrial/left atrial appendage (LA/LAA) thrombus is related to an increased risk of thromboembolic events. Anticoagulation therapy, either with vitamin K antagonists or novel oral anticoagulants (NOACs) is therefore mandatory in AF with LA/LAA thrombus in order to lower the risk of stroke or other systemic embolic events. Despite the efficacy of these treatments, some patients will have persistent LAA thrombus remaining or may have contraindications to oral anticoagulation. Currently, little is known about the occurrence, risk factors and resolution rate of LA/LAA thrombus in patients who are already under optimal chronic oral anticoagulation, including vitamin K antagonists or NOACs. The common action in clinical practice in this scenario is switching from one to another anticoagulant drug exhibiting a different mechanism of action. Repeated cardiac imaging is then advised within several weeks to visually verify thrombus dissolution. Finally, there is a substantial scarcity of data on the role and optimal use of NOACs after LAA occlusion. The aim of this review is to critically evaluate data and provide up-to-date information on the best antithrombotic strategies in this challenging clinical scenario.

Comparison of outcomes between novel oral anticoagulants and warfarin monotherapy in patients with left atrial appendage closure: A systematic review and meta-analysis

Background

Pivotal trials of percutaneous left atrial appendage closure (LAAC) used dedicated post-procedure antithrombotic protocols. However, there is no consensus on the selection of new oral anticoagulants (NOAC) and warfarin monotherapy after LAAC. This study aims to compare NOAC with warfarin monotherapy for efficacy and safety in patients undergoing LAAC.

Methods

A database search was conducted using PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov for trials that compared NOAC with warfarin monotherapy after LAAC. The effective outcomes included any major adverse events (all-cause death, stroke, major bleeding) and their individual components. Safety outcomes included all-cause death, major bleeding, total bleeding, DRT, and PDL >5 mm.

Results

We included 10 non-randomized clinical trials with 10,337 patients, of whom 4,960 patients received NOAC, while 5,377 patients received warfarin. There were no statistically significant differences in any major adverse events (LogOR: −0.11, 95% CI: −0.27, 0.04, P = 0.16), stroke (LogOR: 0.00, 95% CI: −0.42, 0.42, P = 1.00), all-cause death (LogOR: −0.23, 95% CI: −0.48, 0.02, P = 0.07), major bleeding (LogOR: −0.22, 95% CI: −0.45, 0.01, P = 0.06). NOAC was associated with a significant reduction in total bleeding (LogOR: −1.01, 95% CI: −1.47, −0.55, P < 0.0001) compared to warfarin. No statistically significant differences were found in DRT (LogOR: −0.19, 95% CI: −0.15, 0.52, P = 0.27) and PDL >5 mm (LogOR: 0.19, 95% CI: −0.33, 0.72, P = 0.47). Meta-regression and subgroup analysis showed that total bleeding (LogOR: −1.56, 95% CI: −2.15, −0.97, P < 0.001) was significantly lower in the NOAC group in the subgroup of <75 y.

Conclusion

After LAAC, NOAC monotherapy was associated with a lower risk of bleeding compared to warfarin monotherapy for 45 days. There was no significant difference between NOAC and warfarin in terms of other results.

Systematic review registration

www.york.ac.uk/inst/crd, identifier: CRD42022361244.

Direct Oral Anticoagulant Versus Warfarin After Left Atrial Appendage Closure With WATCHMAN: Updated Systematic Review and Meta-analysis

BACKGROUND

In the pivotal WATCHMAN trials, warfarin was used for post-procedural anticoagulation in the first 45 days after left atrial appendage closure. We aimed to investigate the efficacy and safety of direct oral anticoagulant (DOAC) versus warfarin after WATCHMAN.

METHODS

We performed a literature search of five electronic databases to identify studies comparing DOAC with warfarin after WATCHMAN. We pooled outcomes for the efficacy (thromboembolism, device-related thrombus [DRT], peri-device leak [PDL] >5mm) and safety endpoints (bleeding, mortality). Thromboembolism was defined as ischemic stroke, transient ischemic attack, or systemic embolism.

RESULTS

We included 10 cohort studies with 2,440 patients, of whom 1,397 (57.3%) received DOAC. Concerning peri-procedural outcomes (within 7 days following implantation), DOAC was associated with a reduction in major bleeding (Risk ratio [RR] 0.32; 95% confidence interval [CI] 0.11-0.92) compared with warfarin, without significant differences in all bleeding (RR 0.46; 95% CI 0.15-1.42) and thromboembolism (RR 0.93; 95% CI 0.21-4.16). On first follow-up transesophageal echocardiography, DRT (RR 0.79; 95% CI 0.39-1.60) and PDL>5mm (RR 0.44; 95% CI 0.16-1.20) were comparable among groups. With a mean follow-up of 1.5-12 months, DOAC was associated with reductions in major bleeding (RR 0.52; 95% CI 0.30-0.89) and all bleeding (RR 0.38; 95% CI 0.25-0.58) compared with warfarin. The outcomes of thromboembolism (RR 0.79; 95% CI 0.36-1.73) and all-cause mortality (RR 0.49; 95% CI 0.19-1.28) were not significantly different between the two groups.

CONCLUSION

Following WATCHMAN implantation, DOAC was associated with reductions in major bleeding and all bleeding compared with warfarin at mid-term follow-up. The outcomes of thromboembolism, all-cause mortality, DRT, and PDL >5mm were comparable among groups.