Incidence, progression, and predictors of left atrial appendage sealing after Watchman FLX device implantation with computed tomographic assessment.

BACKGROUND: Limited data exists regarding incidence, progression, and predictors of left atrial appendage (LAA) sealing after transcatheter LAA closure. We aimed to evaluate the incidence, progression, and predictive factors associated with LAA sealing after LAA closure. METHODS: This study includes patients who underwent successful LAA closure with Watchman FLX device and had both pre- and postprocedural computed tomography (CT). Postprocedural CT was performed 45 days after LAA closure and used to evaluate residual LAA patency. Patient who had residual LAA patency at 45 days underwent 1-year follow-up CT. RESULTS: A total of 105 patients (mean age: 75.2 ± 9.6 years; 53.3% female) who underwent successful LAA closure with Watchman FLX device and had pre- and postprocedural CT at 45 days were included. Residual patency was observed in 35 (33.3%) patients: 21 (20.0%) patients showed complete contrast opacification in LAA (complete LAA patency) while 14 (13.3%) patients showed contrast opacification only in the distal LAA (distal LAA patency). Among patients with residual LAA patency at 45 days, the rate of LAA sealing at 1 year was significantly higher in the distal LAA patency group than in the complete LAA patency group (75.0% vs. 16.7%; p = 0.019). Increased depth oversizing was associated with both distal LAA patency and complete LAA patency. CONCLUSION: Postprocedural CT at 45 days detected patent LAA in one-third of patients after LAA closure. LAA sealing was more frequently observed at 1 year among the distal LAA patency group than the complete LAA patency group.

Cardiac computed tomography angiography for assessment of endothelial insufficiency of left atrial appendage disc-like occluder.

INTRODUCTION: This study was performed to explore the diagnostic value of cardiac computed tomography angiography (CCTA) for endothelial insufficiency (EIS) of a left atrial appendage (LAA) disc-like occluder. METHODS: Fifty-nine patients with nonvalvular atrial fibrillation who underwent placement of an LAA disc-like occluder (LAmbre; Lifetech Scientific) in our hospital were retrospectively analyzed. Patients who were found to have contrast agent entering the LAA at the 3-month postoperative CCTA examination underwent Hounsfield unit (HU) measurement of the LAA and construction of a three-dimensional (3D) model of the device for preliminary discernment between peri-device leakage (PDL) and EIS. These patients were then further examined by transesophageal echocardiography (TEE) to check for concordance with the computed tomography (CT) findings. According to the CT and TEE results, all patients were divided into the PDL group, total endothelialization group, and EIS group. The endothelial conditions and other implantation-related results were also tracked at the 6-month follow-up. RESULTS: All 59 patients underwent successful implantation of the LAmbre LAA closure device with no severe adverse events during the procedure. Thirty-five patients were found to have contrast agent entering the LAA at the 3-month postoperative CCTA follow-up. Based on the CT HU measurement and the 3D construction analysis results, these 35 patients were divided into the PDL group (19 patients) and the EIS group (16 patients). In the PDL group, the contrast agent infiltrated from the shoulder along the periphery of the occluder on two-dimensional (2D) CT images, and the 3D model showed a gap between the LAA and the device cover. However, the CCTA images of the other 16 patients in the EIS group showed that the contrast agent in the occluder on the 2D CTA images and 3D construction model confirmed the absence of a gap between the LAA and the device cover. TEE confirmed all of the CT results. The 6-month follow-up results showed that 14 of 19 patients in the EIS group achieved total endothelialization, whereas this number in the PDL group was only five of 19 patients. CONCLUSION: CCTA can replace TEE for examination of the endothelialization status, and patients with EIS have a higher chance of endothelialization than patients with PDL.

Peridevice Leak After Left Atrial Appendage Occlusion: Incidence, Mechanisms, Clinical Impact, and Management.

Left atrial appendage occlusion is an increasingly adopted stroke prevention strategy in patients with atrial fibrillation. However, peridevice leaks after the procedure are not infrequent and have recently been shown to confer a higher risk for subsequent ischemic events. In this paper, the authors review the available research on the frequency, mechanisms, clinical significance, and management of peridevice leak after percutaneous left atrial appendage occlusion.

Does left atrial appendage morphology and dimension differ amongst etiological stroke subtypes in patients without known atrial fibrillation? Results from the left atrial appendage morphology and dimension assessment by TEE in patients with stroke without known atrial fibrillation (LAMDA-STROKE) study.

CONTEXT: Complex left atrial appendage (LAA) morphology is increasingly associated with cryptogenic ischemic stroke as compared to cardioembolic stroke due to atrial fibrillation (AF). However, data on such an association in patients with other etiological stroke subtypes in the absence of AF is limited. AIM: The study aimed to assess the LAA morphology, dimension and other echocardiographic parameters by transesophageal echocardiography (TEE) in patients with embolic stroke of undetermined source (ESUS) and compare it with other etiological stroke subtypes without known AF. METHODS: This was a single-Centre, observational study involving comparison of echocardiographic parameters including LAA morphology and dimension in ESUS patients (group A; n = 30) with other etiological stroke subtypes i.e., TOAST (Trial of Org 10172 in Acute Stroke Treatment) class I-IV without AF (group B; n = 30). RESULTS: Complex LAA morphology was predominant in group A (18 patients in group A versus 5 patients in group B, p-Value = 0.001). Mean LAA orifice diameter (15.3 + 3.5 mm in group A versus 17 + 2.0 mm in group B, p-Value = 0.027) and LAA depth were significantly lower in group A (28.4 + 6.6 mm in group A versus 31.7 + 4.3 mm in group B, p-Value = 0.026). Out of these three parameters only complex LAA morphology was found to be independently associated with ESUS [OR = 6.003, 95% CI {1.225-29.417}, p = 0.027]. CONCLUSION: Complex LAA morphology is a predominant feature in ischemic stroke patients with ESUS and may contribute to an increased risk of stroke in these patients.

Assessment of left atrial appendage function by echocardiography.

The left atrial appendage (LAA) is considered not only to be the most frequent site of thrombus formation, but also to play a pivotal role in maintaining normal cardiac function. Transesophageal echocardiography (TEE) is widely used to assess LAA function. The LAA flow velocity has been used as a surrogate for LAA function, and it varies with multiple interrelated factors including age, hemodynamics, type of arrhythmia, and antiarrhythmic interventions. Relatively great importance of LAA function is involved with intraatrial thrombus formation and subsequent thromboembolism, and thus, understanding of characteristics and behaviors of the LAA under various clinical conditions may help determine strategies against atrial thrombosis. Also, techniques other than TEE-derived Doppler to assess LAA function, such as tissue Doppler imaging, have been proposed. In this review, we introduce clinical and echocardiographic correlates of LAA function, the LAA flow velocity in particular, its significance, and how to interpret functional patterns of the LAA each relevant to specific clinical settings.

Assessment of LAA Strain and Thrombus Mobility and Its Impact on Thrombus Resolution-Added-Value of a Novel Echocardiographic Thrombus Tracking Method.

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.

Joint Analysis of Morphological Parameters and In Silico Haemodynamics of the Left Atrial Appendage for Thrombogenic Risk Assessment.

Background: Atrial fibrillation (AF) is considered the most common human arrhythmia. In nonvalvular AF, around 99% of thrombi are formed in the left atrial appendage (LAA). Nevertheless, there is not a consensus in the community about the relevant factors to stratify the AF population according to thrombogenic risk. Objective: To demonstrate the need for combining left atrial morphological and haemodynamics indices to improve the thrombogenic risk assessment in nonvalvular AF patients. Methods: A cohort of 71 nonvalvular AF patients was analysed. Statistical analysis, regression models, and random forests were used to analyse the differences between morphological and haemodynamics parameters, extracted from computational simulations built on 3D rotational angiography images, between patients with and without transient ischemic attack (TIA) or cerebrovascular accident (CVA). Results: The analysis showed that models composed of both morphological and haemodynamic factors were better predictors of TIA/CVA compared with models based on either morphological or haemodynamic factors separately. Maximum ostium diameter, length of the centreline, blood flow velocity within the LAA, oscillatory shear index, and time average wall shear stress parameters were found to be key risk factors for TIA/CVA prediction. In addition, TIA/CVA patients presented more flow stagnation within the LAA. Conclusion: Thrombus formation in the LAA is the result of multiple factors. Analyses based only on morphological or haemodynamic parameters are not precise enough to predict such a phenomenon, as demonstrated in our results; a better patient stratification can be obtained by jointly analysing morphological and haemodynamic features.

Clinical Outcomes at 1 Year Following Transcatheter Left Atrial Appendage Occlusion in the United States.

OBJECTIVES: The aim of this study was to report 1-year clinical outcomes following commercial transcatheter left atrial appendage occlusion (LAAO) in the United States. BACKGROUND: The National Cardiovascular Data Registry LAAO Registry was initiated to meet a condition of Medicare coverage and allow the assessment of clinical outcomes. The 1-year rates of thromboembolic events after transcatheter LAAO in such a large cohort of "real-world" patients have not been previously reported. METHODS: Patients entered into the National Cardiovascular Data Registry LAAO Registry for a Watchman procedure between January 1, 2016, and December 31, 2018, were included. The primary endpoint was ischemic stroke. Key secondary endpoints included the rate of ischemic stroke or systemic embolism, mortality, and major bleeding. Major bleeding was defined as any bleeding requiring hospitalization, and/or causing a decrease in hemoglobin level > 2g/dL, and/or requiring blood transfusion that was not hemorrhagic stroke. The Kaplan-Meier method was used for 1-year estimates of cumulative event rates. RESULTS: The study population consisted of 36,681 patients. The mean age was 76.0 ± 8.1 years, the mean CHA2DS2-VASc score was 4.8 ± 1.5, and the mean HAS-BLED score was 3.0 ± 1.1. Prior stroke was present in 25.5%, clinically relevant bleeding in 69.5%, and intracranial bleeding in 11.9%. Median follow-up was 374 days (IQR: 212-425 days). The Kaplan-Meier-estimated 1-year rate of ischemic stroke was 1.53% (95% CI: 1.39%-1.69%), the rate of ischemic stroke or systemic embolism was 2.19% (95% CI: 2.01%-2.38%), and the rate of mortality was 8.52% (95% CI: 8.19%-8.87%). The 1-year estimated rate of major bleeding was 6.93% (95% CI: 6.65%-7.21%). Most bleeding events occurred between discharge and 45 days following the procedure. CONCLUSIONS: This study characterizes important outcomes in a national cohort of patients undergoing transcatheter LAAO in the United States. Clinicians and patients can integrate these data in shared decision making when considering this therapy.

Cardiac Computed Tomography Angiography for Device-Related Thrombus Assessment After WATCHMAN FLX™ Occluder Device Implantation: A Single-Center Retrospective Observational Study.

BACKGROUND/PURPOSE: Device-related thrombosis (DRT) is one of the greatest challenges of transcatheter left atrial appendage device occlusion. Due to the invasive nature of transesophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) is being increasingly utilized in several centers for assessing adequate left atrial appendage closure and monitoring for DRT. There is a paucity of data regarding the standardized definition of DRT on CCTA for the WATCHMAN FLX™ device. METHODS/MATERIALS: A retrospective review was conducted on 43 patients receiving WATCHMAN FLX™ device implantation with CCTA performed at the first follow-up at our institution. A comparative review of DRT predictors was performed on 10 patients who had both CCTA and TEE at the time of follow-up. RESULTS: Hypoattenuated thickening (HAT) was a common finding on CCTA and was noted to be present in 95.35% of the patients. The combination of a large device size, peridevice gap >4 mm, and HAT located on the device gutter and 1 shoulder were characteristics present on CCTA observed in 2 patients with confirmed DRT on TEE. CONCLUSION: CCTA is a noninvasive imaging modality for DRT monitoring, with guidelines still in development. We report potential predictors of DRT on CCTA. Additional studies are needed to further determine standardized parameters for DRT detection on CCTA and the significance of HAT with multimodality correlation.

Safety, Efficacy, and Cost-Effectiveness of Same-Day Discharge for Left Atrial Appendage Occlusion.

BACKGROUND: Percutaneous left atrial appendage occlusion (LAAO) with the Watchman device is FDA approved for stroke prevention in patients with nonvalvular atrial fibrillation who have an appropriate indication. During the COVID-19 pandemic, a same-day discharge protocol (SDDP) was employed to improve resource utilization, relieve hospital occupation, and reduce the possible risk of in-hospital virus transmission. OBJECTIVES: We sought to analyze the safety, feasibility, and cost effectiveness for SDDP in patients receiving LAAO. METHODS: A prospective analysis of 142 consecutive patients, 119 treated prior to SDDP and 23 who underwent SDDP following LAAO with cardiac computed tomography angiography (CTA)-guided pre-procedural planning and intracardiac echocardiogram (ICE). Procedures were performed in a single, large academic hospital in the United States. In-hospital and 45-day procedural success, adverse events, length of procedure, and length-of-stay were evaluated. RESULTS: Baseline patient characteristics including mean CHA2DS2VASc scores and mean HAS-BLED scores were similar in both groups. All procedures were successful. There was no significant difference in rates of procedural complications or in-hospital adverse events. The mean procedure time in the SDDP group was 11 minutes longer than in the conventional group (62.1 ± 5.9 vs 51.1 ± 21; P=.01). Outcomes at 45-day follow-up were similar. SDDP was associated with a reduced length of stay compared with conventional strategy and a 15% reduction in total costs. CONCLUSIONS: Same-day discharge strategy for LAAO appears safe, feasible and could become the new standard approach for LAAO. A protocol including CTA pre-procedural planning, ICE-guided deployment and conscious sedation reduces hospital occupation and lowers costs.

A quantitative gain-independent assessment of the left atrial appendage as a method of thromboembolic risk stratification.

BACKGROUND: Visual assessment of the left atrial appendage (LAA) by echocardiography for the presence of thrombus is inherently qualitative. However, whether quantitative assessments can provide increased value over qualitative assessment has not been thoroughly examined. METHODS: One hundred and thirty-eight patients (mean age 59 ± 13 years, 70% male) undergoing transesophageal echocardiography prior to pulmonary vein isolation or electrical cardioversion were retrospectively studied. LAA were examined by two expert readers and identified as thrombus, sludge, spontaneous echocardiograph contrast, or normal. LAA were then separately examined to calculate a gain-independent ratio between the average pixel density of the LAA cavity and that of the LAA wall (C/W ratio). RESULTS: C/W ratio was significantly related with qualitative LAA analysis (p < 0.0001) and with thromboembolic events (OR 1.60, 95% CI 1.095-2.347, p = 0.02). The C/W ratio (AUC 0.73, 95% CI 0.60-0.86) was a reliable predictor for future thromboembolic events when compared to expert reader LAA assessment (Expert Reader 1 AUC = 0.72, 95% CI 0.53-0.90; Expert Reader 2 AUC = 0.69). CONCLUSIONS: The C/W ratio may be a complementary method to adjudicate thromboembolic risk in patients with AF that is readily quantifiable at time of TEE.

Assessment of independent clinical predictors of early readmission after percutaneous endoluminal left atrial appendage closure with the Watchman device using National Readmission Database.

BACKGROUND: Percutaneous endoluminal left atrial appendage closure (pLAAC) procedure has been used to prevent strokes in patients who are not eligible for long-term prophylactic anticoagulation. Since its approval, multiple studies have looked at its efficacy with comparable outcomes to anticoagulation, the current standard of care. OBJECTIVES: To assess the readmission rate and determine the factors associated with readmission after the endocardial pLAAC procedure using the Watchman device. METHODS: Data was obtained from the National Readmission Database (NRD), and we used SPSS software to determine statistically significant clinical predictors affecting readmission after implantation of the Watchman device at 30 days. RESULTS: The rate of readmission was found to be 9.2%. The true median cost of index hospitalization for the total population in the study was found to be [median (interquartile range = IQR), p] USD 24594 (USD 18883-31,041), whereas the true median cost of admission for those who were getting readmitted after 30 days was [median (IQR)] USD 7699 (USD 4955-14,243). Multivariate analysis of all clinically relevant predictors showed adjusted ratio for [adjusted odds ratio (OR), 95% confidence interval (95% CI), p-value] female genders (1.288, 1.104-1.503, p = 0.001), discharge to home health care (6.155, 1.509-25.096, p = 0.01), chronic kidney disease (CKD) (1.847,1.511-2.258, p < 0.001), chronic lung disease (1.419, 1.194-1.686, p < 0.001), heart failure (1.280, 1.040-1.574, p = 0.02), pericardial disorders (1.485, 1.011-2.179, p = 0.04), fluid and electrolyte disorders (1.456,1.050-2.018, p = 0.02) in those who were getting readmitted at 30-days compared to those who were not readmitted. The median length of stay for the index hospitalization was found to be one day, whereas the median length of stay at the 30-day readmission was reported to be [Median (IQR)] 4 days (2-6 days). Major cardiac reasons for readmission were heart failure, arrhythmias, and pericardial disorders. CONCLUSION: Our study aims to assess 30-day outcomes in the US population after pLAAC using a Watchman device. Our analysis showed that one in ten patients were getting readmitted. In addition, chronic kidney disease, chronic obstructive pulmonary disease, heart failure, and pericardial disorders were associated with higher readmission rates. These findings will help us assess clinical correlations and predict which patients are more at risk of readmission after a Watchman procedure.

The use of cardiac computed tomography angiography in the assessment of percutaneous left atrial appendage closure - Review and experts recommendations endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle.

Atrial fibrillation is the most common cause of arrhythmia which is responsible for over 15% of ischemic strokes, most of these being secondary to migration of a left atrial appendage (LAA) thrombus. In patient with contraindication to anticoagulant therapy, percutaneous closure system placement may be indicated. Cardiac computed tomography (CT) angiography plays a central role in the initial assessment as well as in the follow-up. The purpose of the pre-implantation cardiac CT angiography is to evaluate the anatomy of the LAA in order to select the most suitable prosthesis and check for any contraindication to device implantation. Image analysis is divided into four steps that include analysis of the approach; search for a thrombus in the LAA; investigation of the anatomy of the LAA (morphology of the LAA, dimensions of the LAA and choice of device) and cardiac and thoracic assessments. Follow-up involves CT examination to check for correct placement of the device and to detect any complications. On the basis of the results of currently available published research, a panel of experts has issued recommendations regarding cardiac CT angiography prior to percutaneous LAA closure device placement, which were further endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV).

Saturation recovery-prepared magnetic resonance angiography for assessment of left atrial and esophageal anatomy.

OBJECTIVES: Magnetic resonance angiography (MRA) has been established as an important imaging method in cardiac ablation procedures. In pulmonary vein (PV) isolation procedures, MRA has the potential to minimize the risk of severe complications, such as atrio-esophageal fistula, by providing detailed information on esophageal position relatively to cardiac structures. However, traditional non-gated, first-pass (FP) MRA approaches have several limitations, such as long breath-holds, non-uniform signal intensity throughout the left atrium (LA), and poor esophageal visualization. The aim of this observational study was to validate a respiratory-navigated, ECG-gated (EC), saturation recovery-prepared MRA technique for simultaneous imaging of LA, LA appendage, PVs, esophagus, and adjacent anatomical structures. METHODS: Before PVI, 106 consecutive patients with a history of AF underwent either conventional FP-MRA (n = 53 patients) or our new EC-MRA (n = 53 patients). Five quality scores (QS) of LA and esophagus visibility were assessed by two experienced readers. The non-parametric Mann-Whitney U-test was used to compare QS between FP-MRA and EC-MRA groups, and linear regression was applied to assess clinical contributors to image quality. RESULTS: EC-MRA demonstrated significantly better image quality than FP-MRA in every quality category. Esophageal visibility using the new MRA technique was markedly better than with the conventional FP-MRA technique (median 3.5 [IQR 1] vs median 1.0, p < 0.001). In contrast to FP-MRA, overall image quality of EC-MRA was not influenced by heart rate. CONCLUSION: Our ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality and esophageal visibility than the established non-gated, breath-holding FP-MRA. Image quality of EC-MRA technique has the additional advantage of being unaffected by heart rate. ADVANCES IN KNOWLEDGE: Detailed information of cardiac anatomy has the potential to minimize the risk of severe complications and improve success rates in invasive electrophysiological studies. Our novel ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality of LA and esophageal structures than the traditional first-pass algorithm. This new MRA technique is robust to arrhythmia (tachycardic, irregular heart rates) frequently observed in AF patients.

Racial, ethnic and socioeconomic disparities in patients undergoing left atrial appendage closure.

OBJECTIVE: This manuscript aims to explore the impact of race/ethnicity and socioeconomic status on in-hospital complication rates after left atrial appendage closure (LAAC). METHODS: The US National Inpatient Sample was used to identify hospitalisations for LAAC between 1 October 2015 to 31 December 2018. These patients were stratified by race/ethnicity and quartiles of median neighbourhood income. The primary outcome was the occurrence of in-hospital major adverse events, defined as a composite of postprocedural bleeding, cardiac and vascular complications, acute kidney injury and ischaemic stroke. RESULTS: Of 6478 unweighted hospitalisations for LAAC, 58% were male and patients of black, Hispanic and 'other' race/ethnicity each comprised approximately 5% of the cohort. Adjusted by the older Americans population, the estimated number of LAAC procedures was 69.2/100 000 for white individuals, as compared with 29.5/100 000 for blacks, 47.2/100 000 for Hispanics and 40.7/100 000 for individuals of 'other' race/ethnicity. Black patients were ~5 years younger but had a higher comorbidity burden. The primary outcome occurred in 5% of patients and differed significantly between racial/ethnic groups (p<0.001) but not across neighbourhood income quartiles (p=0.88). After multilevel modelling, the overall rate of in-hospital major adverse events was higher in black patients as compared with whites (OR: 1.60, 95% CI 1.22 to 2.10, p<0.001); however, the incidence of acute kidney injury was higher in Hispanics (OR: 2.19, 95% CI 1.52 to 3.17, p<0.001). No significant differences were found in adjusted overall in-hospital complication rates between income quartiles. CONCLUSION: In this study assessing racial/ethnic disparities in patients undergoing LAAC, minorities are under-represented, specifically patients of black race/ethnicity. Compared with whites, black patients had higher comorbidity burden and higher rates of in-hospital complications. Lower socioeconomic status was not associated with complication rates.