Retrospective Cohort Study Examining Reduced Intensity and Duration of Anticoagulant and Antiplatelet Therapy Following Left Atrial Appendage Occlusion with the WATCHMAN Device

Single versus dual antiplatelet therapy following percutaneous left atrial appendage closure-A systematic review and meta-analysis

BACKGROUND

In the last few years, percutaneous LAA occlusion (LAAO) has become a plausible alternative in atrial fibrillation (AF) patients with contraindications to anticoagulation therapy. Nevertheless, the optimal antiplatelet strategy following percutaneous LAAO remains to be defined.

METHODS

Studies comparing single antiplatelet therapy (SAPT) versus dual antiplatelet therapy (DAPT) following LAAO were systematically searched and screened. The outcomes of interest were ischemic stroke, device-related thrombus (DRT) and major bleeding. A random-effect meta-analysis was performed comparing outcomes in both groups. The moderator effect of baseline characteristics on outcomes was evaluated by univariate meta-regression analyses.

RESULTS

Sixteen observational studies with 3255 patients treated with antiplatelet therapy (SAPT, n = 1033; DAPT, n = 2222) after LAAO were included. Mean age was 74.5 ± 8.3 years, mean CHA2DS2-VASc and HAS-BLED scores were 4.3 ± 1.5 and 3.2 ± 1.0, respectively. At a weighted mean follow-up of 12.7 months, the occurrence of stroke (RR 1.33; 95% CI 0.64-2.77; p =.44), DRT (RR 1.52; 95% CI 0.90-2.58; p =.12), and the composite of stroke and DRT (RR 1.26; 95% CI 0.67-2.37; p =.47) did not differ significantly between SAPT and DAPT groups. The rate of major bleedings was also not different between groups (RR 1.41; 95% CI 0.64-3.12; p =.39).

CONCLUSIONS

Among AF patients at high bleeding risk undergoing percutaneous LAAO, a post-procedural minimalistic antiplatelet strategy with SAPT did not significantly differ from DAPT regimens regarding the rate of stroke, DRT and major bleeding.

Short-term antiplatelet versus anticoagulant therapy after left atrial appendage closure: a systematic review and meta-analysis

This meta-analysis compared the efficacy and safety of different antithrombotic regimens after left atrial appendage closure (LAAC). PubMed, Embase, Medline, Cochrane Library databases were systematically searched from their inception to March 2023. Patients were divided into short-term oral anticoagulation (OAC) group and antiplatelet therapy (APT) group. The incidence of events were performed using RevMan 5.4. The events including device-related thrombus (DRT), ischemic stroke/systemic embolization (SE), major bleeding, any bleeding, any major adverse event and all-cause mortality. Subgroup analysis were based on OAC alone or OAC plus single antiplatelet therapy (SAPT) in OAC group. Oral anticoagulants include warfarin and direct oral anticoagulant (DOAC). Fourteen studies with 35,166 patients were included. We found that the incidence of DRT (OR = 0.49, 95% CI 0.36-0.66, P＜0.0001) and all-cause mortality (OR = 0.71, 95% CI 0.57-0.89, P = 0.002) were significantly lower in OAC group than APT group. However, there was no statistical differences in the incidence rates of ischemic stroke/SE (OR = 0.77, 95% CI 0.49-1.20, P = 0.25), major bleeding (OR = 0.84, 95% CI 0.55-1.27, P = 0.84), any bleeding (OR = 0.83, 95% CI 0.56-1.22, P = 0.34) and any major adverse event (OR = 0.56, 95% CI 0.30-1.03, P = 0.06) in the two groups. Subgroup analysis found that the incidence of DRT, all-cause mortality and any major adverse event in OAC monotherapy were lower than that in APT group (P＜0.05), but not statistically different from other outcome. The incidence of DRT, all-cause mortality, any major adverse event and any bleeding in DOAC were significantly better than APT group (P＜0.05). While warfarin only has better incidence of DRT than APT (P＜0.05), there was no statistical difference between the two groups in other outcome (P＞0.05). The incidence of DRT was significantly lower than APT group (P＜0.05), major bleeding were higher, and the rest of the outcome did not show any statistically significant differences(P＞0.05) when OAC plus SAPT. Based on the existing data, short-term OAC may be favored over APT for patients who undergo LAAC. DOAC monotherapy may be favored over warfarin monotherapy or OAC plus APT, when selecting anticoagulant therapies.

Residual leaks following percutaneous left atrial appendage occlusion and outcomes: a meta-analysis

BACKGROUND AND AIMS

Residual leaks are not infrequent after left atrial appendage occlusion. However, there is still uncertainty regarding their prognostic implications. The aim of this study is to evaluate the impact of residual leaks after left atrial appendage occlusion.

METHODS

A literature search was conducted until 19 February 2023. Residual leaks comprised peri-device leaks (PDLs) on transoesophageal echocardiography (TEE) or computed tomography (CT), as well as left atrial appendage patency on CT. Random-effects meta-analyses were performed to assess the clinical impact of residual leaks.

RESULTS

Overall 48 eligible studies (44 non-randomized/observational and 4 randomized studies) including 61 666 patients with atrial fibrillation who underwent left atrial appendage occlusion were analysed. Peri-device leak by TEE was present in 26.1% of patients. Computed tomography-based left atrial appendage patency and PDL were present in 54.9% and 57.3% of patients, respectively. Transoesophageal echocardiography-based PDL (i.e. any reported PDL regardless of its size) was significantly associated with a higher risk of thromboembolism [pooled odds ratio (pOR) 2.04, 95% confidence interval (CI): 1.52-2.74], all-cause mortality (pOR 1.16, 95% CI: 1.08-1.24), and major bleeding (pOR 1.12, 95% CI: 1.03-1.22), compared with no reported PDL. A positive graded association between PDL size and risk of thromboembolism was noted across TEE cut-offs. For any PDL of >0, >1, >3, and >5 mm, the pORs for thromboembolism were 1.82 (95% CI: 1.35-2.47), 2.13 (95% CI: 1.04-4.35), 4.14 (95% CI: 2.07-8.27), and 4.44 (95% CI: 2.09-9.43), respectively, compared with either no PDL or PDL smaller than each cut-off. Neither left atrial appendage patency, nor PDL by CT was associated with thromboembolism (pOR 1.45 and 1.04, 95% CI: 0.84-2.50 and 0.52-2.07, respectively).

CONCLUSIONS

Peri-device leak detected by TEE was associated with adverse events, primarily thromboembolism. Residual leaks detected by CT were more frequent but lacked prognostic significance.

Short-term antithrombotic strategies after left atrial appendage occlusion: a systematic review and network meta-analysis

Background: Percutaneous left atrial appendage occlusion (LAAO) has emerged as a stroke prevention strategy in patients with nonvalvular atrial fibrillation (NVAF), and these patients were required to receive antithrombotic therapy post-procedure. However, the optimal antithrombotic strategy after LAAO remains controversial. This study explored the safety and efficacy of different antithrombotic strategies after LAAO through a network comparison method. Methods: We systematically searched the MEDLINE, Embase, and Cochrane Library databases for studies that reported the interested efficacy and safety outcomes (stroke, device-related thrombus (DRT), and major bleeding) of different antithrombotic strategies [DAPT (dual antiplatelet therapy), DOACs (direct oral anticoagulants), and VKA (vitamin k antagonist)] in patients who had experienced LAAO. Pairwise comparisons and network meta-analysis were performed for the interested outcomes. Risk ratios (RRs) with their confidence intervals (CIs) were calculated using a random-effects model. The rank of the different strategies was calculated using the surface under the cumulative ranking curve (SUCRA). Results: Finally, 10 observational studies involving 1,674 patients were included. There was no significant difference in stroke, DRT, and major bleeding among the different antithrombotic strategies (DAPT, DOACs, and VKA). Furthermore, DAPT ranked the worst in terms of stroke (SUCRA: 19.8%), DRT (SUCRA: 3.6%), and major bleeding (SUCRA: 6.6%). VKA appeared to be superior to DOACs in terms of stroke (SUCRA: 74.9% vs. 55.3%) and DRT (SUCRA: 82.3% vs. 64.1%) while being slightly inferior to DOACs in terms of major bleeding (SUCRA: 71.0% vs. 72.4%). Conclusion: No significant difference was found among patients receiving DAPT, DOACs, and VKA in terms of stroke, DRT, and major bleeding events after LAAO. The SUCRA indicated that DAPT was ranked the worst among all antithrombotic strategies due to the higher risk of stroke, DRT, and major bleeding events, while VKAs were ranked the preferred antithrombotic strategy. However, DOACs are worthy of consideration due to their advantage of convenience.

Clinical follow-up of left atrial appendage occlusion in patients with atrial fibrillation ineligible of oral anticoagulation treatment-a systematic review and meta-analysis

PURPOSE

The recommended stroke prevention for patients with atrial fibrillation (AF) and increased risk of ischemic stroke is oral anticoagulation (OAC). Parts of the patient population are not eligible due to contraindication, and percutaneous left atrial occlusion (LAAO) can then be a preventive treatment option. The aim of this systematic review and meta-analysis is to estimate the long-term clinical effectiveness of LAAO as stroke prevention in patients with AF, increased risk of ischemic stroke, and contraindication to OAC.

METHODS

We performed a systematic review and meta-analysis, using Poisson random effect models, to estimate the incidence rate (events per 100 patient-years) of ischemic stroke, transient ischemic attack, major bleeding, and all-cause death after LAAO treatment. We also calculated the risk reduction of ischemic stroke with LAAO compared with no stroke prevention estimated through a predicted risk in an untreated population (5.5 per 100 patient-years).

RESULTS

We included 29 observational studies in our meta-analysis, including 7 951 individuals and 12 211 patient-years. The mean CHA2DS2-VASc score among the patients in the included studies is 4.32. The pooled incidence rate of ischemic stroke is 1.38 per 100 patient-years (95% CI 1.08; 1.77). According to a meta-regression model, the estimated incidence rate of ischemic stroke at CHA2DS2-VASc 4 is 1.39 per 100 patient-years. This implies a risk reduction of 74.7% with LAAO compared to predicated risk with no stroke prevention.

CONCLUSIONS

Our results suggest that LAAO is effective as stroke prevention for patients with AF, increased risk of stroke, and contraindication to oral anticoagulation.

Short-Term Antiplatelet Versus Anticoagulant Therapy After Left Atrial Appendage Occlusion: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this study was to compare bleeding, thromboembolic, device-related thrombus (DRT), and all-cause mortality events between patients treated with short-term oral anticoagulation (OAC) and those treated with short-term antiplatelet therapy (APT) following left atrial appendage occlusion (LAAO).

BACKGROUND

Short-term OAC is recommended for patients following LAAO. However, in practice many patients receive APT rather than OAC because of excessive bleeding risk. However, the safety and efficacy of APT compared with OAC have been debated.

METHODS

A search was conducted of databases for studies comparing OAC with APT following LAAO. The outcomes of interest were all-cause stroke, major bleeding, DRT, and all-cause mortality. Noncomparative studies were pooled into a single study to generate comparisons of the studies' outcomes. Effects measure were pooled using the random-effect model.

RESULTS

A total of 83 studies with 12,326 patients (APT, n = 7,900; OAC, n = 4,151) were included. Mean CHA2DS2-VASc and HAS-BLED scores were 4.1 ± 1.6 and 3.0 ± 1.3, respectively. There were no significance differences between the APT and OAC groups with regard to stroke (risk ratio [RR]: 1.04; 95% confidence interval [CI]: 0.54 to 1.98; p = 0.91; I2 = 31%), major bleeding (RR: 1.12; 95% CI: 0.68 to 1.84; p = 0.65; I2 = 53%), DRT (RR: 1.33; 95% CI: 0.74 to 2.39; p = 0.33; I2 = 36%), and all-cause mortality (RR: 1.29; 95% CI: 0.40 to 4.09; p = 0.18; I2 = 36%). These findings persisted in multiple secondary analyses: 1) excluding studies that reported no events; 2) including comparative studies only; 3) excluding patients who were treated with single APT; and 4) removing one study at a time to assess the effect of each study on the overall effect size. There was also no difference in the studies' endpoints among patients who received different LAAO devices.

CONCLUSIONS

In a meta-analysis of observational data, there were no differences in the occurrence of stroke, major bleeding DRT, and all-cause mortality in patients treated with short-term OAC or APT following LAAO.

Left atrial appendage closure with WATCHMAN in Asian patients: 2 year outcomes from the WASP registry

Background

Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk non-valvular atrial fibrillation patients, but has not been widely studied in Asian patients. The prospective WASP registry assessed real-world outcomes for patients undergoing WATCHMAN implant in the Asia-Pacific region.

Methods

Data were collected from consecutive patients across 9 centres. Major endpoints included procedural success, safety and long-term outcomes including occurrence of bleeding, stroke/transient ischaemic attack/systemic embolism and all-cause mortality.

Results

Subjects (n = 201) had a mean age of 70.8 ± 9.4 years, high stroke risk (CHA₂DS₂-VASc: 3.9 ± 1.7), elevated bleeding risk (HAS-BLED: 2.1 ± 1.2) with 53% patients from Asian countries. Successful implantation occurred in 98.5% of patients; 7-day device/procedure-related SAE rate was 3.0%. After 2 years of follow-up, the rates of ischaemic stroke/TIA/SE and major bleeding were 1.9 and 2.2 per 100-PY, respectively, representing relative reductions of 77% and 49% versus expected rates per risk scores. The relative risk reductions versus expected rates were more pronounced in Asians vs. Non-Asians (89% vs 62%; 77% vs 14%). Other significant findings included larger mean LAA ostium diameter for Asians vs. Non-Asians (23.4 ± 4.1 mm vs. 21.2 ± 3.2 mm, p < 0.001) and hence requirement for larger median device size (27 mm for Asians, 24 mm for non-Asians [p < 0.0001]).

Conclusion

Real-world experience of left atrial appendage closure with WATCHMAN has demonstrated low peri-procedural risk, and long-term efficacy for stroke and bleeding prevention in a primarily Asian cohort.