Editorial: Seeing clearly now: Imaging guidance modalities for left atrial appendage occlusion.

Key Findings▪Percutaneous left atrial appendage (LAA) occlusion has emerged as an alternative strategy to oral anticoagulants in selected patients with atrial fibrillation.▪The landmark trials comparing LAA occlusion to an oral anticoagulation strategy enrolled patients with no apparent contraindications to the use of warfarin.▪LAA occlusion has limited head-to-head comparison against the direct-acting oral anticoagulants.▪Observational data to date have generally shown specific adverse events after LAA occlusion in specific subgroups of patients (women, patients with kidney disease and heart failure, patients belonging to racial/ethnic subgroups and with advanced age), but further large-scale studies are necessary to elucidate reasons for increased adverse events associated with LAA occlusion in these subgroups of patients before recommending this modality as first-line therapy in all patient groups. ▪Percutaneous left atrial appendage (LAA) occlusion has emerged as an alternative strategy to oral anticoagulants in selected patients with atrial fibrillation.▪The landmark trials comparing LAA occlusion to an oral anticoagulation strategy enrolled patients with no apparent contraindications to the use of warfarin.▪LAA occlusion has limited head-to-head comparison against the direct-acting oral anticoagulants.▪Observational data to date have generally shown specific adverse events after LAA occlusion in specific subgroups of patients (women, patients with kidney disease and heart failure, patients belonging to racial/ethnic subgroups and with advanced age), but further large-scale studies are necessary to elucidate reasons for increased adverse events associated with LAA occlusion in these subgroups of patients before recommending this modality as first-line therapy in all patient groups.

Pulmonary Artery Perforation by Plug Anchoring System After Percutaneous Closure of Left Appendage

Contemporary left atrial appendage management during adult cardiac surgery

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

Commentary: Making it look like open cardiac surgery and better

Left atrial appendage closure in the presence of thrombus: incidence, technique and outcomes

Objective To evaluate the role of real-time three-dimensional transesophageal echocardiography(RT-3D TEE) in left atrial appendage (LAA) occlusion. Methods Consecutive 10 atrial fibrillation (AF) patients (CHADS2≥2) with high risk bleeding underwent LAA occlusion under the guidance of TEE. The LAA orifice shape and characteristics of lobes were assessed, the size of LAA with RT-3D TEE wee measured before closer implanation, and the position of the LAA occlusion device were evaluated by RT-3D TEE.The correlational analysis between LAA diameter and occluder size was conducted. Results Among 10 patients, the test results revealed 8 cases with complete LAA occlusion and 1 case with incomplete occlusion, and 1 case with failed occlusion. Five cases showed approximate round LAA ostium, and the other 5 showed approximate oval ostium. The average number of LAA lobes were 2.2±0.7. LAA ostium long diameter were larger by 3D TEE compared with 2D TEE[(21.8±5.1)mm vs (20.8±4.1)mm], and ostium short diameter were smaller by 3D TEE compared with 2D TEE[(16.1±3.0)mm vs (17.0±2.6)mm], however there were no significant differences between 2D and 3D TEE measurements, and the mean ostium diameter and LAA depth were comparable between two methods. LAA ostium long diameter, short diameter, average diameter and LAA depth assessed by 3D TEE and 2D TEE showed good correlation with occluder diameter (3D TEE: r=0.719, 0.690, 0.791, 0.711, and P=0.029, 0.040, 0.011, 0.032, respectively; 2D TEE: r=0.887, 0.894, 0.932, 0.896, and P=0.001, 0.001, 0.000, 0.000, respectively). LAA occlusion device position assessed by RT-3D: 6 cases with appropriate position, acceptable position with 2 cases, and 1 case with malposition. Conclusions RT-3D TEE can play important role in evaluating the morphology of LAA, accurately judging LAA ostium shape and size and position of the occlusion device. Key words: Echocardiography, transesophageal; Echocardiography, real-time three-dimensional; Left atrial appendage; Occlusion

The implantation of a left atrial appendage (LAA) occluder has evolved into an established non-pharmacological alternative to oral anticoagulation (OAC) in the prevention of cardioembolic stroke in patients with atrial fibrillation. While 2 randomized trials investigated the LAA occluder as an alternative treatment in patients who can also undergo OAC, current guidelines recommend the LAA occluder rather as a second line therapy if permanent OAC is not possible due to contraindications. This is in line with current practice where an LAA occluder is usually only implanted if OAC is contraindicated or stopped due to bleeding. The LAA occluder seems most promising for patients with a high risk for both, stroke without OAC and severe bleeding with OAC. After patient informed consent, the LAA occluder may also represent an option for patients who are unwilling to undergo OAC. Since a large proportion of patients do not receive OAC despite an indication (because of contraindications or mere fear of bleeding) and since the majority of patients have to stop OAC during the course of 2 years, mostly due to bleeding, the LAA occluder may play an important role in the long-term prophylaxis of cardioembolic stroke due to atrial fibrillation.

Atrial cardiomyopathy has been recognized as having important consequences for cardiac performance and clinical outcomes. The pathophysiological role of the left atrial (LA) appendage and the effect of percutaneous left atrial appendage occlusion (LAAO) upon LA mechanics is incompletely understood. We evaluated if changes in LA stiffness due to endocardial LAAO can be detected by LA pressure-volume (PV) analysis and whether stiffness parameters are associated with baseline characteristics. Patients undergoing percutaneous endocardial LAAO (n = 25) were studied using a novel PV analysis using near-simultaneous three-dimensional LA volume measurements by transesophageal echocardiography (TEE) and direct invasive LA pressure measurements. LA stiffness (dP/dV, change in pressure with change in volume) was calculated before and after LAAO. Overall LA stiffness significantly increased after LAAO compared with baseline (median, 0.41–0.64 mmHg/mL; P ≪ 0.001). LA body stiffness after LAAO correlated with baseline LA appendage size by indexed maximum depth (Spearman’s rank correlation coefficient Rs = 0.61; P < 0.01). LA stiffness change showed an even stronger correlation with baseline LA appendage size by indexed maximum depth (Rs = 0.70; P < 0.001). We found that overall LA stiffness increases after endocardial LAAO. Baseline LA appendage size correlates with the magnitude of increase and LA body stiffness. These findings document alteration of LA mechanics after endocardial LAAO and suggest that the LA appendage modulates overall LA compliance.NEW & NOTEWORTHY Our study documents a correlation of LA appendage remodeling with the degree of chronically abnormal LA body stiffness. In addition, we found that LA appendage size was the baseline parameter that best correlated with the magnitude of a further increase in overall LA stiffness after appendage occlusion. These findings offer insights about the LA appendage and LA mechanics that are relevant to patients at risk for adverse atrial remodeling, especially candidates for LA appendage occlusion.

Commentary: The appendage strikes back: The last surgeon

Background Percutaneous left atrial (LA) appendage closure is increasingly used to prevent strokes in patients with atrial fibrillation (AF). While LA appendage plays a key role in LA physiology, data regarding the impact of LA appendage occlusion on LA hemodynamics are lacking. The alteration of LA compliance by LA appendage occlusion may represent a clinical issue in AF patients which are at high risk of heart failure. Purpose To describe the impact of LA appendage occlusion on LA hemodynamics. Material and methods From july 2015 to january 2020, all patients undergoing LA occlusion procedure at Pitié-Salpêtrière Hospital (Paris, France) in whom LA pressure curves were recorded, before and immediately after device implantation, were included. The LA mean pressure was measured at baseline and after LA appendage occlusion during the same procedure. Abnormal LA mean pressure was defined as &amp;gt;15mmHg. We also recorded cardiovascular death and hospitalization for congestive heart failure at longest follow-up. Results We enrolled 85 patients (78±8 years, 46 men), the CHA2DS2-VASc score was 5±1 and the HAS-BLED score was 4±1. The mean LA volume index was 51±15mL/m2, the left ventricular ejection fraction was 60±7%. The LA mean pressure increased significatively after LA appendage closure from 12.6±3.9mmHg to 15.5±5.2mmHg (p&amp;lt;0.0001, Figure). The prevalence of abnormal LA pressure was 20% (17/85) at baseline and 45% (38/85) after LA appendage closure (p=0.005). Post procedural LA pressure elevation was not related to procedure duration nor to fluid expansion volume. During a median follow-up of 364 [124–726] days, 3 (3.5%) patients died from a cardiovascular cause. Hospitalization for heart failure occurred in 6 (16%) of the 38 patients with abnormal postprocedural LA pressure, whereas no congestive episode was observed in the rest of the study population (p=0.006). Conclusion Catheter-based LA appendage occlusion induces an acute alteration of LA hemodynamics. Post procedural abnormal LA pressure may be linked to heart failure episodes in some patients. Further studies are warranted to investigate heart failure as a potential late complication of LA appendage closure. Variations of mean LA pressure Funding Acknowledgement Type of funding source: None

Left atrial appendage (LAA) occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC), it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC) and mitral valve replacement (MVR) too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS) and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

Objective To evaluate the accuracy of simulated operation before the left atrial appendage (LAA) occlusion by filed LAA model with soft materials, which is based on transesophageal three-dimensional echocardiography (3D-TEE). Methods Silica and hydrogel were mixed to imitate cardiac tissue. Silica and hydrogel mixed materials, silica and Tangoplus were subjected to mechanical detection and ultrasonic shear wave elastography (SWE). The preoperative and postoperative 3D-TEE image processing was performed on 21 patients undergoing LAA occlusion. The silica and hydrogel LAA 3D model, silicone model and Tangoplus model were acquired to evaluate the accuracy of 3D model. LAA closure was simulated using the 3D models and the compression ratio of the device in models was compared with the value measured in operation. Results The silica and hydrogel mixed materials were successfully prepared. The elastic modulus and stress-strain curve were closer to the myocardial tissue. Twenty-one 3D printing models of three materials were obtained in 21 patients based on 3D-TEE images.There was no significant difference in the anchor zone between the 3D model and 3D-TEE (P>0.05). The 3D model measurements were consistent with the 3D-TEE measurements. The compression ratios of the decive in the 3D models of all three materials were greater than those measured in operation, and the compression ratio of the device in the 3D model of silica and hydrogel materials had a better correlation with that measured in operation (r=0.900, P<0.01). Conclusions The 3D model of LAA made of silica and hydrogel material based on 3D-TEE can improve the accuracy of the LAA occlusion simulation, also can optimize the preparation of LAA occlusion. Key words: Echocardiography, transesophageal, three-dimensional; Three-dimensional printing; Left atrial appendage; Soft printing material

PERCUTANEOUS LEFT ATRIAL APPENDAGE OCCLUSION UNDER INTRA-CARDIAC ECHOCARDIOGRAPHY GUIDANCE FROM THE LEFT ATRIUM

Objective To assess the value of transesophageal echocardiography (TEE) in left atrial appendage (LAA) closer with Amplatzer Cardiac Plug (ACP). Methods Consecutive 32 atrial fibrillation patients (CHADS2≥1) with high risk bleeding underwent LAA occlusion with ACP LAA occlusion device under the guidance of TEE. Measurements of LAA anchoring area diameter (AAD) and LAA anatomical orifice diameter (AOD) including maximum, minimum values, and LAA depth on 2 dimentional TEE (2D TEE) were conducted before closer device implantation. The outcomes of LAA occlusion were analyzed. Results Among 32 patients, 27 cases achieved successful LAA occlusion, including 2 cases with peripheral leakage ≤5 mm, and 5 cases failed occlusion.Among 5 failed closed patients, 3 cases with LAA AAD≥ 30 mm, 1 case with LAA of short depth, and 1 case with anatomical variation of LAA of low position that access sheath could not be positioned in the LAA. LAA AAD maximum, minimum and LAA depth were (25.9±4.9)mm, (20.0±3.8)mm, (31.0±5.6)mm, respectively, and LAA AOD maximum, minimum diameters were (26.2±6.2)mm, (19.4±4.3)mm, respectively. Among 10 cases with LAA AAD≥30 mm, 7 cases achieved successful LAA occlusion, but 3 cases failed. The implanted device diameter was (26.4±3.8)mm, and device compression rate was (7.6±5.5)%. The coefficient of correlation between device diameter and large LAA AAD and AOD is 0.770 and 0.717, respectively. There was no complication but 1 case with pericardial effusion. Conclusions Two dimentional TEE measurements of LAA have clinical guiding significance in the selection of proper size of ACP LAA occluder. The AAD of 2D TEE has the good correlation with ACP occluder′s size, the AADs are important factors which affect the success of LAA occlusion. Key words: Echocardiography, transesophageal; Left atrial appendage; Occlusion; Amplatzer Cardiac Plug