Epicardial Left Atrial Appendage Research Articles

Augmented Reality-Supported Totally Thoracoscopic Epicardial Left Atrial Appendage Closure in a Patient With Liver Cirrhosis.

Augmented Reality-Supported Totally Thoracoscopic Epicardial Left Atrial Appendage Closure in a Patient With Liver Cirrhosis.

Left atrial appendage clipping during hybrid atrial fibrillation ablation: a very long-term, single-center experience

Abstract Background/introduction Epicardial left atrial appendage (LAA) clipping is an effective strategy for stroke prophylaxis in high thromboembolic (TE) and bleeding risk patients with atrial fibrillation (AF). In addition to LAA exclusion from systemic circulation, clipping promotes concomitant appendage isolation, which might have positive impacts on arrhythmia control. Purpose The aim of this study was to report safety, success rate, and the long-term clinical outcomes of LAA clipping in a large cohort of AF patients undergoing concomitant hybrid ablation. Methods Consecutive patients undergoing hybrid AF ablation between 2013 and 2023 were enrolled. Hybrid ablation was performed in a one-step procedure consisting of thoracoscopic epicardial radiofrequency (RF) ablation followed by endocardial mapping and ablation, if needed. Ablation lesion set included pulmonary vein (PV) and posterior wall (PW) isolation, as well as RF applications to the LAA/posterolateral ridge. LAA clipping was performed via Atriclip exclusion system (Atricure, Inc., The Nederlands) after epicardial ablation. Additional endocardial lesions were performed in case of incomplete epicardial ablation or at physician’s discretion. Results A total of 130 patients were included (mean age: 65±9.4; 72.3% males); among them, 19.2% and 55.4% had persistent or long-standing persistent AF, respectively. Mean CHA2DS2-VASC and HAS-BLED were 3.1±1.1 and 2.3+-0.5. Five patients (3.8 %) had absolute contraindication to long-term oral anticoagulation, 3 (2.3%) had previous life-threatening bleeding events, 17 (13.1%) had a previous TE event. The final clip size was 35mm in 90.7% cases. Acute success was achieved in 97.7%; failure was due to LAA size (n=1), proximity to phrenic nerve (n=1), or bypass graft (n=1). One patient had incomplete occlusion due to a large secondary lobe, which required a second clip. No periprocedural complications related to clipping were documented. At a mean follow-up of 51±35 months, one (0.8%) patient had a stroke and 3 (2.3%) a transient ischemic attack (4 events per 552 patient/years; 0.7%). One patient had a microreentrant tachycardia mapped from the area near the LAA clipping. Conclusion In a large cohort undergoing hybrid AF ablation, epicardial LAA clipping was safe and highly successful. Acute failure was rare and due to LAA morphology or proximity to phrenic nerve and bypass graft. Thromboembolic event rate was very low.

Epicardial left atrial appendage clipping versus direct oral anticoagulant to reduce stroke risk in non-paroxysmal atrial fibrillation (LAA-CLIP): rationale, design and study protocol for a multicentre randomised controlled trial

IntroductionThe prevalence of atrial fibrillation (AF) is increasing globally, and stroke prevention is the key to reduce the morbidity and mortality related to AF. Currently, direct oral anticoagulants (DOACs) are...

Associations of the left atrial epicardial fat thickness with the thrombosis prevalence and left atrial appendage flow velocity in patients with persistent non-valvular atrial fibrillation

Aim. To study the associations of the left atrial epicardial fat (LAEF) thickness with the thrombosis prevalence and left atrial appendage (LAA) flow velocity in patients with persistent non-valvular atrial fibrillation (AF).Material and methods. Transesophageal echocardiography in 475 patients with persistent non-valvular AF (men 58,9%, age 64,0 (58,3-70,0) years) assessed LAA flow velocity, interatrial septum and left lateral ridge thickness. Their average thickness was used to estimate the LAEF volume.Results. LAA thrombus was detected in 42 (8,8%) patients. LAA flow velocity without thrombus was 32,0 (26,0-39,0) cm/s, with thrombus — 20,0 (14,0-25,8) cm/s (p<0,0001). Depending on the LAEF thickness, patients were divided into 3 tertile groups: group 1 (n=168) — 5,6-7,4 mm, group 2 (n=154) — 7,45-8,2 mm, group 3 (n=153) — 8,25-10,9 mm. In group 1, no thrombus was detected, in group 2, thrombus was detected in 2 (1,3%) patients, in group 3 — in 40 (26,0%) patients (p<0,0001). In the absence of LAA thrombus, flow velocity in the selected groups did not differ (32,0 (26,0-39,0) cm/s, 31,0 (26,0-7,8) cm/s and 31,5 (25,0-40,0) cm/s, (p=0,9514)).Conclusion. EFL thickness, calculated as the average of interatrial septum and left lateral ridge thickness, can be used to study the relationship between epicardial obesity and LAA thrombosis in patients with AF. In patients with persistent non-valvular AF with a LAEF thickness >8,2 mm, LAA thrombosis occurs more than 40 times more often than in patients with a lower LAEF thickness. The influence of LAEF thickness on LAA flow velocity was not revealed in the pre­sent study.

Minimally invasive epicardial surgical left atrial appendage exclusion for atrial fibrillation patients at high risk for stroke and for bleeding

BackgroundAtrial fibrillation (AF) patients at high risk for stroke and for bleeding may be unsuitable for either oral anticoagulation or endocardial left atrial appendage (LAA) occlusion. However, minimally invasive, epicardial left atrial appendage exclusion (LAAE) may be an option. ObjectiveThe purpose of this study was to evaluate outcomes of LAAE in high-risk AF patients not receiving oral anticoagulation. MethodsA retrospective analysis of Medicare claims data was conducted to evaluate thromboembolic events in AF patients who underwent LAAE compared to a 1:4 propensity score–matched group of patients who did not receive LAAE (control). Neither group was receiving any oral anticoagulation at baseline or follow-up. Fine-Gray models estimated hazard ratios and evaluated between-group differences. Bootstrapping was applied to generate 95% confidence intervals (CIs). ResultsThe LAAE group (n = 243) was 61% male (mean age 75 years). AF was nonparoxysmal in 70% (mean CHA2DS2-VASc score 5.4; mean HAS-BLED score 4.2). The matched control group (n = 972) had statistically similar characteristics. One-year adjusted estimates of thromboembolic events were 7.3% (95% CI 4.3%–11.1%) in the LAAE group and 12.1% (95% CI 9.5%–14.8%) in the control group. Absolute risk reduction was 4.8% (95% CI 0.6%–8.9%; P = .028). Adjusted hazard ratio for thromboembolic events for LAAE vs non-LAAE was 0.672 (95% CI 0.394–1.146). ConclusionIn AF patients not taking oral anticoagulation who are at high risk for stroke and for bleeding, minimally invasive, thoracoscopic, epicardial LAAE was associated with a lower rate of thromboembolic events.

Postoperative Coagulation Changes in Patients after Epicardial Left Atrial Appendage Occlusion Varies Based on the Left Atrial Appendage Size.

Left atrial appendage occlusion affects systemic coagulation parameters, leading to additional patient-related benefits. The aim of this study was to investigate the differences in coagulation factor changes 6 months after epicardial left atrial appendage occlusion in patients with different LAA morphometries. This is the first study to analyze these relationships in detail. A prospective study of 22 consecutive patients was performed. Plasminogen, fibrinogen, tPA concentration, PAI-1, TAFI and computed tomography angiograms were performed. Patients were divided into subgroups based on left atrial appendage body and orifice diameter enlargement. The results of blood tests at baseline and six-month follow-up were compared. In a population with normal LAA body size and normal orifice diameter size, a significant decrease in analyzed clotting factors was observed between baseline and follow-up for all parameters except plasminogen. A significant decrease between baseline and follow-up was observed with enlarged LAA body size in all parameters except TAFI, in which it was insignificant and plasminogen, in which a significant increase was observed. Occlusion of the left atrial appendage is beneficial for systemic coagulation. Patients with a small LAA may benefit more from LAA closure in terms of stabilizing their coagulation factors associated with potential thromboembolic events in the future.

Combination of percutaneous left appendage epicardial ligation and endo-epicardial atrial fibrillation ablation.

Atrial fibrillation (AF) is the main cause of cardioembolic stroke. In high-bleeding-risk patients, long-life anticoagulation therapy is not permitted, and left atrial appendage (LAA) closure may be considered. LAA is also a critical substrate for AF. Epicardial LAA occlusion has several advantages: LAA ligation results in a favorable electrical and structural atrial remodeling, which decreases AF recurrence. Endocardial ablation alone is not efficient for all patients, and new evidence shows better outcomes in patients affected by persistent AF after a combined hybrid endo-epicardial ablation. Considering the synergic potential of these techniques, in this case series, they were both combined in a single procedure. We describe the treatment of 5 patients referred for refractory AF ablation and LAA closure. All patients had high thrombotic and previous major hemorrhage, with relative contraindication to life-long therapy with anticoagulation. A combined procedure of LAA ligation and endo-epicardial ablation was scheduled with short-term anticoagulation. LAA closure was performed with an epicardial approach using the LARIAT system. Then, LA mapping and ablation were performed, endocardially and then epicardially.All procedures were concluded without complications.At follow-up, in all patients, transesophageal echocardiography showed the complete occlusion of the LAA; therefore, anticoagulation therapy was interrupted. All patients were asymptomatic, and in the sinus rhythm, no hemorrhage or ischemic events occurred. The combination of percutaneous LAA ligation and endo-epicardial ablation was revealed to be feasible and safe and might represent a new approach for the treatment of refractory AF in patients with indication of LAA occlusion.

Coronary Obstruction Following Epicardial Left Atrial Appendage Closure: A Rare Entity

Coronary Obstruction Following Epicardial Left Atrial Appendage Closure: A Rare Entity

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture)

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

Thoracoscopic Left Atrial Appendage Exclusion for Atrial Fibrillation Patients Intolerant to Anticoagulation.

Outcomes associated with isolated epicardial left atrial appendage (LAA) exclusion in atrial fibrillation (AF) patients with a contraindication or intolerance to anticoagulation are not clearly defined, especially in patients with prior stroke. This study evaluated the perioperative safety, medication use, and stroke outcomes for isolated thoracoscopic LAA exclusion for stroke prevention. A single-center retrospective study was performed of adults undergoing isolated thoracoscopic LAA exclusion with an epicardial exclusion device without a concomitant surgical procedure. Descriptive statistics were performed. Twenty-five patients met the inclusion criteria. The cohort was 68% male (n = 17) with a mean age of 76.4 ± 6.5 years, a mean preoperative CHA2DS2-VASc score of 4.2 ± 1.4, and a mean preoperative HAS-BLED score of 2.68 ± 1.03. Seventeen patients (68%) had nonparoxysmal AF. There were 11 patients with intolerance of anticoagulation due to intracranial hemorrhage (44%), 6 due to gastrointestinal bleeding (24%), and 4 due to genitourinary bleeding (16%). All procedures were performed thoracoscopically with 100% technical success-the mean LAA stump length was 5.5 ± 2.3 mm on intraoperative transesophageal echocardiography. The median hospital length of stay was 2 (interquartile range [IQR] 1, 6.5) days. The median follow-up time was 430 (IQR 125, 972) days. During follow-up, 1 patient with cerebral angiopathy had temporary neurologic deficits at an outside institution, with brain imaging showing no evidence of ischemic injury. There were no other thromboembolic events over the 38.8 postoperative patient-years examined. All patients were off anticoagulation at last follow-up. This study shows the perioperative safety, technical success, freedom from anticoagulation, and stroke outcomes of isolated thoracoscopic LAA exclusion in patients with AF at high risk for thromboembolic disease.

The Significant Decrease of Serum Sodium and Blood Pressure following Thoracoscopic Left Atrial Appendage Clipping

Background: The epicardial left atrial appendage (LAA) closure may induce unwanted natriuretic peptides caused by the isolation of the LAA from circulation. Thus, this study aims to explore the possible change of blood pressure and electrolytes following the procedure. Methods: This was a retrospective, observational study including 52 atrial fibrillation (AF) patients with a history of thrombolic stroke who underwent thoracoscopic LAA clipping. Electrolytes, blood pressure, and brain natriuretic peptide were measured before the procedure, immediately after the device release, on the 1st day, the 2nd day postoperation, and discharge. Results: Thirty-five (66.04%) patients’ serum sodium level decreased by more than 4 mmol/L during 48 h postoperation. The systolic blood pressure at discharge was significantly lower than the baseline level (118.99 ± 12.29 mmHg vs. 122.93 ± 13.82 mmHg, p = 0.034), while the diastolic blood pressure was not significantly different to the baseline (78.00 ± 7.39 mmHg vs. 77.22 ± 7.72 mmHg, p = 0.502). A significant increase in brain natriuretic peptide was observed postoperatively, although it showed a trend of decline at discharge. Conclusion: Epicardial LAA clipping could induce an acute decrease in serum sodium postoperation, which indicates to the surgeons that the postoperative intake fluid amounts and serum sodium level management should be more appropriate. The decrease in systolic blood pressure indicates the possibility of expanding the benefits that patients received from LAA clipping, though further studies are needed to determine if this phenomenon is persistent in the long-term follow-up.

Anterior Pathway for Epicardial Left Atrial Appendage Clip Occlusion During Minimally Invasive Atrioventricular Valve Surgery.

The left atrial appendage occlusion (LAAO) by endocardial suture is sometimes inadequate and thrombogenic with uncertain electrical competence. Moreover, epicardial LAAO clip placement through the transverse sinus can be technically challenging during minimally invasive atrioventricular valve surgery. Here, we describe our new endoscopic technique via an anterior access pathway in 5 patients with concomitant atrial fibrillation using an epicardial clip device (AtriClip Pro 1 or AtriClip Pro 2, AtriCure, Mason, OH, USA) for LAAO. The LAAO was successful in all patients without residual perfusion and surgical complications. Epicardial LAAO by clip via the anterior access pathway represents a novel and feasible endoscopic technique for minimally invasive atrioventricular valve surgery.

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

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. 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. 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). 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.

Left Atrial Appendage Morphology and Course of the Circumflex Artery: Anatomical Implications for Left Atrial Appendage Occlusion Procedures.

The aim of this study was to evaluate the anatomic topography of the circumflex artery (Cx) and left atrial appendage (LAA) and to determine the safety zones for epicardial LAA closure and LAA occlusion procedures. The left coronary artery was segmented and visualized from 116 computed tomography angiography scans. Four points were located on the Cx portion periappendicularly, starting from the entry point. The landing zone plane was defined as parallel to the LAA orifice at the level of the beginning of the periappendicular course of the Cx, and the plane of the neck bend was located at the end of the LAA neck. A distance smaller than 2 mm was considered a dangerous distance. The distance between the Cx and the LAA landing zone was 4.3 ± 2 mm. The distance between the Cx and the LAA neck bend was 5.1 ± 2.2 mm. The distance between the Cx and the LAA bottom surface was 5.8 ± 2.9 mm. In 38.8% of patients, at least 1 distance between Cx and LAA was smaller than 2 mm in at least 1 dimension. These distances occurred in 30.2% of the LAA landing zone dimensions, 19.8% of LAA neck bend dimensions, and 11.2% of the LAA bottom surface distances. The study showed that most dangerous distances (30.2%) occurred in the LAA landing zone dimension. The data showed that landing zones more distal from the orifice of the LAA are safer in terms of Cx damage. Therefore, LAA closure should always be performed with caution, to avoid iatrogenic complications.

Metabolic effects of the left atrial appendage exclusion (the heart hormone study).

The effect of epicardial left atrial appendage (LAA) occlusion therapy on lipid and glucose metabolism in atrial fibrillation (AF) patients over the long-term follow-up are unclear. In a single-center prospective observational study, 60 patients with longstanding persistent AF with cardiovascular risk factors had undergone an epicardial exclusion procedure. Anthropometric parameters and glucose, glycated hemoglobin (HbA1c), insulin, leptin, adiponectin, free fatty acids, beta-hydroxybutyrate, and total cholesterol levels were evaluated on fasting at baseline before the procedure and compared with levels at 24 h, 7 days, 1, 3, 6, and 24 months follow the procedure. The mean age of the patients was 67.5 ± 8.1. Insulin levels significantly increased at 7 days, 1, 3, 6, 12, and 24 months follow-up. The leptin levels showed a significant increase in 6, 12, and 24 months when compared to baseline. Whereas the adiponectin levels showed a significant decrease at 3, 6, 12, and 24 months when compared to baseline levels. In patients with the epicardial procedure, when compared to baseline, glucose, glycated hemoglobin, total cholesterol, and beta-hydroxybutyrate levels did not show any significant changes at baseline and 24 months follow-up. The epicardial exclusion ligation in AF patients was associated with significant changes in insulin, leptin, and adiponectin over long follow-up.

Left atrial epicardial adipose tissue is closely associated with left atrial appendage flow velocity in patients with nonvalvular atrial fibrillation

Epicardial adipose tissue (EAT) can play an important role in the occurrence and development of atrial fibrillation and stroke. In this study, we explored the relationship between left atrial epicardial adipose tissue (LA-EAT) and left atrial appendage flow velocity (LAA-FV) in patients with nonvalvular atrial fibrillation (NV-AF). A total of 145 patients with NV-AF who underwent their first radiofrequency ablation were enrolled. They underwent left aortopulmonary vein computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before AF ablation. Left atrial (LA) electroanatomical mapping was performed intraoperatively to assess left atrial voltage. Univariate regression analysis showed that LAA-FV was lower in patients with a low voltage zone (LAA-FV; 35.02 ± 10.78 cm/s vs. 50.60 ± 12.17 cm/s, P < 0.001). A multiple linear regression model showed that the left atrial low voltage zone (β = − 0.311 P < 0.001), LA-EAT volume (β = − 0.256 P < 0.001), left atrial appendage shape (β = − 0.216 P = 0.041), LAVI (β = − 0.153 P = 0.041), and type of atrial fibrillation (paroxysmal vs. persistence) (β = − 0.146 P < 0.048) were independent predictors of LAA-FV. In NV-AF patients, the increase in LA-EAT volume is related to the decrease in LAA-FV.

Thoracoscopic AF ablation in situs inversus dextrocardia with interrupted inferior vena cava continuation in azygos vein

IntroductionSitus inversus totalis, dextrocardia with interrupted inferior vena cava, and azygos vein continuation concomitant with symptomatic atrial fibrillation requiring ablation. This case was deemed not suitable for percutaneous ablation due to anatomic variations and the lack of case reports in the literature.Methods and ResultsWe performed bilateral thoracoscopic epicardial ablation and epicardial left atrial appendage exclusion. The direct vision allowed for a complete box lesion set with bipolar radiofrequency device. Patient remained in sinus rhythm at the 12‐months follow‐up.ConclusionSurgical thoracoscopic epicardial ablation is safe and effective also in congenital defects. Multidisciplinary expertise can offer minimally invasive ablation treatments.

Real world outcomes of minimally invasive epicardial surgical left atrial appendage exclusion in atrial fibrillation patients with high risk of stroke and bleeding

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): AtriCure, Inc Introduction The left atrial appendage (LAA) is the site of thrombus formation in patients with atrial fibrillation (AF) and first line therapy for reducing the risk of stroke is oral anticoagulation (OACs). A subset of patients with AF carry a very high risk of stroke and bleeding and are ineligible for OAC and percutaneous LAA occlusion; these patients may be suitable for minimally invasive thoracoscopic epicardial surgical LAA exclusion (LAAE) which can be used with a wide variety of LAA morphologies with a ~98% rate of complete exclusion. While use of LAAE is well studied as a concomitant procedure, there are relatively few data on its use as a stand-alone procedure. Purpose To compare real-world outcomes of LAAE versus no-LAAE in AF patients at high risk of stroke and bleeding who are not on OACs. Methods We performed an analysis of Medicare beneficiaries with AF who were not on OACs and received LAAE (ICD10-PCS code 02L74CK, Oct 2015 – Dec 31, 2017) in the absence of a concomitant surgical or catheter AF ablation procedure. Patients were propensity-matched (1:4) to otherwise similar patients who did not receive LAAE (control), using age, gender, race, region, AF type, CHA2DS2-VASc, HAS-BLED, and co-morbidities. The primary endpoint was hospital readmission for a thromboembolic event (ischemic stroke, systemic embolism, or transient ischemic attack). Kaplan Meier event rates were calculated and 95% CI were generated via bootstrapping. Results A total of 243 patients who underwent LAAE and 1.7M control patients met study criteria. In the matched cohort, the mean age was 75 years, 61% were men, 77% had non-paroxysmal AF, and the mean CHADS2-VASC and HAS-BLED scores were 5.5 and 4.2, respectively. The 1-year rate of thromboembolism in the LAAE and control arms were 7.3% (95% CI 4.3% -10.9%) and 13.6 (95% CI 11.0% -16.4%) (Figure), respectively, with an absolute and relative risk reduction of 6.2% (95% CI 2.0-10.3, p-value=0.001, NNT 17) and 0.54 (95% CI 0.29-0.68, p=0.001). Conclusion Among high-risk AF patients who were not on OAC, LAAE was associated with a clinically meaningful and significantly lower risk of TE. Additional studies are needed to confirm these finding.

Long Term Impact of Epicardial Left Atrial Appendage Ligation on Systemic Hemostasis: LAA HOMEOSTASIS-2.

Background: Recent data suggest that epicardial left atrial appendage closure (LAAC) is associated with several short-term neurohormonal effects. However, the long-term effects are currently unknown. Objective: To investigate the effects of percutaneous epicardial left atial appendage (LAA) exclusion using LARIAT on neurohormonal profiles at long-term follow-up. Methods: In a prospective single centre study, 60 patients with long-standing, persistent atrial fibrillation (AF) LARIAT were treated. The major hormones of the adrenergic system, renin-angiotensin-aldosterone system (RAAS), and natriuretic peptides were assessed before the intervention and at regular intervals during the following two years. Results: In patients with epicardial LAAC, atrial natriuretic peptide (ANP) levels were significantly increased from baseline at 24 h and decreased at 7 days, 1 month, and 3 months, while remaining unchanged at 12 and 24 months. Noradrenaline levels were significantly lower at 24 h, 7 days, 1 month, 6 months, 12 months, and 24 months, while epinephrine levels decreased significantly at 1 month, 6 months, 12 months, and 24 months. Plasma renin activity significantly decreased at 7 days, 1 month, 6 months, 12 months, and 24 months, while aldosterone levels significantly decreased at 6 months, 12 months, and 24 months. Endothelin-1 and vasopressin showed a significant increase and decrease, respectively, at 24 h, 7 days, 1 month, 6 months, 12 months, and 24 months. There was also a significant decrease in systolic and diastolic blood pressure at 3 months, 6 months, 1 year, and 2 years after the intervention. Conclusions: Epicardial LAAC in AF patients is associated with persistent neurohormonal changes favouring blood pressure reduction.

Abstract 10920: Cost-Effectiveness of Pulmonary Vein Isolation with Epicardial Left Atrial Appendage Ligation for the Treatment of Non-Paroxysmal Atrial Fibrillation

Introduction: Electrical isolation of the left atrial appendage (LAA) using percutaneous epicardial ligation may improve catheter ablation outcomes for non-paroxysmal atrial fibrillation (AF) patients. Little is known regarding the cost effectiveness of this procedure. Hypothesis: We hypothesized that cost-effectiveness between pulmonary vein isolation (PVI) + LAA epicardial ligation using a percutaneous LARIAT ® Suture Delivery Device would be cost effective (CE) compared to PVI alone over 5 years. Methods: A Markov model simulated outcomes for a population with annual stroke risk of 4.6% (CHA 2 DS 2 -VASc score 3). Model inputs for procedure efficacy, stroke and bleed events, health utility, and event costs were estimated from literature. Procedure costs from Medicare rates were used. The model had a 5-year time-horizon and US payer perspective. Univariate and probabilistic sensitivity analyses (PSA) were performed. Outcomes were health care costs and quality-adjusted life-years (QALYs). In the base case, PVI + LAA ligation efficacy from published studies was 67% after 1-year, with an estimated 25% oral anticoagulant (OAC) utilization in PVI + LAA ligation patients in normal sinus rhythm 13-60 months after the index procedure. Cost effectiveness thresholds were evaluated with alternative PVI + LAA ligation efficacy and OAC utilization rates, including 1-year PVI + LAA ligation efficacies of 67%, 70%, 75%, and 80% and OAC utilization of 20-60%. Results: In the base case, PVI + LAA ligation had a mean 5-year cost of $72,865 with 3.25 QALYs and PVI alone had mean cost of $69,936 with 3.19 QALYs. The incremental cost-effectiveness ratio was $46,716; PVI + LAA ligation was CE at $50,000 per QALY gained. In PSA, 64% and 82% of simulations were CE at $50,000 and $100,000 per QALY gained, respectively. In various scenarios, procedure efficacy of 75% combined with OAC utilization of 50% or below yielded CE at $50,000 per QALY gained. Reduction of OAC utilization to 30% yielded CE at $50,000 per QALY gained, regardless of efficacy. Conclusions: In the base case, PVI + LAA ligation was CE at $50,000 per QALY gained when compared to PVI alone. The CE threshold for efficacy was 75% and OAC utilization was 30%. Cost savings were driven by reductions in OAC use and increased efficacy.