Real-world experience with percutaneous left atrial appendage closure in patients with atrial fibrillation in China (English version)

Shaobo Shi; Tao Liu; Bin Kong; Bo Cui; Yu Liu; Gang Wu; Qinyan Zhao; Bo Yang; Congxin Huang; He Huang

doi:10.4103/ijhr.ijhr_11_20

ORIGINAL ARTICLE

Year : 2020 | Volume : 5 | Issue : 2 | Page : 19-24

Real-world experience with percutaneous left atrial appendage closure in patients with atrial fibrillation in China (English version)

Shaobo Shi, Tao Liu, Bin Kong, Bo Cui, Yu Liu, Gang Wu, Qinyan Zhao, Bo Yang, Congxin Huang, He Huang
Department of Cardiology, Renmin Hospital of Wuhan University; Cardiovascular Research Institute, Wuhan University; Hubei Key Laboratory of Cardiology, Wuhan, Hubei Province, China

Date of Submission	05-Nov-2020
Date of Decision	15-Nov-2020
Date of Acceptance	21-Nov-2020
Date of Web Publication	28-Jan-2021

Correspondence Address:
Dr. He Huang
Department of Cardiology, Renmin Hospital of Wuhan University; Cardiovascular Research Institute, Wuhan University, Wuhan; Hubei Key Laboratory of Cardiology, Wuhan 430060, Hubei Province
China

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ijhr.ijhr_11_20

Abstract

Background: This study aimed to display the real-world application of percutaneous left atrial appendage closure (LAAC) in patients with atrial fibrillation (AF) through analyzing the clinical data and operation information. Materials and Methods: AF patients who had received LAAC were selected from the database of China AF Center from November 2018 to November 2019. The clinical characteristics, surgical parameters, surgical complications, and end-of-operation rhythm were collected and analyzed. Comparisons of clinical characteristics, rate of success, and complications were performed between the simple LAAC group and the LACC combined with catheter ablation group. The study was approved by the Expert Committee of the Chinese AF Center in 2019. The study trial was registered with the Chinese Clinical Trial Registry (registration No. ChiCTR1900021250) on February 3, 2019. Results: A total of 2001 eligible patients from 175 hospitals were included in the final analysis in this real-world study, with 1178 males (58.9%). The mean age was 69.4 years (29–91 years). The proportion of paroxysmal AF was 44.6% (892 patients). The mean of CHA₂DS₂-VAS_C score congestive heart failure, hypertension, age ≥75 [doubled], diabetes mellitus, prior stroke or transient ischemic attack [doubled], vascular disease, age 65–74, female) and HAS-BLED score (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly [>65 years], and drugs/alcohol concomitantly) was 3.7 and 3.9, respectively. The main occluder was Watchman (1,276/2,001, 63.8%), surgical complications were 9.5% (190 patients), residual peri-device flow was 5.1% (102 patients), success rate was 98.9% (1979 patients), and final sinus rhythm was 63.4% (1269 patients). Compared with the simple LAAC group (1,075 patients, 53.7%), the LACC combined with catheter ablation group (926 patients, 46.3%) was younger, with a higher proportion of paroxysmal AF (624 [67.4%] vs. 268 [24.9%], P < 0.001), higher CHA₂DS₂-VAS_C score (4.0 ± 1.5 vs. 3.7 ± 1.4, P < 0.001), lower HAS-BLED score (3.6 ± 1.6 vs. 3.9 ± 1.2, P < 0.001), lower residual peri-device flow (26 [2.8%] vs. 76 [7.1%], P < 0.001), and higher sinus rhythm after surgery (96.7% vs. 34.8%, P < 0.001). However, the rates of success (99.2% vs. 98.7%, P = 0.275) and complications (9.7% vs. 9.3%, P = 0.670) were similar. Conclusion: There is a high success rate and low incidence of severe complications in the real-world use of LAAC in patients with AF. LAAC combined with catheter ablation is also safe and effective due to lower complications and higher proportion of sinus rhythm.

Keywords: Atrial fibrillation, catheter ablation, left atrial appendage closure, real-world experience

How to cite this article:
Shi S, Liu T, Kong B, Cui B, Liu Y, Wu G, Zhao Q, Yang B, Huang C, Huang H. Real-world experience with percutaneous left atrial appendage closure in patients with atrial fibrillation in China (English version). Int J Heart Rhythm 2020;5:19-24

How to cite this URL:
Shi S, Liu T, Kong B, Cui B, Liu Y, Wu G, Zhao Q, Yang B, Huang C, Huang H. Real-world experience with percutaneous left atrial appendage closure in patients with atrial fibrillation in China (English version). Int J Heart Rhythm [serial online] 2020 [cited 2023 Jun 3];5:19-24. Available from: https://www.ijhronline.org/text.asp?2020/5/2/19/308169

This manuscript is an English version based on Shi S, Liu T, Kong B, Cui B, Liu Y, Wu G, Zhao Q, Yang B, Huang C, Huang H. Real-world experience with percutaneous left atrial appendage closure in patients with atrial fibrillation in China. Chin J Cardiac Arrhyth 2020;24(3):265-269. DOI: 10.3760/cma.j.cn.113859-20200402-00082. The second publication of this manuscript has obtained the permission from Chinese Journal of Cardiac Arrhythmias.

Introduction

Since the first clinical application of percutaneous left atrial appendage closure (LAAC) in August 2001, it has been proven to be as effective as warfarin in preventing thromboembolic events in patients with atrial fibrillation (AF).^[1],[2] In recent years, LAAC has been successively launched in many China's medical centers. The number of LAAC surgeries has increased rapidly, and the characteristics of patients, surgical parameters, and outcomes have also changed, which may present new features.^[3],[4] This study analyzed the application data of LAAC obtained from the database of the China AF Center from November 2018 to November 2019 and explored its current application status in China to provide information for further optimizing the surgical management of LAAC.

Materials and Methods

Study design

The present observational study was part of the “Chinese Atrial Fibrillation Real World Study” and aimed to assess the application status of LAAC. Briefly, in the database of the China AF Center (which design to collect AF diagnosis and treatment data from the construction unit of the Chinese AF Center and was a single-disease database of AF aimed at improving the comprehensive management of AF in China, the website www.china-afc.org), we used “left atrial appendage closure surgery” as the keyword to search data from November 2018 to November 2019 and collected relevant hospitalization data and surgical information. The study was approved by the Expert Committee of the Chinese AF Center in 2019 and conducted in accordance with the Declaration of Helsinki. The study protocol was registered with the Chinese Clinical Trial Registry (registration No. ChiCTR1900021250) on February 3, 2019.

Inclusion and exclusion criteria

Inclusion criteria were as follows: age ≥18 years old; confirmed AF; the indication for surgery is the prevention and treatment of AF-related thromboembolic events. Exclusion criteria included incomplete medical data, errors, repetitions, and other cases that affect data analysis.

Data extraction and sorting

The following data were extracted: demographic information (age, gender, height, and weight), history of disease, CHA₂DS₂-VAS_C score (congestive heart failure, hypertension, age ≥75 [doubled], diabetes mellitus, prior stroke or transient ischemic attack [doubled], vascular disease, age 65–74 years, female) and HAS-BLED score (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly [>65 years], and drugs/alcohol concomitantly), brain natriuretic peptide (BNP), N-terminal brain natriuretic peptide (NT-proBNP), creatinine clearance, results of cardiac echocardiographic, antithrombotic drugs, surgical parameters (e.g., anesthesia, X-ray exposure, LAA structure, occluder model, and occlusion process parameters), surgical complications, and heart rhythm before and after the operation of LAAC. Two researchers independently collated the data. If the conclusions are inconsistent, another researcher will join the discussion until a consistent conclusion is achieved.

Body mass index (BMI) and surgery success rate were calculated according to the formula. The success rate of occlusion in this study was defined as the immediate success rate at the end of the operation, which was confirmed by contrast and transesophageal echocardiography that there was no forward and reverse blood flow through the occluder, and the residual peri-device flow did not exceed 3 mm.

Grouping

According to the operation method, the included patients were divided into a simple LAAC group and a LAAC combined with catheter ablation group. Patients were not required to give informed consent to the study because anonymous data used were obtained after each patient agreed to treatment by written consent , which was approved by the Expert Committee of the Chinese AF Center.

Statistical analysis

Data analysis was performed using SPSS 21.0 software (IBM, Armonk, NY, USA). Continuous variables were expressed as the mean ± standard deviation or median (interquartile range), and categorical variables were expressed as number (percentage). Comparisons between groups were conducted using independent-samples t-test, nonparametric rank-sum test, Fisher's exact test, or Chi-square test. P < 0.05 was considered statistically significant.

Results

Clinical characteristics

[Figure 1] depicts the flowchart for participant selection. Briefly, a total of 2029 patients who had undergone LAAC in 175 hospitals were initially screened, and 28 cases were excluded due to missing information, data errors, and duplication of data. Finally, 2001 cases were included in the final analysis. The mean age of the included patients was 69.4 years (29–91 years), and male patients accounted for 58.9% (1178/2001). The incidence of paroxysmal AF was 44.6% (892/2001), the average CHA₂DS₂-VAS_C score was 3.7, and the average HAS-BLED score was 3.9. Simple LAAC accounted for 53.7% (1075/2001), and 46.3% (926/2001) of patients underwent LAAC combined with catheter ablation surgery. The clinical features are shown in [Table 1].

Figure 1: Flowchart for participant selection. LAAC: Left atrial appendage closure

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Table 1: Demographic and clinical characteristics and antithrombotic treatment of 2001 included cases

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Compared with the simple LAAC group, patients in the LAAC combined with catheter ablation group were younger and had higher BMI, proportion of vascular diseases, and CHA₂DS₂-VAS_C score, but lesser proportion of chronic heart failure, lower HAS-BLED score, smaller proportion of HAS-BLED score (>3 points), smaller median of BNP and NT-proBNP, smaller left atrium diameter, and more usage of non-Vitamin K antagonist oral anticoagulants. The other clinical characteristics of the two groups were similar [Table 1].

Surgical data

The most common shape of the LAA was the single lobe (940/2001, 46.9%), and the main occluders were Watchman occluder (1276/2,001, 63.8%) and LAmbre occluder (508/2001, 25.4%). The operation success rate was 98.9% (1979/2001). Compared with the simple LAAC group, the LAAC combined with catheter ablation group presented shorter activated whole blood coagulation time and smaller LAA depth, orifice diameter, occluder anchor area diameter, and compression ratio, but higher frequency of occluder release, and less proportion of occluder recovery. The X-ray exposure time, exposure volume, left atrial pressure, number of occluder replacement, and surgical success rate were similar between the two groups [Table 2].

Table 2: Comparison of surgery-related parameters in 2001 included cases

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Surgical complications and heart rhythm

The residual peri-device flow was the most common surgical complication (102/2,001, 5.1%), with an average diameter of 2.1 mm, followed by vascular complications, a small amount of pericardial effusion, cardiac tamponade requiring drainage, embolic stroke, and peripheral thromboembolism. There were no serious complications such as device detachment, severe hemorrhage, arrhythmia, pulmonary artery stenosis, esophagoatrial fistula, and death occurred [Table 3]. Compared with the simple LAAC group, the LAAC combined with catheter ablation group had fewer residual peri-device flows. However, the incidence of other complications was similar between the two groups [Table 3]. Preoperative sinus rhythm and AF accounted for 38.8% and 61.2%, respectively. After surgery, the proportion of sinus rhythm increased to 63.4% and the proportion of AF decreased to 36.6%. In the LAAC combined with catheter ablation group, sinus rhythm was predominant before and after surgery, while AF was still predominant in the simple LAAC group. The composition ratio of the heart rhythm between the two groups was different. The sinus rhythm ratio was significantly higher in the LAAC combined with catheter ablation group than that in the simple LAAC group (at the end of operation: 96.7% vs. 34.8%, P < 0.001).

Table 3: Complications in 2001 included cases

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Discussion

The present study showed that LAAC has been gradually popularized in China, followed by low surgical complications and high surgical success rate. These results demonstrated a good safety and effectiveness of LACC. Compared with simple LAAC, LAAC combined with catheter ablation surgery does not increase the surgical complications and has the combined advantages of restoring sinus rhythm and reducing the risk of thrombosis, which would produce long-term benefits for patients.

LAAC has been proven to be effective as warfarin in preventing thrombotic events in patients with non-valvular AF.^[1],[2] Since 2012, the European Society of Cardiology began to recommend the usage of LAAC in patients with non-valvular AF, who have high thromboembolic risk and long-term anticoagulation contraindications.^[5],[6],[7]

Based on the increasing evidence-based studies and the improvement of the safety of surgery, the applicable population of LAAC has expanded in recent years. The consensus of experts in the management of AF in China recommends that LAAC be used in patients with non-valvular AF, who have CHA₂DS₂-VASC ≥2 points (women ≥3 points), and one of the following conditions: not be suitable for long-term standard anticoagulation therapy; thromboembolic events still occur on the basis of long-term standard anticoagulation therapy; and HAS-BLED score ≥3 points.^[8],[9]

In recent years, issues on the application of LAAC have been extensively discussed and actively explored, and certain clinical experience has been obtained in China.^[10] In particular, a prospective, multicenter clinical study conducted in 2015 using LAmbre occluder, which produced in China and had completely independent intellectual property rights, provided Chinese data for the application of LAAC. The study included 153 patients with non-valvular AF in 12 centers, which showed the incidence of stroke in patients treated with LAAC is 80% lower than the predicted rate.^[11] With the increase in the number of hospitals and patients performed LAAC in China, the population characteristics and surgical features of patients have also changed. First of all, in terms of clinical characteristics, the most common comorbidities in patients undergoing LAAC are hypertension and ischemic stroke, both of whom are at high risk of stroke, suggesting that the surgical indications for LAAC in China are strictly controlled. Second, in terms of surgery, LAAC combined with catheter ablation surgery reached 46.3%. Since Swans firstly tried LAAC combined with catheter ablation surgery in 2012, doctors in China have also been actively exploring, showing that the level of treatment of AF has kept pace with the world.^[12],[13] Finally, in terms of surgical efficacy and safety, the surgical success rate is high, and the proportion of residual peri-device flow >3 mm is only 1.1%. Interestingly, the lower residual peri-device flow rate in the LAAC combined with catheter ablation group may be related to the following factors: compared with the simple LAAC group, the LAAC combined with catheter ablation surgery patients are younger, have a higher proportion of paroxysmal AF, and have a smaller left atrium, shallower LAA depth, and smaller orifice diameter, indicating that the atrial remodeling in this group is lighter, which may be the main reason for the lower residual peri-device flow rate; it is also related to the surgical experience because the LAAC combined with catheter ablation surgery is commonly conducted in experienced hospitals. Finally, the overall incidence of stroke and cardiac tamponade related to surgery is 0.1%–0.2%, respectively, showing a sufficient safety.

In terms of strategic choice, LAAC combined with catheter ablation surgery can solve the two major problems of AF management in suitable patients, especially in paroxysmal AF and high stroke risk population. On the one hand, it can restore sinus rhythm and relieve AF-related symptoms, and prevent AF-related stroke.^{[14],[15],[16]}

It has also been found in several studies that catheter ablation can better maintain sinus rhythm, which will help reduce the risk of stroke.^[17] In patients with AF originating from the LAA, or a catheter ablation that requires electrical isolation of the LAA, choosing the LAAC combined with catheter ablation surgery is an important strategy to avoid stroke after the electrical isolation of LAA. These suggest that simple LAAC or LAAC combined with catheter ablation provides a new treatment for non-valvular AF with a high risk of thrombosis.

Limitations

Although this study included a large number of patients from multicenters, it has several limitations. First, the enrolled cases come from the real world, and this study lacks a randomized, double-blind design, so the research results need to be interpreted carefully. Second, the case selection process may be biased in this cross-sectional study, and it is necessary to select cases continuously from the medical record system. Finally, long-term clinical outcomes need to be further investigated in future.

Conclusion

LAAC treatments for patients with non-valvular AF have been gradually popularized in the past year. The selected cases for surgery are strict, the success rate is high, and the surgical complications are low in China. Of course, the long-term efficacy and safety of LAAC require long-term follow-up, and even prospective, double-blind, controlled studies, to obtain more detailed and rigorous application data in China, and provide scientific data for better standardization and promotion of LAAC.

Institutional review board statement

The study was approved by the Expert Committee of the Chinese AF Center in 2019 and conducted in accordance with the Declaration of Helsinki.

Declaration of patient consent

The authors certify that they have obtained all appropriate consent from patients. In the forms the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity.

Financial support and sponsorship

This work was supported by the National Natural Science Foundation of China (No. 81800447), the Science Foundation of Hubei Province (No. 2017CFB204), and the Major Program of Technological Innovation of Hubei Province (No. 2016ACA153).

Conflicts of interest

There are no conflicts of interest.

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