Abstract
Background
We aimed to evaluate efficacy and safety of left atrial appendage (LAA) closure with the new Watchman FLX and analyze procedural features in a consecutive series of high risk non-valvular atrial fibrillation patients.
Methods and results
Twelve consecutive non-valvular atrial fibrillation patients (age 76.6 ± 7.8 years) at high risk for stroke (CHA 2 DS 2 -VASc-Score 5.5 ± 0.9) and bleeding (HAS-BLED-Score 3.8 ± 0.9), received LAA closure with the Watchman FLX. Bench testing demonstrated easy repositioning as well as optimized sealing and anchoring. Follow-up was done at 30 days, and at 3 and 6 months including transesophageal echocardiography after 3 months. Compression was calculated as occluder size to diameter at shoulder in final position. The device was successfully implanted in all patients. Partial recapture was necessary in 6 (50%) of cases, and full recapture in one (8.3%). There were no procedure-related complications. In 83.3% of cases ( N = 10/12) compression was between 10 and 27%, and mean compression was 24.0 ± 11.1%. Mean implantation depth was 4.0 ± 4.4 mm distal of LAA ostium. There was no residual flow. Proximal shift in device position was noticed in 2 patients. One device was embolized at 30 day follow-up, and another device showed thrombus formation. There was no disabling or non-disabling stroke through 6 months of follow-up with dual antiplatelet therapy for 3 months.
Conclusion
LAA closure with the new Watchman FLX is associated with a good periprocedural safety, complete sealing of the LAA and simple repositioning.
Summary
We evaluated the efficacy and safety of left atrial appendage (LAA) closure with the new Watchman FLX and analyzed procedural features in a consecutive series of high risk non-valvular atrial fibrillation patients. This is a first observational study demonstrating procedural safety, complete sealing of the LAA and simple technique for repositioning. There was no stroke within a 6 month follow-up.
Highlights
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In a first experience the Watchman FLX device displayed good periprocedural safety, complete sealing of the LAA and simple repositioning technique.
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There was no stroke within a 6 month follow-up.
1
Introduction
Left atrial appendage (LAA) closure has been established as an alternative to oral anticoagulation in non-valvular atrial fibrillation (AF) patients at high stroke and bleeding risk . The Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) trial demonstrated non-inferiority to warfarin for a combined endpoint in non-valvular atrial fibrillation (AF) patients. In the prospective randomized evaluation of the Watchman Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy (PREVAIL) trial non-inferiority was confirmed while procedural safety was improved.
The Watchman FLX (Boston Scientific Corp., Marlborough; MA, USA) is a second generation LAA closure device optimized regarding exact positioning and effective sealing of the LAA, featuring an option to be fully recaptured, re-maneuvered and redeployed to achieve optimal positioning even in demanding LAA anatomies. We evaluated in a first consecutive series of high risk non-valvular AF patients the safety and efficacy of LAA closure with focus on procedural techniques and patient outcome during 6 months of follow-up with the new Watchman FLX LAA closure device.
2
Methods
From November 2015 on, consecutive patients ( N = 12) with non-valvular atrial fibrillation and a high risk for stroke with a CHA 2 DS 2 -VASc Score ≥ 1 and high bleeding risk (HAS-BLED Score > 3) were treated with Watchman FLX left atrial appendage closure system (Boston Scientific Corp., Marlborough; MA, USA) for LAA closure. Patients had contraindications for long-term oral anticoagulation, had bleeding events during oral anticoagulation or were difficult to treat with warfarin and not eligible for new oral anticoagulants. Written informed consent was obtained from all patients before procedure. All patients underwent diagnostic evaluation with routine laboratory testing, medical history with current medication and calculation of CHA 2 DS 2 -VASc and HAS-BLED Scores as well as electrocardiography (ECG). Transthoracic and transesophageal echocardiography was done to evaluate the left atrium and to exclude thrombus in the LAA. TEE was performed with a multiplane, phased-array 4- to 7-MHz transesophageal echocardiography probe with a CX50 (Philips Medical Systems, Best, the Netherlands). Size and morphology of the LAA were assessed by TEE. Patients with intracardial thrombus were not included. Transthoracic control echocardiography was performed immediately post-procedure, on days one and two post procedure. Patients were followed up by assessing their clinical history at scheduled outpatient controls or through telephone contacts after one, three and 6 months. At each contact the same questionnaire (stroke, transient ischemic attack, bleeding, endocarditis, device dislocation, and other complications) was used. Patients were scheduled for control TEE at 3 months after device implantation for exclusion of device or procedure-related adverse events. Position of occluder device in LAA, residual flow (<5 mm or ≥5 mm) and possible thrombus formation on device were evaluated.
2.1
The Watchman FLX LAA closure device
The Watchman FLX LAA closure device (Boston Scientific Corp., Marlborough; MA, USA) consists of a self-expandable 18 struts nitinol frame with a polyethylenterephtalate membrane. Twelve “J” shaped fixation barbs arranged in two rows are designed to reduce the risk of dislocation and embolization. The occluder features an atraumatic closed distal end, enabling atraumatic advancement even when partially deployed. With the second generation Watchman FLX device profile is 10–20% shortened compared with its predecessor to be available for shallow appendages also ( Fig. 1 ). The proximal flat surface is designed with a recessed screw to reduce risk of thrombus formation and facilitate endothelialization. The occluder is introduced via a 14 French femoral venous access single or double curve sheath. Available occluder sizes were 20, 24, 27, 31 and 35 mm to treat ostia from 15 mm to 32 mm. The distal point is featured by a fluoroscopic marker to visualize device position. In case of unproper placement, the Watchman FLX can be fully or partially recaptured and remaneuvered to optimize position and compression in the LAA.
2.2
Procedure
Procedures were performed in the catheterization laboratory under conscious sedation as described elsewhere . For intraprocedural guidance transesophageal echocardiography was used. After obtaining femoral venous access, transseptal puncture at the posterior–inferior portion of the fossa ovalis was performed under echocardiographic and fluoroscopic guidance to optimize proper orientation of the delivery system. After transseptal puncture heparin was administered with an activated clotting time of >300 s. A 5 French pigtail marker catheter was inserted in the LAA through the transseptal sheath. Selective angiography was done in the 20° right oblique–20° cranial and 20° right oblique–20° caudal view to evaluate LAA anatomy and dimensions. TEE views were obtained at 0°, 45°, 90° and 135° for multimodality sizing of LAA ostia and landing zone with maximum and minimum diameters.
2.3
Sizing
The Watchman FLX device was available in 5 sizes. Oversizing was calculated in dimension to the LAA landing zone with minimum and maximum diameters to allow accurate sizing even in oval anatomies. Compression was calculated as given occluder size at shoulder of occluder to diameter at occluder shoulder in final position. Relation of oversizing to compression level and depth of implantation distal to LAA ostium was calculated. Oversizing with the Watchman FLX is intended to achieve a final range of compression between 10 and 27% according to instructions for use.
2.4
Anticoagulation
Oral anticoagulation, if present, was discontinued ≥48 h prior to procedure. Dual antiplatelet therapy with aspirin 100 mg and clopidogrel 75 mg was recommended for 3 months after device implantation, followed by long-term antiplatelet therapy with aspirin 100 mg daily . No oral anticoagulation was recommended after device implantation.
2.5
Statistical analysis
Categorical parameters are presented as counts and percentages. Continuous variables are presented as mean ± standard deviation (SD). Statistical analysis was performed using Statistica release 7.1 (StatSoft, Tulsa, Oklahoma).
2
Methods
From November 2015 on, consecutive patients ( N = 12) with non-valvular atrial fibrillation and a high risk for stroke with a CHA 2 DS 2 -VASc Score ≥ 1 and high bleeding risk (HAS-BLED Score > 3) were treated with Watchman FLX left atrial appendage closure system (Boston Scientific Corp., Marlborough; MA, USA) for LAA closure. Patients had contraindications for long-term oral anticoagulation, had bleeding events during oral anticoagulation or were difficult to treat with warfarin and not eligible for new oral anticoagulants. Written informed consent was obtained from all patients before procedure. All patients underwent diagnostic evaluation with routine laboratory testing, medical history with current medication and calculation of CHA 2 DS 2 -VASc and HAS-BLED Scores as well as electrocardiography (ECG). Transthoracic and transesophageal echocardiography was done to evaluate the left atrium and to exclude thrombus in the LAA. TEE was performed with a multiplane, phased-array 4- to 7-MHz transesophageal echocardiography probe with a CX50 (Philips Medical Systems, Best, the Netherlands). Size and morphology of the LAA were assessed by TEE. Patients with intracardial thrombus were not included. Transthoracic control echocardiography was performed immediately post-procedure, on days one and two post procedure. Patients were followed up by assessing their clinical history at scheduled outpatient controls or through telephone contacts after one, three and 6 months. At each contact the same questionnaire (stroke, transient ischemic attack, bleeding, endocarditis, device dislocation, and other complications) was used. Patients were scheduled for control TEE at 3 months after device implantation for exclusion of device or procedure-related adverse events. Position of occluder device in LAA, residual flow (<5 mm or ≥5 mm) and possible thrombus formation on device were evaluated.
2.1
The Watchman FLX LAA closure device
The Watchman FLX LAA closure device (Boston Scientific Corp., Marlborough; MA, USA) consists of a self-expandable 18 struts nitinol frame with a polyethylenterephtalate membrane. Twelve “J” shaped fixation barbs arranged in two rows are designed to reduce the risk of dislocation and embolization. The occluder features an atraumatic closed distal end, enabling atraumatic advancement even when partially deployed. With the second generation Watchman FLX device profile is 10–20% shortened compared with its predecessor to be available for shallow appendages also ( Fig. 1 ). The proximal flat surface is designed with a recessed screw to reduce risk of thrombus formation and facilitate endothelialization. The occluder is introduced via a 14 French femoral venous access single or double curve sheath. Available occluder sizes were 20, 24, 27, 31 and 35 mm to treat ostia from 15 mm to 32 mm. The distal point is featured by a fluoroscopic marker to visualize device position. In case of unproper placement, the Watchman FLX can be fully or partially recaptured and remaneuvered to optimize position and compression in the LAA.
2.2
Procedure
Procedures were performed in the catheterization laboratory under conscious sedation as described elsewhere . For intraprocedural guidance transesophageal echocardiography was used. After obtaining femoral venous access, transseptal puncture at the posterior–inferior portion of the fossa ovalis was performed under echocardiographic and fluoroscopic guidance to optimize proper orientation of the delivery system. After transseptal puncture heparin was administered with an activated clotting time of >300 s. A 5 French pigtail marker catheter was inserted in the LAA through the transseptal sheath. Selective angiography was done in the 20° right oblique–20° cranial and 20° right oblique–20° caudal view to evaluate LAA anatomy and dimensions. TEE views were obtained at 0°, 45°, 90° and 135° for multimodality sizing of LAA ostia and landing zone with maximum and minimum diameters.
2.3
Sizing
The Watchman FLX device was available in 5 sizes. Oversizing was calculated in dimension to the LAA landing zone with minimum and maximum diameters to allow accurate sizing even in oval anatomies. Compression was calculated as given occluder size at shoulder of occluder to diameter at occluder shoulder in final position. Relation of oversizing to compression level and depth of implantation distal to LAA ostium was calculated. Oversizing with the Watchman FLX is intended to achieve a final range of compression between 10 and 27% according to instructions for use.
2.4
Anticoagulation
Oral anticoagulation, if present, was discontinued ≥48 h prior to procedure. Dual antiplatelet therapy with aspirin 100 mg and clopidogrel 75 mg was recommended for 3 months after device implantation, followed by long-term antiplatelet therapy with aspirin 100 mg daily . No oral anticoagulation was recommended after device implantation.
2.5
Statistical analysis
Categorical parameters are presented as counts and percentages. Continuous variables are presented as mean ± standard deviation (SD). Statistical analysis was performed using Statistica release 7.1 (StatSoft, Tulsa, Oklahoma).
3
Results
3.1
Patient selection
A series of 12 consecutive patients were enrolled ( Table 1 ). Mean age was 76.6 ± 7.8 years (range 61–86 years). All patients had non-valvular AF (33% paroxysmal, 8.3% persistent, 58.3% permanent). CHA 2 DS 2 -VASc Score was 5.2 ± 0.9 (range 4–7) and HAS-BLED Score 3.8 ± 0.9. Coronary artery disease was present in 33.3% of patients and reduced renal function in 58.3%. Half of patients had a history of stroke or transient ischemic attack prior to the procedure. Clinical indication for LAA closure and contraindication for long-term oral anticoagulation were gastrointestinal bleeding (91.6%), epistaxis with syncopes and need for transfusion (8.3%).
