Table of Contents
RESEARCH ARTICLE
Year : 2016  |  Volume : 1  |  Issue : 3  |  Page : 9-12

First clinical experience with new left atrial appendage closure device: WATCHMAN FLX® System


1 Department of Cardiology, No. 2 Hospital of Jilin University, Changchun, China
2 Department of Cardiology, Helmut-G.-Walther Klinikum, The Second Hospital, Lichtenfels, Germany

Date of Web Publication26-Dec-2018

Correspondence Address:
Prof. Jiangtao Yu
Department of Cardiology, Helmut-G.-Walther Klinikum, The Second Hospital, Lichtenfels
Germany
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2470-7511.248352

Get Permissions

  Abstract 


Background: Percutaneous left atrial appendage closure (LAAC) with WATCHMAN (WM) has been recognized as a new interventional routine, but the development of device is continuing. The WATCHMAN FLX® system (WMF) is a new equipment for LAAC which was used in patients since December 2015 until now; however, there is still lack of WMF clinical experience. We therefore evaluate selection of patient, safety, feasibility, and the early results of LAAC with WMF in a single hospital. Results: LAAC was performed using WMF in 16 nonvalvular atrial fibrillation (NVAF) patients mostly with long-term oral anticoagulant contraindication. Mean age at LAAC was 75 ± 5 years, and 70.6% were male. Hypertension, diabetes, and stroke before operation were present in 87.5%, 25%, and 18.8%, respectively. Mean CHADS2, CHA2DS-VASc, and HASBLED scores were 3.0 ± 1.1, 4.0 ± 1.5, and 3.0 ± 1.2, respectively. The success rate of device implantation was 100%, and there were no severe major procedural complications. Transesophageal echocardiography (TEE) was performed in the first 6 weeks and 6 months after LAAC; 100% of patients finished 6 weeks follow-up. No device-related death was recorded. No ischemic stroke/transient ischemic attack was observed. However, three cases experienced device dislocation. WMF devices were out of left appendage, two at descending aorta and one at ascending aorta. Fortunately, all the lost devices were found and successfully captured with Caesar Grasping Forceps System via arteria femoralis (18F sheath). Twelve patients have already accepted 6 months TEE, with one patient detected thrombosis on the WMF surface. Conclusions: LAAC with WM is a safe and effective therapy to prevent stroke in NVAF patients. The WMF is upgrading novel and updated version of the WATCHMAN device, but not the final device. It still needs accumulating clinical experience with WMF, product, and device dislocation should be also be closely monitored.

Keywords: Device dislocation, left atrial appendage closure, WATCHMAN FLX


How to cite this article:
Xue X, Duenninger E, Muenzel M, Fazakas A, Schneider N, Chang J, Yu J. First clinical experience with new left atrial appendage closure device: WATCHMAN FLX® System. Cardiol Plus 2016;1:9-12

How to cite this URL:
Xue X, Duenninger E, Muenzel M, Fazakas A, Schneider N, Chang J, Yu J. First clinical experience with new left atrial appendage closure device: WATCHMAN FLX® System. Cardiol Plus [serial online] 2016 [cited 2021 Dec 9];1:9-12. Available from: https://www.cardiologyplus.org/text.asp?2016/1/3/9/248352




  Introduction Top


Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting 3%–5% of the population aged 65–75 years, and up to 8% of those older than 80 years.[1] The risk of stroke in AF patients increases with age; AF accounts for up to 30% of strokes in patients over 80 years old.[2] Oral anticoagulant treatment (OAC) is recommended for stroke prevention in AF patients.

Percutaneous left atrial appendage closure (LAAC) with WATCHMAN (WM) (Boston Scientific, Marlborough, MA, USA) is an evolving therapy in AF. The results of the PROTECT-AF study prove that the effectiveness of this method in preventing thrombosis complications of AF is better than OAC therapy.[3],[4],[5] However, WM has a long study curve and requires abundant operation experience; for the beginner, unexpected complications often occur in peri-intervention. To short the study curve, and reduce the unexpected complications, new device should be developed.

The WATCHMAN FLX® system (WMF) (Boston Scientific, Marlborough, MA, USA) is a upgrading device; compared with WM, it has wider range of device size, shorter device length, longer distal fabric coverage, more strut frames, and more anchors (two rows); what's more, WMF has a closed distal end and is allowed to be partial recaptured and advanced into LAA, and it has a recessed metal screw on proximal face [Figure 1].
Figure 1: WATCHMAN FLX® and Watchman

Click here to view


We evaluate the selection of patient, safety, feasibility, and the early results of LAAC with WMF in a single hospital without on-site cardiac surgery backup.


  Methods Top


From December 2015 to February 2016, percutaneous LAAC (WMF) was performed in a total of 16 patients, including one patient who had undergone two times of procedures. The implantation procedure was performed by the same experienced investigators under transesophageal echocardiography (TEE) guidance.

This was a retrospective study designed to investigate the safety and efficacy of LAAC with WMF. Patients were over 18 years with documented chronic or paroxysmal nonvalvular AF (NVAF) and had an estimated life expectancy of at least 2 years.

Patient selection

Inclusion criteria

Patients with:

  • Sign the informed consent
  • With AF at high risk of thromboembolic complications
  • One of the following conditions screened


    • Bleeding complication while using OAC
    • Bleeding medical history leading to markedly elevated risk of recurrence if use OAC
    • HASBLED score ≥3
    • Difficult to manage the dose of warfarin to keep the stable international normalized ratio
    • Refuse OAC.


Exclusion criteria

Patients with:

  • Symptomatic valvular disease
  • Symptomatic carotid disease
  • Pregnancy
  • Intracardiac thrombus in the LAA visualized by TEE within 48 h of the planned implantation
  • Indication other than AF for OAC therapy.


Device implantation

The device implantation procedure is the same with WM which was described previously in detail.[6] Patients were staying in hospital overnight and discharged the next day after transthoracic echocardiography examination to the exclusion of pericardial effusion. TEE follow-up was repeated at 45 days and 6 months, to make sure that there was no thrombus or leakage around the device.

Medical treatment

When there was no contraindication of warfarin, anticoagulation therapy with warfarin was given for 45 days if there was no thrombus or leakage around the device. This was confirmed by TEE and then dual antiplatelet therapy (DAPT) with Aspirin (100mg/day) and Clopidogrel (75mg/day) given for up to 6 months after implantation. This was then followed by oral administration of 100mg/day Aspirin.

Patients with contraindication for warfarin were under the following therapy: Enoxaparin sc. 0.01 mg/kg twice daily for 45 days. If no evidence of thrombus or leakage from TEE at 45-day follow-up then one initiated a therapy of 100 mg aspirin plus 75 mg clopidogrel once daily until 6 months after implantation, and finally followed by 100 mg aspirin.

In case of a peridevice leak flow >5 mm on follow-up TEE, the initial anticoagulation regimen (either warfarin or aspirin/clopidogrel) was prolonged for another 6 weeks followed by TEE.

Endpoints

The primary endpoint was successful implantation of the WMF device. The secondary endpoints included complications during device implantation and the occurrence of adverse events within the whole follow-up period. Successful sealing of the LAA was determined by TEE, by no leak flow, or with minimal leak (gap <5 mm). Sealing was confirmed at three different time points: at the end of the implantation procedure, after 45 days, and after 6 months. Major adverse events were defined as death, stroke, transient ischemic attack (TIA), systemic embolism, device thrombosis, and major bleeding requiring invasive treatment or blood transfusion.

Statistical analysis

Estimated frequencies of event occurrence are expressed as percentage or rate. Continuous variables are summarized as mean ± standard deviation.


  Results Top


LAAC was performed using WMF in 16 NVAF patients mostly with long-term OAC contraindication. Mean age was 75 ± 5 years, and 70.6% were male. Hypertension, diabetes, and stroke before operation were present in 87.5%, 25%, and 18.8%, respectively. Mean CHADS2, CHA2DS-VASc, and HASBLED scores were 3.0 ± 1.1, 4.0 ± 15, and 3.0 ± 1.2, respectively [Table 1].
Table 1: Baseline demographic and clinical characteristics of the study population

Click here to view


The success rate of device implantation was 100% and no severe major procedural complications were observed.

During the procedure, no cases needed to change different size, seven cases (35.3%) needed to recapture, and gap was discovered in one case (5.9%) [Table 2].
Table 2: Characteristics of the procedure (n=17)

Click here to view


TEE was performed in the first 6 weeks and 6 months after LAAC, 100% patients finished 6 weeks follow-up. No device-related death was recorded; no ischemic stroke/TIA was observed. However, three cases experienced device dislocation. The WMF devices were out of left appendage, two at descending aorta and one at ascending aorta. Fortunately, we found all of the lost devices and successfully captured the device with Caesar grasping forceps system (COOK Medical, Winston-Salem, Ireland) via arteria femoralis (18F sheath). Two of the dislocation cases were implanted Watchman device instead, and one was implanted another smaller WMF (from 27 mm to 24 mm). Twelve patients have already accepted 6 months TEE; unfortunately, there was one patient with thrombosis on the WMF surface [Table 3].
Table 3: Complication during follow-up

Click here to view



  Discussion Top


Currently, OAC therapy is the traditional way to prevent stroke in NVAF patients; however, more than half of the patients do not receive this therapy for various reasons.[4] The main caution for prescription OAC is afraid of bleeding particularly cerebral and gastrointestinal bleeding. In NVAF, over 90% thrombus was found in the LAA;[7] it is reasonable to seal the LAA to prevent thrombus formation.

WM has the most adequate evidence in stroke prevention of NVAF.[8],[9] WMF is the upgrading product of WM. However, until now, we have few experiences about this device.

WM and WMF have the similar design idea, but WMF has some key improvements according to the manufacturer's instruction. WMF is more flexible and has a flat top to prevent perforation of LAA wall during the release process, and two rows of hooks are placed to fix the device more firmly. Theoretically, WMF will be easy and safe to be implanted; however, now, it has some troubles in the real world.

Three of 17 cases experienced unexpected dislocation in 6 weeks after the procedure out of peri-intervention. The main operator of our center is skillful to use WM, so we think that there is no relationship between the operate skills. In fact, we do not understand the real reason of dislocation. Maybe, some factors should be carefully considered.

We noticed that one of the three patients suffering from device dislocation accepted another operation by implanting the second WMF smaller than the first one. It indicates that compression ratio cannot be too large for the WMF. The WMF's big compression ratio not only affects LCX (left circumflex coronary artery) but also affects the stability of the device.

The WMF is short, so the demand of LAA's depth is so strict when implantation, but the device capacity center may move to the orifice of the LAA. As a result, dislocation may happen.

WMF has two rows of hooks, it is more than WM, but hooks' angle and length have many differences. Hence, hooks may not work well and fixed firmly.

What's more, the flexibility of the WMF is better than WM, but it needs a long time to release device to a final posture during the operation. We doubt that WMF may still have a minigesture change after the tractive test and the mini change may cause the dislocation.

In our research, one of 17 cases occurred device surface thrombosis; in fact, we speculate that it might be a result of small possibility event. Further study with a large of sample size should be implemented to draw a conclusion.

According to our experience, the device characters including the length, flexibility and the hooks' placed way may need some improvements.

Study limitations

This study is a retrospective and small scale with limited 17 cases, which is our main limitation.


  Conclusions Top


LAAC with WM is a safe and effective therapy to prevent stroke in NVAF patients. The WMF is the new upgrading product of the WM device, but not the final device. It still needs accumulating clinical experience with WMF, and the device dislocation should also be alerted.

Financial support and sponsorship

Nil.

Conflicts of interest

Dr. Yu has research donation or travel expense reimbursement of the following companies and received in the last 12 months: Abbott, Avidal, BBraun, Biotronic, Boston Scientific, Daiichi-Sankyo, Lifetech, Symetis.



 
  References Top

1.
Go AS, Hylek EM, Phillips KA, Chang Y, Henault LE, Selby JV, et al. Prevalence of diagnosed atrial fibrillation in adults: National implications for rhythm management and stroke prevention: The AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study. JAMA 2001;285:2370-5.  Back to cited text no. 1
    
2.
Benjamin EJ, Wolf PA, D'Agostino RB, Silbershatz H, Kannel WB, Levy D, et al. Impact of atrial fibrillation on the risk of death: The Framingham heart study. Circulation 1998;98:946-52.  Back to cited text no. 2
    
3.
Reddy VY, Sievert H, Halperin J, Doshi SK, Buchbinder M, Neuzil P, et al. Percutaneous left atrial appendage closure vs. warfarin for atrial fibrillation: A randomized clinical trial. JAMA 2014;312:1988-98.  Back to cited text no. 3
    
4.
van Walraven C, Jennings A, Oake N, Fergusson D, Forster AJ. Effect of study setting on anticoagulation control: A systematic review and metaregression. Chest 2006;129:1155-66.  Back to cited text no. 4
    
5.
Camm AJ, Lip GY, De Caterina R, Savelieva I, Atar D, Hohnloser SH, et al. 2012 focused update of the ESC guidelines for the management of atrial fibrillation: An update of the 2010 ESC guidelines for the management of atrial fibrillation – Developed with the special contribution of the European Heart Rhythm Association. Europace 2012;14:1385-413.  Back to cited text no. 5
    
6.
Möbius-Winkler S, Sandri M, Mangner N, Lurz P, Dähnert I, Schuler G, et al. The WATCHMAN left atrial appendage closure device for atrial fibrillation. J Vis Exp 2012;60:e3671.  Back to cited text no. 6
    
7.
Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg 1996;61:755-9.  Back to cited text no. 7
    
8.
Yu J, Guan S, Huemmer H, Cheng F, Halmàgyi L, Muenzel M, et al. Percutaneous left atrial appendage closure in patients with non-valvular atrial fibrillation with Watchman® left atrial appendage device: Single center experience and results up to three years follow-up. J Am Coll Cardiol 2015;66:8297.  Back to cited text no. 8
    
9.
Holmes DR Jr., Kar S, Price MJ, Whisenant B, Sievert H, Doshi SK, et al. Prospective randomized evaluation of the Watchman left atrial appendage closure device in patients with atrial fibrillation versus long-term warfarin therapy: The PREVAIL trial. J Am Coll Cardiol 2014;64:1-2.  Back to cited text no. 9
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Methods
Results
Discussion
Conclusions
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed1952    
    Printed189    
    Emailed0    
    PDF Downloaded175    
    Comments [Add]    

Recommend this journal