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Purpose: The mobility of left atrial appendage (LAA) thrombi and changes hereof under anticoagulation may serve as a marker of both risk of embolism and efficacy of treatment. In this study, we sought to evaluate thrombus mobility and hypothesized that LAA dynamics and thrombus mobility could serve as a baseline marker of thrombus dissolvability., Methods: Patients with two-dimensional transesophageal echocardiographic images of the LAA, and with evidence of LAA thrombus were included in this study. Using a speckle tracking algorithm, functional information from the LAA and thrombi of different patients was computed. While the LAA motion was quantified through the longitudinal strain, thrombus mobility was evaluated using a novel method by directly tracking the thrombus, isolated from the global cardiac motion. Baseline characteristics and echocardiographic parameters were compared between responders (thrombus resolution) and non-responders (thrombus persistence) to anticoagulation., Results: We included 35 patients with atrial fibrillation with evidence of LAA thrombi. Patients had a mean age of 72.9 ± 14.1 years, exhibited a high risk for thromboembolism (CHA2DS2-VASc-Score 4.1 ± 1.5) and had moderately reduced LVEF (41.7 ± 14.4%) and signs of diastolic dysfunction (E/E' = 19.7 ± 8.5). While anticoagulation was initiated in all patients, resolution was achieved in 51.4% of patients. Significantly higher LAA peak strain (- 3.0 ± 1.3 vs. - 1.6 ± 1.5%, p < 0.01) and thrombus mobility (0.33 ± 0.13 mm vs. 0.18 ± 0.08 mm, p < 0.01) were observed in patients in whom thrombi resolved (i.e. responders against non-responders). Receiver operating characteristic (ROC) analysis revealed a high discriminatory ability for thrombus mobility with regards to thrombus resolution (AUC 0.89)., Conclusion: Isolated tracking of thrombus mobility from echocardiographic images is feasible. In patients with LAA thrombus, higher thrombus mobility appeared to be associated with thrombus resolution. Future studies should be conducted to evaluate the role of the described technique to predict LAA thrombus resolution or persistence., (© 2022. The Author(s).)

Objective: To investigate the rate and clinical impact of a persisting iatrogenic atrial septal defect (iASD) after percutaneous left atrial appendage occlusion (LAAO)., Background: Percutaneous LAAO is an alternative to oral anticoagulation (OAC) for the prevention of ischemic stroke and systemic embolism in patients with atrial fibrillation (AF). Data regarding incidence and persistence of iASD after LAAO procedures and its clinical relevance is scarce., Methods: We retrospectively analyzed 144 patients that underwent LAAO at our center between 2009 and 2020 who had at least one follow-up including transesophageal echocardiography (TEE). Baseline clinical, procedural data and echocardiographic characteristics in patients with and without evidence of an iASD were compared. We furthermore determined the rate of iASD persistence over time and evaluated outcomes of patients with and without spontaneous iASD closure., Results: After a median of 92 days (IQR 75-108 days) after LAAO, 50 patients (50/144, 34.7%) showed evidence of an iASD. Patients with iASD had higher CHADS-VASc-scores (4.9±1.5 vs 4.2±1.2, p = 0.03), larger left atrial volumes (80.5±30.5 ml vs 67.1±19.7 ml, p = 0.01) and were more likely to have relevant mitral regurgitation (≥° II) (46.0% vs 12.3%, p = 0.001). LAAO procedures took longer (50.1±24.3 vs 41.1±17.8 min, p = 0.06) in patients with a persisting iASD. Furthermore, larger device sizes were implanted (24.3±3.4 mm vs 22.1±2.8 mm, p = 0.03). The presence of an iASD had no impact on RV dysfunction, thromboembolism or mortality. Spontaneous closure of an iASD was documented in 52.0% (26/50). Hereby, similar risk factors were identified for the persistence of an iASD in follow-up., (© 2021 The Authors. Echocardiography published by Wiley Periodicals LLC.)

Atrial fibrillation (AF) is the most frequent arrhythmic disease in humans, which leads to thrombus formation in the left atrial appendage and stroke through peripheral embolization. Depending on their origin, large extracellular vesicles (lEVs) can exert pro-coagulant functions. In the present study, we investigated how different types of AF influence the levels of large EV subtypes in three distinct atrial localizations. Blood samples were collected from the right and left atrium and the left atrial appendage of 58 patients. 49% of the patients had permanent AF, 34% had non-permanent AF, and 17% had no history of AF. Flow cytometric analysis of the origin of the lEVs showed that the proportion of platelet-derived lEVs in the left atrial appendage was significantly higher in permanent AF patients compared to non-permanent AF. When we grouped patients according to their current heart rhythm, we also detected significantly higher levels of platelet-derived lEVs in the left atrial appendage (LAA) in patients with atrial fibrillation. In vitro studies revealed, that platelet activation with lipopolysaccharide (LPS) leads to higher levels of miR-222-3p and miR-223-3p in platelet-derived lEVs. Treatment with lEVs from LPS- or thrombin-activated platelets reduces the migration of endothelial cells in vitro. These results suggest that permanent atrial fibrillation is associated with increased levels of platelet-derived lEVs in the LAA, which are potentially involved in LAA thrombus formation., (© 2021. The Author(s).)

Background: Left atrial appendage closure is an established therapy in patients with atrial fibrillation. Although device-related thrombosis (DRT) is relatively rare, it is potentially linked to adverse events. As data on DRT characteristics, outcome, and treatment regimen are scarce, we aimed to assess these questions in a multicenter approach., Methods: One hundred fifty-six patients with the diagnosis of DRT after left atrial appendage closure were included in the multinational EUROC-DRT registry. Baseline characteristics included clinical and echocardiographic data. After inclusion, all patients underwent further clinical and echocardiographic follow-up to assess DRT dynamics, treatment success, and outcome., Results: DRT was detected after a median of 93 days (interquartile range, 54–161 days) with 17.9% being detected >6 months after left atrial appendage closure. Patients with DRT were at high ischemic and bleeding risk (CHA2DS2-VASc 4.5±1.7, HAS-BLED 3.3±1.2) and had nonparoxysmal atrial fibrillation (67.3%), previous stroke (53.8%), and spontaneous echo contrast (50.6%). The initial treatment regimens showed comparable resolution rates (antiplatelet monotherapy: 57.1%, dual antiplatelet therapy: 85.7%, vitamin K antagonists: 80.0%, novel oral anticoagulants: 75.0%, and heparin: 68.6%). After intensification or switch of treatment, complete DRT resolution was achieved in 79.5% of patients. Two-year follow-up revealed a high risk of mortality (20.0%) and ischemic stroke (13.8%) in patients with DRT. Patients with incomplete DRT resolution showed numerically higher stroke rates and increased mortality rates (stroke: 17.6% versus 12.3%, P=0.29; mortality: 31.3% versus 13.1%, P=0.05)., Conclusions: A substantial proportion of DRT is detected >6 months after left atrial appendage closure, highlighting the need for imaging follow-up. Patients with DRT appear to be at a high risk for stroke and mortality. While DRT resolution was achieved in most patients, incomplete DRT resolution appeared to identify patients at even higher risk. Optimal DRT diagnostic criteria and treatment regimens are warranted.

Aims: Acute kidney injury (AKI) remains a frequent complication after cardiac interventions, such as left atrial appendage closure (LAAC), yet limited data are available on the incidence and clinical implication of AKI in this setting. We sought to assess incidence, predictors and relevance of AKI after LAAC., Methods and Results: We retrospectively analyzed 95 LAAC patients in three European centers. AKI was defined according to the Acute Kidney Injury Network (AKIN) classification. The incidence of AKI was 13.7% with mild AKI in 92.3% and AKI stage > II in 7.7%. Total contrast volume was not linked to the occurrence of AKI (AKI: 127 ± 83 vs. no AKI: 109 ± 92 ml, p = 0.41), however increasing contrast volume (CV) to glomerular filtration rate (GFR) ratio (CV/GFR ratio) was associated with an increased risk of AKI (OR, per unit increase: 1.24, 95% CI 0.97-1.58, p = 0.08). ROC-analysis revealed a moderate predictive value of CV/GFR ratio for the prediction of AKI (AUC: 0.67, 95% CI 0.50-0.84, p = 0.05). Furthermore, AKI was associated with significantly increased mortality 6 months and 1 year after LAAC. No significant difference in the incidence of AKI was observed between patients with mere fluoroscopic and additional echocardiographic guidance (16.3% vs. 11.5%, p = 0.56)., Conclusion: Whereas mild AKI is common in patients after LAAC, severe AKI is rare. AKI after LAAC is associated with poor baseline renal function, increased doses of contrast (CV/GFR ratio) and impaired outcome. Future studies will be needed to elaborate the benefit of reducing or avoiding contrast volume regarding this endpoint.

Endoluminal left atrial appendage occlusion is an emerging therapy to treat patients suffering from atrial fibrillation with contraindications against oral anticoagulation. Different occlusion devices have been introduced into the clinical setting while comparative studies between the devices are sparse. This in vitro study compares several endoluminal left atrial appendage occlusion systems regarding 2 mechanical properties: radial (RF) and tug force (TF). Seven different occluder systems of various sizes (24 in total) underwent testing throughout their recommended sizing range. RF was measured in a commercial RF tester. TF was assessed according to a recently published bench test. RF increased with compression of the devices: The LAmbre 2228 device exerted the highest RF (8.6 N) at maximum compression of 16 mm. The lowest RF of 0.1 N was exhibited by the 27 mm Occlutech occluder at minimal compression. The highest TFs were exerted by the WaveCrest devices at maximum compression with 4.6 and 3.6 N for the 22 mm and the 27 mm device, respectively. The lowest TFs were measured for the first-generation Occlutech devices, particularly for the 24 mm device with 1.1 N at maximum compression and 0.4 N at minimum compression. A strong positive correlation was found between the number of hooks per millimeter circumference of an occluder and its tug force (r = 0.87, P < 0.01). The analysis revealed device stability to be more dependent on anchoring structures than on RF. The wide range of mechanical properties makes comparison of current LAA occluders difficult and emphasizes the need for standardized preclinical testing to prompt clinical compatibility., (© 2019 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Aims: Percutaneous left atrial appendage occlusion (LAAo) is commonly performed under fluoroscopy including the use of contrast dye. In this study, we aimed to assess feasibility and safety of contrast-free, 3D-echo-based LAAo with the use of the AMPLATZER™ Amulet™ device., Methods and Results: We analyzed 20 patients (74 ± 10 years, 65% males) at an increased thromboembolic and bleeding risk (CHA 2 DS 2 VASC 4.0 ± 1.3; HAS-BLED 3.5 ± 0.9) with chronic renal failure (GFR 41 ± 21 ml/min) undergoing LAAo without the use of contrast dye at our center and compared the results with a propensity-matched cohort (1:1 matching) of conventionally treated patients receiving contrast agent. Contrast-free LAAo was associated with less radiation exposure (13.1 ± 19.2 vs. 32.9 ± 21.2 Gy*cm 2 , p < 0.01) and fluoroscopy time (5.0 ± 3.4 vs. 11.6 ± 4.9 min, p < 0.01). Procedural success rates were excellent in both groups (100%) without severe periprocedural complications (i.e. procedural death, stroke/systemic embolism, myocardial infarction, cardiac tamponade or major bleeding)., Conclusions: Echocardiographically guided LAAo without the use of contrast dye appears safe and feasible. This approach appears to be associated with reduced radiation exposure and may represent an alternative to traditional LAAo, especially in patients in whom the avoidance of contrast dye is warranted.

The aim of this study was to establish in vitro bench-tests of left atrial appendage occlusion (LAAo) devices regarding tug force, radial force and sealing capacity. Two LAAo devices, namely the WATCHMAN™ and the Occlutech ® , of three different sizes underwent testing in novel dedicated in vitro setups. Radial force was assessed in a commercial radial force tester. At baseline, tug force of the WATCHMAN™ was significantly higher when compared to Occlutech ® for all devices. Repeated resheathing resulted in a reduction of device-diameter in the WATCHMAN™ devices of max. 7.9%, whereas diameters of Occlutech ® occluders remained unchanged. Tug force was not significantly impacted by resheathing in both devices. At baseline, sealing capacity in a bench-test using silicone LAA-models did not differ between the devices. Resheathing lead to an in vitro loss of sealing capacity of the WATCHMAN™ devices, increasing with resheathing and resulting in a max. peridevice leak of 91.1 ± 7.9%. Radial force was higher for the Occlutech ® devices and decreased for WATCHMAN™ occluders after resheathing. The WATCHMAN™ occluder series showed progressive deformation, increased peridevice leakage and decreased radial force after resheathing, presumably as a result of diameter reduction. Tug force of the WATCHMAN™ was not impaired by resheathing and was significantly higher than that of the Occlutech ® device.

Introduction: Left atrial appendage closure (LAAC) is considered an alternative to oral anticoagulation therapy in patients with atrial fibrillation (AF). The aim of this study was to compare the safety and efficacy of the first- and second-generation AMPLATZER Devices for LAAC, AMPLATZER Cardiac Plug (ACP) versus AMPLATZER Amulet™., Methods: Procedural data, such as fluoroscopy time, radiation dose, and contrast-dye, as well as VARC criteria and major adverse events (MAEs) were assessed for both devices. The rate of peridevice leaks was analyzed at echocardiographic follow-up., Results: A total of 196 patients with AF underwent LAAC with the ACP ( n = 99) or Amulet device ( n = 97). The use of Amulet was associated with significantly lower fluoroscopy time (14.8 ± 7.4 min versus 10.6 ± 4.1 min; p < 0.001), lower radiation dose (4833 ± 3360 cGy⁎cm 2 versus 3206 ± 2169 cGy⁎cm 2 ; p < 0.001), and reduced amount of contrast-dye (150.2 ± 83.9 ml versus 128.8 ± 46.0 ml; p = 0.03). Furthermore, LAAC with Amulet devices resulted in lower device-resizing rates (3 versus 16 cases; p = 0.001). Peridevice leaks were less frequent in the Amulet group (12 versus 4; p = 0.03). MAE occurred in 6 ACP and 4 Amulet patients ( p = 0.58)., Conclusions: The Amulet device is associated with shorter fluoroscopy times and radiation dosages, reduced use of contrast-dye, lower recapture rates, and less peridevice leaks as compared to the ACP.