A Randomized Trial of Preoperative Planning of Left Atrial Appendage Occlusion Using Cardiac Computed Tomography Angiography

Abstract

Objective. To evaluate the value of individualized planning of left atrial appendage occlusion (LAAO) using cardiac computed tomography angiography (CCTA) reconstruction techniques. Methods. A total of 96 patients treated for LAAO with the Watchman occluder were included in this study. All patients were randomized by random number table in a 2:1 ratio into the CCTA (+) and CCTA (−) groups according to whether CCTA was performed preoperatively. 3D cardiac reconstruction was performed preoperatively in the CCTA (+) group to plan the location of the atrial septal puncture site, left atrial appendage(LAA) landing zone, predict the size of the occluder and simulate occluder release. In the CCTA(−) group, only transesophageal echocardiography (TEE) and fluoroscopy were used to guide LAAO. Results. The number of occluders used in a single procedure (1.06 ± .24 vs 1.22 ± .42), the number of intraoperative angiography positions (1.23 ± .58 vs 2.28 ± .85) and the procedure time (45.88 ± 5.08 vs 62.44 ± 5.60) in the CCTA(+) group were lower than in the CCTA(−) group (P < .05), and the first-attempt blocking success rate was higher than that of the CCTA(−) group (85.9% vs 65.6%, P = .021). Furthermore, the Bland-Altman plots showed good agreement between the longest diameter of the CCTA-predicted landing zone and the longest diameter of the actual landing zone (95% LoA −7.49, 10.24). A strong positive correlation was observed between the predicted compression ratio and the actual compression ratio (r = .890, P < .001). In addition, a strong positive correlation was found between the CCTA-predicted longest diameter of the landing zone and the actual occluder size (r = .863, P < .001). Conclusion. Accurate planning for LAAO using preoperative CCTA can reduce intraoperative angiography positions and occluder changes, shorten the procedure time, increase the success rate of first-attempt blocking and reduce the difficulty of the procedure.

Keywords

atrial fibrillation interventional cardiology left atrial appendage occlusion cardiac computed tomography angiography watchman occlude

Introduction

The prevalence of non-valvular atrial fibrillation (NVAF) is 1%-2% in people over 60 years of age and more than 10% in people over 80 years of age. Chugh SS et al in 2010 study¹ showed that there were 33,500,000 cases of atrial fibrillation (AF) worldwide, with a prevalence of 78/10,000 in men and 60/10,000 in women. The number of AF cases in China exceeds 10 million and is expected to increase exponentially in the next 20 years.^2,3 Most patients need oral anticoagulants to avoid thromboembolic complications of AF. Although anticoagulants can improve the prognosis of patients, there is still a considerable number of patients with bleeding events. For patients with a history of severe bleeding (intracranial, digestive tract, etc.), routine anticoagulants should be avoided. Previous studies have pointed out that more than 90% of thrombosis in patients with NVAF originates from the left atrial appendage (LAA).⁴ Left atrial appendage occlusion (LAAO) is an alternative treatment for patients unsuitable for long-term anticoagulation. Meanwhile, the Protect-AF study⁵ showed that LAAO was not inferior to warfarin alone in preventing stroke and improving cardiovascular prognosis. The technical difficulty of LAAO is mainly due to the complex anatomical structure of the LAA, especially the chicken wing-shaped LAA. Therefore, the application of LAA imaging is of great importance in this procedure. Transesophageal echocardiography (TEE) is considered the gold standard of LAA imaging.⁶ However, TEE is an invasive technique with low spatial resolution, which has certain limitations. At present, cardiac computed tomography angiography (CCTA) imaging is increasingly used for preoperative planning and postoperative occluder detection of LAAO. Since CCTA examination is non-invasive and has a high spatial resolution, comprehensive imaging of the LAA with complex anatomical structure can be carried out. The complex anatomical structure can also be visualized by three-dimensional multi-plane reconstruction of the image.^7,8 Therefore, preoperative 3D reconstruction of the LAA by CCTA may replace TEE in LAAO. At present, CCTA generally refers to TEE for the selection of the LAA landing zone, which is the line from 1 to 2 cm below the highest point of the left upper pulmonary vein ridge to the circumrotatory artery,^9,10 and predicts the size of the occluder according to the corresponding parameters in this area. However, the actual intraoperative landing zone should be selected according to LAA morphology, axial direction, pectinate muscle distribution and other variable factors, which is different across patients. Preoperative CT planning can evaluate the shape and spatial position of the LAA, which may shorten the operation time, improve the success rate of the operation, and reduce complications.The purpose of this study was to explore the guiding value of CCTA individualized planning for LAAO.

Materials and Methods

Study Subjects

This is a prospectively designed study and a total of 96 patients with atrial fibrillation (AF) who underwent LAAO in Taizhou People’s Hospital from December 2019 to February 2022 were enrolled in this single-center trial. All patients were randomly divided into the CCTA (+) and CCTA (−) groups in a 2:1 ratio using random number table. In the CCTA (+) group, CCTA reconstruction was performed before operation, the location of the atrial septal puncture point and LAA landing zone was planned, the size of the occluder was predicted, and the release of the occluder was simulated. In the CCTA (−) group, only TEE and fluoroscopy were used to guide the LAAO procedure. Inclusion criteria: CHA₂DS₂-VASc≥2 (Congestive heart failure/Left ventricular dysfunction: 1 point, Hypertension: 1 point, Age ≥ 75: 2 points, Diabetes: 1 point, Stroke/Transient ischemic attack/Thromboembolism history: 2 points, Vascular disease: 1 point, Age 65-74: 1 point, Female: 1 point.), anticoagulant contraindication or unwillingness to accept long-term oral anticoagulant therapy, and previous stroke of more than 3 months from the date of the operation, which was in line with LAAO indications. Exclusion criteria: New York Heart Association (NYHA) Cardiac function Grade Ⅳ; Complicated with acute myocardial infarction; Atrial septal defect or other intracardiac structural diseases; Severe hepatic or renal insufficiency or abnormal coagulation. All enrolled patients were operated by 2 operators with the experience of independently carrying out more than 200 LAAO operations, and the operations were performed strictly in accordance with the 2019 Chinese Society of Cardiology (CSC) expert consensus.¹¹ The same doctor participated in LAAOs preplanned an unplanned by CCTA.The study was approved by the Ethics Committee of the hospital (IRB KY2021-080-01), and informed consent was signed by the patients or their families.

CCTA Image Acquisition

Dual-source CT (Siemens Somatom Force) was used with 80 mL of non-ionic contrast agent (Iomeron 350) injected at 4-5 mL/s. Scanning parameters: voltage 100∼120 kV, effective tube current 800∼1235 mA, collimator width 256 × .625 mm, frame rotation time 270 ms, spacing .2. After image collection, the data was transmitted to Syngo. The VB10 work station and the MM Reading software were used for image post-processing analysis.

Planning before Watchman Occluder Device Implantation

The left atrium, pulmonary vein and LAA were reconstructed using volume rendering (VR) technology, and the position (low, middle and high), morphology and spatial relationship between the LAA and adjacent tissues were determined (Figure 1). Based on the above reconstruction, the location of the atrial septal puncture site was roughly determined. The following principles should be followed: (1) For general types of LAA, the puncture point should be infero-posterior as far as possible; (2) For anti-chicken wing LAA, the puncture point should be infero-anterior as far as possible; (3) For LAA with low position, the atrial septal puncture position should be evaluated by TEE to ensure a sufficiently low position.

Volume reconstruction (VR) was used to reconstruct and clip the LAA, which was rotated to the angle of maximum expansion. The rotation angle was determined according to the shape and axial direction of each LAA (Not fixed right anterior oblique(RAO) 30°/caudal (CAUD)20°) (Figure 2). The VR image was converted into a maximum density projection (MIP) image at the current angle to simulate an intraoperative angiography image. Combined with VR and MIP maps, experienced operator and radiologists preliminarily determined the location of the landing zone according to LAA morphology, axial direction and distribution of the pectinate muscles. The width, diameter and depth of the landing zone were measured at the maximum expansion angle, and the cross-section of LAA landing zone was displayed under multiplanar reconstruction (MPR), and then the longest diameter, the shortest diameter and perimeter of the ostium were measured. Based on the above measurements, the appropriate size of the Watchman device was selected. The prediction method of the occluder device model was obtained by adding 4-6 mm to the longest diameter. When multiple models were predicted, the larger size was selected if the depth was sufficient. When the longest diameter exceeded the shortest diameter by 6 mm or more, the average diameter of the longest diameter and the shortest diameter was used for prediction.¹²

The Watchman occluder was delineated in VR or MIP diagram, and the placement angle of the occluder was adjusted according to the shape and axial direction of the atrial appendage, providing a reference for the actual operation. (Figures 3 and 4) Finally, the average compression ratio was estimated based on (estimated occluder device circumference - landing zone circumference)/occluder device circumference to evaluate the stability of the occluder device. If the ostium was larger than the maximum Watchman occluder size or if the depth was too shallow to stabilize the Watchman occluder, another type of occluder was prepared. (Figure 5)

LAAO and Postoperative Follow-Up

On the day of the operation, the patients underwent LAAO via the femoral vein under general anesthesia. After successful puncture of the atrial septum, heparin was administered at 80 IU/Kg and the patient’s activated clotting time (ACT) of whole blood was monitored in real-time for >250 s. The size of occluder was selected based on the intraoperative angiography results, preoperative TEE, and/or CCTA measurements of the LAA landing zone, and LAAO was performed under the guidance of TEE and fluoroscopy. The occluder release should follow the PASS principle,¹³ and the operator should perform repeated pull tests and check for residual leakage at the edge of the occluder and for an occluder compression ratio of 8%-30% at all TEE angles before the final release of the occluder. The mean compression ratio was estimated intraoperatively by averaging the compression ratios measured at TEE 45°, 90°, 145° and 180°, which would be used for comparison with CCTA predictions. The patient’s TEE or CCTA was reviewed at 3 and 6 months post-operatively to re-evaluate the oral anticoagulation regimen based on occluder stability, marginal residual leak, device-related thrombosis, etc. The criteria for a successful LAAO procedure were a post-operative residual leak of <5 mm.¹⁴ At the same time, all the adverse events during the perioperative period were recorded, such as thromboembolism, ischemic stroke, sudden death, and occluder related complications.

Statistical Analysis

SPSS26.0 software was used to evaluate the normality of the data using the Shapiro-Wilk test. Continuous variables consistent with normal distribution were described in the form of mean ± standard deviation (Mean ± SD). The group T-test was used for comparison between the 2 groups, and continuous variables inconsistent with normal distribution were described by the median (Q1, Q3). The rank sum test was used for comparison between groups. Categorical variables were expressed as the number of cases and percentage (n, %), while the chi-square test or Fisher’s exact test was used for inter-group comparison. Furthermore, Bland-Altman consistency analysis was used to evaluate the consistency of the 2 groups of data, and Pearson correlation analysis was used to evaluate the correlation between 2 groups of data with normal distribution. Spearman correlation analysis was used to evaluate the correlation between the 2 groups of data with non-normal distribution. All tests were statistically significant with P < .05.

Results

Comparison of Baseline Data Between the Two Groups

A total of 96 AF patients were included and randomly divided into the CCTA preoperative planning group (64 cases) and the control group (32 cases). There were no significant differences in age, gender, CHA₂DS₂-VASc score, HAS-BLED score, atrial fibrillation type, GFR, hypertension, diabetes, stroke, coronary heart disease, left ventricular ejection fraction, atrial appendage morphology and other baseline data between the 2 groups, as shown in Table 1.

Table 1.

Comparison of Baseline Data Between CCTA (+) Group and CCTA (−) Group.

Variables	CCTA (+) Group (n = 64)	CCTA (−) Group (n = 32)	Statistical Value	P-Value
Age (Years), Mean ± SD	68.3 ± 6.3	70.1 ± 5.2	−1.410	.162
Female, n (%)	26 (40.6)	11 (34.4)	.353	.553
CHA₂DS₂-VASc, Mean ± SD	3.6 ± 1.2	3.6 ± 1.4	−.294	.769
HAS-BLED, Mean ± SD	4.2 ± 0.9	4.3 ± 0.8	−.429	.669
Type of AF, n (%)
Paroxysmal AF	27 (42.2)	18 (56.3)	1.694	.193
Persistent AF	37 (57.8)	14 (43.7)	1.694	.193
GFR (ml/min 1.73), Mean ± SD	87.1 ± 14.5	83.3 ± 19.1	1.069	.288
Hypertension, n (%)	38 (59.4)	19 (59.4)	0	1.000
Diabetes, n (%)	18 (18)	10 (20)	.133	.614
Previous stroke/TIA, n (%)	7 (10.9)	5 (15.6)	.429	.513
Coronary heart disease, n (%)	21 (32.8)	17 (53.1)	3.681	.055
LVEF (%), Mean ± SD	63.6 ± 6.0	64.6 ± 6.8	−.747	.457
LAA morphology, n (%)
Cauliflower type	22 (34.4)	14 (43.8)	2.174	.537
Cactus type	19 (29.7)	9 (28.1)
Chicken wing type	10 (15.6)	6 (18.8)
Windsock type	13 (20.3)	3 (9.4)

Abbreviations: SD, standard deviation; AF, atrial fibrillation; GFR, glomerular filtration rate; LVEF, left ventricular ejection fraction; CCTA, cardiac computed tomography angiography; LAA, left atrial appendage occlusion.

Comparison of Surgical Procedures Between the Two Groups

Among patients with CCTA planning, the average number of atrial septal punctures in a single operation was 1.03 ± .2, while 1.23 ± .58 different positions were required for LAA angiography, and 1.06 ± .24 occluders were used. 85.9% of the patients could underwent successful occlusion on the first procedure. The operation time was 45.88 ± 5.08 min. However, in patients without CCTA planning, the number of atrial septal punctures was 1.13 ± .34, and 2.28 ± .85 different positions were required for angiography. Furthermore, 1.22 ± .42 occluders were used, and only 65.6% of patients were successfully occluded on the first time. The operation time was 62.44 ± 5.60 min. The CCTA (+) group resulted in a fewer number of intraoperative angiographic positions than the CCTA (−) group (P < .001), while a fewer number of occluders (P = .023) were used and a shorter operation time (P < .001) was achieved. In addition, the first-attempt occlusion success rate in the CCTA (+) group was higher than that of the CCTA (−) group (P < .05). There were no significant differences between the 2 groups in adjusting the position of the occluder, device size, length and diameter of the landing zone. Table 2

Table 2.

Comparison of operations between CCTA (+) and CCTA (−) groups.

Variables	CCTA(+) Group (n = 64)	CCTA(−) Group (n = 32)	Statistical Value	P-Value
Number of atrial septal punctures, Mean ± SD	1.03 ± 0.2	1.13 ± .34	−1.800	.075
Intraoperative angiographic positions, Mean ± SD	1.23 ± .58	2.28 ± .85	−7.071	<.001
Number of occluders used, Mean ± SD	1.06 ± .24	1.22 ± .42	−2.305	.023
First-attempt successful occlusion	55 (85.9)	21 (65.6)	5.339	.021
Occluder position adjustment
Full-recovery adjustments, n (%)	2 (3.1)	3 (9.4)	.875	.831
Half-recovery adjustments, n (%)	2 (3.1)	2 (6.3)
Micro-recovery adjustments, n (%)	3 (4.7)	2 (6.3)
Multiple-recovery adjustments, n (%)	2 (3.1)	4 (12.5)
Operation time (min), Mean ± SD	45.88 ± 5.08	62.44 ± 5.60	−14.554	<.001
Pericardial effusion, n (%)	1 (1.6)	1 (3.1)	.255	.613
Implanted device size(mm), Md(Q1, Q3)	30 (27,30)	28.50 (24.75,30)	−.284	.776
Actual length of LAA landing zone(mm), Mean ± SD	25.01 ± 3.69	24.29 ± 3.65	.904	.368
DRT, n (%)	2 (3.1)	2 (6.3)	.522	.470
Residual shunt, n (%)	23 (35.9)	11 (34.4)	.023	.880

Abbreviations: SD, standard deviation; CCTA, cardiac computed tomography angiography; LAA, left atrial appendage occlusion.

Operation-Related Complications

There were no perioperative adverse events such as thromboembolism, heart failure and sudden death in the selected patients, and no patients required a second operation. A total of 2 patients had pericardial effusion during the operation, 1 patient (CCTA (−) group) received pericardiocentesis after drainage, and 1 patient (CCTA (−) group) received only conservative treatment, as shown in Table 2.

Comparison Between CCTA Measurement/Predicted Value and Actual Value

The longest diameter of the landing zone measured by CCTA was 26.39 ± 3.41 mm, and the longest diameter of the actual landing zone was 25.01 ± 3.69 mm. The predicted value by CCTA was slightly larger but not statistically significant. However, the average compression ratio predicted by CCTA was significantly higher than that of the actual implanted occluder device (16.51 ± 4.23% vs 12.84 ± 4.63%, P < .001), as shown in Table 3.

Table 3.

Comparison of the Longest Diameter and Compression Ratio of the Landing Zone Measured by CCTA and Fluoroscopy.

Variables	CCTA	Fluoroscopy	Average Error	Absolute Average Error	P-Value
The longest diameter of landing zone (mm), Mean ± SD	26.39 ± 3.41	25.01 ± 3.69	1.38 ± 4.52	3.76 ± 2.83	.129
Occluder compression ratio (%), Mean ± SD	16.51 ± 4.23	12.84 ± 4.63	3.67 ± 2.12	4.00 ± 1.38	<.001

Abbreviations: SD, standard deviation; CCTA, cardiac computed tomography angiography.

The Bland-Altman diagram demonstrates that the average error between the longest diameter of the landing zone measured by CCTA and fluoroscopy was 1.38 mm, showing a good consistency (95% LoA −7.49, 10.24). In 49 cases (76.6%), the CCTA-predicted occluder size was consistent with the actual size used. In these cases, the CCTA prediction of the occluder compression ratio was not consistent with the actual compression ratio (95% LOA-.47, 7.82). Pearson correlation analysis showed a strong positive correlation between the compression ratio predicted by CCTA and the actual compression ratio (r = .890, P < .001) for the patients with the same preoperative occluder size as the actual size. The actual implanted occluders were 30 (27, 30) mm in the CCTA (+) group and 28.50 (24.75, 30) mm in the CCTA (−) group. The Spearman correlation analysis revealed a strong positive correlation between the longest diameter of the landing zone measured by CCTA and the actual size of the occluder (r = .863, P < .001). (Figure 6)

Postoperative Follow-Up

All patients underwent CCTA or TEE in the third month after operation. No displacement or shedding was observed on reexamination. During the follow-up period, DRT was found in 4 patients (4.2%), 2 in the CCTA (+) group and 2 in the CCTA (−) group, showing no statistically significant difference between the 2 groups. In the CCTA (+) group, 23 patients (35.9%) had a residual shunt, but no residual shunt ≥5 mm; in the CCTA (−) group, 11 patients (34.4%) had a residual shunt, and 1 patient had a residual shunt of more than 5 mm (Figure 7) (Table 2).

Discussion

LAAO may lead to atrial perforation, pericardial effusion, occluder shedding, occluder displacement, valve injury, thromboembolism, excessive residual shunt, instrument related thrombosis and other complications.Imaging technology plays an important role in LAAO which can reduce these compliations. Previous studies have reported that 2D-TEE, 3D-TEE, X-ray and cardiac 3D-CT were routinely used to guide the occluder implantation before or during operation.^15,16 The LAA can be divided into “chicken wing type”, “cactus type”, “windsock type” and “cauliflower type” according to its morphology.¹⁷ Some studies¹⁸ have confirmed that “chicken wing type” LAAO with a large angle close to the base is more likely to have complications after operation, which may be related to some procedures such as the recovery of the occluder and adjustments of occluder position. In addition, other anatomical features, such as the position of LAA, the depth of the pectinate muscle and the distal lobule, should be considered during LAAO. Therefore, preoperative CCTA 3D reconstruction to evaluate the shape of the LAA may be performed to assist in LAAO planning. TEE is required to measure the LAA diameter and other parameters at different angles before traditional LAAO to guide the selection of the occluder size. TEE inspection is required again before the occluder device is pre-released to evaluate the occluder effect and determine whether the release criteria are met. Furthermore, TEE was used to check for pericardial effusion and other serious complications after the release of the occluder. Therefore, TEE plays an essential role in traditional LAAO. However, due to the morphological variability of the LAA, the ostium measured by TEE referred to the line from 1 to 2 cm below the highest point of the left upper pulmonary vein ridge to the circumrotatory artery, which could not accurately reflect the ostium diameter of the real landing zone as the direction and shape of the tip of LAA could not be visually displayed. CT image quality is superior to TEE due to higher spatial resolution and is not affected by the distance of the detection window. Currently, CT imaging is increasingly used for baseline imaging and postoperative monitoring of LAAO.¹⁹ Therefore, CCTA plays a major role in LAAO, mainly reflected in the following aspects: (1) In the pre-operative evaluation of the LAA for thrombosis. A thrombus usually presents as a filling defect in imaging. CCTA can determine the presence of a thrombus by comparing the images collected in the filling phase and the emptying phase of the LAA. Meta-analysis showed that the average sensitivity, average specificity and negative predictive value of CT in diagnosing LAA thrombosis were 98%, 96% and 99%-100%, respectively.²⁰ Therefore, some scholars believe that TEE examination is unnecessary for patients who underwent CT examination before LAAO to exclude LAA thrombosis. (2) Estimation of the site of atrial septal puncture. For the normal shape LAA with middle or high position, the atrial septal puncture point is located at the lower and posterior part of the oval fossa. For anti-chicken wing LAA, the puncture point is located in the infero-anterior part of the oval fossa.For Low position left atrial appendage, the atrial septal puncture point should be as lower as possible undering the guidance of TEE or intracardiac ultrasound, but at the same time, it should avoid penetrating into the coronary sinus. According to the position, shape and axial direction of LAA, the selection of appropriate atrial septal puncture sites is helpful in reducing the difficulty of operation and improving the efficiency of operation. (3) The intraoperative angiography position is recommended according to the maximum LAA expansion angle determined by CCTA to reduce unnecessary fluoroscopy, shorten the operation time and reduce the radiation dose. (4) To determine the best landing zone location before operation according to LAA morphology, axial direction and pectinate muscle distribution. The size of the occluder is predicted according to the parameters related to the landing zone. The ostium of LAA and its morphological trend has great variation, which can be divided into round, oval, droplet and footprint shapes. Preoperative identification of these shapes and diameters is very important for the selection of occluder type and size. The anatomical structure of the LAA can be reconstructed by CT. By rotating the measurement window at different angles in 3 dimensions, the shape of the ostium and the maximum aperture of the LAA can be displayed more accurately. It should be noted that the LAA diameter is greatly affected by the patient’s body fluid volume. Patients are usually in an Empty state during TEE examination, while there is no need to restrict diet during CT examination. So the diameter measured by CT is usually larger than TEE.²¹ Saw J et al in 2016 study²² compared the orifice size of LAA under TEE, CCTA and fluoroscopy, and the results showed that the orifice diameter measured by CCTA was the largest, followed by TEE and fluoroscopy, which were partially consistent with our results. The method used in this study can reduce the number of using occluder devices and operation time, improve the first-attempt blocking success rate and reduce the difficulty of operation. The maximum diameter of the landing zone measured by this method was in good consistency with the actual value and can reflect the actual situation basically. Although the average compression ratio predicted by CCTA was not consistent with the actual value, a strong correlation was observed. This can be used as a reference to evaluate the stability of occluder implantation. In this study, the compression ratio predicted by CCTA was larger than the actual value. The compression ratio was estimated on the assumption that the proximal connecting cap of the occluder could enter the ostium of the scheduled landing area completely in parallel, which was difficult to achieve in actual operation. The proximal end of some occluders were obliquely inserted into the ostium of the landing area, resulting in the actual compression ratio being less than the CCTA predicted value. (5) CCTA can provide adequate preoperative evaluation and reduce secondary operations. In particular, for patients with ostium larger than the maximum Watchman occluder size or with shallow depths where the Watchman occluder cannot be stably implanted, CCTA can be used to plan alternative occluders based on the characteristics of each LAA. (6) CCTA can be used for routine follow-up evaluation of complete occlusion and thrombosis after LAAO. Due to the higher resolution of CT, the evaluation of LAAO endothelium by CT is more sensitive than that by TEE. In addition, CT can more accurately display the position relationship between the occluder and LAA through 3D reconstruction and axial adjustment, so CT is superior to TEE in assessing the position of the postoperative occluder. CCTA may be the most accurate and intuitive imaging method and shows promising prospects.

Limitations

This is a single-center study with small number of patients and short period of time for follow up and the size number inequality which may lack generalizability. The procedure of different operators during the process may have some influence on the observed indicators.

Conclusion

Accurate planning of CCTA before LAAO can reduce the number of intraoperative angiography positions and occluder replacements, shorten the operation time, increase the success rate of first-attempt blocking and reduce the difficulty of operation. The planned landing zone of the new method is closer to the actual landing zone, and the longest diameter measured by the new method is consistent with the longest diameter of the actual landing zone, which can be used to predict the size of occluder device before operation. There is a strong correlation between the predicted average compression ratio based on the landing zone and the occluder device circumference and the actual average compression ratio, which can be used as a reference to predict the stability of the occluder device.

Footnotes

Author Contributions

Study Conception and design: Wei Li

Administrative support: Wei Li, Meixiang Wang

Provision of study materials or patients: Meixiang Wang, Juan Zhao

Collection and assembly of data: Meixiang Wang, Wei Li, Juan Zhao

Data analysis and interpretation: Wei Li, Juan Zhao

Manuscript writing: All authors

Final approval of manuscript: All authors

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Wei Li

References

Chugh

Havmoeller

Narayanan

, et al. Worldwide epidemiology of atrial fibrillation: A Global Burden of Disease 2010 Study. Circulation. 2014;129(8):837-847.

Wang

Chen

Wang

et al. for China Hypertension Survey Group. The disease burden of atrial fibrillation in china from a national cross-sectional survey. Am J Cardiol. 2018;122(5):793-798.

Guo

Tian

Wang

Lip

GYH

. Prevalence, incidence, and lifetime risk of atrial fibrillation in China: New insights into the global burden of atrial fibrillation. Chest. 2015;147(1):109-119.

Blackshear

Odell

. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg. 1996;61(2):755-759.

Reddy

Sievert

Halperin

, et al. Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: A randomized clinical trial. JAMA. 2014;312(19):1988-1998.

Ribeiro

Teixeira

Puga

Costa

Goncalves

. Comparison of intracardiac and transoesophageal echocardiography for guidance of percutaneous left atrial appendage occlusion: A meta-analysis. Echocardiography. 2019;36:1330-1337.

Prosper

Shinbane

Maliglig

Saremi

Wilcox

Lee

. Left atrial appendage mechanical exclusion: Procedural planning using cardiovascular computed tomographic angiography. J Thorac Imaging. 2020;35(4):W107-W118.

Korsholm

Jensen

Nielsen-Kudsk

. Cardiac computed tomography for left atrial appendage occlusion: Acquisition, analysis, advantages, and limitations. Interv Cardiol Clin. 2018;7(2):229-242.

Cho

Kim

Lee

, et al. Pre-procedural determination of device size in left atrial appendage occlusion using three-dimensional cardiac computed tomography. Sci Rep. 2021;11(1):24107.

10.

Korsholm

Berti

Iriart

, et al. Expert recommendations on cardiac computed tomography for planning transcatheter left atrial appendage occlusion. JACC Cardiovasc Interv. 2020;13(3):277-292.

11.

Chinese Society of Cardiology of Chinese Medical Association, Editorial Board of Chinese Journal of Cardiology . 2019 Chinese Society of Cardiology (CSC) expert consensus statement on left atrial appendage closure in the prevention of stroke in patients with atrial fibrillation[J]. Zhonghua Xin Xue Guan Bing Za Zhi. 2019;47(12):937-955.

12.

Saw

Lopes

Reisman

McLaughlin

Nicolau

Bezerra

. Cardiac computed tomography angiography for left atrial appendage closure. Can J Cardiol. 2016;32(8):1033.e1-1033.e9.

13.

Qamar

Jalal

Nicolaou

Tsang

Gilhofer

Saw

. Comparison of cardiac computed tomography angiography and transoesophageal echocardiography for device surveillance after left atrial appendage closure. EuroIntervention. 2019;15(8):663-670.

14.

Viles-Gonzalez

Kar

Douglas

, et al. The clinical impact of incomplete left atrial appendage closure with the Watchman Device in patients with atrial fibrillation: A PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) substudy. J Am Coll Cardiol. 2012;59(10):923-929.

15.

Chow

Bieliauskas

Sawaya

, et al. A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure. Open Heart. 2017;4(2):e000627.

16.

López-Mínguez

González-Fernández

Fernández-Vegas

, et al. Comparison of imaging techniques to assess appendage anatomy and measurements for left atrial appendage closure device selection. J Invasive Cardiol. 2014;26(9):462-467.

17.

Wang

Di Biase

Horton

Nguyen

Morhanty

Natale

. Left atrial appendage studied by computed tomography to help planning for appendage closure device placement. J Cardiovasc Electrophysiol. 2010;21(9):973-982.

18.

Di Biase

Santangeli

Anselmino

, et al. Does the left atrial appendage morphology correlate with the risk of stroke in patients with atrial fibrillation? Results from a multicenter study. J Am Coll Cardiol. 2012;60(6):531-538.

19.

Saw

Fahmy

DeJong

, et al. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure. Eur Heart J Cardiovasc Imaging. 2015;16(11):1198-1206.

20.

Romero

Cao

Garcia

Taub

. Cardiac imaging for assessment of left atrial appendage stasis and thrombosis. Nat Rev Cardiol. 2014;11(8):470-480.

21.

Jaguszewski

Manes

Puippe

, et al. Cardiac CT and echocardiographic evaluation of peri-device flow after percutaneous left atrial appendage closure using the AMPLATZER cardiac plug device. Catheter Cardiovasc Interv. 2015;85(2):306-312.

22.

Saw

Fahmy

Spencer

, et al. Comparing measurements of CT Angiography, TEE, and fluoroscopy of the left atrial appendage for percutaneous closure. J Cardiovasc Electrophysiol. 2016;27(4):414-422.