Demonstration of Patient-Specific Simulations to Assess Left Atrial Appendage Thrombogenesis Risk

Atrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos), and three without a LAA thrombus or TIA (LAAT/TIA-neg). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. Finally, fixed-wall and moving-wall simulations produced different LA hemodynamics and residence time predictions for each patient. Consequently, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis worse than moving-wall simulations, particularly patients with intermediate LAA residence time. Overall, these results suggest that both wall kinetics and LAA morphology contribute to LAA blood stasis and thrombosis.

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Demonstration of Patient-Specific Simulations To Assess Left Atrial Appendage Thrombogenesis Risk

10.1101/2020.05.07.083220 ◽

2020 ◽

Author(s):

Manuel García-Villalba ◽

Lorenzo Rossini ◽

Alejandro Gonzalo ◽

Davis Vigneault ◽

Pablo Martinez-Legazpi ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Bleeding Risk ◽

Atrial Appendage ◽

Patient Specific ◽

Immersed Boundary ◽

Moving Wall ◽

History Of ◽

Small Cohort ◽

And Function

AbstractAtrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three without a LAA thrombus (LAAT/TIA-neg), and three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. While the flow dynamics of fixed-wall and moving-wall simulations differ significantly, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis only slightly worse than moving-wall simulations.

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Endocardial left atrial appendage occlusion in atrial fibrillation: computational fluid dynamics simulations to assess stroke risk

EP Europace ◽

10.1093/europace/euab116.173 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

A Masci ◽

N D"alessandro ◽

A Scivoletto ◽

S Severi ◽

F Ansaloni ◽

...

Keyword(s):

Fluid Dynamics ◽

Atrial Fibrillation ◽

Computational Fluid Dynamics ◽

Blood Flow ◽

Left Atrial ◽

Left Atrial Appendage ◽

Blood Stasis ◽

Atrial Appendage ◽

Patient Specific ◽

Hemodynamic Changes

Abstract Funding Acknowledgements Type of funding sources: None. Background Percutaneous endocardial left atrial appendage (LAA) occlusion (LAAO) in non-valvular atrial fibrillation (AF) seems comparable to anticoagulation therapy (OAC) as regards thromboembolic risk reduction with a possible additional decrease in major bleeding. LAAO is currently limited to patients with contraindications to OAC, due to its high costs and procedural risks, but better pre-procedural planning and operative techniques might improve the outcome widening practical indications. Computational fluid dynamics (CFD) represents a valuable non-invasive approach to estimate physiologically significant hemodynamic parameters in a complex fluid dynamics system. It might provide a helpful in silico simulation of blood flow patterns within the LA and LAA by using 3D patient-specific models, allowing LAAO planning and effects prediction. Purpose This study’s aim was to simulate the fluid dynamics effects of LAAO in AF patients to predict patient-specific hemodynamic changes caused by applying the two most popular devices. Methods LAAO was simulated on the 3D LA anatomical models obtained from CT data in 5 AF patients, considering the device specific shape. CFD simulations in AF condition were performed both on the whole LA model and on the models with the LAAO performed with the two devices. Significant fluid dynamics indices (blood velocity, vortex structures, LAA ostium velocity, LA blood stasis) were computed to evaluate the changes in the flow patterns after LAAO in relation to the thrombogenic risk. Results Overall we found a more effective washout within the LA after LAAO, in terms of a different spatial distribution of velocities (see figure for a qualitative evaluation of LA blood flow velocity in one patient: (A) model with LA and LAA; models after LAAO applying the Amulet (B) and the Watchman (C) device) and vortex structures (after LAAO, they were decreased in number and increased in size). Moreover, a higher velocity at the mitral valve and at the LAA ostium (peak velocity: 12-17 cm/s in the models with LAA, 40-60 cm/s in LAAO_A and 35-65 in LAAO_W) was detected together with a slightly improved washout effect in terms of blood stasis with the Watchman device (stasis: 3.1-5.7% in the models with LAA, 1.9-4.1% in LAAO_A, 1.7-3.7% in LAAO_W). Conclusions A workflow for simulating the fluid dynamics effects of endocardial LAAO in AF was developed and tested. CFD provides a valuable tool to quantify hemodynamic changes after LAAO and assess thrombogenic risk in patient-specific LA and LAA. Our preliminary results suggest that endocardial LAAO favourably affects blood fluid dynamics in the LA. Abstract figure

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Left atrial appendage closure device complicated by late-onset pericardial effusion and tamponade: a case report

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytab058 ◽

2021 ◽

Vol 5 (3) ◽

Author(s):

Stefano Albani ◽

Nicola Berlier ◽

Francesco Pisano ◽

Paolo Scacciatella

Keyword(s):

Pericardial Effusion ◽

Left Atrial ◽

Left Atrial Appendage ◽

Late Onset ◽

Oral Anticoagulants ◽

Bleeding Risk ◽

Atrial Appendage ◽

Closure Device ◽

Device Implantation ◽

First Case

Abstract Background Late-onset complications of left atrial appendage occlusion (LAAO) device procedure are anecdotal and there are no such complications reported in literature using Cardia Ultraseal (Cardia, Inc., Eagan, MN, USA). Case summary We report the case of a 74-year-old Caucasian man affected by paroxysmal atrial fibrillation with significant bleeding risk (familiar thrombocytopenia, macroscopic haematuria episodes during therapy with direct oral anticoagulants, HAS-BLED risk score: 4) and ischaemic risk as well (CHADSVASC score: 3). The patient was treated with LAAO device implantation for high bleeding risk. Subsequently, after 26 days from LAAO procedure, he was admitted to the emergency department for haematic cardiac tamponade. The patient was successfully treated with subxyphoidal pericardiocentesis in the acute phase, unfortunately cardiac arrest occurred during the transfer to the referral hospital for urgent cardiac surgery. Permanent neurological damage was reported and the patient died on day 28. Discussion LAAO late-onset complications are very rare and the case presented is the first case described of late-onset pericardial effusion and tamponade secondary to the Cardia Ultraseal LAAO device implantation. We present a revision of the literature regarding the occurrence of similar adverse events and discuss the hypothetical mechanism of this major complication.

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P3731The improvement in left atrial strain among patients undergoing percutaneous left atrial appendage closure

European Heart Journal ◽

10.1093/eurheartj/ehz745.0585 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

S Ijuin ◽

A Hamadanchi ◽

F Haertel ◽

L Baez ◽

C Schulze ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Transesophageal Echocardiography ◽

Left Atrial ◽

Left Atrial Appendage ◽

Lateral Wall ◽

Bleeding Risk ◽

Atrial Appendage ◽

Left Atrial Appendage Closure ◽

Left Atrial Strain

Abstract Background Percutaneous left atrial appendage closure (LAAC) is being established as an alternative option for atrial fibrillation (AF) patients with high bleeding risk. Few studies reported the influence of percutaneous LAAC on left atrial (LA) performance, but most of the studies demonstrated no remarkable changes in their parameters after the procedure. Method The study included 95 patients (age: 75±6.7 years, 67% male) whom underwent percutaneous LAAC in a single center between September 2012 and November 2018. LA strain was evaluated at three different time intervals by transesophageal echocardiography (baseline, 45 days and 180 days after procedure). All data were analyzed using a dedicated. 70 patients had atrial fibrillation whereas 25 were in sinus rhythm. Analysis was performed for peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) from segment of lateral wall in mid-esophageal 4 chamber view. The validity of lateral wall left atrial analysis was recently shown by our group. PACS was obtained in patients with sinus rhythm during exams. Results Compared to baseline, PALS was significantly increased after 45 days (12.4±8.4% vs 16.0±10.7%, p=0.001) and remained stable after 180 days (13.8±9.0% vs 17.0±12.4%, p=0.098). Even in only patients with atrial fibrillation during exams, it was increased (10.8±7.7% vs 13.4±7.1%, p=0.012 and 8.5±5.1% vs 13.9±8.1%, p=0.014). Similarly, compared with the baseline, PACS was significantly increased after 45 days and 180 days (5.8±3.9% vs 10.6±7.6%, p=0.001 and 4.5±2.6% vs 7.9±3.1%, p=0.036). The Changes in PALS and PACS Conclusion Our study has demonstrated for the first time the improvement in LA strain following LAAC within 45 days of implantation by transesophageal echocardiography and these values were maintained at least for 6 months. Further appraisal is warranted for confirmation of these preliminary findings.

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Long-term outcomes in patients with non-valvular atrial fibrillation and left atrial appendage closure in a large UK tertiary centre: 10-year experience

EP Europace ◽

10.1093/europace/euab116.283 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

A Briosa E Gala ◽

MTB Pope ◽

C Monteiro ◽

M Leo ◽

TR Betts

Keyword(s):

High Risk ◽

Major Bleeding ◽

Left Atrial ◽

Left Atrial Appendage ◽

Bleeding Risk ◽

Atrial Appendage ◽

Tertiary Centre ◽

Left Atrial Appendage Occlusion

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Left atrial appendage occlusion (LAAO) is a well-established stroke prevention strategy in patients with non-valvular atrial fibrillation (AF) and high risk of bleeding or contra-indication to oral anticoagulation (OAC). Despite encouraging randomised control trial and international registry safety and efficacy data, long-term outcome data remains sparce. Purpose This study sought to evaluate the long-term outcomes in ‘real-world’ AF patients undergoing left atrial appendage occlusion in a large UK tertiary centre. Methods This retrospective study included all patients that had a LAAO device implanted in our institution from January 2010 to December 2020. Medical notes, electronic patient records, procedural and imaging reports were reviewed. Annual bleeding risk was extrapolated from the Swedish National Cohort study according to CHA2DS2-VASc and HASBLED score. Results During the study period a total of 225 patients underwent LAAO device implant. Seventy-two percent were male, age 74 ± 8 years, BMI 27 ± 6 kg/m2, CHA2DS2-VASc score 4.4 ± 1.2, HASBLED score 3.2 ± 0.8 and at high risk of stroke (98 ischaemic strokes and 129 haemorrhagic strokes) and bleeding (151 life-threatening bleeding episodes). Three different LAAO devices were used: 136 Watchman, 54 Watchman FLX and 35 Amplatzer Cardiac plugs. Three patients (1.3%) had fatal complications related to the procedure. At discharge, 10% were taking single antiplatelet (ATP), 79% dual-antiplatelet (DAPT), 1.4% OAC, 3.6% ATP and OAC, 3.1% DAPT and OAC, 1.3% were not taking any anti-thrombotic. Nine (4%) patients had device-related thrombus on follow-up transoesophageal echocardiography with no significant difference between devices (5.0%, 2.8% and 6.7% p = 0.8, respectively) and anticoagulation strategy (p = 0.7). Over a total follow-up of 889 patient-years (mean follow-up 3.9 ± 3.7 years), 24 (10.4%) patients died, 55 patients (6.2/100 patient-years) suffered an adverse event, 15 ischaemic strokes (1.7/100 patient-years) and 20 non-procedural major bleeding episodes (2.3/100 patient-years) occurred. Compared to estimated annual stroke and bleeding risk adjusted for CHA2DS2-VASc and HASBLED score, our cohort had a 79% and 65% relative risk reduction in ischaemic stroke and major bleeding, respectively. Conclusion In this cohort of "real-world" high-risk patients, major bleeding and thromboembolic rate remained low on long-term follow-up. Abstract Figure 1

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Acute Device-Related Thrombus after Watchman Device Implant

Case Reports in Cardiology ◽

10.1155/2019/8397561 ◽

2019 ◽

Vol 2019 ◽

pp. 1-4

Author(s):

Muhammad Ajmal ◽

Vijendra Swarup

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Blood Clot ◽

Heart Rhythm ◽

Bleeding Risk ◽

Atrial Appendage ◽

Acute Thrombosis ◽

Increased Risk ◽

Watchman Device ◽

Laa Closure

Atrial fibrillation is characterized by irregularly irregular heart rhythm with an increased morbidity and mortality. It is associated with an increased risk of thromboembolism due to formation of blood clot in the left atrium. Most of these blood clots are formed in the left atrial appendage. The risk of blood clot formation is reduced with the use of anticoagulants. The patients who cannot take anticoagulants due to an increased bleeding risk can undergo percutaneous left atrial appendage (LAA) closure. A Watchman device is used for this purpose. LAA closure with the Watchman device is associated with some adverse effects, and one of them is device-related thrombus. Currently, there are no specific guidelines for the management of device-related thrombus. We present a case of Watchman device-related thrombus which developed 16 hours after the device placement. We will also discuss various options for the management of acute thrombosis.

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Left atrial appendage anatomy and function: short term response to sustained atrial fibrillation

Heart ◽

10.1136/hrt.82.5.555 ◽

1999 ◽

Vol 82 (5) ◽

pp. 555-558 ◽

Cited By ~ 6

Author(s):

M J Weigner ◽

S E Katz ◽

P S Douglas ◽

W J Manning

Keyword(s):

Atrial Fibrillation ◽

Left Atrial ◽

Left Atrial Appendage ◽

Atrial Appendage ◽

Short Term ◽

And Function ◽

Term Response

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P2467Fusion imaging (Anatomical Intelligence) enables automated left atrial appendage sizing in real-time a single center pilot study

European Heart Journal ◽

10.1093/eurheartj/ehz748.0799 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

S Afzal ◽

V Veulemans ◽

K Hellhammer ◽

K Piayda ◽

N Nijhof ◽

...

Keyword(s):

Real Time ◽

Left Atrial ◽

Left Atrial Appendage ◽

Fusion Imaging ◽

Atrial Appendage ◽

Patient Specific ◽

Heart Model ◽

Landing Zone ◽

Device Selection ◽

The Mean

Abstract Background and purpose Percutaneous left atrial appendage occlusion (LAAO) depicts an alternative treatment for patients with atrial fibrillation who are deemed for long-term oral anticoagulation therapy. In order to perform a successful LAAO accurate sizing of left atrial appendage (ostium, landing zone and depth) for device selection is essential. Echo-Fluoro fusion imaging in real-time offers with its latest prototype a patient-specific segmented automated 3D heart model and sizing of left atrial appendage (LAA). We therefore aimed to evaluate the automated segmented LAA sizing by comparing to 2D transesophageal (TOE) and MSCT measurements as gold standard. Methods We studied prospectively data of 8 consecutive patients who were admitted to our clinic for left atrial appendage closure. MSCT was performed preprocedural and analyzed with commercially available 3mensio software (Pie medical imaging). 2D TOE measurements and automated segmentation of the LAA and sizing were performed during the procedure by a highly experienced team of periinterventional cardiac imaging specialist and structural heart disease interventionalist who were blinded to the prior MSCT analysis. Dimension of ostium, landing zone (10 mm into the LAA parallel to the ostial plane at the level of the left circumflex for Amplatzer device) and depth (perpendicular to the ostial plane) were obtained in different TOE views according to instructions for use of Amulet Occluder. In order to generate an automated 3 D heart model, a high-quality 3D TOE image of the LAA volume and surrounding structures was acquired. After successful ECG-gated segmentation a 3 D heart model was generated. Automated LAA sizing followed in real-time. All measurements were taken into consideration before device selection. A Kruskal Wallis test was used to compare mean ranks of independent samples. A concordance analysis according to Kendall W was carried out to investigate reliability. Results The mean age of the patients was 82,6±4.15 years and half of the patients were female. All procedures were conducted successfully. The mean values of ostium and landing zone were comparable in TOE, automated sizing and MSCT sizing (ostium: 23,78±2,15 mm vs 25,71±5,25 mm vs 27,35±3,3 mm; (p=0,175); landing zone 22,13±3,18 mm vs 23,57±3,31 mm vs 24,00±3,51 mm; (p=0,377)). Furthermore, a significant concordance between the measurements was shown (ostium W= 0,991; p=0.045, landing zone W=0,835, p=0.014). Conclusion Automated LAA sizing acquired by fusion imaging may be an elegant real-time alternative for precise LAA Occluder device selection and needs to be investigated further.

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