Catheterization and Cardiovascular Interventions 85:306–312 (2015)
Cardiac CT and Echocardiographic Evaluation of PeriDevice Flow After Percutaneous Left Atrial Appendage Closure Using the AMPLATZER Cardiac Plug Device Milosz Jaguszewski,1 MD, Costantina Manes,1 MD, Gilbert Puippe,2 MD, € ller,1 BSc, Volkmar Falk,3 MD, Thomas Lu € scher,1 MD, Sacha Salzberg,3 MD, Maja Mu 4 2 Andreas Luft, MD, Hatem Alkadhi, MD, MPH, EBCR, and Ulf Landmesser,1* MD Objectives: The aim of the study was to examine frequency, size, and localization of peridevice leaks after percutaneous left atrial appendage (LAA)-closure with the AMPLATZERCardiac-Plug (ACP) by using a multimodal imaging approach, i.e. combined cardiac-CT and TEE follow-up. Background: Catheter-based LAA-occlusion using ACP aims to reduce the risk of stroke in patients with atrial fibrillation. Detection of peri-device leaks after ACP implantation by TEE is challenging, the few available data are inconsistent and the frequency of LAA leaks after ACP implantation remains therefore unclear. Methods: Cardiac-CT using a multi-phase protocol and a second-generation dual-source-CT-system was performed in 24 patients with non-valvular atrial fibrillation starting 3 months after LAAclosure by ACP. Color Doppler multiplane TEE was used to evaluate peri-device flow. Results: Cardiac-CT follow-up detected any persistent LAA contrast filling in 62% of patients (n 5 15), but leak-sizes were small (1.5 6 1.4 mm). Peri-device leaks were almost exclusively localized at the posterior portion of the LAA-orifice (>90%). TEE follow-up revealed peri-device flow in 36% of patients (jet-sizes: 4 mm). ACP-lobe compression (>10%) and perpendicular ACP-lobe orientation to the LAA-neck axis, that was also dependent on LAA anatomy, were substantially more frequent in patients with complete LAA closure. Conclusion: The present study evaluates for the first time peri-device flow after LAA closure by ACP using a combined cardiac-CT and TEE follow-up. Persistent LAA-perfusion was frequently detected, leak-sizes were small and were less frequent when lobe compression was >10% and lobe orientation was perpendicular to the LAA-neck axis, that was also related to the LAA anatomy. The clinical significance of these small leaks after LAA-closure using ACP needs to be further evaluated in future studies. VC 2014 Wiley Periodicals, Inc. Key words: left atrial appendage closure; atrial fibrillation; first generation AMPLATZER Cardiac Plug; peri-device leaks; cardiac-CT; stroke
INTRODUCTION
Atrial fibrillation is a frequent cause of severe embolic strokes [1]. Transesophageal echocardiographic (TEE) and autopsy studies have suggested that more than 90% of atrial thrombi are located in the left atrial 1
Division of Cardiology, University Heart Center, University Hospital Zurich, Zurich, Switzerland 2 Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland 3 Division of Cardiac and Vascular Surgery, University Hospital Zurich, Zurich, Switzerland 4 Department of Neurology, University Hospital Zurich, Zurich, Switzerland. Additional Supporting Information may be found in the online version of this article. Conflicts of interest: UL has received consulting fees from St. Jude Medical. C 2014 Wiley Periodicals, Inc. V
appendage (LAA) in patients with non-valvular atrial fibrillation [2]. Chronic anticoagulation is associated with a significant risk of major bleedings and persistent use of anticoagulation with warfarin has been reported to be below 50% in patients after stroke [3]. LAA
Milosz Jaguszewski, Costantina Manes, and Gilbert Puippe contributed equally to this work. *Correspondence to: Ulf Landmesser, MD, Division of Cardiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland. E-mail: [email protected] Received 2 October 2013; Revision accepted 6 September 2014 DOI: 10.1002/ccd.25667 Published online 9 September 2014 in Wiley Online Library (wileyonlinelibrary.com)
Evaluation of Peri-Device Leaks After LAA Closure Using ACP
closure devices have therefore been developed as an alternative approach to reduce the risk of stroke in patients with non-valvular atrial fibrillation [4,5]. In the PROTECT-AF study, the efficacy and safety of LAA occlusion using the Watchman device was compared to anticoagulation with warfarin in patients with non-valvular atrial fibrillation [6]. In this study all patients undergoing Watchman device implantation were examined for peri-device flow into the LAA by TEE after 45 days, and 14% of these patients had a jet into the LAA with 5 mm width and were continued on anticoagulation [6]. If the peri-device jet was 10% and a perpendicular lobe orientation to the LAA neck axis (Table III). We have observed that criteria for optimal device implantation, in particular, disk-lobe separation (>2 mm) and a device axis consistent with the landing zone were less frequently present in patients with a Chicken-Wing LAA morphology (Supporting Information Table 2 and Fig. 5), compatible with the concept that this is a more challenging LAA morphology for optimal ACP-device implantation. Indeed, a special technique for transcatheter LAA occlusion with ACP in patients with Chicken-Wing LAA morphologhy has recently been reported [17] in particular when the bend of the LAA is very early and severe. In these patients, the deployment of the distal lobe of the device inside the Chicken-Wing bend has been proposed and may have to be considered for this anatomical setting [17].
DISCUSSION
Here, we report the first combined cardiac-CT and TEE follow-up after LAA-closure using ACP. We have observed a high rate of persistent flow into the LAA after LAA closure using the ACP device, i.e. 62% by cardiac CT and 36% by extensive TEE analysis. However, all observed leak sizes were small, i.e. < 4 mm, by cardiac CT and TEE. Of note, in the PROTECT-AF study, patients were only discontinued with anticoagulation when they had a jet size into the LAA (as assessed by TEE) of 2 mm) Lobe compression (>10%) Device axis consistent with landing zone Concave disc Criteria
Perfusion present
Perfusion absent
P value
21% 64% 50%
56% 100% 100%
0.09 0.04 0.01
79% 2.1 (61.1)
100% 3.6 (60.5)
0.14 90%) were localized in the posterior portion of the disk occluding the LAA orifice. This observation suggests that the anatomy in this portion of the left atrium predisposes for small leaks when using a diskbased device to cover the LAA orifice. Interestingly, a lobe compression > 10% and perpendicular orientation of the lobe to the LAA neck axis was more frequent in patients with a complete LAA closure by ACP, sug-
gesting that these may be criteria favoring complete LAA closure after ACP implantation. A high occurrence of unsuccessful surgical LAA closure after exclusion by sutures has been reported previously and was associated with an increased risk of thrombus formation in the LAA [19]. A recent analysis from the PROTECT-AF study using the Watchman device has examined the impact of peri-device flow severity, defined as minor, moderate, or major (3 mm, respectively) on the composite primary efficacy endpoint (stroke, systemic embolism, and cardiovascular death) [7]. In this analysis, no association between small peri-device leaks and an increased risk of thromboembolism was observed [7]. The clinical significance of the frequently observed small leaks after LAA closure with ACP as reported in the present study after careful cardiac CT and TEE analysis remains, however, to be further determined. We have observed in our cardiac CT follow-up one luminal device associated thrombus (at the screw of the ACP device) in a patient after ACP closure who had prematurely stopped clopidogrel. The thrombus was successfully dissolved after 3 weeks of LMWH treatment. Plicht et al. have recently reported thrombus formation in >17% of patients after ACP implantation despite dual antiplatelet therapy [20]. Also in this analysis all thrombi originated from the central screw, and one massive thrombus covered the whole device [20]. In the PROTECT-AF study, a deviceassociated thrombus was observed in 4.2% of the implanted patients [21]. These observations further suggest the need of a careful imaging follow-up after LAA occlusion [5]. Although the detection of luminal thrombi at the device is likely of clinical significance (and these thrombi can usually be dissolved by shortterm anti-coagulation), the detection of thrombi within the device may not be of clinical significance and likely represents part of the healing response toward the device.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
312
Jaguszewski et al.
Limitations of the Study The present study has several limitations, including a limited sample size. Moreover, the clinical significance of small peri-device leaks after LAA closure by ACP as well as their long-term natural history, i.e. whether they grow or resolve, is not known at present and should be determined in future studies. Thus in summary, our study for the first time carefully reports by a combined cardiac CT and TEE follow-up the frequency, size and localization of peridevice leaks into the LAA following closure with the ACP device. Using a combined CT and TEE follow-up we have frequently detected peri-device leaks after LAA closure using ACP. However, all observed leaks were small (4 mm) by both, cardiac CT and TEE analysis. The almost exclusive localization of the observed peridevice leaks in the posterior part of the LAA orifice suggests that the anatomy in this region represents a challenge for a complete LAA sealing using a device with a disk covering the LAA orifice. However, lobe compression >10% and perpendicular orientation to the LAA neck axis were more frequent in patients with a complete LAA closure, suggesting that these may be criteria favoring complete LAA closure after ACP implantation. LAA morphology may impact on the chance of achieving an optimal result after ACP-implantation. In particular, Chicken-Wing LAA morphology was associated with a lower presence of fulfilled criteria for optimal device implantation. REFERENCES 1. Lin HJ, Wolf PA, Kelly-Hayes M, et al. Stroke severity in atrial fibrillation. The Framingham Study. Stroke 1996;27:1760–1764. 2. Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg 1996;61:755–759. 3. Glader EL, Sjolander M, Eriksson M, Lundberg M. Persistent use of secondary preventive drugs declines rapidly during the first 2 years after stroke. Stroke 2010;41:397–401. 4. Holmes DR Jr, Schwartz RS. Left atrial appendage occlusion eliminates the need for warfarin. Circulation 2009;120:1919– 1926; discussion 1926. 5. Landmesser U, Holmes DR Jr. Left atrial appendage closure: A percutaneous transcatheter approach for stroke prevention in atrial fibrillation. Eur Heart J 2012;33:698–704. 6. Holmes DR, Reddy VY, Turi ZG, et al. Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: A randomised noninferiority trial. Lancet 2009;374:534–542. 7. Viles-Gonzalez JF, Kar S, Douglas P, 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 Warfa-
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
rin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) substudy. J Am Coll Cardiol 2012;59:923–929. Freixa X, Tzikas A, Sobrino A, Chan J, Basmadjian AJ, Ibrahim R. Left atrial appendage closure with the Amplatzer Cardiac Plug: Impact of shape and device sizing on follow-up leaks. Int J Cardiol 2013;168:1023–1027. Urena M, Rodes-Cabau J, Freixa X, et al. Percutaneous left atrial appendage closure with the AMPLATZER cardiac plug device in patients with nonvalvular atrial fibrillation and contraindications to anticoagulation therapy. J Am Coll Cardiol 2013; 62:96–102. Guerios EE, Schmid M, Gloekler S, et al. Left atrial appendage closure with the Amplatzer cardiac plug in patients with atrial fibrillation. Arq Bras Cardiol 2012;98:528–536. Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJ, Lip GY. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: The Euro Heart Survey. Chest 2010;138:1093–1100. Lip GY, Frison L, Halperin JL, Lane DA. Comparative validation of a novel risk score for predicting bleeding risk in anticoagulated patients with atrial fibrillation: The HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score. J Am Coll Cardiol 2011;57:173–180. Camm AJ, Lip GY, De Caterina R, 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. Eur Heart J 2012;33:2719–2747. Holmes DR Jr, Kereiakes DJ, Kleiman NS, Moliterno DJ, Patti G, Grines CL. Combining antiplatelet and anticoagulant therapies. J Am Coll Cardiol 2009;54:95–109. Di Biase L, Santangeli P, Anselmino M, 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;60:531–538. Wang Y, Di Biase L, Horton RP, Nguyen T, Morhanty P, Natale A. Left atrial appendage studied by computed tomography to help planning for appendage closure device placement. J Cardiovasc Electrophysiol 2010;21:973–982. Freixa X, Tzikas A, Basmadjian A, Garceau P, Ibrahim R. The chicken-wing morphology: An anatomical challenge for left atrial appendage occlusion. J Interv Cardiol 2013;26:509–514. Viles-Gonzalez JF, Reddy VY, Petru J, et al. Incomplete occlusion of the left atrial appendage with the percutaneous left atrial appendage transcatheter occlusion device is not associated with increased risk of stroke. J Interv Card Electrophysiol 2012;33:69–75. Kanderian AS, Gillinov AM, Pettersson GB, Blackstone E, Klein AL. Success of surgical left atrial appendage closure: Assessment by transesophageal echocardiography. J Am Coll Cardiol 2008;52:924–929. Plicht B, Konorza TF, Kahlert P, et al. Risk factors for thrombus formation on the amplatzer cardiac plug after left atrial appendage occlusion. JACC Cardiovasc Interv 2013;6: 606–613. Reddy VY, Holmes D, Doshi SK, Neuzil P, Kar S. Safety of percutaneous left atrial appendage closure: Results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry. Circulation 2011;123:417–424.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Cardiac CT and Echocardiographic Evaluation of PeriDevice Flow After Percutaneous Left Atrial Appendage Closure Using the AMPLATZER Cardiac Plug Device Milosz Jaguszewski,1 MD, Costantina Manes,1 MD, Gilbert Puippe,2 MD, € ller,1 BSc, Volkmar Falk,3 MD, Thomas Lu € scher,1 MD, Sacha Salzberg,3 MD, Maja Mu 4 2 Andreas Luft, MD, Hatem Alkadhi, MD, MPH, EBCR, and Ulf Landmesser,1* MD Objectives: The aim of the study was to examine frequency, size, and localization of peridevice leaks after percutaneous left atrial appendage (LAA)-closure with the AMPLATZERCardiac-Plug (ACP) by using a multimodal imaging approach, i.e. combined cardiac-CT and TEE follow-up. Background: Catheter-based LAA-occlusion using ACP aims to reduce the risk of stroke in patients with atrial fibrillation. Detection of peri-device leaks after ACP implantation by TEE is challenging, the few available data are inconsistent and the frequency of LAA leaks after ACP implantation remains therefore unclear. Methods: Cardiac-CT using a multi-phase protocol and a second-generation dual-source-CT-system was performed in 24 patients with non-valvular atrial fibrillation starting 3 months after LAAclosure by ACP. Color Doppler multiplane TEE was used to evaluate peri-device flow. Results: Cardiac-CT follow-up detected any persistent LAA contrast filling in 62% of patients (n 5 15), but leak-sizes were small (1.5 6 1.4 mm). Peri-device leaks were almost exclusively localized at the posterior portion of the LAA-orifice (>90%). TEE follow-up revealed peri-device flow in 36% of patients (jet-sizes: 4 mm). ACP-lobe compression (>10%) and perpendicular ACP-lobe orientation to the LAA-neck axis, that was also dependent on LAA anatomy, were substantially more frequent in patients with complete LAA closure. Conclusion: The present study evaluates for the first time peri-device flow after LAA closure by ACP using a combined cardiac-CT and TEE follow-up. Persistent LAA-perfusion was frequently detected, leak-sizes were small and were less frequent when lobe compression was >10% and lobe orientation was perpendicular to the LAA-neck axis, that was also related to the LAA anatomy. The clinical significance of these small leaks after LAA-closure using ACP needs to be further evaluated in future studies. VC 2014 Wiley Periodicals, Inc. Key words: left atrial appendage closure; atrial fibrillation; first generation AMPLATZER Cardiac Plug; peri-device leaks; cardiac-CT; stroke
INTRODUCTION
Atrial fibrillation is a frequent cause of severe embolic strokes [1]. Transesophageal echocardiographic (TEE) and autopsy studies have suggested that more than 90% of atrial thrombi are located in the left atrial 1
Division of Cardiology, University Heart Center, University Hospital Zurich, Zurich, Switzerland 2 Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland 3 Division of Cardiac and Vascular Surgery, University Hospital Zurich, Zurich, Switzerland 4 Department of Neurology, University Hospital Zurich, Zurich, Switzerland. Additional Supporting Information may be found in the online version of this article. Conflicts of interest: UL has received consulting fees from St. Jude Medical. C 2014 Wiley Periodicals, Inc. V
appendage (LAA) in patients with non-valvular atrial fibrillation [2]. Chronic anticoagulation is associated with a significant risk of major bleedings and persistent use of anticoagulation with warfarin has been reported to be below 50% in patients after stroke [3]. LAA
Milosz Jaguszewski, Costantina Manes, and Gilbert Puippe contributed equally to this work. *Correspondence to: Ulf Landmesser, MD, Division of Cardiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland. E-mail: [email protected] Received 2 October 2013; Revision accepted 6 September 2014 DOI: 10.1002/ccd.25667 Published online 9 September 2014 in Wiley Online Library (wileyonlinelibrary.com)
Evaluation of Peri-Device Leaks After LAA Closure Using ACP
closure devices have therefore been developed as an alternative approach to reduce the risk of stroke in patients with non-valvular atrial fibrillation [4,5]. In the PROTECT-AF study, the efficacy and safety of LAA occlusion using the Watchman device was compared to anticoagulation with warfarin in patients with non-valvular atrial fibrillation [6]. In this study all patients undergoing Watchman device implantation were examined for peri-device flow into the LAA by TEE after 45 days, and 14% of these patients had a jet into the LAA with 5 mm width and were continued on anticoagulation [6]. If the peri-device jet was 10% and a perpendicular lobe orientation to the LAA neck axis (Table III). We have observed that criteria for optimal device implantation, in particular, disk-lobe separation (>2 mm) and a device axis consistent with the landing zone were less frequently present in patients with a Chicken-Wing LAA morphology (Supporting Information Table 2 and Fig. 5), compatible with the concept that this is a more challenging LAA morphology for optimal ACP-device implantation. Indeed, a special technique for transcatheter LAA occlusion with ACP in patients with Chicken-Wing LAA morphologhy has recently been reported [17] in particular when the bend of the LAA is very early and severe. In these patients, the deployment of the distal lobe of the device inside the Chicken-Wing bend has been proposed and may have to be considered for this anatomical setting [17].
DISCUSSION
Here, we report the first combined cardiac-CT and TEE follow-up after LAA-closure using ACP. We have observed a high rate of persistent flow into the LAA after LAA closure using the ACP device, i.e. 62% by cardiac CT and 36% by extensive TEE analysis. However, all observed leak sizes were small, i.e. < 4 mm, by cardiac CT and TEE. Of note, in the PROTECT-AF study, patients were only discontinued with anticoagulation when they had a jet size into the LAA (as assessed by TEE) of 2 mm) Lobe compression (>10%) Device axis consistent with landing zone Concave disc Criteria
Perfusion present
Perfusion absent
P value
21% 64% 50%
56% 100% 100%
0.09 0.04 0.01
79% 2.1 (61.1)
100% 3.6 (60.5)
0.14 90%) were localized in the posterior portion of the disk occluding the LAA orifice. This observation suggests that the anatomy in this portion of the left atrium predisposes for small leaks when using a diskbased device to cover the LAA orifice. Interestingly, a lobe compression > 10% and perpendicular orientation of the lobe to the LAA neck axis was more frequent in patients with a complete LAA closure by ACP, sug-
gesting that these may be criteria favoring complete LAA closure after ACP implantation. A high occurrence of unsuccessful surgical LAA closure after exclusion by sutures has been reported previously and was associated with an increased risk of thrombus formation in the LAA [19]. A recent analysis from the PROTECT-AF study using the Watchman device has examined the impact of peri-device flow severity, defined as minor, moderate, or major (3 mm, respectively) on the composite primary efficacy endpoint (stroke, systemic embolism, and cardiovascular death) [7]. In this analysis, no association between small peri-device leaks and an increased risk of thromboembolism was observed [7]. The clinical significance of the frequently observed small leaks after LAA closure with ACP as reported in the present study after careful cardiac CT and TEE analysis remains, however, to be further determined. We have observed in our cardiac CT follow-up one luminal device associated thrombus (at the screw of the ACP device) in a patient after ACP closure who had prematurely stopped clopidogrel. The thrombus was successfully dissolved after 3 weeks of LMWH treatment. Plicht et al. have recently reported thrombus formation in >17% of patients after ACP implantation despite dual antiplatelet therapy [20]. Also in this analysis all thrombi originated from the central screw, and one massive thrombus covered the whole device [20]. In the PROTECT-AF study, a deviceassociated thrombus was observed in 4.2% of the implanted patients [21]. These observations further suggest the need of a careful imaging follow-up after LAA occlusion [5]. Although the detection of luminal thrombi at the device is likely of clinical significance (and these thrombi can usually be dissolved by shortterm anti-coagulation), the detection of thrombi within the device may not be of clinical significance and likely represents part of the healing response toward the device.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
312
Jaguszewski et al.
Limitations of the Study The present study has several limitations, including a limited sample size. Moreover, the clinical significance of small peri-device leaks after LAA closure by ACP as well as their long-term natural history, i.e. whether they grow or resolve, is not known at present and should be determined in future studies. Thus in summary, our study for the first time carefully reports by a combined cardiac CT and TEE follow-up the frequency, size and localization of peridevice leaks into the LAA following closure with the ACP device. Using a combined CT and TEE follow-up we have frequently detected peri-device leaks after LAA closure using ACP. However, all observed leaks were small (4 mm) by both, cardiac CT and TEE analysis. The almost exclusive localization of the observed peridevice leaks in the posterior part of the LAA orifice suggests that the anatomy in this region represents a challenge for a complete LAA sealing using a device with a disk covering the LAA orifice. However, lobe compression >10% and perpendicular orientation to the LAA neck axis were more frequent in patients with a complete LAA closure, suggesting that these may be criteria favoring complete LAA closure after ACP implantation. LAA morphology may impact on the chance of achieving an optimal result after ACP-implantation. In particular, Chicken-Wing LAA morphology was associated with a lower presence of fulfilled criteria for optimal device implantation. REFERENCES 1. Lin HJ, Wolf PA, Kelly-Hayes M, et al. Stroke severity in atrial fibrillation. The Framingham Study. Stroke 1996;27:1760–1764. 2. Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg 1996;61:755–759. 3. Glader EL, Sjolander M, Eriksson M, Lundberg M. Persistent use of secondary preventive drugs declines rapidly during the first 2 years after stroke. Stroke 2010;41:397–401. 4. Holmes DR Jr, Schwartz RS. Left atrial appendage occlusion eliminates the need for warfarin. Circulation 2009;120:1919– 1926; discussion 1926. 5. Landmesser U, Holmes DR Jr. Left atrial appendage closure: A percutaneous transcatheter approach for stroke prevention in atrial fibrillation. Eur Heart J 2012;33:698–704. 6. Holmes DR, Reddy VY, Turi ZG, et al. Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: A randomised noninferiority trial. Lancet 2009;374:534–542. 7. Viles-Gonzalez JF, Kar S, Douglas P, 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 Warfa-
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
rin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) substudy. J Am Coll Cardiol 2012;59:923–929. Freixa X, Tzikas A, Sobrino A, Chan J, Basmadjian AJ, Ibrahim R. Left atrial appendage closure with the Amplatzer Cardiac Plug: Impact of shape and device sizing on follow-up leaks. Int J Cardiol 2013;168:1023–1027. Urena M, Rodes-Cabau J, Freixa X, et al. Percutaneous left atrial appendage closure with the AMPLATZER cardiac plug device in patients with nonvalvular atrial fibrillation and contraindications to anticoagulation therapy. J Am Coll Cardiol 2013; 62:96–102. Guerios EE, Schmid M, Gloekler S, et al. Left atrial appendage closure with the Amplatzer cardiac plug in patients with atrial fibrillation. Arq Bras Cardiol 2012;98:528–536. Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJ, Lip GY. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: The Euro Heart Survey. Chest 2010;138:1093–1100. Lip GY, Frison L, Halperin JL, Lane DA. Comparative validation of a novel risk score for predicting bleeding risk in anticoagulated patients with atrial fibrillation: The HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score. J Am Coll Cardiol 2011;57:173–180. Camm AJ, Lip GY, De Caterina R, 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. Eur Heart J 2012;33:2719–2747. Holmes DR Jr, Kereiakes DJ, Kleiman NS, Moliterno DJ, Patti G, Grines CL. Combining antiplatelet and anticoagulant therapies. J Am Coll Cardiol 2009;54:95–109. Di Biase L, Santangeli P, Anselmino M, 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;60:531–538. Wang Y, Di Biase L, Horton RP, Nguyen T, Morhanty P, Natale A. Left atrial appendage studied by computed tomography to help planning for appendage closure device placement. J Cardiovasc Electrophysiol 2010;21:973–982. Freixa X, Tzikas A, Basmadjian A, Garceau P, Ibrahim R. The chicken-wing morphology: An anatomical challenge for left atrial appendage occlusion. J Interv Cardiol 2013;26:509–514. Viles-Gonzalez JF, Reddy VY, Petru J, et al. Incomplete occlusion of the left atrial appendage with the percutaneous left atrial appendage transcatheter occlusion device is not associated with increased risk of stroke. J Interv Card Electrophysiol 2012;33:69–75. Kanderian AS, Gillinov AM, Pettersson GB, Blackstone E, Klein AL. Success of surgical left atrial appendage closure: Assessment by transesophageal echocardiography. J Am Coll Cardiol 2008;52:924–929. Plicht B, Konorza TF, Kahlert P, et al. Risk factors for thrombus formation on the amplatzer cardiac plug after left atrial appendage occlusion. JACC Cardiovasc Interv 2013;6: 606–613. Reddy VY, Holmes D, Doshi SK, Neuzil P, Kar S. Safety of percutaneous left atrial appendage closure: Results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry. Circulation 2011;123:417–424.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
