Interventional left atrial appendage closure vs novel anticoagulation agents in patients with atrial fibrillation indicated for long-term anticoagulation (PRAGUE-17 study)

Should left atrial appendage closure be considered in resistant left atrial appendage thrombus cases? 'Former Foe, New Ally'

BACKGROUND

The study explores left atrial appendage closure (LAAC) as a safe and effective alternative to anticoagulation for atrial fibrillation (AF) patients at high bleeding risk. Complications, such as cardioembolic events due to left atrial appendage thrombus (LAAT), highlight the need for alternative stroke prevention strategies.

AIMS

This research assesses LAAC's safety and efficacy in patients with LAAT, aiming to offer valuable insights into its potential as a viable option for stroke prevention in such cases.

METHODS

The study included 205 patients who underwent LAAC using specific devices between September 2015 and February 2023. Among them, 32 patients had persistent LAAT. Baseline characteristics, antithrombotic medications, risk scores, and LAAC indications were documented. Patients were followed to monitor significant clinical events like stroke, cardiovascular mortality, and all-cause mortality.

RESULTS

The mean age was 71.9 and mostly female. Indications for LAAC were ischemic cerebrovascular events (CVE) despite anticoagulation (25%), bleeding complications (major/minor, 37.5% each), or both. Successful LAA closure was achieved in all cases, with minimal pericardial effusion in one. One-month follow-up showed no major events or device-related issues. Median follow-up of 16.5 months saw 21.9% non-cardiac deaths. The study underscores LAAC's efficacy for stroke prevention in patients with persistent LAAT.

CONCLUSIONS

The LAAC in cases of LAAT, whether pursued initially or as a deferred approach, demonstrates feasibility and safety, exhibiting notable procedural success and minimal incidence of periprocedural complications.

Real-World Management Strategies of Anticoagulated Atrial Fibrillation Patients After a Clinically Significant Bleeding Episode

BACKGROUND

Systemic anticoagulation for stroke prevention in patients with atrial fibrillation (AF) carries inherent bleeding risks, and determining whether and when to resume anticoagulation after significant bleeding is a common dilemma. We aimed to describe the clinical characteristics of AF patients discharged after a bleeding event, document real-life thromboembolic prevention strategy (TPS), and analyse their associated clinical outcomes.

METHODS

We retrospectively reviewed the charts of anticoagulated AF patients admitted for bleeding from 2017 to 2019.

RESULTS

A total of 140 patients were included, with a mean age of 78.6 years. Four discharge groups were defined: 75 patients (53.5%) had optimal anticoagulation (OA), 37 (26.4%) had a suboptimal antithrombotic regimen (SAR; low-dose direct oral anticoagulants without dose-reduction criteria or antiplatelet therapy), 10 (7.1%) were referred for left atrial appendage occlusion (LAAO), and 18 (12.9%) left without any TPS. All-cause mortality at 2 years was high (28.6%) but not statistically different between groups (P = 0.71). Patients discharged with a TPS (OA/SAR/LAAO referral) were more likely to be readmitted for bleeding at 2 years (34% vs 0%; P = 0.002), and those discharged without a TPS had higher rates of stroke (16.6% vs 1.4%; P = 0.003). SAR yielded readmission rates for bleeding similar to resumption of OA (27% vs 34.7%; P = 0.41) but was associated with high rates of death or readmission at 2 years.

CONCLUSIONS

This real-life cohort reveals that clinicians frequently downgrade or discontinue long-term thromboembolic protection after a bleeding event despite current guideline recommendations to the contrary, and downgrading resulted in bleeding risk similar to OA.

Direct oral anticoagulants versus percutaneous left atrial appendage occlusion in atrial fibrillation: 5-year outcomes

BACKGROUND

LAAO is an emerging option for thromboembolic event prevention in patients with NVAF. We previously reported data on comparison between LAAO and DOAC at two-year follow-up in NVAF patients at HBR (HAS-BLED ≥3).

AIMS

Limited data are available on long term follow-up. We aimed to evaluate the efficacy and safety of DOACs versus LAAO indication after 5 years.

METHODS

We enrolled 193 HBR treated with LAAO and 189 HBR patients with DOACs. At baseline, LAAO group had higher HAS-BLED (4.2 vs 3.3, p < 0.001) and lower CHADS-VASc (4.3 vs. 4.7, p = 0.005). After 1:1 PSM, 192 patients were included (LAAO n = 96; DOACs n = 96).

RESULTS

At 5-year follow-up the rate of the combined safety and effectiveness endpoint (ISTH major bleeding and thromboembolic events) was significantly higher in LAAO group (p = 0.042), driven by a higher number of thromboembolic events (p = 0.047). The rate of ISTH-major bleeding events was similar (p = 0.221). After PSM no significant difference in the primary effectiveness (LAAO 13.3% vs DOACs 9.5%, p = 0.357) and safety endpoint (LAAO 7.5% vs DOACs 7.5%; p = 0.918) were evident. Overall bleeding rate was significantly higher in DOACs group (25.0% vs 13.7%, p = 0.048), while a non-significant higher number of TIA was reported in LAAO group (5.4% vs 1.1%, p = 0.098). All-cause and cardiovascular mortality were higher in LAAO group at both unmatched and matched analysis.

CONCLUSION

We confirmed safety and effectiveness of both DOAC and LAAO in NVAF patients at HBR, with no significant differences in thromboembolic events or major bleeding were at 5-year follow-up. The observed increased mortality after LAAO warrants further investigations in RCTs.

Percutaneous left atrial appendage occlusion: impact on left atrial deformation indices

BACKGROUND

Percutaneous left atrial appendage occlusion (LAAO) is an accepted alternative to thromboprophylaxis in patients with atrial fibrillation (AF) who are: (i) intolerant to oral anticoagulation (OAC) (e.g. life-threatening haemorrhage), (ii) non-adherent to OAC, or (iii) at a high bleeding risk with OAC. Improvement in LA mechanics was shown post-LAAO in the LAFIT-LARIAT study, using the Lariat device. No significant change was seen in LA mechanics after LAAO with the Watchman device in the LAFIT-Watchman study. The impact of LAAO with the Amplatzer or Amulet device on LA deformation mechanics has not been investigated.

PURPOSE

To evaluate the impact of LAAO with the Amplatzer or Amulet device on echocardiographic LA deformation indices.

METHODS

All patients undergoing percutaneous LAAO from 2013 to 2021 at a single centre were included from an ongoing clinical registry. LA reservoir (ε_reservoir), conduit (ε_conduit) and contractile strain (ε_contractile) and strain rate (SR_reservoir, SR_conduit, SR_contractile) were assessed with two-dimensional speckle tracking echocardiography from an apical four-chamber view. Conduit and contractile strain and strain rates were only recorded for patients without AF at the time of echocardiography. Changes in LA deformation indices over time were compared with a linear mixed model.

RESULTS

28 LAAO recipients (mean age 73 ± 12 years, 68% male) were analysed. 5 (18%) patients had AF pre- or post-procedure. After a mean follow-up of 1.6 ± 1.4 months, the mean LA ε_reservoir increased from 10.15 ± 6.44% to 10.18 ± 8.72% (p = 0.985), the mean LA ε_conduit increased from 5.12 ± 5.48% to 5.31 ± 6.11% (p = 0.891) and the mean LA ε_contractile decreased from 5.14 ± 4.32% to 4.95 ± 5.30% (p = 0.898). During the same time interval, the mean LA SR_reservoir decreased from + 0.54 ± 0.23.s^- 1 to + 0.48 ± 0.43.s^- 1 (p = 0.566), the mean LA SR_conduit remained stable: -0.47 ± 0.41.s^- 1 to -0.47 ± 0.32.s^- 1 (p = 0.997) and the mean LA SR_contractile decreased from - 0.66 ± 0.50.s^- 1 to -0.55 ± 0.46.s^- 1 (p = 0.660).

CONCLUSION

No significant improvement in LA mechanical function was seen after LAAO with the Amplatzer or Amulet device. Different LAAO devices therefore appear to have divergent effects on LA deformation, the clinical implications of which may warrant further study.

Preliminary findings on left atrial appendage occlusion simulations applying different endocardial devices

Atrial fibrillation (AF) is one of the most investigated arrhythmias since it is associated with a five-fold increase in the risk of strokes. Left atrium dilation and unbalanced and irregular contraction caused by AF favour blood stasis and, consequently, stroke risk. The left atrial appendage (LAA) is the site of the highest clots formation, increasing the incidence of stroke in AF population. For many years oral anticoagulation therapy has been the most used AF treatment option available to decrease stroke risk. Unfortunately, several contraindications including bleeding risk increase, interference with other drugs and with multiorgan functioning, might outweigh its remarkable benefits on thromboembolic events. For these reasons, in recent years, other approaches have been designed, including LAA percutaneous closure. Unfortunately, nowadays, LAA occlusion (LAAO) is restricted to small subgroups of patients and require a certain level of expertise and training to successfully complete the procedure without complications. The most critical clinical problems associated with LAAO are represented by peri-device leaks and device related thrombus (DRT). The anatomical variability of the LAA plays a key role in the choice of the correct LAA occlusion device and in its correct positioning with respect to the LAA ostium during the implant. In this scenario, computational fluid dynamics (CFD) simulations could have a crucial role in improving LAAO intervention. The aim of this study was to simulate the fluid dynamics effects of LAAO in AF patients to predict hemodynamic changes due to the occlusion. LAAO was simulated by applying two different types of closure devices based on the plug and the pacifier principles on 3D LA anatomical models derived from real clinical data in five AF patients. CFD simulations were performed on the left atrium model before and after the LAAO intervention with each device. Blood velocity, particle washout and endothelial damage were computed to quantify flow pattern changes after the occlusion in relation to the thrombogenic risk. Our preliminary results confirmed an improved blood washout after the simulated implants and the capability of foreseeing thrombogenic risk based on endothelial damage and maximum blood velocities in different scenarios. This tool may help to identify effective device configurations in limiting stroke risk for patient-specific LA morphologies.

2019 Chinese expert consensus statement on left atrial appendage closure in patients with atrial fibrillation

The left atrial appendage closure (LAAC), the efficacy and safety of which has been proved by a number of randomized controlled trials and registries, is recommended by several guidelines to prevent stroke in high‐risk patients with non‐valvular atrial fibrillation. However, current guidelines only discuss the indications and contraindications of LAAC, as an emerging technology, there still lacks comprehensive recommendations involved with LAAC, including devices, image assessment modality, identification and treatment of complications, perioperative medication, and postoperative management. Therefore, the Chinese Society of Cardiology (CSC) of Chinese Medical Association (CMA) and the Editorial Board of Chinese Journal of Cardiology jointly issued the expert consensus statement on LAAC in the prevention of stroke in patients with atrial fibrillation after comprehensive discussion by experts with different backgrounds. This consensus provided three levels of recommendations to guide and standardize the clinical application of LAAC based on existing evidence and clinical practice experience, including appropriate (more potential benefits or fewer harms), uncertain (somehow reasonable but need more evidence), and inappropriate (unlikely to benefit, or have more complications).

2021 Focused update of the 2017 consensus guidelines of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation

The consensus of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation (AF) has been published in 2017 which provided useful clinical guidance for cardiologists, neurologists, geriatricians, and general practitioners in Asia-Pacific region. In these years, many important new data regarding stroke prevention in AF were reported. The Practice Guidelines subcommittee members comprehensively reviewed updated information on stroke prevention in AF, and summarized them in this 2021 focused update of the 2017 consensus guidelines of the APHRS on stroke prevention in AF. We highlighted and focused on several issues, including the importance of AF Better Care (ABC) pathway, the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) for Asians, the considerations of use of NOACs for Asian patients with AF with single 1 stroke risk factor beyond gender, the role of lifestyle factors on stroke risk, the use of oral anticoagulants during the "coronavirus disease 2019" (COVID-19) pandemic, etc. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician's decision remains the most important factor in the management of AF.

2021 Focused Update Consensus Guidelines of the Asia Pacific Heart Rhythm Society on Stroke Prevention in Atrial Fibrillation: Executive Summary

The consensus of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation (AF) has been published in 2017 which provided useful clinical guidance for cardiologists, neurologists, geriatricians, and general practitioners in the Asia-Pacific region. In these years, many important new data regarding stroke prevention in AF were reported. The practice guidelines subcommittee members comprehensively reviewed updated information on stroke prevention in AF, and summarized them in this 2021 focused update of the 2017 consensus guidelines of the APHRS on stroke prevention in AF. We highlighted and focused on several issues, including the importance of the AF Better Care pathway, the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) for Asians, the considerations of use of NOACs for Asian AF patients with single one stroke risk factor beyond gender, the role of lifestyle factors on stroke risk, the use of oral anticoagulants during the “coronavirus disease 2019” pandemic, etc. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician's decision remains the most important factor in the management of AF.

Left Atrial Appendage Closure versus Non-Warfarin Oral Anticoagulation in Atrial Fibrillation: 4-Year Outcomes of PRAGUE-17

BACKGROUND

The PRAGUE-17 trial demonstrated that left atrial appendage closure (LAAC) was non-inferior to non-warfarin oral anticoagulants (NOAC) for preventing major neurological, cardiovascular or bleeding events in high-risk patients with atrial fibrillation (AF).

OBJECTIVE

To assess the pre-specified long-term (4-year) outcomes in PRAGUE-17.

METHODS

PRAGUE-17 was a randomized non-inferiority trial comparing percutaneous LAAC (Watchman or Amulet) with NOACs (95% apixaban) in non-valvular AF patients with a history of cardioembolism, clinically-relevant bleeding, or both CHA₂DS₂-VASc > 3 and HASBLED > 2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically-relevant bleeding, or procedure/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat (mITT).

RESULTS

We randomized 402 AF patients (201 per group, age 73.3±7.0 years, 65.7% male, CHA₂DS₂-VASc 4.7+1.5, HASBLED 3.1+0.9). After 3.5 years median follow-up (1,354 patients-years), LAAC was non-inferior to NOAC for the primary endpoint by mITT (subdistribution hazard ratio[sHR] 0.81, 95% CI 0.56-1.18; p=0.27; p for non-inferiority=0.006). For the components of the composite endpoint, the corresponding sHRs (and 95% CIs) were 0.68 (0.39-1.20; p=0.19) for cardiovascular death, 1.14 (0.56-2.30; p=0.72) for all-stroke/TIA, 0.75 (0.44-1.27; p=0.28) for clinically-relevant bleeding, and 0.55 (0.31-0.97; p=0.039) for non-procedural clinically-relevant bleeding. The primary endpoint outcomes were similar in the per-protocol [sHR 0.80 (95% CI 0.54-1.18), p=0.25] and on-treatment [sHR 0.82 (95% CI 0.56-1.20), p=0.30] analyses.

CONCLUSION

In long-term follow-up of PRAGUE-17, LAAC remains non-inferior to NOACs for preventing major cardiovascular, neurological or bleeding events. Furthermore, non-procedural bleeding was significantly reduced with LAAC.

The Watchman device for preventing stroke in patients with atrial fibrillation

ABSTRACT

Atrial fibrillation (AF) is one of the most common sustained dysrhythmias that increases in prevalence with age, and is associated with strokes that can lead to significant patient morbidity and mortality. AF prevalence is projected to double over the next 25 years, demonstrating the need for innovative and effective stroke prevention modalities. Two options are direct oral anticoagulants and left atrial appendage occlusion. This article discusses the Watchman device, a left atrial appendage occlusion device that provides an option for patients with contraindications for anticoagulation.

Percutaneous Left Atrial Appendage Occlusion: An Emerging Option in Patients with Atrial Fibrillation at High Risk of Bleeding

Atrial fibrillation (AF) is a common cardiac arrhythmia with an estimated prevalence of 1% in the general population. It is associated with an increased risk of ischemic stroke, silent cerebral ischemia, and cognitive impairment. Due to the blood flow stasis and morphology, thrombus formation occurs mainly in the left atrial appendage (LAA), particularly in the setting of nonvalvular AF (NVAF). Previous studies have shown that >90% of emboli related to NVAF originate from the LAA, thus prevention of systemic cardioembolism is indicated. According to the current guidelines, anticoagulant therapy with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs), represents the standard of care in AF patients, in order to prevent ischemic stroke and peripheral embolization. Although these drugs are widely used and DOACs have shown, compared to VKAs, non-inferiority for stroke prevention with significantly fewer bleeding complications, some issues remain a matter of debate, including contraindications, side effects, and adherence. An increasing number of patients, indeed, because of high bleeding risk or after experiencing life-threatening bleedings, must take anticoagulants with extreme caution if not contraindicated. While surgical closure or exclusion of LAA has been historically used in patients with AF with contradictory results, in the recent years, a novel procedure has emerged to prevent the cardioembolic stroke in these patients: The percutaneous left atrial appendage occlusion (LAAO). Different devices have been developed in recent years, though not all of them are approved in Europe and some are still under clinical investigation. Currently available devices have shown a significant decrease in bleeding risk while maintaining efficacy in preventing thromboembolism. The procedure can be performed percutaneously through the femoral vein access, under general anesthesia. A transseptal puncture is required to access left atrium and is guided by transesophageal echocardiography (TEE). Evidence from the current literature indicates that percutaneous LAAO represents a safe alternative for those patients with contraindications for long-term oral anticoagulation. This review summarizes scientific evidences regarding LAAO for stroke prevention including clinical indications and an adequate patient selection.

[Left Atrial Appendage Closure - step by step]

Thrombus formation due to atrial fibrillation is the most common cause of embolic stroke. Anticoagulation offers an effective prophylaxis. However, anticoagulation in turn has an inherent increased risk of bleeding. Patients with non-valvular atrial fibrillation who have contraindications for anticoagulation may profit from a closure of the left atrial appendage. The most commonly and best studied devices for this are the WATCHMAN™ and the AMPLATZER Amulet™ Occluders.In this How-To article, the aim is to offer a general overview of the indications, contraindications and complications as well as the implantation and postoperative management of patients receiving LAA closure by example of the WATCHMAN FLX™ Occluder.

Non-vitamin K antagonist oral anticoagulation versus left atrial appendage occlusion for primary and secondary stroke prevention after cardioembolic stroke

INTRODUCTION

This study aimed to evaluate the performance of non-vitamin K antagonist oral anticoagulation (NOAC) in patients with previous stroke and non-valvular atrial fibrillation (AF) compared with left atrial appendage occlusion (LAAO) in primary and secondary stroke prevention settings.

METHODS

This was a prospective, single-center, non-randomized cohort study of 302 consecutive patients with non-valvular AF and at high risk for stroke. Two treatment strategies were compared: LAAO (n=91) and long-term treatment with NOAC (n=149). The primary outcome was the composite endpoint of death, stroke and major bleeding. Propensity score and cause-of-death analyses were performed to compare outcomes.

RESULTS

In a mean follow-up of 13 months, there were 30 deaths (LAAO 8.8% vs. NOAC 14.8%), five strokes (LAAO 1.1% vs. NOAC 2.7%) and six major bleeds (LAAO 1.1% vs. NOAC 3.4%). There was a non-significant trend for a lower incidence of the primary endpoint in the LAAO group (11.0% vs. 20.9%; HR 0.42, 95% CI 0.17-1.05, p=0.064). Considering only secondary prevention LAAO patients (34.1% of the LAAO group), there was also a non-significant lower incidence of the primary endpoint (LAAO 6.5% vs. 20.9%; HR 0.30, 95% CI 0.07-1.39, p=0.12). While about a fifth of LAAO patients stopped antiplatelet treatment six months after device implantation due to recurrent minor bleeding, no adverse cardiovascular event or major bleeding occurred in this subset of patients.

CONCLUSION

In this registry-based study, LAAO was a reasonable alternative to NOAC for the prevention of a composite endpoint of all-cause mortality, stroke and major bleeding in patients at high risk for stroke.

Non-vitamin K antagonist oral anticoagulation versus left atrial appendage occlusion for primary and secondary stroke prevention after cardioembolic stroke

INTRODUCTION

This study aimed to evaluate the performance of non-vitamin K antagonist oral anticoagulation (NOAC) in patients with previous stroke and non-valvular atrial fibrillation (AF) compared with left atrial appendage occlusion (LAAO) in primary and secondary stroke prevention settings.

METHODS

This was a prospective, single-center, non-randomized cohort study of 302 consecutive patients with non-valvular AF and at high risk for stroke. Two treatment strategies were compared: LAAO (n=91) and long-term treatment with NOAC (n=149). The primary outcome was the composite endpoint of death, stroke and major bleeding. Propensity score and cause-of-death analyses were performed to compare outcomes.

RESULTS

In a mean follow-up of 13 months, there were 30 deaths (LAAO 8.8% vs. NOAC 14.8%), five strokes (LAAO 1.1% vs. NOAC 2.7%) and six major bleeds (LAAO 1.1% vs. NOAC 3.4%). There was a non-significant trend for a lower incidence of the primary endpoint in the LAAO group (11.0% vs. 20.9%; HR 0.42, 95% CI 0.17-1.05, p=0.064). Considering only secondary prevention LAAO patients (34.1% of the LAAO group), there was also a non-significant lower incidence of the primary endpoint (LAAO 6.5% vs. 20.9%; HR 0.30, 95% CI 0.07-1.39, p=0.12). While about a fifth of LAAO patients stopped antiplatelet treatment six months after device implantation due to recurrent minor bleeding, no adverse cardiovascular event or major bleeding occurred in this subset of patients.

CONCLUSION

In this registry-based study, LAAO was a reasonable alternative to NOAC for the prevention of a composite endpoint of all-cause mortality, stroke and major bleeding in patients at high risk for stroke.

Who watches the WATCHMAN™? A case of incomplete endothelialization at 3 years after device implantation

WATCHMAN™ is a left atrial appendage (LAA) occlusion device used to prevent thromboembolism in patients with atrial fibrillation. Endothelialization of the device is required to completely occlude the LAA. Prior to endothelialization, the device is thrombogenic. The duration of dual-antiplatelet therapy after device insertion is based on animal studies demonstrating endothelialization at 3 months. A 73-year-old man presented with symptomatic severe mitral regurgitation 3 years after the WATCHMAN device was implanted. During mitral valve repair, we found that the WATCHMAN device was not endothelialized. The device was removed and the LAA was ligated after repair of the mitral valve. The long-term incidence and clinical significance of incomplete endothelialization after LAA-occlusion must be investigated. Postimplantation and perioperative antiplatelet and anticoagulation protocols require re-evaluation. The potential role of thoracoscopic epicardial LAA clipping must be considered.

Plugs for left atrial appendage occlusion: an overview of available devices

INTRODUCTION

Approximately one-third of all ischemic strokes and the ensuing health and economic burden can be attributed to the presence of atrial fibrillation (AF). The global prevalence of AF continues to rise, thus making it by far the most common diagnosed cardiac arrhythmia. Percutaneous left atrial appendage (LAA) occlusion or obliteration has been developed to protect from the occurrence of stroke in patients with nonvalvular AF.

AREAS COVERED

We address the characteristics and techniques for implantation as well as some clinical registries and randomized trials of the various catheter-based devices for the occlusion of the LAA that are either currently available or in the clinical evaluation stage.

EXPERT OPINION

Over less than 2 decades, LAA occlusion progressed from being a concept applied in a few specialized centers to a globally recognized procedure implemented in numerous hospitals as part of daily interventional practice. The respective devices are to date safer and easier to deploy than initially. Periprocedural and postprocedural complications will continue to decrease as already evident from prospective randomized trials and registries. Although current indications focus on patients with nonvalvular AF and contraindications for oral anticoagulation, it is all but certain that the future will bring a widening in the spectrum of indications, applicability, and usage of these devices.

Percutaneous left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

Patients with atrial fibrillation (AF) have a fivefold higher risk of stroke than persons in sinus rhythm. Effective stroke prevention is achieved with oral anticoagulants such as vitamin K antagonists or nonvitamin K oral anticoagulants. An alternative for stroke prevention in patients with AF is the closure of the left atrial appendage (LAA) with a percutaneously applied closure system. The two large randomized studies PROTECT-AF and PREVAIL failed to show superiority of LAA closure over anticoagulation in patients with AF. Meta-analyses of studies and registries, however, suggest that LAA closure has particular advantages with regard to the reduction of severe bleeding complications. Currently, several prospective randomized studies are being conducted in different patient populations to evaluate the benefit of LAA closure in comparison to standard of care. Currently, LAA closure is recommended in patients after intracranial hemorrhage, with advanced renal failure, after severe gastrointestinal bleeding, in patients with a high risk of recurrent ischemic stroke and elderly patients with high risk of bleeding and falling.

[Therapeutic management of nonvalvular atrial fibrillation]

Atrial fibrillation (AF) is the most frequent persistent cardiac arrhythmia and is associated with an increased mortality. Therefore, an effective differential treatment of patients is mandatory. After a risk stratification oral anticoagulation (OAC) should be initiated depending on the individual stroke risk of each patient. Alternatively, in the presence of contraindications for OAC and an increased risk for bleeding and/or stroke, the implantation of a left atrial appendage closure device can be considered. Symptomatic patients should undergo a rhythm control strategy if possible. Based on the risk-benefit considerations, catheter ablation (CA) of AF plays an increasingly important role in establishing long-term medicinal rhythm control. A pulmonary vein isolation can lead to freedom from AF for 1 year in 70-80% of patients with paroxysmal AF (and approximately 50% in persistent AF). So far, a survival advantage of CA could only be shown in patients with heart failure, so that in most cases this is only a symptomatic treatment for improvement in the quality of life.

Left atrial appendage occlusion in patients with atrial fibrillation and large prevalence of prior intracranial bleeding

BACKGROUND

Left atrial appendage occlusion (LAAO) represents an alternative approach for the prevention of cardioembolic stroke in patients with nonvalvular atrial fibrillation (NVAF) and contraindication for oral anticoagulation (OAC). The aim of our study was to analyse the outcomes in patients treated with LAAO, with a focus on cases with previous intracranial bleeding.

METHODS

Sixty patients with NVAF underwent LAAO (75.4 ± 9 years); mean CHA2DS2-VASc was 4.4 ± 1.7, mean HAS-BLED 3.2 ± 0.9. Thirty-two patients (53.3%) reported previous intracranial bleeding. Ischaemic and bleeding events recorded during follow-up were compared with expected event rates according to CHA2DS2-VASc and HAS-BLED scores.

RESULTS

Device implantation was successful in 58 patients (96.7%). The antiplatelet therapy was tailored according to patients' bleeding risk. During follow-up (2.32 ± 1.5 years) 3 ischaemic strokes and 1 transient ischaemic attack occurred, versus 13 total expected thromboembolic events (P = 0.033); 5 major bleedings were observed, versus 7 expected ones, if the patients were under OAC. Considering the combined endpoint (thromboembolic and major bleeding events) 9 events were observed versus 20 expected major events (P = 0.031). In the prespecified subgroup of patients with previous intracranial bleeding, two ischaemic strokes and one transient ischaemic attack were observed during follow-up versus six total expected thromboembolic events; no intracranial bleeding recurrence was recorded. Regarding the combined endpoint four major events were recorded versus nine expected ones.

CONCLUSION

LAAO is an efficient and safe option for the prevention of cardioembolic stroke in patients with NVAF, high thromboembolic risk and contraindication to OAC, particularly in patients with previous intracranial bleeding.

[Left atrial appendage closure for stroke prevention in atrial fibrillation : An update]

Atrial fibrillation (AF) is one of the most frequent causes of ischemic stroke. Without treatment the annual risk of ischemic stroke is on average approximately 5-6%/year in patients with atrial fibrillation, depending on the overall cardiovascular risk profile. Oral anticoagulation with new oral anticoagulants (NOAC) or vitamin K antagonists (VKA) is recommended for patients with AF and an elevated risk for stroke (CHA₂DS₂-VASc score ≥1); however, severe bleeding complications are potential reasons for discontinuation of this treatment. Overall, up to 30 % of the patients with AF remain without effective thromboembolism prophylaxis. Left atrial appendage (LAA) closure represents an alternative to pharmaceutical stroke prevention. Catheter-based and surgical LAA closure techniques are available. For catheter-based procedures with closure systems, high implantation success rates and relatively low periprocedural complication rates have been observed in recent registry studies. The reason for the restrained recommendation in the European guidelines is the as yet limited experience from large randomized studies.

[Left atrial appendage occlusion in patients with nonvalvular atrial fibrillation : Present evidence, ongoing studies, open questions]

About every fifth ischemic stroke is caused by atrial fibrillation. Oral anticoagulation is highly effective in secondary stroke prevention, but a relevant portion of patients with atrial fibrillation is not (permanently) anticoagulated for a variety of reasons. Based on present evidence, no general recommendation can be given for left atrial appendage occlusion in patients with nonvalvular atrial fibrillation. However, left atrial appendage occlusion is a treatment option after severe anticoagulation-related bleeding, if the cause of bleeding is not treatable. Left atrial appendage occlusion is critical in patients with a relative contraindication for oral anticoagulation or lack of adherence to given medication. It seems to be important that further randomized studies confirm a benefit of left atrial appendage occlusion in selected patients with nonvalvular atrial fibrillation. In addition, it is vital to clarify whether discontinuation of antiplatelets is feasible after catheter-based left atrial appendage occlusion, as antiplatelets are associated with a risk of bleeding. Within this review article, we discuss present evidence, gaps of knowledge and provide an overview on ongoing clinical studies. In addition, we summarize the design of the CLOSURE-AF study. This randomized multicenter study will start recruitment soon and is funded by the German Center for Cardiovascular Research e. V.

Transesophageal Echocardiography to Diagnose Watchman Device Infection

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The authors report a rare case of infected Watchman device 4 months after placement.

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A high index of suspicion allowed timely diagnosis of Watchman device infection.

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Transesophageal echocardiography led to diagnosis of an infected Watchman device.

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High clinical morbidity is associated with Watchman device endocarditis.

[Left atrial appendage closure in non-valvular atrial fibrillation]

Atrial fibrillation is the most frequent cardiac arrhythmia worldwide, causing approximately 20% of all ischemic strokes. Therefore, oral anticoagulation is recommended in patients with atrial fibrillation with at least a moderate risk of stroke; however, there is a significant proportion of patients who cannot undergo long-term oral anticoagulation. As the left atrial appendage is of major relevance for atrial fibrillation-induced thrombus formation, catheter-based or surgical closure of the left atrial appendage appears to be a promising therapeutic option. Large registry studies including patients with catheter-based left atrial appendage closure have proven its effectiveness and a decreasing procedure-related complication rate. This review article summarizes the current knowledge and introduces major ongoing randomized studies, which will investigate the impact of left atrial appendage closure on stroke prevention. The authors hope that the results of the randomized CLOSURE AF trial, which is funded by the German Center for Cardiovascular Research e. V. and is now recruiting patients in Germany, will help to solve many of the currently prevalent clinical questions.

The left atrial appendage in humans: structure, physiology, and pathogenesis

For many years, the left atrial appendage (LAA) was considered a dormant embryological remnant; however, it is a structurally complex and functional organ that contributes to cardiac haemodynamic changes and volume homeostasis through both its contractile properties and neurohormonal peptide secretion. When dysfunctional, the LAA contributes to thrombogenesis and subsequent increased predisposition to cardioembolic events. Consequently, the LAA has gained much attention as a therapeutic target to lower this risk. In addition, attention has focused on the LAA in its role as an electrical trigger for atrial tachycardia and atrial fibrillation with ablation of the LAA to achieve electrical isolation showing promising results in the maintenance of sinus rhythm. This in-depth review explores the structure, physiology and pathophysiology of the LAA, as well as LAA intervention and their sequelae.

Percutaneous devices for left atrial appendage occlusion: A contemporary review

Patient with atrial fibrillation (AF) are at risk of developing stroke with the left atrial appendage (LAA) being the most common site for thrombus formation. If left untreated, AF is associated with 4 to 5 folds increase in the risk of ischemic stroke in all age groups. About 5% to 15% of AF patients have atrial thrombi on transesophageal echocardiography, and 91% of those thrombi are located in the LAA in patient with nonrheumatic AF. Although oral anticoagulants are the gold-standard treatment for stroke prevention in patients with non-valvular AF, some patients are at high risk of bleeding and deemed not candidates for anticoagulation. Therefore, LAA occlusion (LAAO) has emerged as alternative approach for stroke prevention in those patients. Surgical LAAO is associated with high rate of unsuccessful closure and recommended only in patients with AF and undergoing cardiac surgery. Percutaneous LAAO uses transvenous access with trans-septal puncture and was first tested using the PLAATO device. Watchman is the most common and only Food and Drug Administration (FDA) approved device for LAAO. LAAO using Watchman device is non-inferior to warfarin therapy in preventing ischemic stroke/systemic thromboembolism. However, it is associated with lower rates of hemorrhagic stroke, bleeding and death. Amplatzer is another successful LAAO device that has CE mark and is waiting for FDA approval. Optimal antithrombotic therapy post LAAO is still under debate and highly patient-specific. The aim of this paper is to systematically review the current literature to evaluate the efficacy and safety of different LAAO devices.

[Catheter-based atrial appendage closure-current data and future developments]

In Germany more than 1.6 million patients suffer from atrial fibrillation (AF). Within the next decades this number will substantially increase due to current demographic trends with the increasing average age of the population. When untreated, patients with atrial fibrillation have a five times higher risk for stroke as compared with a control cohort. A potent stroke prevention therapy reducing the risk of stroke by approximately 70-80% is primarily treatment with new oral anticoagulants (NOACs). The risk scores for stroke (CHA₂DS₂-VASc) and major bleeding (HAS-BLED) in patients with atrial fibrillation share common variables, so that patients with the highest stroke risk often carry a very high bleeding risk. A significant number of patients (ca. 20-30%) are, however, not eligible for long-term anticoagulation, e.g. because of a high bleeding risk. For this population there is an urgent need for alternative stroke prevention strategies, such as catheter-based percutaneous left atrial appendage closure. Current data about the efficiency and safety of this treatment as well as a discussion of ongoing recruitment for randomized studies are discussed in this review.

The Left Atrial Appendage, Including LAA Occlusion Devices Line Watchman, Amulet, and Lariat

Atrial fibrillation is a very common arrhythmia whose prevalence is expected to increase significantly as the population ages. The associated stroke risk is a major cause of morbidity and mortality. Stroke prevention by anticoagulation carries its own risks, leading to the search for alternative strategies. Multiple techniques have been developed to exclude the left atrial appendage (the main source of thromboembolism in atrial fibrillation) from the circulation. Such techniques offer the hope of stroke prevention without the risks of anticoagulation. This article describes the percutaneous approaches being currently performed in the United States. Particular emphasis is placed on the use of transesophageal echocardiography to guide these procedures.

Left Atrial Appendage Occlusion: What Are the Options and Where is the Evidence?

Left atrial appendage occlusion (LAAO) has emerged as an effective site-directed therapy in patients with nonvalvular atrial fibrillation (AF) for stroke prevention, who are ineligible for long-term oral anticoagulation. The objective of this study was to assess the safety, efficacy, and availability of LAAO devices by reviewing the literature and to review the development and effectiveness of LAAO by the transcatheter approach with plugging devices such as WATCHMAN™ (Boston Scientific, Natick, MA, USA); AMPLATZER™ Cardiac Plug and AMPLATZER™ Amulet™ (Abbott Laboratories, Chicago, IL, USA); and the LARIAT^® Suture Delivery Device (SentreHEART, Redwood City, CA, USA), which features an entirely unique hybrid (endocardial and epicardial) approach in closing the left atrial appendage (LAA). The conducted literature review ultimately revealed a substantial body of literature supporting the safety and efficacy of various LAAO strategies, including endocardial, epicardial, and hybrid approaches, in AF patients who are not eligible for long-term oral anticoagulant use. Specifically, the most attractive population suitable for LAA closure appears to be patients at high risk for ischemic stroke with a longer life expectancy but a moderate-to-high bleeding risk with long-term oral anticoagulation. The benefit of LAA closure in reducing the incidence of stroke in patients with nonvalvular AF has been evolving gradually, and we are confident that this new field of percutaneous LAA closure will continue to emerge as a game-changer in the treatment of AF.

[Recent and upcoming randomized trials for left atrial appendage occlusion : Need for a definite assessment of the situation]

Atrial fibrillation (AF) is the most common arrhythmia affecting more than 1.6 million patients in Germany. Based on demographic developments, an the number is expected to increase. Embolic strokes in AF patients are particularly severe, and individualized new oral anticoagulant (NOAC) therapy reduces the incidence of stroke in these patients by approximately 70%. Besides vitamin K antagonists, the NOACs rivaroxaban, dabigatran, apixaban, and edoxaban have been introduced into clinical practice; however, major bleeding still occurs at a rate of 2-3% per year. Moreover, randomized studies and real-life registries suggest that >20% of patients with AF and an indication for anticoagulation cannot tolerate chronic oral anticoagulant therapy. Therefore, an alternative method for stroke prevention in AF patients has been developed, i. e., catheter-based exclusion of the left atrial appendage (LAA), a location that is prone for thrombus formation in these patients. The randomized trials of catheter-based LAA occlusion have compared this interventional therapy with vitamin K antagonists. In the future, however, LAA exclusion needs to be compared with NOAC therapy. Moreover, percutaneous LAA exclusion in clinical practice is mostly offered to patients ineligible for long-term oral anticoagulation or with high bleeding risk. However, no controlled, randomized trial data exist for this patient population. These data are needed for appropriate clinical judgment and optimal clinical management. Ongoing studies and scientific questions that are important to define the future for catheter-based LAA closure are discussed in this review.

Managing the Left Atrial Appendage in Atrial Fibrillation: Current State of the Art

BACKGROUND

Patients with atrial fibrillation are at increased risk for thromboembolic stroke originating predominantly in the left atrial appendage. To reduce the risk, the standard of care is anticoagulation. In addition, several devices for exclusion of the left atrial appendage have been developed.

METHODS

PubMed was searched for articles relevant to left atrial appendage management. The resulting articles were reviewed as were relevant articles in their bibliographies. Relevant journals were manually searched for sources.

RESULTS

Devices are being used for left atrial appendage exclusion by percutaneous and surgical approaches. Their indications, limitations, and outcomes are reviewed.

CONCLUSIONS

Excision and exclusion of the left atrial appendage is safe and as effective as medical management of atrial fibrillation for stroke prevention. The choice of treatment should be made based on patients' anatomy, history, and preference informed by an appropriate left atrial appendage management team.

Left atrial appendage occlusion: 2016 in review

A significant body of data has emerged in the area of Percutaneous Left Atrial Appendage Occlusion (LAAO). In this article, we present an overview of the most notable publications along with a review of the most important publications on LAAO in 2016. We also present important historical data such as landmark clinical studies, review of most utilized occlusion devices, and important clinical studies that are underway.