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Aims: To assess the reproducibility of interpreting hypoattenuated thickening (HAT) and peridevice leak (PDL) using cardiac computed tomography (CT) imaging following Watchman FLX left atrial appendage closure (LAAC)., Methods and Results: In this multicentre retrospective reproducibility study, 100 anonymized post-LAAC cardiac CT scans were evaluated within the same cardiac phase by an experienced and a novice rater blinded to prior evaluations. All scans were evaluated twice by each rater, assessing overall HAT and PDL categories as well as specific associated findings based on suggested algorithms for post-LAAC interpretation. Inter- and intra-rater agreement and reliability were evaluated using absolute agreement, Cohen's kappa, and Kendall's tau for categorical variables, and mean difference, Bland-Altman plots, limits of agreement (lower and upper), and intra-class correlation coefficients (ICCs) for continuous variables. Within overall categories of both HAT and PDL, substantial agreement (kappa ≥0.61) and reliability (Kendall's tau-b ≥ 0.75) were observed. Specifically, identifying high-grade HAT (kappa ≥0.78) and distal patency (kappa ≥0.85) displayed the highest agreement within HAT and PDL interpretation. Meanwhile, measuring the height of the proximal screw hub cove represented the least reliable HAT assessment among both inter- and intra-rater comparisons (ICC < 0.75), while suspected leak mechanism represented the least reproducible PDL measure., Conclusion: Despite only minimal training of one rater, overall high levels of inter- and intra-rater agreement and reliability were observed across the chosen algorithms for interpretation of HAT and PDL following Watchman FLX LAAC. The prognostic implications of the included variables are to be explored in future trials and registries., Competing Interests: Conflict of interest: J.E.N.-K. has received institutional research grants from Abbott and Boston Scientific and is on the advisory board of Boston Scientific. M.A. is on the advisory board of Boston Scientific, Abbott, and Philips. K.K. has received lecture fees from Abbott and Boston Scientific. The remaining authors have no conflicts to declare., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Left atrial appendage occlusion (LAAO) is rapidly growing as valid stroke prevention therapy in atrial fibrillation. Cardiac imaging plays an instrumental role in preprocedural planning, procedural execution, and postprocedural follow-up. Recently, cardiac computed tomography (CCT) has made significant advancements, resulting in increasing use both preprocedurally and in outpatient follow-up. It provides a noninvasive, high-resolution alternative to the current standard, transesophageal echocardiography, and may display advantages in both the detection and characterization of device-specific complications, such as peridevice leak and device-related thrombosis. The implementation of CCT in the follow-up after LAAO has identified new findings such as hypoattenuated thickening on the atrial device surface and left atrial appendage contrast patency, which are not readily assessable on transesophageal echocardiography. Currently, there is a lack of standardization for acquisition and interpretation of images and consensus on definitions of essential findings on CCT in the postprocedural phase. This paper intends to provide a practical and standardized approach to both acquisition and interpretation of CCT after LAAO based on a comprehensive review of the literature and expert consensus among European and North American interventional and imaging specialists., Competing Interests: Funding Support and Author Disclosures Dr Korsholm has received speaker honorarium from Abbott and Boston Scientific. Dr Saw has received unrestricted research grant support from AstraZeneca, Abbott, Boston Scientific, and Servier; has received speaker honorarium from AstraZeneca, Abbott, Boston Scientific, and Sunovion; and is a consultant/proctor for Boston Scientific, AstraZeneca, and Abbott. Dr Wang has received research grant support from Boston Scientific; and is a consultant for Edwards Lifesciences, Boston Scientific, and Materialise. Dr Berti is a proctor for Abbott and Edwards Lifesciences. Dr Galea has received speaker honorarium from Boston Scientific. Dr De Backer is a consultant for Abbott. Dr Räber has received research grants to the institution from Abbott Vascular, Biotronik, Boston Scientific, Heartflow, Sanofi, Regeneron, Medis Medical Imaging Systems, and Bangerter-Rhyner Stiftung; and has received speaker or consultation fees from Abbott Vascular, Amgen, AstraZeneca, Canon, Novo Nordisk, Medtronic, Occlutech, and Sanofi outside the submitted work. Dr Alkhouli is on the Advisory Board for Abbott and Boston Scientific. Dr Nielsen-Kudsk is a consultant for Boston Scientific; and is a consultant/proctor for Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

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., (© 2024 The Author(s). Echocardiography published by Wiley Periodicals LLC.)

Background: Left atrial appendage (LAA) occluder embolization is an infrequent but serious complication., Objectives: We aim to describe timing, management and clinical outcomes of device embolization in a multi-center registry., Methods: Patient characteristics, imaging findings and procedure and follow-up data were collected retrospectively. Device embolizations were categorized according to 1) timing 2) management and 3) clinical outcomes., Results: Sixty-seven centers contributed data. Device embolization occurred in 108 patients. In 70.4 % of cases, it happened within the first 24 h of the procedure. The device was purposefully left in the LA and the aorta in two (1.9 %) patients, an initial percutaneous retrieval was attempted in 81 (75.0 %) and surgery without prior percutaneous retrieval attempt was performed in 23 (21.3 %) patients. Two patients died before a retrieval attempt could be made. In 28/81 (34.6 %) patients with an initial percutaneous retrieval attempt a second, additional attempt was performed, which was associated with a high mortality (death in patients with one attempt: 2.9 % vs. second attempt: 21.4 %, p < 0.001). The primary outcome (bailout surgery, cardiogenic shock, stroke, TIA, and/or death) occurred in 47 (43.5 %) patients. Other major complications related to device embolization occurred in 21 (19.4 %) patients., Conclusions: The majority of device embolizations after LAA closure occurs early. A percutaneous approach is often the preferred method for a first rescue attempt. Major adverse event rates, including death, are high particularly if the first retrieval attempt was unsuccessful., Condensed Abstract: This dedicated multicenter registry examined timing, management, and clinical outcome of device embolization. Early embolization (70.4 %) was most frequent. As a first rescue attempt, percutaneous retrieval was preferred in 75.0 %, followed by surgical removal (21.3 %). In patients with a second retrieval attempt a higher mortality (death first attempt: 2.9 % vs. death second attempt: 24.1 %, p < 0.001) was observed. Mortality (10.2 %) and the major complication rate after device embolization were high., Competing Interests: Declaration of competing interest A. Aminian is a consultant and proctor for Boston Scientific and Abbott. I. Akin received lecture and proctoring fees from Boston Scientific for the Watchman Okkluder. J. Lund discloses a clinical advisor (proctor) role in LAAC (Abbott) and lecture fees (Abbott, Boston scientific). E. Guerios serves as proctor for LAA closure for Abbott and Lifetech Scientific. N. Amabile has received proctoring and consulting fees from Abbott Vascular and Boston Scientific. C. Skurk has received proctor honoraria from Boston Scientific and speaker fees from Boston Scientific and Lifetech Scientific. J. Harvey is proctor for Abiomed, Boston Scientific and Medtronic and part of the Speaker's bureau for Abiomed, Boston Scientific and Medtronic. He also is part of the advisory board for Avail, Boston Scientific and Medtronic. H. Sievert has received study honoraria to institution, travel expenses and consulting fees from 4tech Cardio, Abbott, Ablative Solutions, Adona Medical, Akura Medical, Ancora Heart, Append Medical, Axon, Bavaria Medizin Technologie GmbH, Bioventrix, Boston Scientific, Cardiac Dimensions, Cardiac Success, Cardimed, Cardionovum, Celonova, Contego, Coramaze, Croivalve, CSL Behring LLC, CVRx, Dinova, Edwards, Endobar, Endologix, Endomatic, Esperion Therapeutics, Inc., Hangzhou Nuomao Medtech, Holistick Medical, Intershunt, Intervene, K2, Laminar, Lifetech, Magenta, Maquet Getinge Group, Metavention, Mitralix, Mokita, Neurotronic, NXT Biomedical, Occlutech, Recor, Renal Guard, Shifamed, Terumo, Trisol, Vascular Dynamics, Vectorious Medtech, Venus, Venock, Vivasure Medical, Vvital Biomed and Whiteswell. M. Kühne received personal fees from Bayer, Böhringer Ingelheim, Pfizer BMS, Daiichi Sankyo, Medtronic, Biotronik, Boston Scientific, Johnson & Johnson, and F. Hoffmann-La Roche Ltd., as well as grants from Bayer, Pfizer, Boston Scientific, BMS, Biotronik, and Daiichi Sankyo. S. Sabir is part of the Boston Scientific WATCHMAN advisory board. J. Kim has received proctoring fees from Abbott Vascular. M. Montorfano received consultant fees from Abbott, Boston Scientific, Kardia. M. Ancona received consultant fees from Abbott. Relevant research funding went to Vanderbilt University Medical Center from Boston Scientific, Boehringer-Ingelheim, Medtronic and Atricure, where C. Ellis is practicing. He also reseves a consultant and advisor fee from Abbott Medical, Atricure, Boston Scientific, Medtronic. L. Nombela-Franco is proctor for Abbott Vascular and has received lectures fees from Boston Scientific. A. Natale has received speaker honoraria from Boston Scientific, Biosense Webster, St. Jude Medical, Biotronik, and Medtronic. He also is a consultant for Biosense Webster, St. Jude Medical, and Janssen. All other authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier Inc.)

Background: Left atrial appendage occlusion (LAAO) provides mechanical cardioembolic protection for atrial fibrillation (AF) patients who cannot use oral anticoagulation therapy (OAT). Patients with a thrombotic event despite OAT are at high risk for recurrence and may also benefit from LAAO., Objectives: This study sought to investigate the efficacy of LAAO in AF patients with a thrombotic event on OAT compared to: 1) LAAO in AF patients with a contraindication for OAT; and 2) historical data., Methods: The international LAAO after stroke despite oral anticoagulation (STR-OAC LAAO) collaboration included patients who underwent LAAO because of thrombotic events on OAT. This cohort underwent propensity score matching and was compared to the EWOLUTION (Evaluating Real-Life Clinical Outcomes in Atrial Fibrillation Patients Receiving the WATCHMAN Left Atrial Appendage Closure Technology) registry, which represents patients who underwent LAAO because of OAT contraindications. The primary outcome was ischemic stroke. Event rates were compared between cohorts and with historical data without OAT, yielding relative risk reductions based on risk scores., Results: Analysis of 438 matched pairs revealed no significant difference in the ischemic stroke rate between the STR-OAC LAAO and EWOLUTION cohorts (2.5% vs 1.9%; HR: 1.37; 95% CI: 0.72-2.61). STR-OAC LAAO patients exhibited a higher thromboembolic risk (HR: 1.71; 95% CI: 1.04-2.83) but lower bleeding risk (HR: 0.39; 95% CI: 0.18-0.88) compared to EWOLUTION patients. The mortality rate was slightly higher in EWOLUTION (4.3% vs 6.9%; log-rank P = 0.028). Relative risk reductions for ischemic stroke were 70% and 78% in STR-OAC LAAO and EWOLUTION, respectively, compared to historical data without OAT., Conclusions: LAAO in patients with a thrombotic event on OAT demonstrated comparable stroke rates to the OAT contraindicated population in EWOLUTION. The thromboembolic event rate was higher and the bleeding rate lower, reflecting the intrinsically different risk profile of both populations. Until randomized trials are available, LAAO may be considered in patients with an ischemic event on OAT., Competing Interests: Funding Support and Author Disclosures Dr Maarse has received an educational grant from Boston Scientific. Dr Tondo serves on the advisory board of Boston Scientific; and has received lecture and tutoring fees from Boston Scientific and Abbott Medical. Dr Demkow has received proctoring fees from Boston Scientific and Abbott. Dr de Backer has received institutional research grants and consulting fees from Abbott and Boston Scientific. Dr Nielsen-Kudsk has received grants from Abbott and Boston Scientific. Dr Estevez-Loureiro is a proctor for Abbott Vascular, Boston Scientific, and Lifetech. Dr de Prado is a proctor for Boston Scientific. Dr Nombela-Franco is a proctor for Abbott Vascular, Edwards Lifesciences, and Boston Scientific. Dr Salinas is a proctor for Abbott Vascular. Dr Berti is a proctor for Edwards Lifesciences, Boston Scientific, and Abbott. Dr Millan has received consultant fees/honoraria from Abbott Laboratories and Boston Scientific. Dr Arzamendi has received consultant fees/honoraria from Abbott Laboratories and Boston Scientific. Dr Agarwal is a member of the Speaker Bureau and proctor for Medtronics, Abbott, Edwards Lifesciences, and Boston Scientific. Dr Spoon is a speaker for Medtronic, Abiomed, and Abbott. Dr El-Chami is a consultant for Medtronic and Boston Scientific. Dr Adamo has received speaker honoraria from Abbott Structural Heart. Dr van Dijk is a proctor for Boston Scientific. Dr Swaans is a proctor/lecturer for Abbott Vacular, Bioventrix Inc, Boston Scientific, Cardiac Dimensions, Edwards Lifesciences, GE Healthcare, and Philips Healthcare. Dr Vireca is an employee of Boston Scientific. Dr Bergmann has received speaker honoraria from Boston Scientific and Abbott; and has received research support from Boston Scientific and Abbott. Dr Boersma is a consultant for Boston Scientific; and is a proctor for Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Left atrial appendage occlusion (LAAO) is performed increasingly, but long-term follow-up imaging data are lacking., Aims: The aim of this study was to evaluate the safety and durability of the Amplatzer Amulet device >4 years after LAAO., Methods: This was a prospective observational cohort study including 52 patients implanted with the Amplatzer Amulet device at Aarhus University Hospital, Denmark. A >4-year follow-up cardiac computed tomography (CT) scan after LAAO was performed and compared with the results from the 2-month and 12-month scans. The primary outcome was left atrial appendage (LAA) sealing based on distal LAA contrast patency and peridevice leakage (PDL), stratified into complete occlusion (grade 0 [G0]) and grade 1-3 leakage (G1-3), respectively. Secondary outcomes were low- and high-grade hypoattenuated thickening (HAT), device-related thrombosis (DRT) and device durability., Results: The median (interquartile range [IQR]) follow-up time from LAAO to the latest CT scan was 5.8 years (4.5; 6.3). At 2-month (n=52), 12-month (n=27) and >4-year CT follow-ups (n=52), rates of both complete occlusion (33%, 37%, 35%) and G2 leaks (52%, 52%, 48%) remained stable. Rates of G1 leaks varied (14%, 4%, 6%) and G3 leaks rose (2%, 7%, 12%) from earliest to latest follow-up. The median left atrial (LA) volume increased from 127 mL (96; 176) to 144 mL (108; 182) and 147 mL (107; 193). No DRT was found. The structural device integrity was preserved., Conclusions: This study indicates a stable LAA sealing status throughout the follow-up period, emphasising the importance of the procedural result in avoiding PDL. Few patients displayed PDL progression, which might partly be related to LA remodelling with increasing volume. The long-term device durability appears excellent. Larger studies are warranted to confirm these findings.

Background: Amplatzer Amulet is a frequently used device for left atrial appendage occlusion (LAAO). The current sizing protocol is based on the maximum diameter of the left atrial appendage (LAA) landing zone. However, mean, perimeter-, or area-derived diameter might be more accurate measures for device sizing., Methods: Retrospective analysis of 150 consecutive patients undergoing LAAO is guided by pre-procedural cardiac CT. A total of 117 patients were included; 7 were excluded due to renal failure and 26 due to closure with the sandwich technique. The maximum, mean, area-, and perimeter-derived diameters of the landing zone were derived from pre-procedural cardiac CT scans, and their accuracy to predict the implanted device size was investigated. The predicted device size was determined based on the currently recommended sizing algorithm. Peri-device leak (PDL) was assessed (grade 1-3) along with the underlying mechanism., Results: Device-sizing accuracy was superior for mean, area-, and perimeter derived diameters compared with the maximal diameter, especially for eccentric landing zones. Mean difference between predicted and actually implanted device size was 0.08 mm (± 2.77), 0.30 mm (± 2.40), - 0.39 mm (± 2.43), and - 2.55 mm (± 2.57) across mean, area-derived, perimeter-derived, and maximal diameter, respectively. Grade 3 peri-device leak was seen in 8.5% of implants without a significant association to the eccentricity of the landing zone. The leading mechanism for PDL was device malalignment., Conclusion: Our results indicate mean, area-, and perimeter-derived diameters of the device landing zone to perform similar and superior in device-sizing accuracy compared with the maximum diameter., (© 2023. The Author(s).)

Background: The optimal antithrombotic therapy following left atrial appendage occlusion (LAAO) remains debated. Ideally, this therapy should effectively prevent device-related thrombosis (DRT) while minimising the associated bleeding risk., Aims: We aimed to evaluate the long-term safety and efficacy of a postprocedural single antiplatelet therapy (SAPT) strategy following Amplatzer LAAO in a large consecutive cohort., Methods: This retrospective, single-centre, observational study included all patients discharged on SAPT after LAAO with the Amplatzer Cardiac Plug (ACP) or Amplatzer Amulet between March 2010 and December 2021 at Aarhus University Hospital, Denmark. Baseline, procedural, and imaging data were obtained locally, while clinical outcomes and medication data were extracted from the Danish national health registries., Results: A total of 553 patients underwent Amplatzer LAAO during the specified time frame. Of these, 431 (77.9%) high bleeding risk patients were discharged on SAPT with either acetylsalicylic acid (n=403, 72.9%) or clopidogrel (n=28, 5.1%). At 6 months, 173 (41.7%) patients were not on any antithrombotic therapy. The mean CHA2DS2-VASc and HAS-BLED scores were 3.9±1.5 and 3.4±1.1, respectively. DRT was detected in 6 (1.5%) patients on 8-week follow-up imaging using cardiac computed tomography (n=386, 89.6%) or transoesophageal echocardiography (n=27, 6.3%). The 1-year ischaemic stroke rate was 2.2% (95% confidence interval [CI]: 1.1-4.2). One-year rates for major bleeding and cardiovascular death were 5.9% (95% CI: 4.0-8.9) and 2.9% (95% CI: 1.6-5.1), respectively., Conclusions: SAPT following Amplatzer LAAO displayed rates of DRT and stroke comparable to those reported with more intensive antithrombotic regimens. Meanwhile, we observed low rates of major bleeding.

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., (© 2023. The Author(s).)

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., Competing Interests: Funding Support and Author Disclosures Dr Alkhouli is on the advisory boards of Boston Scientific, Abbott, and Philips. Dr Nielsen-Kudsk is on the advisory boards of Boston Scientific and Philips. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023. Published by Elsevier Inc.)

Background: Scarce data exist on the evolution of device-related thrombus (DRT) after left atrial appendage closure (LAAC)., Objectives: This study sought to assess the incidence, predictors, and clinical impact of persistent and recurrent DRT in LAAC recipients., Methods: 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., Results: 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)., Conclusions: 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., Competing Interests: Funding Support and Author Disclosures Dr Rodés-Cabau holds the Research Chair “Fondation Famille Jacques Larivière” for the Development of Structural Heart Disease Interventions (Laval University, Quebec City, Canada). He also has received institutional research grants from Boston Scientific. Dr Maarse has received an unrestricted grant from Boston Scientific. Dr Pérez de Prado has served as a proctor for Boston Scientific. Dr Gupta has served as a proctor for Abbott. Dr Sanchez has served as a speaker and proctor for Boston Scientific. Dr Wang has served as a consultant for Edwards Lifesciences, Boston Scientific, and Neochord; and received research grant support from Boston Scientific assigned to his employer, the Henry Ford Health System. Dr Demkow has served as a proctor for Abbott and Boston Scientific. Dr Alkhouli has served as a consultant for Boston Scientific. All other authors have reported that they have 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.)

Background: The left atrial appendage (LAA) sealing properties of the Amplatzer Amulet and Watchman FLX devices were compared using cardiac computed tomography (CT) follow-up., Methods: Single-center cohort study of patients undergoing LAAO between 2017 and 2020. Two consecutive cohorts were enrolled, one treated with the Amplatzer Amulet (n = 150) up till 2019, and a second cohort treated with the Watchman FLX (n = 150) device from 2019. Cardiac CT was performed 2 months postprocedure. The primary outcome was complete LAA occlusion defined as no visible peri-device leak (PDL) and absence of contrast patency in the distal LAA. Secondary outcomes included PDL, contrast patency without visible PDL, PDL area, and periprocedural complications., Results: Complete occlusion was achieved in 39 (30.5%) of the Amulet group, compared to 89 (71.8%) of the FLX group, p < 0.001. A PDL at the Amulet disc was present in 65 (50.8%), at the lobe in 16 (12.5%), and at both the disc and lobe in 13 (10.2%). For FLX, a PDL was present in 20 (16.1%). Contrast patency without visible PDL was observed in 24 (18.8%) and 15 (12.1%) of the Amulet and FLX group, respectively. The PDL area at the Amulet mid-lobe was 92 mm 2 (59-158) and 32 mm 2 (IQR 28-96) for FLX, p = 0.019. Device-related thrombosis occurred in 1 (0.7%) and 2 (1.3%), respectively (p = 0.99), with periprocedural adverse events occurring in 6 (4%) and 8 (5.3%) of the Amulet and FLX group (p = 0.79)., Conclusion: Complete LAA occlusion was achieved in a significantly higher proportion treated with the Watchman FLX compared to the Amulet device. PDL was smaller with the FLX than the Amulet. Conceptual device design differences make interpretation of results complex, and additional studies with clinical outcomes are needed., (© 2022. The Author(s).)

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

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., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Purpose: The present article aims to compare a novel sizing chart based on both maximum and minimum diameters (novel MATRIX) with the current sizing recommendation instructions for use (IFU) based on the maximum diameter., Background: Current IFU with the Amulet device are still based on the maximum left atrial appendage (LAA) diameter, which might lead to inappropriate oversizing, especially in elliptic appendages., Methods: This was a retrospective analysis of patients undergoing LAA occlusion in two high-volume centers. Two hundred patients were included (100 patients with baseline cardiac computed tomography angiography [CCTA] and 100 with baseline 2D and 3D-transesophageal echocardiography [TEE]). The degree of concordance between the predicted device size recommendation and the actual device selection was the primary outcome., Results: The novel MATRIX showed a higher level of concordance between the predicted and implanted device size, regardless of imaging modalities. CCTA showed the strongest, and 2D-TEE the weakest concordance between the predicted and implanted device for both MATRIX and IFU charts. The percentage of patients in whom the disagreement among the predicted and implanted device represented &gt;1 size was higher when using the IFU chart. In elliptical LAA anatomies, the differences favoring the use of MATRIX compared to the IFU in terms of predicted/implanted agreement were higher. Finally, no significant differences in clinical or imaging endpoints were observed between the two different sizing charts., Conclusions: Incorporating both the LAA maximum and minimum diameters, as opposed to just maximum diameter, appears to improve sizing accuracy. The proposed MATRIX sizing chart offered a higher level of concordance between predicted and implanted device compared to the current IFU., (© 2022 Wiley Periodicals LLC.)

Background: This propensity-score matched study investigated clinical outcomes associated with left atrial appendage occlusion (LAAO) versus direct oral anticoagulation (DOAC) in patients with AF and prior ischemic stroke., Methods: AF patients enrolled in the Amulet Observational Study with a history of ischemic stroke and successful LAAO (n = 299) were compared with a propensity-score matched cohort of incident AF patients with prior ischemic stroke and treated by DOAC (n = 301). The control cohort was identified through the Danish National Patient Registries. Propensity score matching was based on covariates of the CHA 2 DS 2 -VASc and HAS-BLED scores, with a 1:2 ratio and using Greedy 5:1 digit matching with replacement. The analysis included 2-years follow-up, with a primary composite outcome of ischemic stroke, major bleeding (BARC ≥ 3) or all-cause mortality., Results: Mean (SD) CHA 2 DS 2 -VASc scores were 5.26 (1.42) and 5.40 (1.31) and HAS-BLED scores were 3.95 (0.91) and 4.03 (0.96), for the LAAO and DOAC group, respectively. Total number of primary composite outcome events were 61 (12.4 events/100 patient-years) and 117 (26.9 events/100 patient-years) in the LAAO and DOAC group, respectively. Risk of the primary composite outcome was significantly lower in the LAAO group, hazard rate ratio [HR] 0.48 (95% CI: 0.35-0.65). Ischemic stroke risk was comparable, HR 0.71 (95% CI: 0.34-1.45), while risk of major bleeding, HR 0.41 (95% CI: 0.25-0.67), and all-cause mortality, HR 0.48 (95% CI: 0.32-0.71), were significantly lower with LAAO. Cardiovascular mortality did not differ statistically between the LAAO and DOAC group, HR 0.75 (95% CI: 0.39-1.42). Results were consistent across sensitivity analyses., Conclusion: This study indicated significantly lower risk of the composite outcome of stroke, major bleeding and all-cause mortality with LAAO therapy compared to DOAC, in patients with AF and prior stroke. The stroke prevention effectiveness appeared similar, with a significantly lower risk of major bleeding events with LAAO. The suggested clinical benefit of LAAO over DOAC require confirmation in the ongoing randomized OCCLUSION-AF trial., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Despite improvement in treatment strategies of atrial fibrillation (AF), a considerable number of patients still experience recurrence of atrial tachyarrhythmia (ATA) following catheter ablation (CA). This study aimed to investigate the prognostic value of left atrial (LA) deformation analysis in a large group of patients undergoing CA for AF., Methods: This study included 678 patients with AF. Echocardiography including two-dimensional speckle tracking echocardiography (2DSTE) was performed in all patients prior to CA. Logistic regression analysis was used to assess the association between ATA recurrence and LA strain during reservoir phase (LASr), LA strain during contraction phase (LASct), and LA strain during conduit phase (LAScd)., Results: During one-year follow-up, 274 (40%) experienced ATA recurrence. Median age of the included study population was 63.2 years (IQR: 55.5, 69.5) and 485 (72%) were male. Patients with recurrence had lower LASr (22.6% vs. 25.1%, p = 0.001) and LASct (10.7% vs. 12.4%, p < 0.001). No difference in LAScd was observed. After adjusting for potential clinical and echocardiographic confounders LASr (OR = 1.04, CI95% [1.01; 1.07], p = 0.015, per 1% decrease) and LASct (OR = 1.06, CI95% [1.02; 1.11], p = 0.007, per 1% decrease) remained independent predictors of recurrence. However, in patients with a normal-sized LA (LA volume index<34 mL/m 2 ), only LASct remained an independent predictor of recurrence (OR = 1.07, CI95% [1.01; 1.12], p = 0.012, per 1% decrease)., Conclusion: In patients undergoing CA for AF, LA deformation analysis by 2DSTE could be of use in risk stratification in clinical practice regarding ATA recurrence, even in patients with a normal-sized LA., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Purpose: Advanced targeted therapy has resulted in increasing life expectancy and incidence of age-related cardiovascular diseases like atrial fibrillation in patients with haemophilia. Oral anticoagulation constitutes a significant dilemma in this patient category as the risks of stroke and bleeding are difficult to balance. We sought to demonstrate the feasibility of left atrial appendage occlusion (LAAO) in patients with haemophilia and atrial fibrillation., Methods: All patients with haemophilia treated with LAAO at Aarhus University Hospital, Denmark, were identified from a local prospective database comprising all consecutive LAAO procedures from 2010 up to November 2020. Based on review of the medical records, a retrospective descriptive analysis was performed., Results: Seven patients with haemophilia A and atrial fibrillation underwent LAAO after multidisciplinary conference. Peri-procedural coagulation management was guided by factor VIII activity and treated with repeated bolus administrations of recombinant factor VIII targeting an activity of 100%. The implantation was successful in all patients with only minor bleeding complications post-procedurally. Based on these experiences, a suggested regime has been formulated., Conclusions: LAAO is feasible in haemophilia patients with concurrent atrial fibrillation. However, special care including intravenous substitution with coagulation factors must be given in the periprocedural management., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The natural history of peridevice leak (PDL) following left atrial appendage occlusion (LAAO) is unknown. This study sought to investigate changes of PDL from 2 until 12 months after LAAO, using cardiac computed tomography (CT), and to assess the potential association between persistent PDL and clinical outcomes METHODS: Single-center observational study of Amplatzer LAAO implants between 2010 and 2017 (n = 206). Patients with 2 and 12 months cardiac CT were included in the study (n = 153). Images were blindly analyzed. PDL was characterized by frequency and size at the device disc, lobe, and left atrial appendage contrast patency. Patients were followed for the composite outcome of ischemic stroke, transient ischemic attack, systemic embolism, or all-cause death. Median follow up from LAAO was 3.1 (2.3-4.3) years., Results: Contrast patency was present in 101 (66%) and 72 (47%) (p < 0.001) at 2 and 12 months, respectively. PDL was identified at the disc in 103 (67%) patients at 2 months versus 93 (61%) at 12 months (p = 0.08), and at the lobe in 29 (19%) at both time points. PDL area at the disc did not change significantly over time, ∆ $\unicode{x02206}$ area: -8.95 mm (95% confidence interval [CI]: -18.9; 1.01) p = 0.08. Permanent atrial fibrillation was independently associated with persistent PDL. Persistent versus no PDL was associated with a 62% worse clinical outcome, however not statistically significant, hazard ratio (HR): 1.62 (95% CI: 0.9-2.93), p = 0.11., Conclusion: Persistent PDL was frequently observed following LAAO with Amplatzer devices. The PDL frequency and size appeared unchanged between 2 and 12 months. Persistent PDL was not significantly associated with worse clinical outcomes, yet this needs further delineation in future studies., (© 2022 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

Background: The prevalence of atrial fibrillation (AF) is increasing globally, which is a major clinical and public health concern due to the 5-fold increased risk of stroke. Oral anticoagulation with novel oral anticoagulants (NOACs) is the current primary option for stroke prevention in patients with AF, although it increases the risk of major bleeding. Patients with prior ischemic cerebrovascular events are at particularly high risk of both recurrent ischemic events and major bleeding. Left atrial appendage occlusion (LAAO) provides an alternative option for stroke prevention in high-risk patients, however, with currently limited evidence. Thus, randomized trials comparing LAAO to NOACs are needed., Objective: The Occlusion-AF trial is designed to assess whether LAAO is non-inferior to NOAC therapy for reduction of the combined endpoint of stroke, systemic embolism, major bleeding (Bleeding Academic Research Consortium ≥ 3) and all-cause mortality in patients with AF and a recent ischemic stroke or transient ischemic attack (TIA)., Methods and Analysis: Investigator-initiated multicenter, multinational, randomized open-label non-inferiority trial with blinded outcome evaluation (PROBE design). Patients with documented AF, and an ischemic stroke or TIA within 6 months will be eligible for enrollment. Major exclusion criteria are modified Rankin Scale > 3 at enrollment, glomerular filtration rate < 15 ml/min, and life-expectancy less than 2 years. A total of 750 patients will be randomized 1:1 to receive either a NOAC or LAAO using the Amplatzer Amulet (Abbott, MN, USA) or Watchman FLX (Boston Scientific, MN, USA) with subsequent life-long aspirin 75 mg daily. Follow-up will be based on in-office and telephone follow-up in combination with long-term follow-up (10 years) through national hospital discharge registries in the individual Nordic countries. The primary outcome will be a composite endpoint of stroke, systemic embolism, major bleeding (BARC ≥ 3) and all-cause mortality at 2-year follow-up., Conclusions: The Occlusion-AF trial is designed to compare LAAO to NOAC therapy for secondary stroke prevention in AF patients with a high risk of recurrent thromboembolic events, i.e. with previous ischemic stroke or TIA, and otherwise eligible for anticoagulation. The results are expected to contribute significantly to the understanding of the effects of LAAO compared to the standard contemporary pharmacological treatment in these patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Transcatheter left atrial appendage occlusion (LAAO) is an increasingly used alternative to oral anticoagulation in selected patients with atrial fibrillation. Intraprocedural imaging is a crucial for a successful intervention, with transesophageal echocardiography (TEE) as the current gold standard. Since some important limitations may affect TEE use, intracardiac echocardiography (ICE) is increasingly used as an alternative to TEE for guiding LAAO. The lack of a standardized imaging protocol has slowed the adoption of ICE into clinical practice. On the basis of current research and expert consensus, this paper provides a protocol for ICE support of left atrial appendage occlusion., (© 2021 Wiley Periodicals LLC.)

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., Competing Interests: Funding Support and Author Disclosures Dr Maarse has received an unrestricted grant from Boston Scientific. Dr Pérez de Prado has served as a proctor for Boston Scientific. Dr Gupta has served as a proctor for Abbott. Dr Sanchez has served as a speaker and proctor for Boston Scientific. Dr Demkow has served as a proctor for Abbott and Boston Scientific. Dr Alkhouli has served as a consultant for Boston Scientific. Dr Wang has been a consultant for Edwards LifeSciences, Boston Scientific, and Neochord; and has received research grant support from Boston Scientific assigned to employer Henry Ford health system. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Left atrial appendage occlusion (LAAO) involves a "tug test," in which implanters pull on the device delivery cable to ensure stable occluder placement. The aim of this study was to evaluate the recommendation to perform the tug test, by comparing forces exerted on the device during deployment and subsequent tug test. A secondary objective was to simulate forces experienced on left atrial appendage tissue by placement of a 20-mm device., Methods: The AMPLATZER™ Amulet™ device was used for occlusion. A force transducer recorded forces in the delivery cable during deployment and tug test in 23 patients. Four patients were excluded due to improper transducer placement or technical errors in data collection. For a 20-mm device, the force imparted on the circumferential contact with left atrial appendage wall tissue was simulated in a computational model, using the measured externally applied forces as inputs., Results: For devices < 25-mm in diameter, disc deployment force (mean ± standard deviation) was 1.72 ± 0.43 N, and tug force was 1.01 ± 0.59 N. For devices ≥ 25 mm in diameter, disc deployment force was 2.96 ± 0.57 N, and tug force was 1.04 ± 0.24 N. The increase in disc deployment force compared with tug test force was statistically significant for small devices (< 25 mm; p = 0.049) and large devices (≥ 25 mm; p < 0.001)., Conclusions: Increased force applied on the AMPLATZER™ Amulet™ device during disc deployment compared with during tug test was statistically significant, suggesting that the tug test is redundant in most cases for checking device stability.

Objectives: To describe imaging assessment, procedural and follow-up outcome of patients undergoing left atrial appendage (LAA) occlusion (LAAO) using a "sandwich" technique., Background: The presence of a LAA with chicken wing morphology constitutes a challenge that sometimes requires specific occlusion strategies like the "sandwich" technique. However, procedural and follow-up data focusing on this implanting strategy is scarce., Methods: This multicenter study collected individual data from eight centers between 2012 and 2019. Consecutive patients with chicken-wing LAAs defined as an early (<20 mm from the ostium) and severe bend (>90°) who underwent LAAO with Amplatzer devices and using the "sandwich" technique were included in the analysis., Results: Overall, 190 subjects were enrolled in the study. Procedures were done with the Amulet device (85%) and the Amplatzer Cardiac Plug (15%). Successful implantation was achieved in 99.5% with ≤1 partial recapture in 80% of cases. Single (46.2%) and dual antiplatelet therapy (39.4%) were the most used antithrombotic therapies after LAAO. In-hospital major adverse events rate was 1.5% with no deaths. One patient (0.5%) had cardiac tamponade requiring percutaneous drainage. With a mean follow-up of 19.6 ± 14.8 months, the mortality and stroke rates were 7.7%/year and 2.5%/year, respectively. Follow-up transesophageal echocardiography (TEE) at 2-3 months showed device-related thrombosis in 2.8% and peri-device leak ≥3 mm in 1.2% of patients., Conclusions: In a large series of patients with chicken wing LAA anatomies undergoing LAAO, the use of the "sandwich" technique was feasible and safe. Preprocedural imaging was a key-factor to determine specific measurements., (© 2021 Wiley Periodicals LLC.)

Objectives: This study aimed to investigate cardiac computed tomography (CT) and transesophageal echocardiography (TEE) peridevice leak (PDL) assessments, and the clinical relevance of PDL., Background: PDL assessment is integral during follow-up after left atrial appendage (LAA) occlusion. Comparative studies of TEE and cardiac CT are sparse, and the clinical relevance of PDL is uncertain., Methods: This was a single-center observational study of consecutive patients undergoing LAA occlusion with Amplatzer devices (Amplatzer Cardiac Plug/Amulet) between 2010 and 2018 (N = 415). Patients with both 8-week CT and TEE were included for analysis (n = 346). Images were analyzed by blinded investigators (K.K. and A.S.). PDL on cardiac CT was classified from grade 1 to 3, based on PDL at the device disc, device lobe, and LAA contrast patency. Primary clinical outcome was a composite of ischemic stroke, transient ischemic attack, systemic embolism, or all-cause death., Results: PDL was present in 110 patients (32%) by TEE, with 29 (8%) >3 mm. By cardiac CT, 210 patients (61%) had PDL at the disc, with contrast patency in 204 patients (59%). A grade 3 PDL (gap at disc, lobe, and LAA contrast patency) was present in 63 patients (18%). Bland-Altman analysis showed poor agreement between CT and TEE for leak sizing. CT and TEE detected PDL was not significantly associated with worse outcome, hazard ratio: 1.82 (95 % confidence interval: 0.95 to 3.50); p = 0.07 and hazard ratio: 1.43 (95% confidence interval: 0.74 to 2.76); p = 0.28, respectively., Conclusions: PDL occurrence is substantially higher with CT compared with TEE, with a large discrepancy between modalities in leak quantification. A novel CT-based classification is proposed, yet PDL was not associated with worse clinical outcome., Competing Interests: Author Disclosures This study was funded by an unrestricted grant from Novo Nordisk Foundation (NNF17OC0024868/NNF17OC0029510) and Aarhus University. Dr. Korsholm has received speaker honoraria from Abbott; and has received a travel grant from Boston Scientific. Dr. Saw has received unrestricted research grant support from the Canadian Institutes of Health Research, Heart & Stroke Foundation of Canada, National Institutes of Health, AstraZeneca, Abbott Vascular, St. Jude Medical, Boston Scientific, and Servier; has received salary support from the Michael Smith Foundation for Health Research; has received speaker honoraria from AstraZeneca, Abbott Vascular, Boston Scientific, and Bayer; has received consultancy and advisory board honoraria from AstraZeneca, Boston Scientific, Abbott Vascular, Gore, and Abiomed; and has received proctorship honoraria from Abbott Vascular and Boston Scientific. Dr. Berti has been a proctor for Abbott Vascular and Edwards Lifesciences. Dr. Tzikas has been a proctor/consultant for Abbott Vascular. Prof. Nielsen-Kudsk has been a proctor/consultant for Boston Scientific/Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to investigate clinical outcomes associated with left atrial appendage occlusion (LAAO) versus direct oral anticoagulants (DOACs) in patients with high-risk atrial fibrillation (AF)., Background: LAAO has been shown to be noninferior to warfarin for stroke prevention in AF. However, anticoagulation with DOACs is now preferred over warfarin as thromboprophylaxis in AF., Methods: Patients with AF enrolled in the Amulet Observational Registry (n = 1,088) who had successful LAAO with the Amplatzer Amulet device (n = 1,078) were compared with a propensity score-matched control cohort of incident AF patients (n = 1,184) treated by DOACs identified from Danish national patient registries. Propensity score matching was based on the covariates of the CHA 2 DS 2 -VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) and HAS-BLED (hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores for predicting stroke and bleeding. The primary outcome was a composite of ischemic stroke, major bleeding (Bleeding Academic Research Consortium ≥3), or all-cause mortality, and follow-up was 2 years., Results: AF patients treated with LAAO had a significantly lower risk of the primary composite outcome as compared with patients treated with DOACs (hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.49 to 0.67). Total events and event rates per 100 patient-years were (LAAO vs. DOACs) 256 vs. 461 and 14.5 vs. 25.7, respectively. The risk of ischemic stroke was comparable between groups (HR: 1.11; 95% CI: 0.71 to 1.75), while risk of major bleeding (HR: 0.62; 95% CI: 0.49 to 0.79) and all-cause mortality (HR: 0.53; 95% CI: 0.43 to 0.64) were significantly lower in patients treated with LAAO., Conclusions: Among high-risk AF patients, LAAO in comparison with DOACs may have similar stroke prevention efficacy but lower risk of major bleeding and mortality., Competing Interests: Author Disclosures This study was supported by the Novo Nordisk Research Foundation (NNF17OC0024868; NNF17OC0029510) and an unrestricted research grant from Abbott. Dr. Nielsen-Kudsk has served as a proctor and investigator for Abbott and Boston Scientific. Dr. Diener has received honoraria for participation in clinical trials and contribution to advisory boards or oral presentations from Abbott, Bayer Vital, Bristol Myers Squibb, Boehringer Ingelheim, Daiichi-Sankyo, Medtronic, Pfizer, Portola, Sanofi, and WebMD Global; has received financial support for research projects from Boehringer Ingelheim; and has received research grants from the German Research Council, German Ministry of Education and Research, European Union, National Institutes of Health, Bertelsmann Foundation, and Heinz-Nixdorf Foundation. Dr. Camm has received institutional fees and personal fees from Bayer, Boehringer Ingelheim, Bristol Myers Squibb-Pfizer, and Daiichi-Sankyo; and has received personal fees from Abbott and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to investigate the procedural efficacy and safety of the novel Watchman FLX (Boston Scientific, Marlborough, Massachusetts) device for left atrial appendage occlusion (LAAO) and to assess the feasibility of intracardiac echocardiography (ICE) to guide implantation., Background: The Watchman FLX device for transcatheter LAAO was introduced for a simplified implantation in a wider range of LAA anatomies., Methods: This single-center study included consecutive patients undergoing LAAO with the Watchman FLX between March 2019 and January 2020 (N = 91). Patients underwent cardiac computed tomography (CT) imaging for pre-procedural planning. Initial procedures were guided by transesophageal echocardiography (TEE; n = 8) and thereafter by ICE (n = 83) from the left atrium. TEE and cardiac CT imaging were performed at 8 weeks' follow-up., Results: Technical success was achieved in 90 (99%) patients, with the first device implanted in 86 (96%) procedures. Procedural success was 93.4%. Peri-procedural complications occurred in 5 (5.5%), with pericardial effusion being the most common (2.2%). Only 3.3% had a peri-device leak on TEE follow-up. No device-related thrombosis occurred. The mean device compression rate at end of procedure was 18.3 ± 7.7%, compared with 12.2 ± 7.8% by TEE at 8 weeks' follow-up (p < 0.001) and 5.8 ± 8.8% by cardiac CT imaging at follow-up (p < 0.001)., Conclusions: The Watchman FLX device was suitable for closure of a wide range of LAA anatomies, including shallow appendages. The follow-up closure rate was higher than previously reported with other devices. ICE from the left atrium was used, with high procedural success and a low complication rate, comparable to previous studies on LAAO., Competing Interests: Author Disclosures This study was funded by an unrestricted research grant from Boston Scientific and by the Novo Nordisk Foundation (NNF17OC0024868 and NNF17OC0029510). Dr. Korsholm has received speaker honorarium from Abbott; and has received a travel grant from Boston Scientific. Dr. Nielsen-Kudsk is a proctor/consultant for Abbott and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to report early experience with the new-generation Watchman FLX device (Boston Scientific, Marlborough, Massachusetts)., Background: The new-generation Watchman FLX features a reduced height, improved anchoring and fabric coverage, and a closed distal end. These design modifications aim to simplify implantation, allow full recapture and repositioning, and reduce peridevice leak and device-related thrombosis., Methods: A total of 165 patients undergoing left atrial appendage (LAA) occlusion (LAAO) with Watchman FLX were enrolled in a prospective, multicenter registry at 12 centers participating in the European limited market release program., Results: Mean age was 75.4 ± 8.9 years, and CHA 2 DS 2 -VASc score 4.4 ± 1.4. A total of 128 patients (77.6%) had a history of major bleeding, including previous intracranial hemorrhage in 55 cases (33.3%). LAA landing zone minimal and maximal mean diameters were 19.1 ± 3.6 mm and 22.3 ± 3.7 mm, and 24.2% of LAA were considered complex by dimensions. Technical success was achieved in all patients. Successful implantation at first attempt was achieved in 129 cases (78.2%), and a second device was required in 6 cases (3.6%). Procedure-related complications occurred in 3 patients (1.8%): 2 access-related (1.2%) and 1 pericardial effusion (0.6%). No peri-procedural strokes, deaths, or device embolizations occurred. Forty-nine patients (29.7%) were discharged with single antiplatelet therapy, 105 (63.6%) on dual antiplatelet, and 11 (6.7%) on anticoagulation. Imaging follow-up displayed just 1 peridevice leak ≥5 mm and 7 cases of device-related thrombosis (4.7%). During a median follow-up of 55 days (interquartile range: 45 to 148 days), there were 6 hemorrhagic complications (4.8%), 1 patient (0.8%) had an ischemic stroke, and 1 (0.8%) died. No late device embolizations occurred., Conclusions: LAAO with the Watchman FLX is safe and effective in a wide range of LAA morphologies, with a low procedural complication rate, high degree of LAA sealing, and favorable short-term efficacy., Competing Interests: Author Disclosures Dr. Cruz-González has been proctor for Abbott, Boston Scientific, and Lifetech. Dr. Korsholm has received speaker honorarium from Abbott; and a travel grant from Boston Scientific. Dr. Grygier has been a proctor for and received speaker honoraria from Boston Scientific. Dr. Betts has received honoraria for speaking and proctoring from Boston Scientific. Dr. Schmitz has been a proctor for Boston Scientific. Dr. Nielsen-Kudsk has been proctor for Abbott, Boston Scientific, and Gore Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Optimal preprocedural planning is essential to ensure successful device closure of the left atrial appendage (LAA)., Design: The PREDICT-LAA study is a prospective, international, multicentre, randomised controlled trial (ClinicalTrials.gov NCT04180605). Two hundred patients eligible for LAA closure with an Amplatzer Amulet device (Abbott, USA) will be enrolled in the study. Patients will be allocated to a computational simulation arm (experimental) or standard treatment arm (control) using a 1:1 randomisation. For patients randomised to the computational simulation arm, preprocedural planning will be based on the analysis of cardiac computed tomography (CCT)-based patient-specific computational simulations (FEops HEARTguide, Ghent, Belgium) in order to predict optimal device size and position. For patients in the control arm, preprocedural planning will be based on local practice including CCT analysis. The LAA closure procedure and postprocedural antithrombotic therapy will follow local practice in both arms. The primary endpoint of the study is incomplete LAA closure and device-related thrombus as assessed at 3 months postprocedural CCT. Secondary endpoints encompass procedural efficiency (number of devices used, number of repositioning, procedural time, radiation exposure, contrast dye), procedure-related complications within 7 days postprocedure and a composite of all-cause death and thromboembolic events at 12 months., Conclusion: The objective of the PREDICT-LAA study is to test the hypothesis that a preprocedural planning for LAA closure with the Amplatzer Amulet device based on patient-specific computational simulations can result in a more efficient procedure, optimised procedural outcomes and better clinical outcomes as compared with a standard preprocedural planning., Trial Registration Number: ClinicalTrials.gov Registry (NCT04180605)., Competing Interests: Competing interests: ODB and LS have received institutional research grants from Abbott and FEops NV., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Transcatheter left atrial appendage occlusion is an increasingly used alternative to oral anticoagulation in selected patients with atrial fibrillation. Pre-procedural imaging is a prerequisite to a successful intervention, with transesophageal echocardiography as the current gold standard. However, cardiac computed tomography offers improved imaging with high-quality multiplanar and 3-dimensional reconstructed images. Nevertheless, the lack of a standardized imaging protocol has slowed the adoption of cardiac computed tomography into clinical practice. On the basis of current research and expert consensus, this paper provides a protocol for the preparation, acquisition, and interpretation of cardiac computed tomographic imaging in pre-procedural planning of left atrial appendage occlusion., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Device-related thrombosis (DRT) following left atrial appendage occlusion is a rare but feared complication. The diagnostic value of cardiac compute tomography (CT) for detection of DRT is unknown. This study sought to evaluate the clinical value of cardiac CT for detection of DRT using transesophageal echocardiography (TEE) as the reference standard and to provide insights into the causes, natural history, and risk of DRT., Methods: We reviewed 301 consecutive patients undergoing left atrial appendage occlusion at Aarhus University Hospital, Denmark, between 2010 and 2017. Of these, 248 patients had cardiac CT and TEE imaging available at 8-week follow-up; 139 had complete 12-month imaging. A blinded investigator analyzed all images. On TEE, an echo-dense mass attached to the device was defined as DRT. Cardiac CT was analyzed for presence of hypoattenuated thickening (HAT) on the device, which was subclassified as low grade or high grade. High-grade HAT was considered as definite DRT., Results: At 8 weeks, TEE detected 5 (2%) cases with DRT; and cardiac CT 6 (2.4%) cases with high-grade HAT. At 12 months, both TEE and cardiac CT detected 2 (1.4%) cases with DRT or high-grade HAT, respectively. Cardiac CT demonstrated low-grade HAT in 9 (3.6%) cases at 8 weeks; and 13 cases (9.4%) at 12-months. High-grade HAT/DRT was associated with thromboembolism in 2 cases, whereas low-grade HAT was not related to embolic events. Low-grade HAT resolved spontaneously over time., Conclusions: Cardiac CT seems equally good as TEE for detection of DRT. In addition, cardiac CT demonstrates cases with low-grade HAT, not visualized by TEE. The clinical significance hereof requires further investigation.

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., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to compare the efficacy and safety of intracardiac echocardiography (ICE) from the left atrium (LA) with transesophageal echocardiography (TEE) for procedural guidance of transcatheter left atrial appendage occlusion (LAAO)., Background: TEE with general anesthesia is the current gold standard to guide LAAO. By the use of ICE from the LA, LAAO can be performed in local anesthesia and may potentially have advantages over TEE., Methods: A single-center, cohort study of patients undergoing LAAO with the Amplatzer Cardiac Plug or Amulet (St. Jude Medical, St. Paul, Minnesota). Procedures were guided by ICE from the LA with local anesthesia (n = 109) or TEE using general anesthesia (n = 107). All patients had pre-procedural cardiac computed tomography. Efficacy outcomes were technical success, procedural success, and peridevice leakage at TEE 8 weeks after LAAO. Safety outcome was a composite of periprocedural complications., Results: Technical success was achieved in 99% of both the TEE and ICE group. Procedural success was similar between groups: 94.4% success rate in the TEE-guided group, and 94.5% in the ICE-guided group. Major periprocedural complications occurred in 4.7% of the TEE group and 1.8% of the ICE group. Rate and degree of peridevice leak did not differ between groups at follow-up. Turnover time in the catheter laboratory, and contrast use were reduced with ICE., Conclusions: LA ICE to guide LAAO as compared with TEE appears to be effective and safe, without increased procedure-related complications. The rate of peridevice leak is low and similar to TEE-guided procedures. Time spent in the catheterization room may decrease substantially., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)