Real-world clinical outcomes with a next-generation left atrial appendage closure device: the FLXibility Post-Approval Study

Incidence and predictors of 2-year mortality following percutaneous left atrial appendage occlusion in the EWOLUTION trial

AIMS

Sufficient survival time following left atrial appendage occlusion (LAAO) is essential for ensuring the efficacy and cost-effectiveness of this strategy for stroke prevention. Understanding prognostic factors for early mortality after LAAO could optimize patient selection. In the current study, we perform an in-depth analysis of 2-year mortality after LAAO, focusing particularly on potential predictors.

METHODS AND RESULTS

The EWOLUTION registry is a real-world cohort comprising 1020 patients that underwent LAAO. Endpoint definitions were pre-specified, and death was categorized as cardiovascular, non-cardiovascular, or unknown origin. Mortality rates were calculated from Kaplan-Meier estimates. Baseline characteristics significantly associated with death in univariate Cox regression analysis were incorporated into the multivariate analysis. All multivariate predictors were included in a risk model. Two-year mortality rate was 16.4% [confidence interval (CI): 14.0-18.7%], with 50% of patients dying from a non-cardiovascular cause. Multivariate baseline predictors of 2-year mortality included age [hazard ratio (HR) 1.05, CI: 1.03-1.08, per year increase], heart failure (HR 1.73, CI: 1.24-2.41), vascular disease (HR 1.47, CI: 1.05-2.05), valvular disease (HR 1.63, CI: 1.15-2.33), abnormal liver function (HR 1.80, CI: 1.02-3.17), and abnormal renal function (HR 1.58, CI: 1.10-2.27). Mortality rate exhibited a gradual rise as the number of risk factors increased, reaching 46.1% in patients presenting with five or six risk factors.

CONCLUSION

One in six patients died within 2 years after LAAO. We identified six independent predictors of mortality. When combined, this model showed a gradual increase in mortality rate with a growing number of risk factors, which may guide appropriate patient selection for LAAO.

CLINICAL TRIAL REGISTRATION

The original EWOLUTION registry was registered at clinicaltrials.gov under identifier NCT01972282.

Contrast-free left atrial appendage occlusion in patients using the LAMBRE™ device

BACKGROUND

Advances in imaging have led to procedural optimization of left atrial appendage closure (LAAC). Contrast-free approaches, guided merely by echocardiography, have been established, however data on this topic remains scarce. In this analysis, we assessed contrast-free procedural results with the LAMBRE LAAC device.

METHODS

The multicenter retrospective BoBoMa (Bonn/Bordeaux/Mainz)-Registry included a total of 118 patients that underwent LAAC with LAMBRE devices omitting contrast-dye. Baseline and echocardiographic characteristics as well as intra- and postprocedural complications and outcomes were assessed.

RESULTS

Patients were at a mean age of 77.5 ± 7.5 years with high thromboembolic and bleeding risk (CHADS-VASc-score 4.6 ± 1.4, HAS-BLED-score 3.7 ± 1.0, respectively). Renal function was impaired with a mean glomerular filtration rate (GFR) of 50 ± 22 ml/min. Mean procedural time was 47.2 ± 37.5  minutes with a mean radiation dose of 4.75 ± 5.25 Gy*cm2. Device success, defined as proper deployment in a correct position, was achieved in 97.5% (115/118) of cases with repositioning of the occluder in 7.6% (9/118) and resizing in 3.4% (4/118) of cases. No relevant peri-device leakage (>3 mm) was observed with 42% of occluders being implanted in an ostial position. Periprocedural complications occurred in 6.8% (8/118) of cases, including two cases of device embolization and one case of clinically-relevant pericardial effusion requiring surgical intervention. Other complications included pericardial effusion (2.5%, 3/118) and vascular access site complications (1.7%, 2/118).

CONCLUSION

Echocardiography-guided contrast-free LAAC using the LAMBRE device is safe and feasible. Further prospective studies including the direct comparison of devices as well as imaging techniques are warranted in contrast-free LAAC.

Practical guide on left atrial appendage closure for the non-implanting physician: an international consensus paper

A significant proportion of patients who suffer from atrial fibrillation (AF) and are in need of thromboembolic protection are not treated with oral anticoagulation or discontinue this treatment shortly after its initiation. This undertreatment has not improved sufficiently despite the availability of direct oral anticoagulants which are associated with less major bleeding than vitamin K antagonists. Multiple reasons account for this, including bleeding events or ischaemic strokes whilst on anticoagulation, a serious risk of bleeding events, poor treatment compliance despite best educational attempts, or aversion to drug therapy. An alternative interventional therapy, which is not associated with long-term bleeding and is as effective as vitamin K anticoagulation, was introduced over 20 years ago. Because of significant improvements in procedural safety over the years, left atrial appendage closure, predominantly achieved using a catheter-based, device implantation approach, is increasingly favoured for the prevention of thromboembolic events in patients who cannot achieve effective anticoagulation. This management strategy is well known to the interventional cardiologist/electrophysiologist but is not more widely appreciated within cardiology or internal medicine. This article introduces the devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. Almost all physicians who care for adult patients will have many with AF. This practical guide, written within guideline/guidance boundaries, is aimed at those non-implanting physicians who may need to refer patients for consideration of this new therapy, which is becoming increasingly popular.

Percutaneous left atrial appendage closure with the Watchman device: a systematic review

Atrial fibrillation (AF) is the most commonly observed arrhythmia in the world and its prevalence increases with age. The main and most severe complication of AF is ischemic stroke. Oral anticoagulation (OAC) therapy is the standard of care for stroke prevention in the high risk population. Initiation of this treatment is associated with a substantial risk of bleeding complications. Moreover, there is a group of patients who cannot tolerate OAC. In patients with AF the left atrial appendage (LAA) is the main source of thrombus formation. Percutaneous left atrial appendage closure (LAAC) has become an important non-pharmacological intervention for stroke prevention in patients with non-valvular AF. The procedure aims to reduce the risk of thromboembolism without increasing the risk of bleeding. Over the last few years, the safety and long-term efficacy of the procedure in specific populations have increased and more patients are being treated. The Watchman device is the most studied device in this field. Randomized controlled trials demonstrated non-inferiority of percutaneous left atrial appendage closure using the WATCHMAN 2.5 device to OAC (Boston Scientific, Marlborough, MA, USA). The new generation device, WATCHMAN FLX, was introduced and its use was associated with fewer safety events and a higher success rate of effective appendage closure. Nevertheless, several unsolved problems remain, including device-related thrombosis, the post-LAAC antithrombotic regimen, and peri-device leakage. This review will focus on LAAC with the Watchman device for stroke prevention in AF patients. Current status, available literature, clinical safety and efficacy will be summarized.

Left Atrial Appendage Occlusion and Post-procedural Antithrombotic Management

Left atrial appendage occlusion (LAAO) is an established alternative to oral anticoagulation for stroke prevention in atrial fibrillation. Antithrombotic therapy is used in the post-procedural period to prevent device-related thrombosis (DRT). The risk of DRT is considered highest in the first 45-90 days after device implantation, based on animal studies of the device healing process. Clinically applied antithrombotic regimens vary greatly across studies, continents, and centers. This article gives an overview of the evidence behind current antithrombotic regimens, ongoing randomized trials, and future post-procedural management.

Three-dimensional intracardiac echocardiography for left atrial appendage sizing and percutaneous occlusion guidance

AIMS

Left atrial appendage (LAA) imaging is critical during percutaneous occlusion procedures. 3D-intracardiac echocardiography (ICE) features direct visualization of LAA from multiple cross-sectional planes at a time. We aimed at reporting procedural success of 3D-ICE-guided LAA occlusion and the correlation between pre-procedural transoesophageal echocardiography (TEE) and intraprocedural 3D-ICE for LAA sizing.

METHODS AND RESULTS

Among 274 patients undergoing left atrial appendage occlusion (LAAO) with a Watchman FLX, periprocedural ICE guidance was achieved via a commercially available 2D-ICE catheter (220 patients) or a novel (NUVISION™) 3D-ICE one (54 patients). Primary endpoint was a composite of procedural success and LAA sealing at follow-up TEE. Secondary endpoint was a composite of periprocedural device recapture/resizing plus presence of leaks ≥ 3 mm at follow-up TEE. 3D-ICE measurements of maximum landing zone correlated highly with pre-procedural TEE reference values [Pearson's: 0.94; P < 0.001; bias: -0.06 (-2.39, 2.27)]. The agreement between 3D-ICE-based device selection and final device size was 96.3% vs. 79.1% with 2D-ICE (P = 0.005). The incidence of the primary endpoint was 98.1% with 3D-ICE and 97.3% with 2D-ICE (P = 0.99). 2D-ICE patients had a trend towards a higher incidence of periprocedural device recapture/redeployment (31.5% vs. 44.5%; P = 0.09). The secondary endpoint occurred in 31.5% of 3D-ICE patients vs. 45.9% of 2D-ICE ones (P = 0.065).

CONCLUSION

Intracardiac echocardiography-guided LAAO showed a very high success, with no major adverse events. A very high level of agreement for LAA sizing was found between pre-procedural TEE and periprocedural 3D-ICE. 3D-ICE performed significantly better than 2D-ICE for FLX size selection and may provide better guidance during device deployment.

Prognostic value of chronic kidney disease in patients undergoing left atrial appendage occlusion

AIMS

Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist and share an increased risk of thrombo-embolism (TE). CKD concomitantly predisposes towards a pro-haemorrhagic state. Our aim was to evaluate the prognostic value of CKD in patients undergoing percutaneous left atrial appendage occlusion (LAAO).

METHODS AND RESULTS

A total of 2124 consecutive AF patients undergoing LAAO were categorized into CKD stage 1+2 (n = 1089), CKD stage 3 (n = 796), CKD stage 4 (n = 170), and CKD stage 5 (n = 69) based on the estimated glomerular filtration rate at baseline. The primary endpoint included cardiovascular (CV) mortality, TE, and major bleeding. The expected annual TE and major bleeding risks were estimated based on the CHA2DS2-VASc and HAS-BLED scores. A non-significant higher incidence of major peri-procedural adverse events (1.7 vs. 2.3 vs. 4.1 vs. 4.3) was observed with worsening CKD (P = 0.14). The mean follow-up period was 13 ± 7 months (2226 patient-years). In comparison to CKD stage 1+2 as a reference, the incidence of the primary endpoint was significantly higher in CKD stage 3 (log-rank P-value = 0.04), CKD stage 4 (log-rank P-value = 0.01), and CKD stage 5 (log-rank P-value = 0.001). Left atrial appendage occlusion led to a TE risk reduction (RR) of 72, 66, 62, and 41% in each group. The relative RR of major bleeding was 58, 44, 51, and 52%, respectively.

CONCLUSION

Patients with moderate-to-severe CKD had a higher incidence of the primary composite endpoint. The relative RR in the incidence of TE and major bleeding was consistent across CKD groups.

Long-term Clinical Outcomes in Contemporary Patients Undergoing Left Atrial Appendage Occlusion Procedures in Ontario, Canada

Background

Percutaneous left atrial appendage occlusion (LAAO) is an alternative for stroke prevention in patients with atrial fibrillation with contraindications to oral anticoagulation. Population-level real-world data describing the use and outcomes of LAAO procedures are evolving, with a paucity of longer-term follow-up data. We report on the patient characteristics, procedure complications, and longer-term clinical outcomes in all patients undergoing LAAO procedures in Ontario, Canada.

Methods

All patients undergoing LAAO procedure between April 1, 2013 and March 31, 2022 were identified. Linked administrative databases were utilized to determine patient clinical and procedural characteristics. Outcomes of interest included procedural complications at 7 and 30 days, and longer-term rates of stroke, bleeding, all-cause rehospitalization, and mortality.

Results

A total of 549 individuals were included in the study cohort. The average age was 75 ± 8 years, with 66% being of male sex, with a mean CHA2DS2VASc score of 4.4 ± 1.6, and with 68% not receiving oral anticoagulation. Follow-up for 2.6 ± 2.0 patient-years was available. Stroke occurred in 2.8% during the follow-up period (1.1 per 100 patient-years), bleeding in 10% (4.0 per 100 patient-years), and any hospital readmission in 63% (43 per 100 patient-years). A total of 29% of the cohort died during the follow-up period (11 per 100 patient-years), with 1.8% of the cohort dying during the procedural hospitalization. The mortality rate was unchanged during the study period (P for trend = 0.72).

Conclusions

Long-term stroke and bleeding rates are low in patients undergoing LAAO procedures in Ontario, Canada. All-cause mortality in this population is high and remained unchanged during the study period.

Mid-Term Feasibility of Percutaneous Left Atrial Appendage Occlusion in Elderly Patients with Non-Valvular Atrial Fibrillation

BACKGROUND

Percutaneous left atrial appendage occlusion (LAAO) therapy using the WATCHMAN system has been introduced to prevent thrombosis and minimize the use of anticoagulants in patients with non-valvular atrial fibrillation. Given the high risk of bleeding and stroke in elderly patients, these patients would be good candidates for this therapy. However, the efficacy and feasibility of LAAO therapy in elderly patients remains uncertain.

METHODS

Consecutive patients who underwent LAAO therapy using the WATCHMAN system in a large academic center between June 2020 and March 2023 were included. The safety and efficacy of LAAO therapy during the 1-year observation period in patients aged ≥85 years old were compared with those in the younger cohort.

RESULTS

A total of 188 patients (78.4 ± 6.9 years old, 133 male patients) were included. 34 patients were ≥85 years old, 96 were between 75 and 84 years old, and 58 were <75 years old. The elderly group had a higher CHA2DS2-VASc score and were at greater risk of falling-related bleeding compared with the younger cohort. The device implantations were successful in all patients except for one. During the 1-year observation period, one patient had a peri-device leak >5 mm and there were 6 device-related cases of thrombosis, whose incidence was not significantly different between the groups (p = 0.98). The cumulative incidences of bleeding and thrombotic events in the elderly group were as low as in the younger cohort (p > 0.05 for both). Most anticoagulants were terminated regardless of age.

CONCLUSION

The mid-term feasibility and efficacy of percutaneous LAAO therapy using the WATCHMAN system in elderly patients aged ≥85 years were as acceptable as in the younger cohort.

Diagnostic and therapeutic pathways for the malignant left atrial appendage: European Heart Rhythm Association physician survey

AIMS

Patients with atrial fibrillation who despite taking oral anti-coagulant therapy (OAT) suffer a stroke or systemic embolism (SSE) without vascular cause or who develop left atrial appendage (LAA) thrombus (LAAT) should be considered as having malignant LAA. The optimal treatment strategy to reduce SSE risk in such patients is unknown. The aim of the study is to investigate the diagnostic and therapeutic pathways for malignant LAA practiced in European cardiac centres.

METHODS AND RESULTS

An 18-item online questionnaire on malignant LAA was disseminated by the European Heart Rhythm Association (EHRA) Scientific Initiatives Committee. A total of 196 physicians participated in the survey. There seems to be high confidence in transoesophageal echocardiography (TEE) imaging, considering LAAT diagnosis. Switching to another direct oral anti-coagulant (DOAC) is the preferred initial step for the treatment of malignant LAA followed by a switch to vitamin K antagonist (VKA), low-molecular-weight heparin, or continued/optimized DOAC dosage, whereas LAA closure is the last option. Left atrial appendage closure is a viable option in patients with embolic stroke despite OAT and no evidence of thrombus at TEE (empty LAA) after comprehensive diagnostic measures to exclude other sources of embolism.

CONCLUSION

This EHRA survey provides a snapshot of the contemporary management of patients diagnosed with malignant LAA. Currently, the majority of patients are treated on an outpatient basis with either shifting from VKA to DOAC or from one DOAC to another. Left atrial appendage closure in this population seems to be reserved for patients with higher bleeding risk or complications of malignant LAA, such as stroke.

Leap or lag: left atrial appendage closure and guidelines

Atrial fibrillation (AF) is associated with life-threatening thromboembolism. Most emboli stem from thrombosis in the left atrial appendage (LAA). The current treatment of choice is oral anticoagulants (OACs), but a small proportion of patients cannot take OACs predominantly because of the so-called unacceptable bleeding risks. However, many who initially accept OACs subsequently stop therapy or reduce the OAC treatment to a potentially non-effective dose leaving them exposed to thromboembolic risk. A relatively simple alternative therapy involves the catheter-based insertion of a LAA closure (LAAC) device to prevent thromboembolism from the LAA. There is a considerable evidence base for this therapy consisting of clinical trials and observational data which suggests comparable therapeutic efficacy with a possible small excess of ischaemic strokes. Although LAAC has been very closely examined by regulators and approved for market release, guidelines from most professional societies give only weak recommendations for use of this device which may be the only known effective therapy available to some at-risk AF patients. Guidance materials from the same societies more enthusiastically endorse LAAC. Clinical practice is running well ahead of the guidelines because equipoise has been lost by physicians faced with patients for whom they have no other effective therapy. Guideline writers are correct in providing recommendations which are less strong for LAAC than for OACs, for those who are able and willing to take OAC treatment, but for those who are not, a stronger recommendation is needed. But, should the guidelines lag behind or leap ahead of the available evidence?