Implant success and safety of left atrial appendage closure with the WATCHMAN device: peri-procedural outcomes from the EWOLUTION registry

Left Atrial Appendage Occlusion: Data Update

Resection of the left atrial appendage (LAA) to prevent recurrent arterial emboli in patients with atrial fibrillation was first suggested more than 60 years ago. Longer-term follow-up from randomized studies of the safety and efficacy of transcatheter LAA occlusion has recently been completed; data from large, observational cohorts are being reported. These recent data provide further insights into procedural safety with current techniques and the ability of LAA closure to reduce thromboembolic stroke compared with warfarin anticoagulation. This review summarizes the latest data regarding transcatheter LAA occlusion, focusing on larger prospective studies and further analyses of seminal clinical trials.

Cardiac Computed Tomography for Left Atrial Appendage Occlusion: Acquisition, Analysis, Advantages, and Limitations

Transcatheter left atrial appendage occlusion is increasingly used for stroke prevention in atrial fibrillation. The technique has proven effective and safe in randomized trials and multiple observational studies. The procedure is challenging due to the complex anatomy of the left atrial appendage; accurate cardiac imaging is essential for procedural guidance. Transesophageal echocardiography is the gold standard, but cardiac computed tomography (CT) has gained increasing interest within recent years. Cardiac CT offers high-resolution imaging allowing for preprocedural anatomic evaluation and device sizing, but may also be useful for exclusion of left atrial appendage thrombus, and follow-up assessment of residual peri-device leaks.

Percutaneous Left Atrial Appendage Closure Is a Reasonable Option for Patients With Atrial Fibrillation at High Risk for Cerebrovascular Events

Background—

Percutaneous left atrial appendage (LAA) closure is an emerging option for patients with atrial fibrillation at high risk for cerebrovascular events. The multicenter FLAAC registry (French Nationwide Observational LAA Closure Registry) was established to assess LAA closure outcomes in everyday practice.

Methods and Results—

Four hundred thirty-six patients referred from April 2013 to September 2015 to 33 French interventional cardiology centers for percutaneous LAA closure were included prospectively in the FLAAC registry. Mean age was 75.4±0.4 years. The stroke risk was high (mean CHA 2 DS 2 –VASc score, 4.5±0.1) and most patients had experienced clinically significant bleeding (HAS-BLED score, 3.1±0.05). The device used was Amplatzer LAA occluder in 58% and the Watchman device in 42% of the patients. The procedural success rate was 98.4%. Median postprocedure follow-up was 12.0 (11.8–12.0) months and a single patient was lost to follow-up. During the periprocedural and subsequent follow-up period, procedure-related severe adverse events occurred in 21 (4.9%) and 10 (2.3%) patients, respectively. One-year cumulative incidences of ischemic stroke and cerebral hemorrhage were 2.9% (1.6–5.0) and 1.5% (0.7–3.2), respectively. Overall, 1-year mortality was 9.3% (6.9–12.5) with 7 of the 39 deaths related or possibly related to the device or procedure.

Conclusions—

This nationwide prospective registry shows that, in the French population, LAA closure is mainly used in patients with high comorbidity rates and a poor prognosis. LAA closure in such patients seems reasonable to decrease the stroke rate. The overall health status of these patients should be taken into account during the preprocedural evaluation process.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02252861.

Interventional Left Atrial Appendage Closure Affects the Metabolism of Acylcarnitines

Background: Left atrial appendage closure (LAAC) represents the interventional alternative to oral anticoagulation for stroke prevention in atrial fibrillation (AF). The metabolism of acylcarnitines was shown to affect cardiovascular diseases. This study evaluates the influence of successful LAAC on the metabolism of acylcarnitines. Methods: Patients undergoing successful LAAC were enrolled prospectively. Peripheral blood samples for metabolomics measurements were collected immediately before (i.e., index) and six months after LAAC (i.e., mid-term). A targeted metabolomics analysis based on electrospray ionization–liquid chromatography–mass spectrometry (ESI–LC–MS/MS) and MS/MS measurements was performed. Results: 44 patients with non-valvular AF (median CHA₂DS₂-VASc score 4, median HAS-BLED score 4) and successful LAAC were included. Significant changes in acylcarnitine levels were found in the total cohort, which were mainly attributed to patients with impaired left ventricular and renal function, elevated amino-terminal pro-brain natriuretic peptide (NT-proBNP) and diabetes mellitus. Adjusted multivariable regression models revealed significant changes of five metabolites over mid-term follow-up: C2, C14:1, C16, and C18:1 decreased significantly (each p < 0.05); short-chain C5 acylcarnitine plasma levels increased significantly (p < 0.05). Conclusion: This study demonstrates that successful LAAC affects the metabolism of acylcarnitines at mid-term follow-up. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02985463.

Safety and Efficacy of Transcatheter Left Atrial Appendage Closure for Stroke Prevention in Patients with Atrial Fibrillation

Atrial Fibrillation (AF) is associated with a substantial risk of thromboembolic stroke. Although long-term treatment with warfarin or the non-vitamin K oral anticoagulants can reduce this risk, such therapy is underutilized, and safe and consistent long-term treatment can be challenging. Transcatheter left atrial appendage (LAA) closure is an emerging alternative to long-term oral anticoagulation. Long-term follow-up of randomized clinical trials demonstrate that Watchman LAA closure provides significant reductions in hemorrhagic stroke, cardiovascular death, and all-cause mortality compared with continued warfarin therapy. Major bleeding is also reduced compared with continued warfarin therapy once the post-implant pharmacologic regimen is completed. This review summarizes the current dataset for the safety and efficacy of transcatheter LAA closure, and highlights the gaps in evidence and future directions for clinical research.

Left Atrial Appendage Closure Devices for Stroke Prevention in Patients with Non-Valvular AF

The left atrial appendage (LAA) may be involved in offloading atrial pressure during left ventricular systole. As ventricular rate increases, LAA emptying decreases during early diastole causing increased risk of thrombus formation particularly in patients with non-valvular AF (NVAF). The LAA is the site of thrombus formation in more than 90 % of patients with NVAF, so is an important target for thromboembolic prophylaxis in these patients. Anticoagulation therapy is used to treat NVAF, but it has long-term complications and may be contraindicated in some patients. Therefore, alternative strategies to reduce embolic risk in patients with AF have been developed. These include percutaneous, thoracoscopic, and open closure strategies. This study reviews the safety and efficacy of these strategies, comparing these approaches and devices with pharmacological strategies. There is little data to endorse one strategy over another. Given the minimal evidence available, recommendations in support of LAA occlusion remain weak and guidelines have called for more research and coding of endpoints for this emerging technology.

Percutaneous Left Atrial Appendage Closure: is there a Role in Valvular Atrial Fibrillation

Atrial fibrillation, a chronic and highly morbid cardiovascular condition which affects over 33 million people worldwide, can be broadly categorized as valvular vs non-valvular in etiology. However, definitions of valvular atrial fibrillation have varied widely in the literature, and there is no clear consensus definition to date. Historically, patients with atrial fibrillation in the setting of rheumatic mitral valve disease have constituted a particularly high risk group for cardioembolic stroke, and for this reason many contemporary trials of pharmaceutical and device therapies for atrial fibrillation have systematically excluded patients with valvular heart disease. Therefore, vitamin K antagonism remains the favored approach to mitigate stroke risk in valvular atrial fibrillation, and the optimal strategy to treat atrial fibrillation patients with valvular heart disease who cannot tolerate oral anticoagulation therapy is unknown. Recent trials have demonstrated an important role for percutaneous left atrial appendage occlusion devices in patients with non-valvular atrial fibrillation, but the role of these devices in patients with valvular atrial fibrillation is uncertain. Given the worldwide burden of valvular atrial fibrillation, future trials intended to clarify the role of percutaneous left atrial appendage closure devices in valvular atrial fibrillation should provide important insight for the care of millions of patients.

[Left atrial appendage clusure in nonvalvular atrial fibrillation : Clinical evidence 2017]

Nonvalvular atrial fibrillation (AF) is the most common arrhythmia with a prevalence of 1-2% and affects approximately 15-20% of all octogenarians. Patients are at increased risk of thromboembolic stroke, with an overall risk of 5% per year. Thrombi form almost exclusively in the left atrial appendage (LAA), a blind sac-like heterogeneous structure trabeculated by pectinate muscles. In the past five decades, life-long oral anticoagulation (OAC) with vitamin K antagonists (VKA) has been the state-of-the art treatment to prevent stroke and systemic embolism from thrombi in AF. In the last decade, nonvitamin K dependent oral anticoagulants (NOAC) have been shown to be superior to VKA. Given the safety issues of indefinite OAC with either VKA or NOAC, it is plausible to consider left atrial appendage closure (LAAC) as an alternative strategy to prevent death, stroke or other systemic embolization, and bleeding. In recent years, LAAC has been compared to VKA in prospective randomized trials, yielding superior results regarding efficacy and noninferiority regarding safety in the mid-term. This review provides an update on the current state of LAAC in the field of prevention of death, stroke, and bleedings in patients suffering from nonvalvular AF. We elucidate the evidence and limitations of anticoagulation as the classical treatment paradigm, and review devices and techniques for LAAC. Most importantly, the current clinical evidence on efficacy and safety is outlined.

[Oral anticoagulation and platelet inhibition after atrial appendage occlusion]

In Europe left atrial appendage occluders (LAAO) are most frequently used in patients with contraindications for oral anticoagulation (OAC); therefore, the classical therapeutic OAC scheme from the PROTECT-AF trial (vitamin K antagonist plus acetylsalicylic acid) is usually changed to dual anti-platelet therapy (DAPT) after implantation of a Watchman® or Amulet® LAAO (St. Jude Medical/Abbott, Eschborn, Germany). For many years, patients with an LAAO received DAPT for 1-6 months. The current standard comprises DAPT for 3 months, followed by permanent acetylsalicylic acid monotherapy if the transesophageal echocardiogram excludes a thrombus at the site of the LAAO. In patients with high risk of bleeding, anti-platelet therapy can be stopped at 3 months after an individual risk-benefit calculation. There are no randomized studies on the risk of bleeding and stroke/embolism in patients with an LAA occluder under DAPT versus OAC. Experience from the EWOLUTION registry shows that NOACs may be used as an alternative with low bleeding and thrombus risks. In patients with a suboptimal implantation result, thrombus on the LAAO or specific risk factors, variations of the standard scheme have to be applied and if necessary lifelong DAPT or NOAC therapy has to be used. Thrombi on the LAAO occur in approximately 4-6% of patients and are associated with a very low short-term stroke risk.

Left Atrial Appendage Closure with Amplatzer Cardiac Plug in Nonvalvular Atrial Fibrillation: Safety and Long-Term Outcome

Background

Atrial fibrillation (AF) is a cardiac arrhythmia with high risk for thromboembolic events, specially stroke.

Objective

To assess the safety of left atrial appendage closure (LAAC) with the Amplatzer Cardiac Plug for the prevention of thromboembolic events in patients with nonvalvular AF.

Methods

This study included 15 patients with nonvalvular AF referred for LAAC, 6 older than 75 years (mean age, 69.4 ± 9.3 years; 60% of the male sex).

Results

The mean CHADS₂ score was 3.4 ± 0.1, and mean CHA₂DS₂VASc , 4.8 ± 1.8, evidencing a high risk for thromboembolic events. All patients had a HAS-BLED score > 3 (mean, 4.5 ± 1.2) with a high risk for major bleeding within 1 year. The device was successfully implanted in all patients, with correct positioning in the first attempt in most of them (n = 11; 73.3%).

Conclusion

There was no periprocedural complication, such as device migration, pericardial tamponade, vascular complications and major bleeding. All patients had an uneventful in-hospital course, being discharged in 2 days. The echocardiographic assessments at 6 and 12 months showed neither device migration, nor thrombus formation, nor peridevice leak. On clinical assessment at 12 months, no patient had thromboembolic events or bleeding related to the device or risk factors. In this small series, LAAC with Amplatzer Cardiac Plug proved to be safe, with high procedural success rate and favorable outcome at the 12-month follow-up.

Outcome of left atrial appendage occlusion in high-risk patients

OBJECTIVE

Percutaneous left atrial appendage (LAA) occlusion can be an interventional alternative to oral anticoagulation for stroke prevention in patients with atrial fibrillation.

METHODS

We delivered LAA occlusion therapy using a standardised approach to patient referral, multidisciplinary team assessment, implant criteria, imaging and follow-up. We analysed patient characteristics, efficacy and safety of the implant procedure, and 12-month outcomes.

RESULTS

Of 143 referrals from October 2014 to December 2016, 83 patients (age 76±8years, 32.5% female, mean CHAD₂S₂-VASc score 4 ±1) were offered LAA occlusion. Eighty (95.3%) had previous major bleeding (intracranial in 59%). LAA occluder implantation with an Amulet device was successful in 82 (98.8%), with periprocedural major adverse events occurring in 5 (6.0%) patients (2 device embolisations including 1 death, 2 major bleeds). Cardiac imaging in 75 (94%) patients 2months following implant showed device-related thrombus in 1 case (1.3%) and minor (<5mm) device leaks in 13 (17.1%). Over a median 12-month follow-up, 3 (3.8%) ischaemic strokes, 2 (2.5%) haemorrhagic strokes and 5 (6.3%) major extracranial bleeds occurred. All-cause mortality was 10%, with most deaths (7, 87.5%) due to non-cardiovascular causes.

CONCLUSIONS

LAA occlusion may be a reasonable option for stroke prevention inhigh-risk patients with atrial fibrillation ineligible for anticoagulation. However, procedural complication rates are not insignificant, and patients remain at risk of serious adverse events and death even after successful implant.

[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.

First results of the Brazilian Registry of Percutaneous Left Atrial Appendage Closure

Background

Left atrial appendage closure (LAAC) is an effective alternative to oral anticoagulation (OA) for the prevention of stroke in patients with non-valvular atrial fibrillation (NVAF).

Objective

To present the immediate results and late outcomes of patients submitted to LAAC and included in the Brazilian Registry of Percutaneous Left Atrial Appendage Closure.

Methods

91 patients with NVAF, high stroke risk (CHA₂DS₂VASc score = 4.5 ± 1.5) and restrictions to OAC (HAS-BLED score = 3.6 ± 1.0) underwent 92 LAAC procedures using either the Amplatzer cardiac plug or the Watchman device in 11 centers in Brazil, between late 2010 and mid 2016.

Results

Ninety-six devices were used (1.04 device/procedure, including an additional non-dedicated device), with a procedural success rate of 97.8%. Associated procedures were performed in 8.7% of the patients. Complete LAAC was obtained in 93.3% of the successful cases. In cases of incomplete closure, no residual leak was larger than 2.5 mm. One patient needed simultaneous implantation of 2 devices. There were 7 periprocedural major (5 pericardial effusions requiring pericardiocentesis, 1 non-dedicated device embolization and 1 coronary air embolism without sequelae) and 4 minor complications. After 128.6 patient-years of follow-up there were 3 deaths unrelated to the procedure, 2 major bleedings (one of them in a patient with an unsuccessful LAAC), thrombus formation over the device in 2 cases (both resolved after resuming OAC for 3 months) and 2 strokes (2.2%).

Conclusions

In this multicenter, real world registry, that included patients with NVAF and high thromboembolic and bleeding risks, LAAC effectively prevented stroke and bleeding when compared to the expected rates based on CHA₂DS₂VASc and HASBLED scores for this population. Complications rate of the procedure was acceptable considering the beginning of the learning curve of most of the involved operators.

[Left atrial appendage closure and embolic events]

Atrial fibrillation (AF) is frequent and responsible for embolic events. Currently, the gold standard to prevent such embolic events is anticoagulant therapy with vitamin K antagonist (VKA) or direct oral anticoagulant in nonvalvular AF. Recently, left atrial appendage closure was proposed as an alternative to anticoagulant inpatient with high embolic risk and contraindication to anticoagulant therapy. Data from randomized trials were consistent with a non-inferiority of left atrial appendage closure in comparison to VKA in terms of stroke and cardiovascular death. However, despite improvements in procedure results and complications reduction, this invasive strategy has to be performed with optimal security as this strategy is a preventive treatment in high-risk patients. These improvements may allow an extension of indications of left atrial appendage closure to lower profile risk patients as an alternative to anticoagulant. Indeed, anticoagulant is a risky therapy with hemorrhagic events and observance is a real issue in an asymptomatic population. Finally, there is a lack of data in recent literature comparing left atrial appendage closure to direct oral anticoagulant, widely used in daily practice, as well as cost-effectiveness of this procedure in comparison to anticoagulant.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

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.

Left Atrial Appendage Occlusion in Patients With Atrial Fibrillation and Previous Major Gastrointestinal Bleeding (from the Amplatzer Cardiac Plug Multicenter Registry)

History of major gastrointestinal (GI) bleeding may represent a frequent clinical indication for left atrial appendage occlusion (LAAO) in patients with non-valvular atrial fibrillation (AF). This study aims to investigate the procedural safety and long-term outcome of patients with previous major GI bleeding (MGIB) who underwent LAAO. Data from the Amplatzer Cardiac Plug multicenter registry on 1,047 patients were analyzed. Patients with previous MGIB as indication for LAAO were compared with patients without previous MGIB. A total of 151 patients (14.4%) with previous MGIB were identified. Periprocedural major bleeding events were more frequent in patients with previous MGIB (4.0% vs 0.8%, p = 0.001). With an average follow-up of 1.3 years, the observed annual rate of stroke/transient ischemic attack and major bleeding for patients with previous MGIB were 2.1% (61.4% relative reduction according to the Congestive Heart failure, Hypertension, Age ≥75 (doubled), Diabetes, Stroke (doubled), Vascular disease, Age 65-74, and Sex (female) [CHA₂DS₂-VASc] score) and 4.6% (20.1% relative reduction according to the expected rate based on the Hypertension, Abnormal renal/liver function (1 point each), Stroke, Bleeding history or predisposition, Labile INR, Elderly (>65 years), Drugs/alcohol concomitantly (1 point each) [HAS-BLED] score), respectively. In conclusion, in patients with non-valvular atrial fibrillation and previous MGIB, LAAO was associated with a low annual rate of stroke/transient ischemic attack. Periprocedural major bleeding events were more frequent in this specific population although the annual major bleeding rate showed a 20.1% relative risk reduction according to the HAS-BLED score.

Potential Clinical Utility and Feasibility of Combined Left Atrial Appendage Closure and Positioning of Miniaturized Pacemaker Through a Single Right Femoral Vein Access

This study assessed the clinical utility and feasibility of concomitant of combined left atrial appendage (LAA) closure and positioning of miniaturized pacemaker (Micra TPS). All consecutive patients who underwent VVI-PM implant from November 2015 to October 2016 were considered. VVI-PM implant was conducted either using transvenous approach or by positioning Micra TPS. In selected patients with concomitant contraindication to OAC, Micra TPS was combined with LAA occlusion ("combined approach"), performed in general anesthesia and guided by multimodality imaging; procedural and follow-up data of these specific patients were registered. Sixty patients were treated with VVI-PM implant. Six patients (10.0%) presented OAC contraindication, of which 4 (6.7%) were eligible for the "combined procedure"; 2 of 4 of these patients presented chronic hemodialysis-dependent renal failure. The combined approach was successful in all 4 patients without intra- or periprocedural complications. No adverse events linked to the combined approach occurred during mid-term follow-up (7.5, interquartile range 5.0 to 7.9 months). In conclusion, VVI-PM indication and concomitant contraindication to OAC is not uncommon; in selected patients, combined LAA closure and positioning of Micra TPS may be a feasible therapeutic option.

Approaches to Left Atrial Appendage Closure: Device Design, Performance, and Limitations

Up to 6.1 million people in the United States have atrial fibrillation (AF), which is associated with an increased risk of stroke. Oral anticoagulants are the mainstay of stroke prevention in AF. For decades, warfarin was the only available drug, fraught with compliance limitations, a narrow therapeutic window, and a high risk of hemorrhage. Pharmacologic developments have produced new anticoagulants that have improved the rates of stroke related to AF; however, they still confer a high risk of bleeding, making them unsuitable for some patients. Studies have shown that roughly 90% of strokes in patients with AF occur in the left atrial appendage (LAA). This understanding has prompted the development and testing of novel percutaneous strategies for LAA closure as an alternative to anticoagulation therapy. The following review examines the relative merits and shortcomings of these strategies and explores future prospects in the prevention of AF-related stroke.

The Assessment of the Watchman Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO) trial

BACKGROUND

Oral anticoagulants (OACs) reduce stroke risks with nonvalvular atrial fibrillation (AF); however, they are underused because of absolute or relative contraindications due to real or perceived risk of bleeding. Although left atrial appendage closure is increasingly performed in OAC-ineligible patients, this has not been studied in a randomized controlled trial.

STUDY OBJECTIVES

The ASAP-TOO study is designed to establish the safety and effectiveness of the Watchman left atrial appendage closure device in patients with nonvalvular AF who are deemed ineligible for OAC. The primary effectiveness end point is the time to first occurrence of ischemic stroke or systemic embolism. The primary safety end point includes all-cause death, ischemic stroke, systemic embolism, or device- or procedural-related event requiring open cardiac surgery or major endovascular intervention.

STUDY DESIGN

This is a multinational, multicenter prospective randomized trial. Patients meeting the inclusion criteria with CHA₂DS₂-VASc score≥2 and who are deemed by 2 study physicians to be unsuitable for OAC will be randomized in a 2:1 allocation ratio to Watchman versus control. Control patients will be prescribed single antiplatelet therapy or no therapy at the discretion of the study physician. Up to 888 randomized subjects will be enrolled from up to 100 global investigational sites. Both device group and control patients will have follow-up visits at 3, 6, and 12months and then every 6months through 60months.

SUMMARY

This trial will assess the safety and efficacy of Watchman in this challenging population of high-stroke risk AF patients.

Impact of operator experience and training strategy on procedural outcomes with leadless pacing: Insights from the Micra Transcatheter Pacing Study

BACKGROUND

Leadless pacemaker systems have been designed to avoid the need for a pocket and transvenous lead. However, delivery of this therapy requires a new catheter-based procedure. This study evaluates the role of operator experience and different training strategies on procedural outcomes.

METHODS

A total of 726 patients underwent implant attempt with the Micra transcatheter pacing system (TPS; Medtronic, Minneapolis, MN, USA) by 94 operators trained in a teaching laboratory using a simulator, cadaver, and large animal models (lab training) or locally at the hospital with simulator/demo model and proctorship (hospital training). Procedure success, procedure duration, fluoroscopy time, and safety outcomes were compared between training methods and experience (implant case number).

RESULTS

The Micra TPS procedure was successful in 99.2% of attempts and did not differ between the 55 operators trained in the lab setting and the 39 operators trained locally at the hospital (P = 0.189). Implant case number was also not a determinant of procedural success (P = 0.456). Each operator performed between one and 55 procedures. Procedure time and fluoroscopy duration decreased by 2.0% (P = 0.002) and 3.2% (P < 0.001) compared to the previous case. Major complication rate and pericardial effusion rate were not associated with case number (P = 0.755 and P = 0.620, respectively). There were no differences in the safety outcomes by training method.

CONCLUSIONS

Among a large group of operators, implantation success was high regardless of experience. While procedure duration and fluoroscopy times decreased with implant number, complications were low and not associated with case number. Procedure and safety outcomes were similar between distinct training methodologies.

Efficacy and safety of left atrial appendage closure with WATCHMAN in patients with or without contraindication to oral anticoagulation: 1-Year follow-up outcome data of the EWOLUTION trial

BACKGROUND

Left atrial appendage (LAA) occlusion with WATCHMAN has emerged as viable alternative to vitamin K antagonists in randomized controlled trials.

OBJECTIVE

EWOLUTION was designed to provide data in routine practice from a prospective multicenter registry.

METHODS

A total of 1025 patients scheduled for a WATCHMAN implant were prospectively and sequentially enrolled at 47 centers. Indication for LAA closure was based on European Society of Cardiology guidelines. Follow-up and transesophageal echocardiography (TEE) were performed per local practice.

RESULTS

The baseline CHA₂DS₂-VASc score was 4.5 ± 1.6; the mean age was 73.4 ± 9 years; previous transient ischemic attack/ischemic stroke was present in 312 (30.5%), 155 (15.1%) had previous hemorrhagic stroke, and 320 (31.3%) had a history of major bleeding; and 750 (73%) were deemed unsuitable for oral anticoagulation therapy. WATCHMAN implant succeeded in 1005 (98.5%) of patients, without leaks >5 mm in 1002 (99.7%) with at least 1 TEE follow-up in 875 patients (87%). Antiplatelet therapy was used in 784 (83%), while vitamin K antagonists were used in only 75 (8%). At 1 year, mortality was 98 (9.8%), reflecting the advanced age and comorbidities in this population. Device thrombus was observed in 28 patients at routine TEE (3.7%) and was not correlated with the drug regimen (P = .14). Ischemic stroke rate was 1.1% (relative risk 84% vs estimated historical data); the major bleeding rate was 2.6% and was predominantly (2.3%) nonprocedure/device related.

CONCLUSION

LAA closure with the WATCHMAN device has a high implant and sealing success. This method of stroke risk reduction appears to be safe and effective with an ischemic stroke rate as low as 1.1%, even though 73% of patients had a contraindication to and were not using oral anticoagulation.