Clinical outcomes three years after PLAATO implantation

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.

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.

Efficacy and Safety of Percutaneous Left Atrial Appendage Occlusion for Stroke Prevention in Nonvalvular Atrial Fibrillation: A Meta-analysis of Contemporary Studies

BACKGROUND

Percutaneous left atrial appendage (LAA) occlusion has emerged as an important treatment for patients with nonvalvular atrial fibrillation (NVAF) who are at high stroke risk and have contraindications for anticoagulation. However, literature about the efficacy and safety of LAA occlusion is minimal to date. We performed a meta-analysis to assess the rates of stroke events and adverse events for patients treated with occlusion devices.

METHODS

We conducted a comprehensive search on PubMed, Web of Science, OVID, SCOPUS databases and the Cochrane Central Register of Controlled Trials databases from inception to December 31, 2014 for studies of percutaneous LAA occlusion for patients with NVAF. Studies were included in the meta-analysis if at least 10 patients were studied with six months or more of follow-up period and reported at least one outcome of interest.

RESULTS

A total of 2779 patients in 25 studies were included in the meta-analysis. Two were randomised control trials (RCTs), others were cohort studies. The adjusted incidence rate of stroke was 1.2/100 person-years (PY) (95% confidence interval [CI], 0.9-1.6/100 PY). The ischaemic and haemorrhagic stroke rates were 1.1/100 PY (95% CI, 0.8-1.4/100 PY) and 0.2/100 PY (95% CI, 0.1-0.3/100 PY), respectively. The combined efficacy outcomes (stroke or transient ischaemic attacks [TIAs], systemic embolism, or cardiovascular death) was 2.7/100 PY (95% CI, 1.9- 3.4/100 PY). Major bleeding and pericardial effusions were the most commonly observed adverse events at a rate of 2.6% (95% CI, 1.5%-3.6%) and 2.5% (95% CI, 1.8%-3.2%), respectively.

CONCLUSIONS

Percutaneous LAA occlusion is a reasonably efficacious and safe therapeutic option in patients with NVAF who are at high risk for stroke and contraindicated for long-term anticoagulation.

Left atrial appendage occlusion for prevention of stroke in nonvalvular atrial fibrillation: a meta-analysis

PURPOSE

When anticoagulation for stroke prevention is contraindicated, left atrial appendage occlusion (LAAO) may be performed. Studies of LAAO have been limited by their small size, disparate patient populations, and lack of control group. Our purpose was to perform a meta-analysis of the safety and efficacy of LAAO in comparison with standard therapy for stroke prevention in nonvalvular AF.

METHODS

Due to the lack of a control group in studies of LAAO, data on stroke prevention from multiple large outcomes studies were used to produce a hypothetical control group based on clinical variables in the individual studies. Results were stratified according to LAAO device type.

RESULTS

We identified 16 studies with a total of 1759 patients receiving LAAO. Summary estimates demonstrate LAAO reduced risk of stroke in comparison with no therapy or aspirin therapy [relative risk (RR), 0.34; 95 % CI, 0.25-0.46] and in comparison with warfarin therapy (RR, 0.65; 95 % CI, 0.46-0.91). Summary estimates differed based on the study used to derive the hypothetical control group. Device deployment was unsuccessful in 6.1 % of patients, and overall complication rate was 7.1 %. Efficacy and safety were similar across LAAO device type although a majority of patients in the meta-analysis received a Watchman device.

CONCLUSION

Our data suggest that LAAO is a reasonable option for stroke prophylaxis in AF when anticoagulation is not an option, and the risk for stroke outweighs the risk of procedural complications. Data were limited with the use of most available devices. To better establish the risk and benefit of LAAO in comparison with standard therapy, more randomized controlled trials are necessary.

Percutaneous left atrial appendage occlusion for stroke prevention in atrial fibrillation: an update

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism leading to fatal or disabling stroke. Oral anticoagulation (OAC, warfarin) is the standard treatment for stroke prevention in patients with AF with an increased stroke risk. However, there are several obstacles to long-term OAC therapy, including the risk of serious bleeding, several drug–drug interactions and the need for frequent blood testing. Although newer oral anticoagulants have been developed, these drugs also face issues of major bleeding and non-compliance. Therefore, alternative treatment options for stroke prevention in patients with AF with a high stroke risk are needed. Percutaneous left atrial appendage (LAA) occlusion is an evolving therapy, which should be taken into consideration in those patients with non-valvular AF with a high stroke risk and contraindications for OAC. This article aims to discuss the rationale for LAA closure, the available LAA occlusion devices and their clinical evidence until now. Moreover, we discuss the importance of proper patient selection, the role of various imaging techniques and the need for a more tailored postprocedural antithrombotic therapy.

Percutaneous methods of left atrial appendage exclusion: an alternative to the internist

Thromboembolic stroke from the left atrial appendage (LAA) is the most feared complication in patients with atrial fibrillation (AF). The cornerstone for the management of chronic non-valvular AF is stroke reduction with oral anticoagulation (OAC). However, poor compliance, maintaining a narrow therapeutic window, and major side effects such as bleeding have severely limited their use, which creates a therapeutic dilemma. As much as 20% of AF patients are not receiving OAC due to contraindications and less than half of AF patients are not on OAC due to reluctance of the prescribing physician and/or patient non-compliance. Fortunately, over the past decade, there have been great interests in providing an alternative strategy unbeknownst to the practicing internist. The introduction of percutaneous approaches for LAA occlusion has added a different dimension to the management of chronic AF in patients with OAC intolerance. Occlusion devices such as the Amplatzer Cardiac Plug and WATCHMAN device are currently being investigated for stroke prophylaxis. More recently, the LARIAT device may provide an alternative means for potential stroke prophylaxis without the need for short-term post-procedural OAC. We aim to review the current literature and bring attention to an alternative strategy for high-risk AF patients intolerant to OAC.

[Techniques for occlusion of the left atrial appendage: chances and risks]

Atrial fibrillation causes 15-20% of ischemic strokes and the overall risk of stroke in patients with non-valvular atrial fibrillation is about 5% per year globally. Warfarin has long been the cornerstone for decreasing risks of stroke in patients with atrial fibrillation and its efficacy has been well established. However, 14-44% of patients with atrial fibrillation who are at risk of stroke are ineligible for anticoagulation therapy, mostly owing to the risks of major bleeding and falls. Occlusion of the left atrial appendage (LAA) appears to be an interesting new tool to prevent thromboembolic events in selected cases. In addition to surgical techniques, percutaneous transcatheter approaches have been introduced to occlude the LAA. Recent results indicate non-inferiority of mechanical occlusion of the LAA in comparison to warfarin therapy.

Stroke prevention in patients with atrial fibrillation: Is the transcatheter occlusion of left atrial appendage already an alternative to anticoagulation?

Cardiac emboli in patients with atrial fibrillation are one of the major causes of ischemic stroke. Because the vast majority of these cardiac emboli descend from the left atrial appendage (LAA), the therapeutic strategy of percutaneous transcatheter occlusion of the LAA by means of a mechanical implant was a logical consequence. Three different devices have been developed and used in humans: PLAATO, WATCHMAN, and ACP. The PLAATO implant, a “soccer ball” shaped self-expanding nitinol cage has demonstrated stroke prevention capability in small, uncontrolled studies. The WATCHMAN implant, a “half rugby ball” shaped self-expanding nitinol cage, has demonstrated non inferiority compared to warfarin treatment in the randomized, controlled PROTECT AF trial. The ACP implant is also a self-expanding nitinol cage. However, its design is of fundamental difference compared to the other two implants. ACP consists of two parts connected by a short waist, which are an “ice-hockey puck” shaped body for the implant fixation in the appendage wall, and a flexible disc for sealing the appendage ostium. Due to the very flexible connecting waist between the two parts, ACP implant adapts itself to the LAA, which appears in significant individual structural variabilities. The currently unpublished initial experience with ACP in Europe is encouraging. Transcatheter occlusion of the LAA offers an appealing way to reduce the incidence of cardioembolic stroke in patients with atrial fibrillation. However, the concerns about procedural safety and the need for long-term follow up should be addressed before this potentially important technology is deployed widely. The transcatheter occlusion of left atrial appendage, therefore, has the potential to become, but is not yet a real alternative to anticoagulation.

Cardioembolic stroke in atrial fibrillation-rationale for preventive closure of the left atrial appendage

Atrial fibrillation is the most common cardiac arrhythmias, and a major cause of morbidity and mortality due to cardioembolic stroke. The left atrial appendage is the major site of thrombus formation in non-valvular atrial fibrillation. Loss of atrial systole in atrial fibrillation and increased relative risk of associated stroke point strongly toward a role for stasis of blood in left atrial thrombosis, although thrombus formation is multifactorial, and much more than blood flow irregularities are implicated. Oral anticoagulation with vitamin-K-antagonists is currently the most effective prophylaxis for stroke in atrial fibrillation. Unfortunately, this treatment is often contraindicated, particularly in the elderly, in whom risk of stroke is high. Moreover, given the risk of major bleeding, there is reason to be skeptical of the net benefit when warfarin is used in those patients. This work reviews the pathophysiology of cardioembolic stroke and critically spotlights the current status of preventive anticoagulation therapy. Various techniques to exclude the left atrial appendage from circulation were discussed as a considerable alternative for stroke prophylaxis.

Percutaneous closure of left atrial appendage to prevent embolic events in high-risk patients with chronic atrial fibrillation

BACKGROUND

Percutaneous closure of the left atrial appendage (LAA) is a novel alternative for the treatment of patients with atrial fibrillation (AF) and with a high risk of stroke who are not eligible for long-term anticoagulation therapy. The aim of this study was to asses the safety, feasibility, and long-term efficacy of this procedure.

METHODS

From July 2004 to June 2007, 20 patients (13 male, mean age 69 +/- 8 years) with non-valvular AF (NV-AF) underwent LAA percutaneous closure using the PLAATO system, implanted through a transeptal access. All patients had contraindications to anticoagulant therapy and were at high risk for cardioembolic stroke (mean CHADS(2) score 3 +/- 1.2). A trans-thoracic echocardiogram was performed at 1, 3, and every 6 months after the procedure, whereas a trans-oesophageal echocardiogram (TOE) was scheduled at 6 months. After 24 months, a phone interview was obtained.

RESULTS

All procedures were successfully performed in 18 patients. In two patients, LAA closure was not feasible for the presence of a multilobed LAA. Two patients underwent percutaneous closure of patent foramen ovale in the same session. In one patient, the procedure was complicated by cardiac perforation with pericardial effusion, treated with pericardiocentesis. At a mean follow up of 40 +/- 10 months, no embolic events occurred. One patient died, after 36 months, for gastric cancer. TOE examination showed the complete exclusion of the LAA in all patients.

CONCLUSIONS

Percutaneous closure of LAA is safe and efficacious to prevent stroke in patients with NV-AF at high risk for cardioembolic events, with contraindications to anticoagulant therapy.

Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a randomised non-inferiority trial

BACKGROUND

In patients with non-valvular atrial fibrillation, embolic stroke is thought to be associated with left atrial appendage (LAA) thrombi. We assessed the efficacy and safety of percutaneous closure of the LAA for prevention of stroke compared with warfarin treatment in patients with atrial fibrillation.

METHODS

Adult patients with non-valvular atrial fibrillation were eligible for inclusion in this multicentre, randomised non-inferiority trial if they had at least one of the following: previous stroke or transient ischaemic attack, congestive heart failure, diabetes, hypertension, or were 75 years or older. 707 eligible patients were randomly assigned in a 2:1 ratio by computer-generated randomisation sequence to percutaneous closure of the LAA and subsequent discontinuation of warfarin (intervention; n=463) or to warfarin treatment with a target international normalised ratio between 2.0 and 3.0 (control; n=244). Efficacy was assessed by a primary composite endpoint of stroke, cardiovascular death, and systemic embolism. We selected a one-sided probability criterion of non-inferiority for the intervention of at least 97.5%, by use of a two-fold non-inferiority margin. Serious adverse events that constituted the primary endpoint for safety included major bleeding, pericardial effusion, and device embolisation. Analysis was by intention to treat. This study is registered with Clinicaltrials.gov, number NCT00129545.

FINDINGS

At 1065 patient-years of follow-up, the primary efficacy event rate was 3.0 per 100 patient-years (95% credible interval [CrI] 1.9-4.5) in the intervention group and 4.9 per 100 patient-years (2.8-7.1) in the control group (rate ratio [RR] 0.62, 95% CrI 0.35-1.25). The probability of non-inferiority of the intervention was more than 99.9%. Primary safety events were more frequent in the intervention group than in the control group (7.4 per 100 patient-years, 95% CrI 5.5-9.7, vs 4.4 per 100 patient-years, 95% CrI 2.5-6.7; RR 1.69, 1.01-3.19).

INTERPRETATION

The efficacy of percutaneous closure of the LAA with this device was non-inferior to that of warfarin therapy. Although there was a higher rate of adverse safety events in the intervention group than in the control group, events in the intervention group were mainly a result of periprocedural complications. Closure of the LAA might provide an alternative strategy to chronic warfarin therapy for stroke prophylaxis in patients with non-valvular atrial fibrillation.

FUNDING

Atritech.

Percutaneous left atrial appendage occlusion for patients in atrial fibrillation suboptimal for warfarin therapy: 5-year results of the PLAATO (Percutaneous Left Atrial Appendage Transcatheter Occlusion) Study

OBJECTIVES

The aim of this study was to determine 5-year clinical status for patients treated with percutaneous left atrial appendage transcatheter occlusion with the PLAATO (Percutaneous Left Atrial Appendage Transcatheter Occlusion) system.

BACKGROUND

Anticoagulation reduces thromboembolism among patients with nonvalvular atrial fibrillation (AF). However, warfarin is a challenging medication due to risks of inadequate anticoagulation and bleeding. Thus, PLAATO was evaluated as a treatment strategy for nonwarfarin candidate patients with AF at high risk for stroke.

METHODS

Sixty-four patients with permanent or paroxysmal AF participated in this observational, multicenter prospective study. Primary end points were: new major or minor stroke, cardiac or neurological death, myocardial infarction, or requirement for cardiovascular surgery related to the procedure within 1 month of the index procedure. Patients were followed for up to 5 years.

RESULTS

Thirty-day freedom from major adverse events rate was 98.4% (95% confidence interval: 90.89% to >99.99%). One patient, who did not receive a PLAATO implant, experienced 2 events within 30 days (cardiovascular surgery, death). Treatment success was 100% 1 month after device implantation. At 5-year follow-up, there were 7 deaths, 5 major strokes, 3 minor strokes, 1 cardiac tamponade requiring surgery, 1 probable cerebral hemorrhage/death, and 1 myocardial infarction. Only 1 event (cardiac tamponade) was adjudicated as related to the implant procedure. After up to 5 years of follow-up, the annualized stroke/transient ischemic attack (TIA) rate was 3.8%. The anticipated stroke/TIA rate (with the CHADS(2) scoring method) was 6.6%/year.

CONCLUSIONS

The PLAATO system is safe and effective. At 5-year follow-up the annualized stroke/TIA rate in our patients was 3.8%/year, less than predicted by the CHADS(2) scoring system.

Risk of stroke and thrombus formation from delay incontinence of a PLAATO-device in Friedreich ataxia

We present the case of a 76-year-old female with suspected Friedreich ataxia, in whom leakage and thrombosis of a percutaneously implanted left atrial appendage occluder (PLAATO) was observed 2 years after implantation. Because of late developing leakages and thrombi, regular transesophageal echocardiographic examinations should be carried out in patients with occluded left atrial appendages. In view of these complications and the potential important hemodynamic role of the left atrial appendage, the benefit of its occlusion is questionable, and the indications of PLAATO should be strongly reconsidered.