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Percutaneous left atrial appendage closure (LAAC) is a valid alternative to oral anticoagulation to prevent ischemic stroke in patients with atrial fibrillation.The devices approved in Europe and United States for percutaneous LAAC contain metal and temporary antithrombotic therapy is strongly recommended following implantation to prevent thrombus formation on the atrial device surface. There is still uncertainty regarding to the optimal antithrombotic drug regimen after device implantation for several reasons. Thus, this review aims at summarizing the available evidence and the remaining challenges related to the management of antithrombotic therapy in the context of LAAC procedure. [ABSTRACT FROM AUTHOR]

Background: Device-related thrombus (DRT) after left atrial appendage occlusion (LAAO) is potentially linked to adverse events. Although clinical reports suggest an effect of the device type and position on the DRT risk, in-depth studies of its mechanistic basis are needed. This in silico study aimed to assess the impact of the position of non-pacifier (Watchman) and pacifier (Amulet) LAAO devices on surrogate markers of DRT risk. Methods: The LAAO devices were modeled with precise geometry and virtually implanted in different positions into a patient-specific left atrium. Using computational fluid dynamics, the following values were quantified: residual blood, wall shear stress (WSS) and endothelial cell activation potential (ECAP). Results: In comparison to an ostium-fitted device position, deep implantation led to more residual blood, lower average WSS and higher ECAP surrounding the device, especially on the device's atrial surface and the surrounding tissue, suggesting increased risk for potential thrombus. For the non-pacifier device, an off-axis device orientation resulted in even more residual blood, higher ECAP and similar average WSS as compared to an ostium-fitted device position. Overall, the pacifier device showed less residual blood, higher average WSS and lower ECAP, compared to the non-pacifier device. Conclusions: In this in silico study, both LAAO device type and implant position showed an impact on potential markers of DRT in terms of blood stasis, platelet adhesion and endothelial dysfunction. Our results present a mechanistic basis for clinically observed risk factors of DRT and the proposed in silico model may aid in the optimization of device development and procedural aspects. [ABSTRACT FROM AUTHOR]

Background Left atrial appendage occlusion (LAAO) is an alternative to anticoagulation for stroke prevention in select patients with atrial fibrillation (AF). In this study, we describe the case of a patient with delayed device-related thrombus (DRT) at 13 months post-LAAO in a setting of atrial stasis due to a worsening mitral bioprosthetic stenosis. Case summary A 69-year-old woman with a history of rheumatic mitral stenosis and regurgitation post-bioprosthetic mitral valve replacement (6 years prior) and paroxysmal AF was referred for percutaneous LAAO due to recurrent severe gastrointestinal bleeding while on anticoagulation. She underwent an uncomplicated LAAO, for which a 35 mm Watchman Flx device was used. Peri-procedural transoesophageal echocardiogram (TEE) at the time of implant showed thickened and calcified mitral bioprosthetic leaflets and a mild mitral stenosis. Her 45-day post-LAAO TEE showed a mild mitral stenosis and no peri-device leak or DRT. At 12 months, the patient had worsening exertional dyspnoea and pedal oedema. Her 12-month transthoracic echocardiogram (TTE) showed a moderate mitral stenosis and LAAO remained free of DRT. Her symptoms were deemed secondary from a worsening mitral valve stenosis. Mitral valve-in-valve (MViV) replacement was planned because the patient was deemed a prohibitive risk for a redo surgical replacement. Transthoracic echocardiogram on the day of MViV showed a large thrombus on the LAAO device. MViV was postponed. After the patient completed 45 days of anticoagulation with warfarin, a repeat TTE was performed, which showed a resolution of DRT. Transcatheter MViV was performed successfully. Discussion This case demonstrates that increased stasis and left atrial dysfunction from prosthetic mitral stenosis can be a risk factor for late DRT after successful LAAO. The use of a LAAO occlusion device in the presence of a mitral bioprosthesis requires more frequent echocardiographic monitoring to assess both the function of the prosthesis and a delayed formation of thrombus. More studies need to be conducted to assess the safety of percutaneous LAAO devices in those with mitral bioprosthesis. [ABSTRACT FROM AUTHOR]

Cardiac compartmental size depends on sex, with smaller values found in (healthy) women compared to a matched group of men. Various types of heart disease may cause dilation of the affected chamber. For example, atrial fibrillation (AF) is associated with enlarged left atrial (LA) size, often also implying increased left ventricular (LV) size. Sex‐specific differences appear to persist during disease states. Thus, chamber volumes depend on both sex and the severity of the underlying disorder, and require quantification to evaluate the effect of interventions. Often, we rely on the popular performance metric ejection fraction (EF) which refers to the ratio of the minimum and maximum LV or LA volumetric values observed during the cardiac cycle. Here we discuss a sex stratified analysis of LVEF and LAEF in AF patients as treated by LA appendage closure, while comparing those with or without device‐related thrombosis. Also, an alternative analysis based on primary data is presented while emphasizing its attractiveness. In any event, age‐ and sex‐specific reference values as broadly documented for various imaging modalities should be applied to LA and LV. [ABSTRACT FROM AUTHOR]

Background: Device‐related thrombosis (DRT) is a common finding after left atrial appendage closure (LAAC) and is associated with worse outcomes. As women are underrepresented in clinical studies, further understanding of sex differences in DRT patients is warranted. Methods and Results: This sub‐analysis from the EUROC‐DRT‐registry compromises 176 patients with diagnosis of DRT after LAAC. Women, who accounted for 34.7% (61/176) of patients, were older (78.0 ± 6.7 vs. 74.9 ± 9.1 years, p =.06) with lower rates of comorbidities. While DRT was detected significantly later in women (173 ± 267 vs. 127 ± 192 days, p =.01), anticoagulation therapy was escalated similarly, mainly with initiation of novel oral anticoagulant (NOAC), vitamin K antagonist (VKA) or heparin. DRT resolution was achieved in 67.5% (27/40) of women and in 75.0% (54/72) of men (p =.40). In the remaining cases, an intensification/switch of anticoagulation was conducted in 50.% (9/18) of men and in 41.7% (5/12) of women. Final resolution was achieved in 72.5% (29/40) cases in women, and in 81.9% (59/72) cases in men (p =.24). Women were followed‐up for a similar time as men (779 ± 520 vs. 908 ± 687 days, p =.51). Kaplan–Meier analysis revealed no difference in mortality rates in women (Hazard Ratio [HR]: 1.73, 95%‐Confidence interval [95%‐CI]:.68–4.37, p =.25) and no differences in stroke (HR:.83, 95%‐CI:.30–2.32, p =.72) within 2 years after LAAC. Conclusion: Evaluation of risk factors and outcome revealed no differences between men and women, with DRT in women being diagnosed significantly later. Women should be monitored closely to assess for DRT formation/resolution. Treatment strategies appear to be equally effective. [ABSTRACT FROM AUTHOR]

Oral anticoagulation therapy (OAC) is a mainstay for mitigating stroke and other embolic events in patients with atrial fibrillation (AF). Despite the demonstrated efficacy of OAC in reducing events, many patients are unable to tolerate OAC due to bleeding risks. Left atrial appendage occlusion (LAAO) devices were developed as implantable technologies to moderate stroke risk in patients with intolerance to OAC. Despite clinical data supporting near-comparable protection against thromboembolic events with OAC, device-related thrombus formation has emerged as a critical complication following LAAO that remains a potential limitation to the safety and efficacy of LAAO. Improved biocompatibility of LAAO devices with fluoropolymers, a well-established stent-coating technology used to reduce thrombus formation and promote endothelialization, may optimize outcomes after LAAO. Article highlights Original concept & evidence of left atrial appendage occlusion To prevent thromboembolism in nonvalvular atrial fibrillation (NVAF) patients, left atrial appendage occlusion (LAAO) technology has evolved as an alternative to oral anticoagulation therapy (OAC) in those with high bleeding risk. Randomized trials demonstrated noninferiority of LAAO in safety and efficacy compared with conventional oral OAC, with similar stroke rates and potentially lower bleeding rates. As LAAO therapy evolves, it could be a viable first-line alternative to direct oral anticoagulants in NVAF patients. Device-related thrombus after the implantation of LAAO Device-related thrombus (DRT) is a critical complication after LAAO that can lead to thromboembolic events, with incidences ranging from 1.6 to 16%. DRT is defined as a density confirmed in multiple planes on imaging transesophageal echocardiography or coronary CT angiography, which appears to be related to device, patients, and anatomical factors. DRT is associated with a higher incidence of thromboembolic events, underscoring its clinical importance. Second-generation WATCHMAN FLX device The second-generation WATCHMAN FLX is one LAAO device that has improved LAA sealing and is designed to facilitate implantation in complex LAA anatomies. The WATCHMAN FLX has demonstrated promising short-term safety and efficacy in accommodating diverse LAA structures, with a reduction in procedural complications and the incidence of DRT as compared with earlier generations. Strategies to prevent DRT Antithrombotic treatment and endothelialization after the device implantation are key to preventing DRT after LAAO. Improving thromboresistance and augmenting endothelialization after device implantation may favorably impact DRT incidence and thromboembolic events. Fluoropolymer coating technology has good biocompatibility and thromboresistance as shown in drug-eluting stents and vascular grafts. New-generation FP coated LAAO device The WATCHMAN FLX Pro device (FP-WATCHMAN) with fluoropolymer coating technology is designed to further improve hemocompatibility and reduce the incidence of DRT compared with the conventional WATCHMAN FLX. An animal study demonstrated that FP-WATCHMAN showed significantly less thrombus formation and inflammation, attributed to greater albumin adsorption which inhibits platelet adhesion and subsequent thrombus formation. FP-WATCHMAN is expected to enhance early endothelial coverage, leading to further improvements in the prevention of DRT. [ABSTRACT FROM AUTHOR]

The left atrial appendage (LAA) occluder is an important medical device for closing the LAA and preventing stroke. The device‐related thrombus (DRT) prevents the implantation of the occluder in exerting the desired therapeutic effect, which is primarily caused by the delayed endothelialization of the occluder. Functional coatings are an effective strategy for accelerating the endothelialization of occluders. However, the occluder surface area is particularly large and structurally complex, and the device is subjected to a large shear friction in the sheath during implantation, which poses a significant challenge to the coating. Herein, a hydrogel coating by the in situ UV‐triggered polymerization of double‐network polyelectrolytes is reported. The findings reveal that the double network and electrostatic interactions between the networks resulted in excellent mechanical properties of the hydrogel coating. The sulfonate and Arg‐Gly‐Asp (RGD) groups in the coating promoted hemocompatibility and endothelial growth of the occluder, respectively. The coating significantly accelerated the endothelialization of the LAA occluder in a canine model is further demonstrated. This study has potential clinical benefits in reducing both the incidence of DRT and the postoperative anticoagulant course for LAA closure. [ABSTRACT FROM AUTHOR]

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

Introduction: Left main (LM) coronary disease is believed to represent a complex, advanced, and potentially life-threatening atherosclerotic syndrome that can be treated by either percutaneous or surgical interventions. Despite its satisfactory results, the declined number of off-pump coronary artery bypass grafting (OPCAB) is observed. Aim: To compare 10-year survival and point out possible mortality risk factors in patients referred for left main and multivessel OPCAB surgery followed by transit time bypass measurements. Material and methods: There were 159 patients (128 (81%) men and 31 (19%) women) in a median age of 66 (60-70) years enrolled in retrospective analysis who were referred to surgical intervention due to left main (51, 32%) and multivessel (108, 68%) disease. The regression analysis for long-term mortality risk and the Kaplan-Meyer survival curve were analyzed. Results: Multivariable analysis pointed female sex (HR = 1.08, 95% CI: 1.03-1.14, p = 0.001) and diabetes mellitus (HR = 6.33, 95% CI: 1.86-21.52, p = 0.003) as possible risk factors for 10-year mortality risk. There was no significant difference in Kaplan-Meyer 10-year mortality comparison between left main and multivessel disease patients treated by off-pump surgical revascularization (HR = 0.93, 95% CI: 0.40-2.13, p = 0.86). Conclusions: Off-pump surgery in the left main disease, compared to multivessel disease, represents a safe surgical technique with satisfactory long-term results. The female sex and diabetes mellitus were found as possible risk factors for 10-year mortality risk in multivariable analysis. [ABSTRACT FROM AUTHOR]

Introduction: Left atrial appendage closure (LAAC) with Watchman device prevents thromboembolism in patients with atrial fibrillation (AF). However, thrombus may develop on the atrial surface of the device. Aim: To investigate the incidence and predictors of device-related thrombus (DRT) in patients with AF who were treated with LAAC. Material and methods: Ninety-one consecutive patients with AF underwent LAAC procedure using first-generation Watchman 2.5 device followed by antiplatelet therapy. In our analysis we have included all patients (n = 78) who had clinical follow-up visits with transesophageal echocardiography (TEE) after the procedure. Results: The median (IQR) CHA2 DS2 -VASc score was 4 (4.0-6.0) and HAS-BLED score was 3 (3.0-4.0). DRTs were observed in 5 (6.4%) patients. When compared with patients without DRT, those with DRT presented more often with lower median ejection fraction (40% (23.5-45.5) versus 55% (48.0-60.0); p = 0.005), lower emptying velocity of LAA (25 cm/s (17.5-27.0) versus 53 cm/s (26.5-78.0); p = 0.009), and with greater depth of implantation (18 mm (14.0-20.5) versus 8 mm (5.0-11.0); p < 0.001). Furthermore, patients with DRT had greater depth of LAA (35 mm (29.5-41.0) versus 29 mm (25.5-31.0); p = 0.003), greater mean (SD) dimension in 900 (22.4 mm (3.2) versus 19 mm (2.7); p = 0.02). Patients with DRT were also younger than those without DRT (67.4 years (7) versus 75 years (8.3), p = 0.045). Conclusions: The DRT after Watchman device implantation remains a rare complication. Its formation was related to several patient and procedural characteristics, which need to be confirmed in larger studies. [ABSTRACT FROM AUTHOR]

BackgroundPercutaneous left atrial appendage closure (LAAC) serves as an alternative prophylactic strategy for patients with non-valvular atrial fibrillation (AF) who cannot undergo anti-coagulation therapy. Proper management of associated complications is crucial to enhancing the procedure's success rate and mitigating perioperative risks and adverse events during follow-up.AimsThis study aims to summarize our center's experience and strategies in managing procedural-related complications encountered in 512 cases of LAAC with or without ablation for AF conducted from January 2020 to December 2023.ResultsWe identified 11 significant intervention-requiring complications associated with LAAC with or without Ablation procedure. These included three cases of intraoperative thrombosis, three instances of pericardial effusion or tamponade, one case of device-related thrombosis, one peri-device leak, one systemic embolism, one bleeding episode, and one additional device-related complication. The categorization of intraoperative thrombosis was as follows: one patient exhibited heparin resistance; one experienced thrombosis due to prolonged device implantation during the LAAC with ablation procedure; and one had unexplained intraoperative thrombosis. The pericardial effusion or tamponade likely resulted from damage to the atrial appendage during LAAC device insertion. Two patients encountered device-related thrombosis and systemic embolism events possibly caused by non-standard postoperative antithrombotic medication use; one patient's peri-device leak may have resulted from incomplete endothelialization of the occluder post-surgery; one patient experienced postoperative bladder bleeding; and one patient's device-related complications occurred due to a dislodged strut frame that damaged the left atrial appendage, leading to pericardial effusion. Our proactive interventions enabled all patients with these surgical-related complications to be safely discharged, with subsequent follow-ups showing no adverse events.ConclusionImplementing targeted interventions for immediate procedural-related complications during the LAAC with or without ablation procedures enhances procedural success rates, diminishes postoperative mortality and patient disability, and bolsters stroke prevention efforts. This approach underscores the importance of a strategic response to complications, affirming the procedure's viability and safety in managing non-valvular AF in patients contraindicated for anticoagulation.

Abstract The left atrial appendage (LAA) occluder is an important medical device for closing the LAA and preventing stroke. The device‐related thrombus (DRT) prevents the implantation of the occluder in exerting the desired therapeutic effect, which is primarily caused by the delayed endothelialization of the occluder. Functional coatings are an effective strategy for accelerating the endothelialization of occluders. However, the occluder surface area is particularly large and structurally complex, and the device is subjected to a large shear friction in the sheath during implantation, which poses a significant challenge to the coating. Herein, a hydrogel coating by the in situ UV‐triggered polymerization of double‐network polyelectrolytes is reported. The findings reveal that the double network and electrostatic interactions between the networks resulted in excellent mechanical properties of the hydrogel coating. The sulfonate and Arg‐Gly‐Asp (RGD) groups in the coating promoted hemocompatibility and endothelial growth of the occluder, respectively. The coating significantly accelerated the endothelialization of the LAA occluder in a canine model is further demonstrated. This study has potential clinical benefits in reducing both the incidence of DRT and the postoperative anticoagulant course for LAA closure.

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

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

Background: Device-related thrombus (DRT) after left atrial appendage closure (LAAC) is associated with adverse outcomes, i.e. ischemic stroke or systemic embolism (SE). Data on predictors of stroke/SE in the context of DRT are limited. Aims: This study aimed to identify predisposing factors for stroke/SE in DRT patients. In addition, the temporal connection of stroke/SE to DRT diagnosis was analyzed. Methods: The EUROC-DRT registry included 176 patients, in whom DRT after LAAC were diagnosed. Patients with symptomatic DRT, defined as stroke/SE in the context of DRT diagnosis, were compared against patients with non-symptomatic DRT. Baseline characteristics, anti-thrombotic regimens, device position, and timing of stroke/SE were compared. Results: Stroke/SE occurred in 25/176 (14.2%) patients diagnosed with DRT (symptomatic DRT). Stroke/SE occurred after a median of 198 days (IQR 37–558) after LAAC. In 45.8% stroke/SE occurred within one month before/after DRT diagnosis (DRT-related stroke). Patients with symptomatic DRT had lower left ventricular ejection fractions (50.0 ± 9.1% vs. 54.2 ± 11.0%, p = 0.03) and higher rates of non-paroxysmal atrial fibrillation (84.0% vs. 64.9%, p = 0.06). Other baseline parameters and device positions were not different. Most ischemic events occurred among patients with single antiplatelet therapy (50%), however, stroke/SE was also observed under dual antiplatelet therapy (25%) or oral anticoagulation (20%). Conclusion: Stroke/SE are documented in 14.2% and occur both in close temporal relation to the DRT finding and chronologically independently therefrom. Identification of risk factors remains cumbersome, putting all DRT patients at substantial risk for stroke/SE. Further studies are necessary to minimize the risk of DRT and ischemic events. [ABSTRACT FROM AUTHOR]

Despite the unprecedented advances in the left atrial appendage occlusion field, device-related thrombus (DRT) remains an unresolved issue with the therapy. This paper aims to provide a state-of-the-art review of the literature on the incidence, clinical impact, predictors and management of DRT and propose a novel classification of DRT and hypoattenuated thickening. [Display omitted] • Device-related thrombus after left atrial appendage occlusion is rare but is associated with adverse clinical outcomes and is challenging to manage. • Independent predictors of DRT include nonmodifiable clinical characteristics (eg, permanent AF) and modifiable procedural factors (eg, deep implantation). • This report proposes a novel mechanistic classification of DRT and HAT that can be used to guide future research. [ABSTRACT FROM AUTHOR]

Scarce data exist on the evolution of device-related thrombus (DRT) after left atrial appendage closure (LAAC). This study sought to assess the incidence, predictors, and clinical impact of persistent and recurrent DRT in LAAC recipients. Data were obtained from an international multicenter registry including 237 patients diagnosed with DRT after LAAC. Of these, 214 patients with a subsequent imaging examination after the initial diagnosis of DRT were included. Unfavorable evolution of DRT was defined as either persisting or recurrent DRT. DRT resolved in 153 (71.5%) cases and persisted in 61 (28.5%) cases. Larger DRT size (OR per 1-mm increase: 1.08; 95% CI: 1.02-1.15; P = 0.009) and female (OR: 2.44; 95% CI: 1.12-5.26; P = 0.02) were independently associated with persistent DRT. After DRT resolution, 82 (53.6%) of 153 patients had repeated device imaging, with 14 (17.1%) cases diagnosed with recurrent DRT. Overall, 75 (35.0%) patients had unfavorable evolution of DRT, and the sole predictor was average thrombus size at initial diagnosis (OR per 1-mm increase: 1.09; 95% CI: 1.03-1.16; P = 0.003), with an optimal cutoff size of 7 mm (OR: 2.51; 95% CI: 1.39-4.52; P = 0.002). Unfavorable evolution of DRT was associated with a higher rate of thromboembolic events compared with resolved DRT (26.7% vs 15.1%; HR: 2.13; 95% CI: 1.15-3.94; P = 0.02). About one-third of DRT events had an unfavorable evolution (either persisting or recurring), with a larger initial thrombus size (particularly >7 mm) portending an increased risk. Unfavorable evolution of DRT was associated with a 2-fold higher risk of thromboembolic events compared with resolved DRT. [Display omitted] [ABSTRACT FROM AUTHOR]

Device-related thrombus (DRT) remains one of the main concerns after left atrial appendage occlusion (LAAO). Several risk factors have been proposed, but most cannot be modulated. A modifiable factor such as device implantation depth is a potential target to adjust the risk for DRT. The aim of this study was to assess the impact of LAAO device implantation depth as a predisposing factor for DRT. The study included patients who underwent successful LAAO at 9 centers in Europe and Canada. Patients were classified into 2 groups: proximal device implantation (covered pulmonary ridge [PR] in the lobe and disc cohort or <5 mm from the PR in the single-lobe cohort) and distal device implantation (uncovered PR in the disc and lobe cohort and ≥5 mm in the single-lobe cohort). A total of 1,317 patients were included. Among these, proximal and distal device implantation was achieved in 732 (55%) and 585 (45%) patients, respectively. No differences in procedural outcomes were observed between the groups. At follow-up, patients with proximal implantation had a lower incidence of DRT (2.3%) than those with distal implantation (12.2%) (P < 0.001). Deeper device implantation and a larger uncovered left atrial appendage area were associated with a higher incidence of DRT (P < 0.001), regardless of device type. In multivariable analysis, distal implant (HR: 5.92; 95% CI: 3.39-10.36) and no or single antiplatelet therapy (HR: 1.62; 95% CI: 0.99-2.62) emerged as independent predictors of DRT. LAAO device implantation depth is an independent risk factor for DRT. Deeper device implantation and larger uncovered left atrial appendage areas were associated with a higher incidence of DRT. [Display omitted] [ABSTRACT FROM AUTHOR]

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices. [ABSTRACT FROM AUTHOR]

Abstract Introduction Left atrial appendage closure (LAAC) is a novel treatment for stroke prevention in high-risk patients with non-valvular atrial fibrillation (NVAF). However, the long-term outcomes after LAAC in Chinese NVAF patients are still lacking. Methods This was a single-center, bidirectional, nonrandomized registered study. Patients who underwent LAAC implantation from May 2014 to April 2021 in a large Chinese center were enrolled. The primary endpoint was combined all-cause death and stroke. Results From May 2014 to April 2021, a total of 673 NVAF patients were enrolled. The overall successful implantation rate was 97.62% (657 of 673). The rate of perioperative adverse events was 1.19% (8 of 673), including 3 cardiac tamponades, 2 ischemic strokes, one device-related thrombus (DRT) and 2 device dislocations. 604 (92.24%) patients completed the follow-up, the median follow-up period was 36.9 months (IQR 24.8–56.5 months). 16 stroke events occurred in 15 patients (one patient suffered from both hemorrhagic and ischemic strokes). 13 patients (2.15%) had ischemic stroke, and the fatal rate was 0.33% (2 of 604). 3 patients (0.15%) suffered from hemorrhagic stroke, and the fatal rate was 0.17% (1 of 604). The overall stroke rate was 0.74% per-year. The combined death and stroke rate was 1.93% per-year. In the multivariate Cox regression analysis, age ≥ 75 (hazard ratio 2.264, 95% CI 1.074–4.772, P = 0.032) and ventricular cardiomyopathy (hazard ratio 2.738, 95% CI 1.060–7.071, P = 0.037) were independent predictors of combined mortality and stroke. Conclusion The overall successful implantation rate of LAAC was 97.62% and the rate of perioperative adverse events was 1.19% in this study, and the stroke rate was 0.74% per year during the long-term follow-up. Age ≥ 75 years and ventricular cardiomyopathy were independent predictors of the primary endpoint. Trial registration This study was retrospectively registered.

[Display omitted] [ABSTRACT FROM AUTHOR]

Introduction: Left atrial appendage closure (LAAC) is a novel treatment for stroke prevention in high-risk patients with non-valvular atrial fibrillation (NVAF). However, the long-term outcomes after LAAC in Chinese NVAF patients are still lacking. Methods: This was a single-center, bidirectional, nonrandomized registered study. Patients who underwent LAAC implantation from May 2014 to April 2021 in a large Chinese center were enrolled. The primary endpoint was combined all-cause death and stroke. Results: From May 2014 to April 2021, a total of 673 NVAF patients were enrolled. The overall successful implantation rate was 97.62% (657 of 673). The rate of perioperative adverse events was 1.19% (8 of 673), including 3 cardiac tamponades, 2 ischemic strokes, one device-related thrombus (DRT) and 2 device dislocations. 604 (92.24%) patients completed the follow-up, the median follow-up period was 36.9 months (IQR 24.8–56.5 months). 16 stroke events occurred in 15 patients (one patient suffered from both hemorrhagic and ischemic strokes). 13 patients (2.15%) had ischemic stroke, and the fatal rate was 0.33% (2 of 604). 3 patients (0.15%) suffered from hemorrhagic stroke, and the fatal rate was 0.17% (1 of 604). The overall stroke rate was 0.74% per-year. The combined death and stroke rate was 1.93% per-year. In the multivariate Cox regression analysis, age ≥ 75 (hazard ratio 2.264, 95% CI 1.074–4.772, P = 0.032) and ventricular cardiomyopathy (hazard ratio 2.738, 95% CI 1.060–7.071, P = 0.037) were independent predictors of combined mortality and stroke. Conclusion: The overall successful implantation rate of LAAC was 97.62% and the rate of perioperative adverse events was 1.19% in this study, and the stroke rate was 0.74% per year during the long-term follow-up. Age ≥ 75 years and ventricular cardiomyopathy were independent predictors of the primary endpoint. Trial registration This study was retrospectively registered. [ABSTRACT FROM AUTHOR]

Background: In atrial fibrillation patients undergoing left atrial appendage occlusion with a Watchman device, surveillance imaging with a transesophageal echocardiogram (TEE) is typically performed at 45 days and 1 year to evaluate for device‐related thrombus (DRT) and peri‐device leak (PDL) before the cessation of oral anticoagulation. The incidence of these complications is relatively low, and the ideal timing and duration of surveillance is unknown. We sought to evaluate the incidence of DRT and PDL after Watchman placement at 45 days and 1 year to determine the necessity of surveillance TEEs. Methods: We retrospectively analyzed 361 patients who received a Watchman device between January 2016 and January 2020. Baseline clinical and echocardiographic data, post‐procedure antithrombotic therapy, and surveillance echocardiographic data were collected from the NCDR LAAO Registry. Nested backward variable elimination regression was performed to derive independent predictors of the composite outcome of DRT and PDL. Results: A total of 286 patients who had post‐procedure TEEs were included in the analysis. At 45 days, 9 patients had DRT (3.2%) and 44 patients had PDL (15.0%). At 1 year, 5 patients had DRT (5.6%) and 8 patients had PDL (8.9%). All DRT at 45 days was treated with continued anticoagulation while no change in protocol occurred with PDL. All DRT at 1 year occurred in new patients without prior thrombus. A history of prior transient ischemic attack (TIA) and thromboembolism was significantly associated with DRT or PDL at 1 year. Conclusions: We identified several patients with device‐related complications at 45 days and 1 year despite appropriate device sizing and adequate use of antithrombotic therapy. The incidence of DRT increased from 45 days to 1 year and occurred in patients without prior thrombus. These findings highlight the importance of surveillance imaging and suggest the potential need for extended surveillance in select patients. [ABSTRACT FROM AUTHOR]

Background: Data on Device-related Thrombus (DRT) after left atrial appendage closure (LAAC) remain scarce. This study aimed to investigate risk factors for DRT from centers reporting to the EUROC-DRT registry. Methods: We included 537 patients (112 with DRT and 425 without DRT) who had undergone LAAC between 12/2008 and 04/2019. Baseline and implantation characteristics, anti-thrombotic treatment and clinical outcomes were compared between both groups in uni- and multivariate analyses. Additional propensity-score matching (PSM) was conducted to focus on the role of implantation characteristics. Results: Patients with DRT showed higher rates of previous stroke/transient ischemic attack (TIA) (49.1% vs. 34.7%, p < 0.01), spontaneous echocardiographic contrast (SEC) (44.9% vs. 27.7%, p < 0.01) and lower left atrial appendage (LAA) peak emptying velocity (35.4 ± 18.5 vs. 42.4 ± 18.0 cm/s, p = 0.02). Occluders implanted in DRT patients were larger (25.5 ± 3.8 vs. 24.6 ± 3.5 mm, p = 0.03) and implanted deeper in the LAA (mean depth: 7.6 ± 4.7 vs. 5.7 ± 4.7 mm, p < 0.01). Coverage of the appendage ostium was achieved less often in DRT patients (69.5% vs. 81.5%, p < 0.01), while DRT patients were less frequently on oral anticoagulation (7.1% vs. 16.7%, p < 0.01). Multivariate analysis identified age, prior stroke/TIA and SEC as independent risk factors for DRT. After PSM, implantation depth was found to be predictive. Rates of stroke/TIA were higher in DRT patients (13.5% vs. 3.8%, Hazard Ratio: 4.21 [95%-confidence interval: 1.88–9.49], p < 0.01). Conclusions: DRT after LAAC is associated with adverse outcome and appears to be of multifactorial origin, depending on patient characteristics, anticoagulation regimen and device position. [ABSTRACT FROM AUTHOR]

Aims: No studies have compared Watchman 2.5 (W2.5) with Watchman FLX (FLX) devices to date. We aimed at comparing the FLX with W2.5 devices with respect to clinical outcomes, left atrial appendage (LAA) sealing properties and device-related thrombus (DRT).Methods and Results: All consecutive left atrial appendage closure (LAAC) procedures performed at two European centres between November 2017 and February 2021 were included. Procedure-related complications and net adverse cardiovascular events (NACE) at 6 months after LAAC were recorded. At 45-day computed tomography (CT) follow-up, intra- (IDL) and peri- (PDL) device leak, residual patent neck area (RPNA), and DRT were assessed by a Corelab. Out of 144 LAAC consecutive procedures, 71 and 73 interventions were performed using W2.5 and FLX devices, respectively. There were no differences in terms of procedure-related complications (4.2% vs. 2.7%, P = 0.626). At 45-day CT, the FLX was associated with lower frequency of IDL [21.3% vs. 40.0%; P = 0.032; odds ratio (OR): 0.375; 95% confidence interval (CI): 0.160-0.876; P = 0.024], similar rate of PDL (29.5% vs. 42.0%; P = 0.170), and smaller RPNA [6 (0-36) vs. 40 (6-115) mm2; P = 0.001; OR: 0.240; 95% CI: 0.100-0.577; P = 0.001] compared with the W2.5 group. At 45 days, rate of DRT as detected by CT and/or transoesophageal echocardiography (TOE), was higher with W2.5 (6.0% vs. 0%, P = 0.045). At 6-month follow-up, NACE did not differ between groups.Conclusions: In this cohort of consecutive LAACs, FLX as compared to W2.5, was associated with similar procedure-related complications and 6-month NACE, but with improved LAA neck coverage, and lower IDL and DRT. [ABSTRACT FROM AUTHOR]

BackgroundPivotal trials of percutaneous left atrial appendage closure (LAAC) used dedicated post-procedure antithrombotic protocols. However, there is no consensus on the selection of new oral anticoagulants (NOAC) and warfarin monotherapy after LAAC. This study aims to compare NOAC with warfarin monotherapy for efficacy and safety in patients undergoing LAAC.MethodsA database search was conducted using PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov for trials that compared NOAC with warfarin monotherapy after LAAC. The effective outcomes included any major adverse events (all-cause death, stroke, major bleeding) and their individual components. Safety outcomes included all-cause death, major bleeding, total bleeding, DRT, and PDL >5 mm.ResultsWe included 10 non-randomized clinical trials with 10,337 patients, of whom 4,960 patients received NOAC, while 5,377 patients received warfarin. There were no statistically significant differences in any major adverse events (LogOR: −0.11, 95% CI: −0.27, 0.04, P = 0.16), stroke (LogOR: 0.00, 95% CI: −0.42, 0.42, P = 1.00), all-cause death (LogOR: −0.23, 95% CI: −0.48, 0.02, P = 0.07), major bleeding (LogOR: −0.22, 95% CI: −0.45, 0.01, P = 0.06). NOAC was associated with a significant reduction in total bleeding (LogOR: −1.01, 95% CI: −1.47, −0.55, P < 0.0001) compared to warfarin. No statistically significant differences were found in DRT (LogOR: −0.19, 95% CI: −0.15, 0.52, P = 0.27) and PDL >5 mm (LogOR: 0.19, 95% CI: −0.33, 0.72, P = 0.47). Meta-regression and subgroup analysis showed that total bleeding (LogOR: −1.56, 95% CI: −2.15, −0.97, P < 0.001) was significantly lower in the NOAC group in the subgroup of

Background Left atrial appendage occlusion devices are commonly used to prevent stroke in patients with persistent atrial fibrillation who are unable to tolerate anticoagulation. However, certain patient- and device-related characteristics increase the risk for the development of a device-related thrombus (DRT). The presence of a DRT increases the risk of stroke and should be treated. Management of DRT lacks consensus but is mostly focused on anticoagulation. In patients with large thrombi that need to be managed urgently, percutaneous extraction may be a viable option. Case summary In this report, we describe the successful management of a DRT via percutaneous thrombus extraction technology in an 81-year-old woman with a large thrombus attached to a WATCHMAN™ device. The patient initially presented with shortness of breath, and on imaging a pedunculated thrombus was detected. The thrombus was extracted using a Penumbra Lightning 12™ (Penumbra Inc. Alameda, CA, USA) catheter with a Sentinel™ (Boston Scientific, Marlborough, MA, USA) cerebral embolic protection device. The patient had no neurologic sequelae and was started on anticoagulation. Discussion Percutaneous thrombectomy can be safely performed to extract large left atrial occlusion DRT that require urgent management, without any neurologic sequelae. We believe this can be used in patients with a large DRT who would not be adequately managed with anticoagulation and in whom surgery is not feasible. [ABSTRACT FROM AUTHOR]

Background: Percutaneous left atrial appendage closure (LAAC) serves as an alternative prophylactic strategy for patients with non-valvular atrial fibrillation (AF) who cannot undergo anti-coagulation therapy. Proper management of associated complications is crucial to enhancing the procedure's success rate and mitigating perioperative risks and adverse events during follow-up., Aims: This study aims to summarize our center's experience and strategies in managing procedural-related complications encountered in 512 cases of LAAC with or without ablation for AF conducted from January 2020 to December 2023., Results: We identified 11 significant intervention-requiring complications associated with LAAC with or without Ablation procedure. These included three cases of intraoperative thrombosis, three instances of pericardial effusion or tamponade, one case of device-related thrombosis, one peri-device leak, one systemic embolism, one bleeding episode, and one additional device-related complication. The categorization of intraoperative thrombosis was as follows: one patient exhibited heparin resistance; one experienced thrombosis due to prolonged device implantation during the LAAC with ablation procedure; and one had unexplained intraoperative thrombosis. The pericardial effusion or tamponade likely resulted from damage to the atrial appendage during LAAC device insertion. Two patients encountered device-related thrombosis and systemic embolism events possibly caused by non-standard postoperative antithrombotic medication use; one patient's peri-device leak may have resulted from incomplete endothelialization of the occluder post-surgery; one patient experienced postoperative bladder bleeding; and one patient's device-related complications occurred due to a dislodged strut frame that damaged the left atrial appendage, leading to pericardial effusion. Our proactive interventions enabled all patients with these surgical-related complications to be safely discharged, with subsequent follow-ups showing no adverse events., Conclusion: Implementing targeted interventions for immediate procedural-related complications during the LAAC with or without ablation procedures enhances procedural success rates, diminishes postoperative mortality and patient disability, and bolsters stroke prevention efforts. This approach underscores the importance of a strategic response to complications, affirming the procedure's viability and safety in managing non-valvular AF in patients contraindicated for anticoagulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Zou, Jiang, Lin, Yu, Li, Zhao, Hu and Sun.)

Atrial fibrillation (AFib) is recognized as a risk factor linked to arterial thromboembolism stemming from blood clot formation in the left atrium, associated with increased morbidity and mortality. Most of these thrombi originate in the left atrial appendage (LAA). Oral anticoagulation (OAC) therapy can help mitigate this risk. LAA occlusion (LAAO) has emerged as an option for patients who cannot safely tolerate long-term OAC. Watchman is one of the commonly used devices with a favorable safety profile demonstrated in numerous studies. One of the most concerning complications of LAAO is device-related thrombus (DRT), which may form on the atrial side of the device and potentially lead to embolization. We present a rare case of immediate DRT formation following the deployment of a Watchman device in a 78-year-old male with persistent AFib. Despite appropriate periprocedural management, a thrombus was observed immediately post implantation. This case emphasizes the need for vigilant surveillance, prompt diagnosis, and therapeutic intervention to manage such complications. The patient was successfully managed with a heparin drip, leading to thrombus resolution. This report underscores the complexities of managing DRT and the importance of ongoing research to optimize outcomes for patients undergoing LAAO., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Sethi et al.)

Objectives: Spontaneous echo contrast (SEC) in the left atrium (LA) is frequently observed in atrial fibrillation (AF) patients and may lead to thromboembolic events. We aimed to investigate both periprocedural and long-term stroke risks associated with LA SEC in AF patients undergoing percutaneous left atrial appendage closure (LAAC).Methods: A total of 408 consecutive AF patients treated with LAAC between March 2015 and February 2019 were divided into two groups based on preprocedural transesophageal echocardiography: the study group (moderate/severe LA SEC; n = 41) and the control group (none, mild, or mild to moderate LA SEC; n = 367). To attenuate the observed imbalance in baseline covariates, a propensity score matching technique was used.Results: No periprocedural stroke/transient ischemic attack (TIA) was documented. The incidence of device-related thrombus was higher in the study group than in the control group (8.8 vs. 1.3%; P = 0.025). The mean follow-up period was 3.2 ± 1.1 years, during which 8 patients (2.2%) in the control group and 4 (9.8%) in the study group experienced stroke/TIA (P = 0.024). Moderate/severe LA SEC was identified as an independent predictor of stroke/TIA in both the original population (HR = 5.71, 95% CI 1.47–22.19, P = 0.012) and the matched population (HR = 9.79, 95% CI 1.44–66.86, P = 0.020).Conclusions: LA SEC did not show a relationship with periprocedural stroke events in patients undergoing percutaneous LAAC. However, moderate/severe LA SEC increased the incidence of device-related thrombus and the risk of late stroke/TIA.

Background: Device-related thrombus (DRT) has been considered an Achilles' heel of left atrial appendage occlusion (LAAO). However, data on DRT prediction remain limited.Objectives: This study constructed a DRT registry via a multicenter collaboration aimed to assess outcomes and predictors of DRT.Methods: Thirty-seven international centers contributed LAAO cases with and without DRT (device-matched and temporally related to the DRT cases). This study described the management patterns and mid-term outcomes of DRT and assessed patient and procedural predictors of DRT.Results: A total of 711 patients (237 with and 474 without DRT) were included. Follow-up duration was similar in the DRT and no-DRT groups, median 1.8 years (interquartile range: 0.9-3.0 years) versus 1.6 years (interquartile range: 1.0-2.9 years), respectively (P = 0.76). DRTs were detected between days 0 to 45, 45 to 180, 180 to 365, and >365 in 24.9%, 38.8%, 16.0%, and 20.3% of patients. DRT presence was associated with a higher risk of the composite endpoint of death, ischemic stroke, or systemic embolization (HR: 2.37; 95% CI, 1.58-3.56; P < 0.001) driven by ischemic stroke (HR: 3.49; 95% CI: 1.35-9.00; P = 0.01). At last known follow-up, 25.3% of patients had DRT. Discharge medications after LAAO did not have an impact on DRT. Multivariable analysis identified 5 DRT risk factors: hypercoagulability disorder (odds ratio [OR]: 17.50; 95% CI: 3.39-90.45), pericardial effusion (OR: 13.45; 95% CI: 1.46-123.52), renal insufficiency (OR: 4.02; 95% CI: 1.22-13.25), implantation depth >10 mm from the pulmonary vein limbus (OR: 2.41; 95% CI: 1.57-3.69), and non-paroxysmal atrial fibrillation (OR: 1.90; 95% CI: 1.22-2.97). Following conversion to risk factor points, patients with ≥2 risk points for DRT had a 2.1-fold increased risk of DRT compared with those without any risk factors.Conclusions: DRT after LAAO is associated with ischemic events. Patient- and procedure-specific factors are associated with the risk of DRT and may aid in risk stratification of patients referred for LAAO. [ABSTRACT FROM AUTHOR]

Background  Left atrial appendage (LAA) closure with the WATCHMAN device is an alternative to anticoagulation therapy for the prevention of stroke in selected patients with atrial fibrillation (AF). Infrequently, left atrial (LA) device-related thrombus formation occurs and it is poorly understood. Thrombus formation due to incomplete covering of the LAA is even rarer and may occur within the first few months after device implantation. Case summary  Here, we present a case of a 68-year-old male patient with permanent AF, drug- and hepatitis induced liver cirrhosis (CILD Score B), and prior aortic valve replacement. The patient had a history of percutaneous LAA closure using a WATCHMAN device. He developed massive peri-device leak and thrombus arising from the space between the device and appendage cleft 2 years after implantation. Because of the high bleeding risk with a HAS-BLED score of 5 points, surgery was chosen as the therapy of choice instead of long-term anticoagulation. The patient was discharged in good clinical condition and has been scheduled for a yearly follow-up. Discussion  This case emphasizes the importance of choosing appropriately sized LAA occluder devices and planning for regular post-interventional follow-ups to minimize the risk of per-device leaks and thrombi. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is nowadays the most common human arrhythmia and it is considered a marker of an increased risk of embolic stroke. It is known that 99% of AF-related thrombi are generated in the left atrial appendage (LAA), an anatomical structure located within the left atrium (LA). Left atrial appendage occlusion (LAAO) has become a good alternative for nonvalvular AF patients with contraindications to anticoagulants. However, there is a non-negligible number of device-related thrombus (DRT) events, created next to the device surface. In silico fluid simulations can be a powerful tool to better understand the relation between LA anatomy, haemodynamics, and the process of thrombus formation. Despite the increasing literature in LA fluid modelling, a consensus has not been reached yet in the community on the optimal modelling choices and boundary conditions for generating realistic simulations. In this line, we have performed a sensitivity analysis of several boundary conditions scenarios, varying inlet/outlet and LA wall movement configurations, using patient-specific imaging data of six LAAO patients (three of them with DRT at follow-up). Mesh and cardiac cycle convergence were also analysed. The boundary conditions scenario that better predicted DRT cases had echocardiography-based velocities at the mitral valve outlet, a generic pressure wave from an AF patient at the pulmonary vein inlets, and a dynamic mesh approach for LA wall deformation, emphasizing the need for patient-specific data for realistic simulations. The obtained promising results need to be further validated with larger cohorts, ideally with ground truth data, but they already offer unique insights on thrombogenic risk in the left atria.

The aim of this study is to review the evidence on the use of antithrombotic therapy and risk of device-related thrombosis after left atrial appendage closure. Left atrial appendage closure (LAAC) is increasingly performed for stroke prevention in patients with nonvalvular atrial fibrillation, especially those who cannot tolerate or are ineligible for oral anticoagulation. After device implantation for LAAC, different antithrombotic regimens with varying duration of therapy are currently used. Such selection depends on patients' risk for bleeding and physicians' choice. Device-related thrombosis remains an Achilles' heel of LAAC, and the etiology remains incompletely understood. Dual-antiplatelet therapy, and direct oral anticoagulation may have similar safety and device-related thrombosis occurrence in real-world LAAC registries compared with warfarin and aspirin. Device imaging surveillance should be routinely performed to assess for device-related thrombosis, which if diagnosed should be treated aggressively, as it is associated with higher thromboembolic risks. Given the uncertainties and therapeutic dilemma, the authors provide an in-depth discussion of the options and rationale for antithrombotic therapy post-LAAC. [ABSTRACT FROM AUTHOR]

Aims Transoesophageal echocardiography studies have reported frequent peri-device leaks and device-related thrombi (DRT) after percutaneous left atrial appendage (LAA) occlusion. We assessed the prevalence, characteristics and correlates of leaks and DRT on cardiac computed tomography (CT) after LAA occlusion. Methods and results Consecutive patients underwent cardiac CT before LAA occlusion to assess left atrial (LA) volume, LAA shape, and landing zone diameter. Follow-up CT was performed after >3 months to assess device implantation criteria, device leaks and DRT. CT findings were related to patient and device characteristics, as well as to outcome during follow-up. One-hundred and seventeen patients (age 74 ± 9, 37% women, CHA2DS2VASc 4.4 ± 1.3, and HASBLED 3.5 ± 1.0) were implanted with Amplatzer cardiac plug (ACP)/Amulet (71%) or Watchman (29%). LAA patency was detected in 44% on arterial phase CT images and 69% on venous phase images. The most common leak location was postero-inferior. LAA patency related to LA dilatation, left ventricular ejection fraction impairment, non-chicken wing LAA shape, large landing zone diameter, incomplete device lobe thrombosis, and disc/lobe misalignment in patients with ACP/Amulet. DRT were detected in 19 (16%), most being laminated and of antero-superior location. DRT did not relate to clinical or imaging characteristics nor to implantation criteria, but to total thrombosis of device lobe. Over a mean 13 months follow-up, stroke/transient ischaemic attack occurred in eight patients, unrelated to DRT or LAA patency. Conclusion LAA patency on CT is common after LAA occlusion, particularly on venous phase images. Leaks relate to LA/LAA size at baseline, and device malposition and incomplete thrombosis at follow-up. DRT is also quite common but poorly predicted by patient and device-related factors. [ABSTRACT FROM AUTHOR]

Background: The Laminar device rotates and closes the left atrial appendage (LAA) using an integrated ball and lock that excludes and eliminates the LAA pouch. There is a low device surface area, minimizing the risk of peridevice leak (PDL) and device-related thrombus (DRT) formation., Objectives: This study evaluates the safety and efficacy of the Laminar LAA exclusion device in healthy animals and human subjects with nonvalvular atrial fibrillation at risk of ischemic stroke and systemic thromboembolism., Methods: The preclinical study implanted the Laminar device into canine subjects that underwent transesophageal echocardiography (TEE) and fluoroscopic evaluation, followed by necropsy and histological assessment at 45 and 150-days post-implant. The early clinical study implanted the device in human subjects, followed to 12 months postimplantation. Procedural success was defined as device implantation in the intended location without residual LAA leak >5 mm as seen by TEE. Safety endpoints included freedom from stroke, systemic embolism, pericardial effusion, or tamponade, life-threatening/major bleeding, or death., Results: The Laminar device was successfully implanted in 10 canines. In all animals at 45 days and 150 days, no PDL or DRT was found, and histological examination showed fully closed LAAs covered with neo-endocardium. The device was successfully implanted in 15 human subjects with no safety events out to 12 months postimplantation. All subjects had successful protocol-defined LAA closure without DRT at 45 days by TEE and computed tomography, which remained stable through 12 months' follow-up., Conclusions: The preclinical and early clinical results demonstrate a promising safety and efficacy profile for the Laminar LAA exclusion device., Competing Interests: Funding Support and Author Disclosures The funding for this study was provided by Laminar, Inc. Drs Bolling, Kar, and Rogers are consultants to Abbott, Boston Scientific, and Laminar. Dr Smith is a consultant to Abbott, Gore, and Laminar. Dr Spangler is a consultant to Laminar. Dr Wong has reported that he has no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)