Clinical Characteristics of Non-Valvular Atrial Fibrillation Patients With a Large Left Atrial Appendage Ostium-Limiting Percutaneous Closure.

BACKGROUND: The left atrial appendage (LAA) is a therapeutic target for preventing cardioembolic stroke in patients with non-valvular atrial fibrillation (NVAF). A large LAA ostium limits percutaneous LAA closure. This study investigated the characteristics and factors associated with a large LAA ostium in Japanese patients with NVAF.Methods and Results: In 1,102 NVAF patients, the maximum LAA diameter was measured using transesophageal echocardiography (TEE). A large LAA ostium was defined by a maximum diameter of >30 mm. Forty-four participants underwent repeated TEEs, and changes in LAA size under lasting AF were assessed. A large LAA ostium was observed in 3.1% of all participants and 8.9% of patients with long-standing persistent AF (LSAF). The large LAA group had greater CHA2DS2-VASc (P=0.024) and HAS-BLED scores (P=0.046) and a higher prevalence of LAA thrombus (P=0.004) than did the normal LAA group. LSAF, moderate or severe mitral regurgitation, left atrial volume ≥42 mL/m2, E/E' ratio ≥9.5, and left ventricular mass ≥85 mg/m2were independently associated with a large LAA ostium (P<0.001, P<0.001, P=0.009, P=0.009, and P=0.032, respectively). In 44 patients with lasting AF, the LAA ostial diameter increased over time (P<0.001). CONCLUSIONS: NVAF patients with a large LAA ostium may have a higher risk of stroke and bleeding. LSAF and factors leading to LA overload may be closely associated with LAA ostial dilatation and can promote it.

A simple method to detect leaks after left atrial appendage occlusion with Watchman.

BACKGROUND: We evaluated the efficacy of a new method in identifying peri-device leak (PDL) using morphology of the thrombus formed inside the left atrial appendage (LAA) as seen on follow-up transesophageal echo (TEE). METHOD: A total of 291 consecutive patients undergoing Watchman procedure were included in this analysis. TEE was performed at 45 days postprocedure. Based on the presence of the thrombus inside the LAA behind the device, patients were grouped as (1) white (W) group: LAA completely filled with thrombus (n = 101), 2) nonwhite (NW) group: LAA completely black or mixed (part black and part white; n = 190). Follow-up TEE was repeated at 6 and 12 months. RESULTS: Baseline characteristics were comparable between groups except the device size, number of patients with chicken-wing morphology, and prevalence of left atrial "smoke" that were significantly higher in the NW group. Detection of black appearance was comparable between the pre-coil closure image and the NW population (26/36 [72.2%] vs 99/154 [64.3%], p = .37). After adjusting for clinically relevant covariates, NW appearance of the LAA was associated with the presence of significant leak (odds ratio: 47.96, 95% confidence interval: 2.91-790.2, p < .001). The 11 patients with mixed appearance at the 6-month TEE remained unchanged (part black and part white) at the 12-month TEE. LAA appearance was white in all 36 patients following coil closure. CONCLUSION: Our findings demonstrated white and nonwhite appearance of the appendage on TEE to be reliable markers of complete closure and leak respectively, following LAA occlusion with the Watchman device.

Comparing Measurements of CT Angiography, TEE, and Fluoroscopy of the Left Atrial Appendage for Percutaneous Closure.

BACKGROUND: Left atrial appendage (LAA) closure requires accurate preprocedural measurements, and trans-esophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) and fluoroscopy can be utilized. However, correlations between these measurements remain inadequately assessed. METHODS: Patients who underwent LAA closure at Vancouver General Hospital who had baseline LAA measurements by CCTA, TEE, and fluoroscopy were included in this analysis. CCTAs were performed with prospective-ECG-gating with Toshiba 320-detector or Siemens second generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation.™ LAA maximal dimensions were obtained for all patients at: (1) Amplatzer Cardiac Plug (ACP)/Amulet landing zone 10 mm within orifice, (2) WATCHMAN ostium, and (3) WATCHMAN depth measurements. Correlations and agreements were compared. RESULTS: We report 50 consecutive patients who underwent LAA closure (8 ACP, 10 Amulet, 32 WATCHMAN). Average age was 75.2 ± 8.7 years, mean CHADS2 score 3.0 ± 1.3, and CHA2 DS2 -VASc 4.7 ± 1.5. Procedural device implantation success was 100%. For ACP landing zone, mean maximal measurements were 24.1 ± 4.7 mm with CCTA, 22.3 ± 4.9 mm TEE, and 19.9 ± 5.6 mm fluoroscopy (P < 0.001); R value 0.81 fluoroscopy/CTA, 0.67 fluoroscopy/TEE, and 0.80 CTA/TEE. For WATCHMAN ostium, mean maximal measurements were 25.8 ± 4.7 mm CCTA (P < 0.001 vs. fluoroscopy, P = 0.16 vs. TEE), 25.1 ± 4.4 mm TEE (P = 0.016 vs. fluoroscopy), and 23.8 ± 4.9 mm fluoroscopy; R value 0.71 fluoroscopy/CTA, 0.65 fluoroscopy/TEE, and 0.74 CTA/TEE. Depth measurements were 34.3 ± 5.7 mm with CCTA, 31.1 ± 6.5 mm TEE, and 27.8 ± 7.1 mm fluoroscopy (all P < 0.01); and correlations with R value 0.28 fluoroscopy/CTA, 0.22 fluoroscopy/TEE, and 0.56 CTA/TEE. CONCLUSIONS: All 3 imaging modalities correlated with ACP landing zone and WATCHMAN ostium measurements, with CCTA providing the largest measurements, followed by TEE and fluoroscopy.

Cardiac Vignette: Giant Left Atrial Appendage Aneurysm.

BACKGROUND: The left atrial appendage (LAA) is a vestigial structure located in the postero-lateral aspect of the left atrium. Aneurysmal enlargement of the LAA is pathological and can predispose to adverse events, including myocardial infarction, atrial fibrillation and systemic thromboembolism. The condition is rare and usually isolated, occurring in the absence of other cardiac defects. In this cardiac vignette, we describe a case of giant left atrial appendage in a middle aged female presenting with chest pain and explore the natural history, different investigative modalities as well as issues in clinical management of this condition.

Surgical treatment of atrial fibrillation in mitral valve surgery: a narrative review.

Background and Objective: Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice, which leads to cardiac decompensation, cardiovascular and cerebrovascular infarction, and other thromboembolic diseases. AF is one of the most common comorbidities of valvular heart disease, especially in mitral valve disease. At the time of their mitral valve surgery, 20-42% of patients have AF. It is beneficial to maintain postoperative sinus rhythm and minimize complications when AF surgery is performed concurrently with mitral valve surgery. This review describes the surgical management of AF in mitral valve surgery, including AF surgical route, surgical ablation technology and surgical approaches. The aim of this review is to enable more patients with AF to receive more appropriate and individualised treatment. Methods: A narrative review was conducted on the literature on PubMed, Embase including all relevant studies published until November 2023. Key Content and Findings: This review focuses on the surgical management of AF during mitral valve surgery, including AF surgical route, surgical ablation technology and surgical approaches. Conclusions: Mitral valve surgery combined with AF surgery facilitates the maintenance of postoperative sinus rhythm in patients, reduces the risk of postoperative stroke, and improves survival. Advances in ablation technology have reduced the difficulty of the procedure, making it possible for more patients to undergo surgical ablation. In the future, it will be possible to tailor specific lesion sets and ablation modalities for individual patients. This would make surgical treatment of AF more effective and applicable to a larger population of patients with AF and mitral valve disease.

The impact of contrast retention on thrombus formation risks in patients with atrial fibrillation: A numerical study.

Background: Contrast retention (CR) is an important predictor of left atrial appendage thrombus (LAAT) and stroke in patients with non-valvular atrial fibrillation (AF). We sought to explore the underlying mechanisms of CR using computational fluid dynamic (CFD) simulations. Methods: A total of 12 patients with AF who underwent both cardiac computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before left atrial appendage occlusion (LAAO) were included in the study. The patients were allocated into the CR group or non-CR group based on left atrial appendage (LAA) angiography. Patient-specific models were reconstructed to evaluate time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP). Additionally, the incidence of thrombosis was predicted using residence time (RT) at different time-points. Results: TAWSS was lower [median (Interquartile Range) 0.27 (0.19-0.47) vs 1.35 (0.92-1.79), p < 0.001] in LAA compared to left atrium. In contrast, RRT [1438 (409.70-13869) vs 2.23 (1.81-3.14), p < 0.001] and ECAP [122.70 (30.01-625.70) vs 0.19 (0.16-0.27), p < 0.001)] was higher in the LAA. The patients in the CR group had significantly higher RRT [(mean ± SD) 16274 ± 11797 vs 639.70 ± 595.20, p = 0.009] and ECAP [610.80 ± 365.30 vs 54.26 ± 54.38, p = 0.004] in the LAA compared to the non-CR group. Additionally, patients with CR had a wider range of thrombus-prone regions [0.44(0.27-0.66)% vs 0.05(0.03-0.27)%, p = 0.009] at the end of the 15th cardiac cycle. Conclusions: These findings suggest that CR might be an indicator of high-risk thrombus formation in the LAA. And CT-based CFD simulation may be a feasible substitute for the evaluation of LAA thrombotic risk in patients with AF, especially in patients with CR.

Novel sizing role of 3D transesophageal echocardiography in a novel left atrial appendage clip device for patients undergoing video-assisted atrial fibrillation ablation: a cohort study.

Background: Three-dimensional (3D) transesophageal echocardiography (TEE) has been successfully used in the sizing of left atrial appendage (LAA) occlusion devices, but its use has not yet been studied in LAA clip devices. We sought to develop and validate the novel use of 3D-TEE sizing in a novel LAA clip device for atrial fibrillation (AF) patients undergoing video-assisted thoracic surgery (VATS) ablation. Methods: Consecutive patients with isolated AF undergoing LAA clipping or excision during VATS ablation were included in the study between June 2021 and September 2022 at Fuwai Hospital. The patients underwent 3D-TEE examinations preoperatively and postoperatively. The VATS length, LAA clip effective length, and LAA excision margin length were recorded. A correlation analysis, intraclass correlation coefficient (ICC) analysis, and Bland-Altman plot analysis were conducted to examine the TEE parameters, VATS length, LAA clip effective length, and LAA excision margin length. Results: In total, 26 AF patients undergoing LAA clipping and 15 undergoing LAA excision were included in the study. In the LAA clipping group, in which the Atriclip size served as the control, the 3D-TEE with volumetric measurement (the perimeter-derived maximum orifice diameter) (R=0.938; ICC =0.934; Bland-Altman plot variability, 3.85%) showed the best sizing efficacy for the LAA clip device among the 3D-TEE with multiplanar reformatting sizing (the perimeter-derived maximum orifice diameter) (R=0.808; ICC =0.772; Bland-Altman plot variability, 3.85%), VATS sizing (R=0.851; ICC =0.756; Bland-Altman plot variability, 11.54%), and VATS plus 0.5-cm sizing (R=0.851; ICC =0.775; Bland-Altman plot variability, 11.54%) measurements (all P<0.001). In addition, for the distribution of matched sizing in the LAA clip group, 3D-TEE with volumetric measurement sizing (20/26) had a higher proportion than 3D-TEE with multiplanar reformatting sizing (11/26, P=0.011), VATS sizing (9/26, P=0.002), and VATS plus 0.5-cm sizing (14/26, P=0.08). Using the LAA excision margin length as the control, the mean difference in the LAA diameter was 1.17 cm [95% confidence interval (CI): 0.71-1.62 cm , P<0.001] in the maximum orifice diameter of two-dimensional-TEE, 0.15 cm (95% CI: -0.32 to 0.61 cm , P=0.523) in the perimeter-derived 3D multiplanar reformatting (the maximum orifice diameter), and 0.03 cm (95% CI: -0.47 to 0.53, P=0.901) in the perimeter-derived 3D volumetric (3DV) measurement (the maximum orifice diameter), and the related Pearson correlation coefficients for these modalities were 0.760 (P=0.001), 0.843 (P<0.001), and 0.963 (P<0.001), respectively. Conclusions: Our study showed that 3D-TEE might be employed in the sizing of a novel LAA clip device using the VATS approach in patients with AF. The 3DV measurement (the perimeter-derived maximum orifice diameter) was superior to the VATS measurement. These findings might also apply to LAA VATS excision patients with AF.

Imaging Modality to Guide Left Atrial Appendage Closure: Current Status and Future Perspectives.

Atrial fibrillation (AF) is the most common cardiac arrhythmia in adults. The left atrial appendage (LAA) is the most likely source of thrombus formation in patients with non-valvular atrial fibrillation (NVAF). Left atrial appendage closure (LAAC) represents an effective alternative to NOAC in patients with NVAF. Expert consensus documents recommend intraprocedural imaging by means of either transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE) in addition to standard fluoroscopy to guide LAAC. TEE-guided LAAC usually requires general anesthesia. The ICE technique is a "minimalist approach", without general anesthesia, but ICE imaging techniques are not yet simplified and standardize, and the ICE may result in inferior image quality compared with that of TEE. Another "minimalist approach" can be the use of ICE via the esophageal route (ICE-TEE), that jet is validated to identify the presence of LAA thrombi in patients and to perform other procedures. In our cath laboratory ICE-TEE to guide LAAC is used in some complex patients. Indeed, our single center experience suggests that ICE-TEE could be a good alternative imaging technique to guide LAAC procedure without general anesthesia.

Feasibility and safety of a percutaneous and non-fluoroscopic procedure for left atrial appendage closure in patients for whom fluoroscopy presents risk: a cohort study.

Background: Most patients undergoing left atrial appendage closure (LAAC) are older adult individuals with atrial fibrillation (AF) and many comorbidities, which may elevate the risk for complications associated with contrast agents with the fluoroscopic image-guided procedure. This retrospective cohort study of patients with AF at high risk for use of contrast agents compared the feasibility and safety of LAAC using percutaneous and non-fluoroscopic procedure with transesophageal echocardiography (TEE) as the only image guidance relative to those under fluoroscopic image guidance. Methods: In this retrospective study, we enrolled 126 patients with AF who underwent LAAC from September 2017 to December 2020. Patients were divided into 2 groups based on the imaging guidance modality: a TEE group (n=32) and a fluoroscopic group (n=94). We analyzed the differences in complete closure rates and device- and procedure-related complications between the 2 groups. Continuous variables were assessed using the Student t-test or Mann-Whitney test, while categorical variables were evaluated using Pearson chi-squared test or Fisher exact test. Propensity-score matching was used to adjust for baseline differences. Results: Propensity-score matching yielded 25 pairs of patients with similarly distributed age (72.9±6.9 vs. 73.1±4.9 years; P=0.925), gender (10:15 vs. 11:14; P>0.99), weight (68.3±11.2 vs. 68.1±12.3 kg; P=0.948), and alanine aminotransferase level (20.0±9.8 vs. 22.5±14.2 U/L; P=0.482). The LAA was successfully occluded in all patients, and the TEE group showed similar results to the fluoroscopic group in terms of success rate (100% vs. 100%; P>0.99) and hospitalization duration [5.0 (IQ1-IQ3: 3.0-7.0) vs. 5.0 (IQ1-IQ3: 3.0-6.0) days; P=0.498]. The groups also demonstrated comparable complication rates, with 1 (4.2%) case of pericardial effusion and 1 (4.2%) case of residual shunt in the TEE group, and 5 (20%) cases of residual shunt, 1 (4.2%) case of pericardial effusion, 1 (4.2%) case of myocardial infarction, and 1 (4.2%) case of access-related complications in the fluoroscopic group. There were no deaths. The overall incidence rate of procedure-related complications (6.2% vs. 18.1%, P=0.153) at mean 22.2±4.5 months follow-up between the 2 groups was similar. Conclusions: In patients with AF of high risk for use of contrast agents, LAAC under non-fluoroscopic guidance appears feasible and safe with similar outcomes to that under fluoroscopic guidance.

Management of oral anticoagulant therapy after intracranial hemorrhage in patients with atrial fibrillation.

Intracranial hemorrhage (ICH) is considered a potentially severe complication of oral anticoagulants (OACs) and antiplatelet therapy (APT). Patients with atrial fibrillation (AF) who survived ICH present both an increased ischemic and bleeding risk. Due to its lethality, initiating or reinitiating OACs in ICH survivors with AF is challenging. Since ICH recurrence may be life-threatening, patients who experience an ICH are often not treated with OACs, and thus remain at a higher risk of thromboembolic events. It is worthy of mention that subjects with a recent ICH and AF have been scarcely enrolled in randomized controlled trials (RCTs) on ischemic stroke risk management in AF. Nevertheless, in observational studies, stroke incidence and mortality of patients with AF who survived ICH had been shown to be significantly reduced among those treated with OACs. However, the risk of hemorrhagic events, including recurrent ICH, was not necessarily increased, especially in patients with post-traumatic ICH. The optimal timing of anticoagulation initiation or restarting after an ICH in AF patients is also largely debated. Finally, the left atrial appendage occlusion option should be evaluated in AF patients with a very high risk of recurrent ICH. Overall, an interdisciplinary unit consisting of cardiologists, neurologists, neuroradiologists, neurosurgeons, patients, and their families should be involved in management decisions. According to available evidence, this review outlines the most appropriate anticoagulation strategies after an ICH that should be adopted to treat this neglected subset of patients.

Novel technique of left atrial appendage occlusion-a pilot study.

A clot in the left atrial appendage (LAA) is an important cause of cardio-embolic stroke. Concomitant occlusion of the LAA during cardiac surgery is found to have reduced postoperative stroke. A study was designed to observe the results of LAA occlusion in 17 patients undergoing coronary artery bypass graft surgery (CABG) and aortic valve replacement (AVR). The LAA was occluded epicardially with a SIRONIX 60-mm linear noncutting stapler (Healthium Medtech Pvt limited, Peenya, Bengaluru). The effectiveness of occlusion was confirmed by trans-esophageal echocardiography and at 2 years of follow-up with trans-thoracic echocardiography. There was no re-canalization of the LAA, and the patients remained in sinus rhythm. Concomitant LAA occlusion with a linear stapler during cardiac surgery is a safe, feasible, and reproducible option.

Factors associated with left atrial appendage filling defects on early-phase cardiac computed tomography in patients with nonvalvular atrial fibrillation: a case-control study.

Background: The significance of left atrial appendage (LAA) filling defects on early-phase cardiac computed tomography (CCT) remains uncertain. This study retrospectively investigated predictive factors of LAA filling defects on early-phase CCT. Methods: A total of 68 patients with nonvalvular atrial fibrillation (AF) and early filling defect on CCT who underwent transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were enrolled [48 males, 20 females; mean ± standard deviation (SD) age 62.72±8.13 years]. Additionally 68 sex- and age-matched patients with normal LAA filling were included as the control group. CCT, ultrasound, clinical and laboratory data were analyzed. Baseline data between groups were analyzed using t-, Mann-Whitney, and chi-squared tests. Multivariable logistic regression analysis was used to adjust for confounders. Pearson correlation analysis was used to confirm correlations between variables. Results: Decreased LAA flow velocity [LAAFV; odds ratio (OR) =0.918; 95% confidence interval (CI): 0.883-0.954; P<0.001] and increased left atrial volume index (LAVI; OR =1.055; 95% CI: 1.012-1.099; P=0.011) were significantly associated with early-phase CCT LAA filling defects. The LAAFV threshold for predicting early LAA filling defects was 40.5 cm/s, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.905 (sensitivity 82.4%, specificity 91.2%); the LAVI predictive threshold was 58.77 mL/m2 (AUC =0.840, sensitivity 85.3%, specificity 72.1%). A significant positive correlation was detected between LAAFV and the Hounsfield unit (HU) ratio of the LAA to ascending aorta on early-phase CCT (r=0.614; P<0.001), as well as the HU difference in LAA between early and delayed phase CCT (r=0.591; P<0.001). There were significant (P<0.05) differences in LAAFV between different filling defects. Conclusions: Decreased LAAFV and increased LAVI are independent factors associated with LAA filling defects only on early-phase CCT. Early-phase CCT LAA filling defect is associated with LAA emptying dysfunction. These findings contribute to thrombosis risk stratification in patients with AF.

Use of left atrial appendage as an autologous tissue source for epicardial micrograft transplantation during LVAD implantation.

We report here the first clinical use of the left atrial appendage (LAA) for epicardial micrograft transplantation during left ventricular assist device (LVAD) implantation. Previously, a sample from the right atrial appendage (RAA) has been available for processing and administering micrograft therapy in cardiac surgery. Both LAA and RAA are rich sources of various types of myocardial cells and are capable of providing both paracrine and cellular support to the failing myocardium. The surgical approach of LAA micrografting facilitates epicardial micrograft therapy dose escalation and treatment of larger myocardial areas than done previously. Moreover, as collection of treated vs. untreated tissues from the recipient heart is possible following LVAD implantation at the time of heart transplantation, the evaluation of the therapy's mechanism of action can be further deciphered at cellular and molecular levels. This LAA modification of the epicardial micrografting technique has the overall potential to facilitate the adoption of cardiac cell therapy during heart surgery.

Morphological changes in the orifices of the left atrial appendage and left atrium in patients with atrial fibrillation.

Background: As an integral part of the left atrium (LA), the left atrial appendage (LAA) plays an important role in atrial fibrillation (AF). However, the relationship between LAA remodeling and AF has not been clearly defined. This retrospective case-control study aimed to assess the morphological and functional features of the LA and the LAA in AF patients using images obtained by computed tomography angiography (CTA). Methods: A total of 140 AF patients and 64 patients without AF or other cardiovascular diseases who underwent CTA scans between September 2016 and August 2017 were enrolled in this observational study as the experimental and the control groups, respectively. The major and minor axes, area, and perimeter of the LAA orifice, the LAA depth, and the volume of both the LAA and LA were analyzed. The data of the AF group and the control group were compared. The t-test was used to analyze the normally distributed data, and the Wilcoxon rank-sum test was used for abnormally distributed data. The best critical value of predictors of AF was calculated using receiver operating characteristic (ROC) curve analysis. The correlation of the LAA volume change with the major and minor axes, area, and perimeter of the LAA orifice, and the LAA depth were analyzed using the Pearson correlation coefficient. Results: The LAA orifice's minor axis, LAA volume, and LA volume were significantly greater (P=0.004, P=0.010, and P<0.001, respectively) in patients with AF than in those without AF. The LAA volume [95% confidence interval (CI): 1.01 to 1.30; P=0.038] and LA volume (95% CI: 1.03 to 1.07; P<0.001) were significantly independent predictors of AF. An LAA volume of 8.75 mL had the highest predictive value for AF [area under the curve (AUC), 0.612], with a sensitivity of 76.6% and a specificity of 48.6%. In contrast, an LA volume of 97.15 mL had the highest predictive value for AF (AUC, 0.771), with a sensitivity of 90.6% and a specificity of 53.6%. The change of LAA volume was positively weakly correlated with the area and perimeter of the LAA orifice (r=0.1703 and r=0.1378, respectively). The LAA emptying fraction was negatively correlated with the major axis and the area of the LAA orifice. The major and minor axes, area, and perimeter of the LAA orifice, and LAA depth were significantly greater in female than in male patients (P=0.003, P=0.003, P=0.001, P=0.019, and P<0.001, respectively). Conclusions: The AF patients had a longer minor axis of the LAA orifice than that of the control group, resulting in a more circular LAA orifice. The LAA orifice area and perimeter were positively correlated with LAA volume change. The LAA orifice major and minor axes, area, and perimeter, and the LAA depth of the female patients were significantly greater than those of their male counterparts in AF patients.

Changes in fibrinolytic activity and coagulation factors after epicardial left atrial appendage closure in patients with atrial fibrillation.

Background: The left atrial appendage (LAA) is known to be the primary source of thrombus formation in atrial fibrillation (AF). We investigate whether epicardial LAA occlusion (LAAO) from the cardiovascular system has an effect on coagulation and prothrombotic status in AF. Methods: Twenty-two patients with nonvalvular AF, who were not currently receiving oral anticoagulation (OAC) therapy, participated in a single-center prospective study. We measured fibrinogen and plasminogen levels along with plasma fibrin clot permeability, clot lysis time (CLT) and endogenous thrombin potential (ETP) before the LAAO procedure, at discharge and 1 month afterward. Results: One month after the LAAO procedure, plasma fibrin clot permeability improved by 39.3% as measured by clots prepared from peripheral blood (P=0.019) and also after adjustment for fibrinogen (P=0.027). Higher plasma fibrin clot permeability was associated with improved clot susceptibility to lysis (r=-0.67, P=0.013). CLT was reduced by 10.3% (P=0.0020), plasminogen activator inhibitor-1 antigen levels were reduced by 52% (P=0.023) and plasminogen activity was increased by 8.9% (P=0.0077). A trend toward decreased thrombin generation, reflected by a decreased ETP and peak thrombin generated was also observed 1 month after LAAO procedure (P=0.072 and P=0.087, respectively). No differences were observed in tissue-type plasminogen activator and thrombin-activatable fibrinolysis inhibitor plasma levels (both P>0.05). Conclusions: Obtained results seem to confirm that LAA plays a key role in thrombogenesis. Elimination of LAA from the circulatory system may improve fibrin clot permeability and susceptibility to fibrinolysis in peripheral blood.

Evaluating left atrial appendage function in a subtype of non-valvular atrial fibrillation using transesophageal echocardiography combined with two-dimensional speckle tracking.

Background: The use of transesophageal echocardiography (TEE) is a clinically feasible method for quantitative analysis of left atrial appendage (LAA) function. LAA dysfunction is closely associated with atrial fibrillation (AF)-related stroke. However, there are few studies on the changes in LAA function in patients with different types of AF. This study aimed to observe changes in LAA systolic motion and function in patients with different types of AF by using speckle-tracking echocardiography (STE). Methods: A retrospective study of 216 patients with non-valvular AF was conducted. The LAA was divided into three parts: the basal segment (B), middle segment (M), and top segment (A). Speck -racking technology was used to measure and record the forward strain values of the basal segment (B), middle segment (M), and top segment (A) of the LAA, and the peak positive strain dispersion of the LAA was calculated. The left atrial appendage mechanical dispersion (LAAMD) was defined as the standard deviation (SD) of the peak positive strain at each segment of the R-R interval. Results: Partial speckle-tracking parameters of the LAA showed statistical significance between the two groups. The peak strain on the top segment of the LAA was reduced in the persistent atrial fibrillation (per-AF) group compared to the paroxysmal atrial fibrillation (par-AF) group [11.87 (6.47-20.12) vs. 16.02 (9.76-24.50); 12.66 (6.66-21.22) vs. 20.16 (14.16-30.56); both P<0.01]. In the group with lower LAAMD, the proportion of patients with persistent AF (per-AF) was higher (66.3% vs. 33.7%; P<0.001), the left atrial dilatation was more significant (45.80±5.656 vs. 42.85±4.867; P<0.001), the LAA filling velocity and LAA empty velocity were lower (42.35±20.354 vs. 51.0±20.599; 38.71±24.39 vs. 51.62±21.282; both P<0.001), the LAA ejection fraction was significantly lower (52.16±25.538 vs. 70.85±20.741; P=0.000), and the peak positive strains of the M and A of the LAA were lower than those in the higher LAAMD group. Conclusions: The deformability of the LAA is decreased diffusely in per-AF, especially in the A of the LAA. Compliance with LAA was worse in patients with per-AF than in those with par-AF.

Abutting Left Atrial Appendage and Left Superior Pulmonary Vein Predicts Recurrence of Atrial Fibrillation After Point-by-Point Pulmonary Vein Isolation.

INTRODUCTION: The role of the spatial relationship between the left superior pulmonary vein (LSPV) and left atrial appendage (LAA) is unknown. We sought to evaluate whether an abutting LAA and LSPV play a role in AF recurrence after catheter ablation for paroxysmal AF. METHODS: Consecutive patients, who underwent initial point-by-point radiofrequency catheter ablation for paroxysmal AF at the Heart and Vascular Center of Semmelweis University, Budapest, Hungary, between January of 2014 and December of 2017, were enrolled in the study. All patients underwent pre-procedural cardiac CT to assess left atrial (LA) and pulmonary vein (PV) anatomy. Abutting LAA-LSPV was defined as cases when the minimum distance between the LSPV and LAA was less than 2 mm. RESULTS: We included 428 patients (60.7 ± 10.8 years, 35.5% female) in the analysis. AF recurrence rate was 33.4%, with a median recurrence-free time of 21.2 (8.8-43.0) months. In the univariable analysis, female sex (HR = 1.45; 95%CI = 1.04-2.01; p = 0.028), LAA flow velocity (HR = 1.01; 95%CI = 1.00-1.02; p = 0.022), LAA orifice area (HR = 1.00; 95%CI = 1.00-1.00; p = 0.028) and abutting LAA-LSPV (HR = 1.53; 95%CI = 1.09-2.14; p = 0.013) were associated with AF recurrence. In the multivariable analysis, abutting LAA-LSPV (adjusted HR = 1.55; 95%CI = 1.04-2.31; p = 0.030) was the only independent predictor of AF recurrence. CONCLUSION: Abutting LAA-LSPV predisposes patients to have a higher chance for arrhythmia recurrence after catheter ablation for paroxysmal AF.

3D transesophageal echocardiography assists in evaluating the morphology, function, and presence of thrombi of left atrial appendage in patients with atrial fibrillation.

BACKGROUND: Left atrial appendage (LAA) is significantly more likely to form thrombi in patients with atrial fibrillation (AFib). Two-dimensional transesophageal echocardiography (2D TEE) is considered the gold standard for assessing and studying LAA morphology and anatomy. However, 2D TEE can only visualize one plane at any given time. Real-time three-dimensional echocardiography (RT-3D TEE) imaging can preserve spatial and temporal resolution, which is a safe, accurate, and reproducible imaging modality. There are few reports of the usage of RT-3D TEE to study LAA in AFib patients. In our research, RT-3D TEE helps to provide detailed LAA information and identifying the presence or absence of thrombi from pectinate muscles in paroxysmal and long-standing AFib patients. METHODS: LAA morphology was analyzed in detail by 2D TEE and RT-3D TEE in 320 patients with paroxysmal or long-standing AFib. The LAA flow pattern, as maximal LAA emptying flow velocity (LAAeV), was retrieved from 2D and 3D TEE imaging. LAA morphological parameters, spontaneous echo contrast (SEC), and thrombi were also detected by 2D and 3D TEE in all patients. In addition, LAA lobes and types were classified according to the morphology by 3D TEE, and the relationship between LAA types and the incidence of thrombi was evaluated. RESULTS: Long-standing AFib had greater enlargement of LAAs (orifice diameters and area), significantly more severe SEC, and a higher thrombi clot incidence rate by 3D-TEE compared with paroxysmal AFib patients (P<0.05). In addition, cauliflower morphology in long-standing AFib patients was associated with a higher LAA thrombus (OR 2.1, 95% CI: 1.1-8.5, P=0.031) and increased prevalence of SEC. Moreover, the uncertainty of thrombi detection was significantly decreased by 3D TEE compared with 2D TEE (P<0.001), and the certainty of thrombi detection by 3D TEE also decreased slightly (P=0.06). CONCLUSIONS: RT-3D TEE is a safe and real-time option for the evaluation of LAA morphology and function. Long-standing AFib has greater LAA and SEC, as well as a higher incidence of thrombi than the paroxysmal group. Cauliflower LAA type was associated with a higher prevalence of SEC and thrombi.

Two-Year Outcome From Combining Cryoballoon Ablation and Left Atrial Appendage Closure: CLACBAC Study.

Objective: Catheter ablation combined with left atrial appendage closure (LAAC) has emerged as a promising strategy for atrial fibrillation (AF) patients at high risk for stroke or with contraindications for oral anticoagulants (OACs). But the evidence for the long-term safety and efficacy of a combined procedure using cryoballoon ablation (CBA) with LAAC is still insufficient. Methods: From October 2015 to December 2017, a total of 76 consecutive non-valvular, drug-refractory AF patients who underwent a combined procedure of CBA and LAAC are included. Peri- and post-procedural safety and efficacy were evaluated through scheduled follow-ups and transesophageal echocardiography (TEE). Results: A total of 74 patients (97.4%) underwent the combined procedure and achieved instant pulmonary vein isolation and satisfactory LAAC. With a mean follow-up time of 23.7 ± 11.0 months, the recurrence of atrial arrhythmia was recorded in 35 patients (48.0%). In addition, a survival analysis shows a non-significant higher recurrence in persistent AF (p = 0.48). The overall OAC withdrawal rate was 97.2%, and one patient (1.4%) had a lethal hemorrhagic stroke while on single antiplatelet therapy. For safety concerns, the overall mortality was 2.7%, which resulted from one case of myocardial infarction on OAC and one hemorrhagic stroke, as mentioned. No other major hemorrhagic events occurred. Among the 72 patients (94.7%) who underwent TEE, one patient (1.4%) had device-related thrombosis and one patient (1.4%) had prominent residual flow (over 3 mm). Both were prescribed long-term OACs without severe complications occurring. Conclusions: Combining CBA with LAAC in a single procedure achieved considerable long-term safety and efficacy, providing a promising strategy for AF management.

Morphometric study of the left atrial appendage related to closure device deployment: a cadaveric study in Thai population.

BACKGROUND: This study aims to investigate the left atrial appendage (LAA) regarding external morphology, positional relation of the ostium of LAA to the left superior pulmonary vein (LSPV), ostium shape, ostium diameter and functional depth. MATERIALS AND METHODS: Left atrial appendages of 65 cadaveric hearts were examined. RESULTS: The prevalence of Cauliflower, Windsock, Cactus and Chicken wing type of LAA were 27.7%, 27.7%, 26.1%, and 18.5%, respectively. LAA with two lobes was the most common. All specimens showed no accessory LAA. The relation of the ostium to the LSPV was found in two types which were mid-type (LAA ostium was at the same level as LSPV) in 29 (44.6%) cases and inferior type (LAA ostium was below the level of LSPV) in 36 (55.4%) cases. The shapes of LAA ostium were oval and round with a prevalence of 55.4% and 44.6%, respectively. The diameter of round type ranged from 9.53 to 21.51 mm with a mean of 14.56 ± 2.6 mm. While in oval type, the long and short diameters ranged from 11.61 to 31.71 mm with a mean of 14.23 ± 4.2 mm and from 6.70 to 23.90 mm with a mean of 11.66 ± 3.5 mm, respectively. The Surface area of the ostium was calculated from the ostium diameter, range from 71.29 to 594.92 mm2 with a mean of 169.56 ± 84.73 mm2. There was no statistically significant difference of the surface area between LAA types. The mean functional depth of LAA was 11.57 ± 4.43 mm. The functional depth of the Windsock-type appeared to be statistically significant from the others. However, there was no correlation between the functional depth and the ostium surface area. CONCLUSIONS: This morphometric data might be beneficial for deployment of LAA closure device in the Thai population.