EHRA/EAPCI expert consensus statement on catheter-based left atrial appendage occlusion

Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia. The estimated prevalence in the general population is 1–2% and increases with age.1–8 Patients with AF are at increased risk of thromboembolism, in particular ischaemic stroke. The risk of stroke in patients with non-valvular (essentially non-rheumatic) AF is ∼5% per year.9 Moreover, strokes related to AF are associated with a higher mortality and morbidity when compared with non-AF strokes, emphasizing the need for more effective stroke prevention in these patients.10 The CHADS2 score (cardiac failure, hypertension, age, diabetes, stroke counted double) was established to assess the risk of thrombo-embolic events in patients with AF of non-valvular origin.11 Although there is a clear relationship between the CHADS2 score and stroke rate, the CHA2DS2-VASc score has recently been introduced and adopted by the European Society of Cardiology (ESC) as well as by American Heart Association, American College of Cardiology, and Heart Rhythm Society and other national bodies’ guidelines for AF in an attempt to improve risk stratification in the low-risk group by considering additional stroke risk factors (gender, vascular disease) in addition to old factors including cardiac failure, hypertension, age (divided to two risk classes) diabetes, and stroke that may influence a decision for anticoagulation therapy.12 Prospective and randomized studies show that oral anticoagulation (OAC) significantly reduces the risk of thromboembolism.13 However, this treatment is underutilized in patients with AF due to poor patient compliance, contraindications, and potential bleeding complications.14–18 The pathogenesis of thrombogenesis in AF is multifactorial and includes the Virchow triad of events leading to thrombus formation, i.e. endothelial or endocardial damage or dysfunction, abnormal blood stasis, and altered haemostasis, platelet function, and fibrinolysis.19 There is evidence for endothelial damage, as well as intense fibrosis and inflammation in the left atrium (LA) in patients with AF.20 These changes are especially prominent in the left atrial appendage (LAA), a particularly low flow area, and may enhance to thrombus formation by their effect on the endocardial surface.21,22 There is also strong evidence for the presence of a prothrombotic and hypercoagulable state in AF, as manifested by increased blood levels of markers reflecting coagulation activity (prothrombin fragments 1 and 2, fibrinopeptide A, thrombin–antithrombin complexes, and D dimer).23,24 The LAA is the remnant of the embryonic LA. The LAA is a tubular blind-ended structure with different lobes and variable morphology. Its complex structure with areas of relative low flow predisposes to stasis, especially during AF when blood flow velocity decreases, as can be visualized on transoesophageal echocardiography (TOE) examination with spontaneous contrast (smoke) or on pulsed-wave Doppler during paroxysms of AF.25–28 It has been shown that in patients with non-valvular AF, 90% of thrombi are located in the LAA.29 Thrombi detected in the LAA as well as a reduced LAA peak flow velocity were identified as independent predictors of an increased thrombo-embolic risk,30,31 and also for recurrence of stroke among non-valvular AF patients recovering from ischaemic stroke.32 Moreover, patients with certain LAA morphologies have been shown to have different levels of thrombo-embolic risk further supporting the role of LAA in embolization.33 Left atrial appendage occlusion or exclusion in AF34–50 is based on the concept that only ∼10% of clinically relevant emboli in non-valvular AF do not originate in the LAA.51–61 The rationale is that, after excluding the LAA as an embolic source, the remaining small risk does not longer warrant OAC with its inherent risk for major bleeds. The risk of embolism from the LAA or the LA increases with age, but so does the risk of bleeding under OAC. Various surgical and catheter-based methods have been developed to exclude the LAA and the success of catheter-based methods attests to the validity of this concept.62 This document reviews the catheter-based methods and their results. Incidental surgical LAA exclusions during heart surgery have been performed for decades.63 A first report by Madden dates back to 1949.34 The popularity of this procedure remained low as it did prolong the surgical procedure and required some specific techniques. Moreover, follow-up TOE often detected residual flow in the LAA in case of a simple suture64 and in a large number of these patients the need for lifelong OAC with a vitamin K antagonist (VKA) remained due to indications unrelated to AF, most commonly mechanical valve prostheses in the mitral position. An electrocardiographically guided thoracoscopic technique for isolated surgical LAA occlusion65 and a percutaneous endocardial/epicardial approach (Lariat, SentreHeart)46,47,50 where an epicardial sling suture is guided by a magnet inside the LAA have been introduced more recently. In addition, a number of other minimally invasive surgical and percutaneous devices including the AtriClip, Cardioablate, and Aegis, are at various stages of advanced animal studies or first in man experiments. The electrophysiologist Michael Lesh conceived a Left Atrial for percutaneous of the by the that during of AF the LAA was first on The a number of and the technique was and The was the were percutaneous LAA occlusion general or in patients was introduced by the and of the devices for occlusion of an atrial or a The for the of the in or occlusion the of the LAA not the of a a the devices and were for LAA The and LAA were introduced in the was introduced by and It has and is in It the only in randomized as and the In an and for of this for in the as an to The and has recently as It was developed with and a different to more at the to LAA with or the LAA a has been by a group in animal or have been developed and The of the endocardial/epicardial suture of the LAA was first in by in in by in and in The has and is by the A of surgical have been in studies and with to LAA occlusion are of the LAA with an occlusion or percutaneous suture an endocardial/epicardial catheter-based devices are for mechanical the and devices and the The is for percutaneous endocardial/epicardial suture have The of a with a the the LA. are to the the of the appendage the risk of and It is to a and a A or can be on the appendage low is to with the is an and a is the LAA a of the LA on the LAA is performed in and the LAA and of the of and is under the for left atrial appendage The is the of the from the of the left the LAA to from the of the LAA and left an is advanced the LAA and the and are for the position. a the left first of at the In this after an is the left and the is the for the a is advanced the to the The has markers to and is advanced the LAA the with the of the the is advanced a to the of the the and are it to is by and A is performed under or TOE of the and the not the LAA on in the for and the with or by residual flow and a of a higher of The is in per the of the with the by the in the is the is or the can be and or 1 the of LAA in an the or with of a of to to the LAA a or A is advanced the LAA and a for the A a is advanced the left and a for the A is advanced the the LAA and the is advanced the the LAA LAA are and the is the The is advanced a case of or the case of the with the the LAA The case of or case of is is to the the and as low as the of the to in the of the the The and are advanced the of the and The is back as a to the to is echocardiography and and a is performed in an the or with of a of to to the LAA a or A is advanced the LAA and a for the A a is advanced the left and a for the A is advanced the the LAA and the is advanced the the LAA LAA are and the is the The is advanced a case of or the case of the with the the LAA The case of or case of is is to the the and as low as the of the to in the of the the The and are advanced the of the and The is back as a to the to is echocardiography and and a is performed left atrial in an the or with of a of to to the LAA a or A is advanced the LAA and a for the A a is advanced the left and a for the A is advanced the the LAA and the is advanced the the LAA LAA are and the is the The is advanced a case of or the case of the with the the LAA The case of or case of is is to the the and as low as the of the to in the of the the The and are advanced the of the and The is back as a to the to is echocardiography and and a is performed in an the or with of a of to to the LAA a or A is advanced the LAA and a for the A a is advanced the left and a for the A is advanced the the LAA and the is advanced the the LAA LAA are and the is the The is advanced a case of or the case of the with the the LAA The case of or case of is is to the the and as low as the of the to in the of the the The and are advanced the of the and The is back as a to the to is echocardiography and and a is performed left atrial LAA occlusion The of a the in the LAA by a to a the appendage are in with to the the is by The and to variable and complex appendage to the the of the is its the be in the may be an under In can be in The more recently introduced of that may improve and of and further the of that can the It also has changes that are to improve and occlusion of the LAA by the The from to on the and LAA and TOE as well as are as The may be advanced the the the is to from the the at inside the the first of the is by and the by it the is by further the on the the be with an to the by a The a and the LAA or at most of it a and of an the is The of a structure and with a the LAA to and a the LA to thrombus formation It is to LAA and are and to effective at the appendage the in The is to the in the LAA during and the is not for and inside the appendage as the is and for the or the devices be large for the may an for the and devices LA is by a in the and a The of the on TOE the from the left to to the of the the of the the has to be in the of the LAA for at and are to the and of the and the the The more of the is related to the concept that may the and the may a to lobes occlusion and the risk of is the the to be back from the and contrast is the to the A on the is performed is and as a In case the are the these the is The endocardial/epicardial approach to LAA occlusion in the heart is more A is by a percutaneous technique at the of the LAA and by suture epicardial is to epicardial for and an epicardial the is established and an 1 by a magnet endocardial is advanced the LAA by a The of the endocardial is contrast the the percutaneous epicardial a magnet epicardial is advanced the LAA and with a magnet located at the of the endocardial located in the LAA The in the LAA is to the appendage and a the epicardial the epicardial to the LAA the is occlusion is by TOE and and a suture is The epicardial and endocardial are of the LAA is but not a and for during of LAA and for LAA a for may to with the this can be by the with or in the LA especially in large LA with LAA increases thrombus the risk of embolism the and to the to or devices the valve and the of the the and under may the during and the and to a a the LAA is the a the LAA is or an the is for an the LAA is for the LAA is large for the or the suture occlusion with the technique be suture in patients with a LAA or in that the of the may be or of the is in patients with heart surgery to and may be or in patients with The not the LAA by of its for a for a for a for a and for a by TOE and not residual of in TOE the be or a small or with of the large or The not more the left the and be in TOE and for and of a for may to with the this can be by the with or in the LA especially in large LA with LAA increases thrombus the risk of embolism the and to the to or devices the valve and the of the the and under may the during and the and to a a the LAA is the a the LAA is or an the is for an the LAA is for the LAA is large for the or the suture occlusion with the technique be suture in patients with a LAA or in that the of the may be or of the is in patients with heart surgery to and may be or in patients with The not the LAA by of its for a for a for a for a and for a by TOE and not residual of in TOE the be or a small or with of the large or The not more the left the and be in TOE and for and of left left atrial transoesophageal and for LAA a for may to with the this can be by the with or in the LA especially in large LA with LAA increases thrombus the risk of embolism the and to the to or devices the valve and the of the the and under may the during and the and to a a the LAA is the a the LAA is or an the is for an the LAA is for the LAA is large for the or the suture occlusion with the technique be suture in patients with a LAA or in that the of the may be or of the is in patients with heart surgery to and may be or in patients with The not the LAA by of its for a for a for a for a and for a by TOE and not residual of in TOE the be or a small or with of the large or The not more the left the and be in TOE and for and of a for may to with the this can be by the with or in the LA especially in large LA with LAA increases thrombus the risk of embolism the and to the to or devices the valve and the of the the and under may the during and the and to a a the LAA is the a the LAA is or an the is for an the LAA is for the LAA is large for the or the suture occlusion with the technique be suture in patients with a LAA or in that the of the may be or of the is in patients with heart surgery to and may be or in patients with The not the LAA by of its for a for a for a for a and for a by TOE and not residual of in TOE the be or a small or with of the large or The not more the left the and be in TOE and for and of left left atrial transoesophageal of various is for a LAA occlusion is for and of the LAA and for The LAA can be visualized with echocardiography but echocardiography cardiac or echocardiography is an for in most but not LAA occlusion to The of be compared the for the LAA and LAA occlusion It is to the of LAA thrombi to LAA The presence of thrombi is a for percutaneous LAA of thrombus may with of or devices in the TOE is the technique for the of thrombi in the In most the LAA can be visualized in some patients there may be in as for in patients with prominent may be as LAA The of LAA thrombus on TOE among patients AF have been was to be low and in patients an CHADS2 score was the of LAA The prevalence of LA or LAA thrombus or a in patients TOE examination for increased from in patients with CHADS2 score of in patients with CHADS2 score of the prevalence of LAA thrombus may be higher in patients for LAA patients may not be of bleeding The of a cardiac for of LAA thrombi was in patients with The and of for the of thrombi in the LAA were and The role of cardiac in for LAA is not well and further studies are LAA occlusion LA for thrombus exclusion has been in a small TOE to the or the LAA or to The LAA is from the the function, the LAA is in and The and presence of lobes of the LAA are only at an of the LAA and the presence of lobes can be by TOE or or and devices specific TOE for the The of the LAA and of the LAA are first The LAA is from the of the left to a from the of the left and from the mitral to a from the and The of the LAA has an It is to the of the The of the LAA is from the to the of the The can be the LAA is or the it is may be an or the may be for to the and are In the at be the some may to the of the LAA is the of the of a may in with the LA. further the and of the to the and to TOE with of the LAA from two of LAA and LAA is for the of the LAA for and is a for as the procedure can be may not be However, the of the procedure in general with TOE in with some under to the and or TOE during LAA occlusion be well and with the procedure and the required for the of are on LAA occlusion but this may the procedure to be performed under of the LAA with the in the LA or compared with a in the atrium or the in the LA in the of a a is Left atrial appendage occlusion with only be performed by with in and of TOE can a of the LAA and the of the LAA A report that of LAA were related with In this TOE significantly LAA and as compared with studies the and of TOE during LAA occlusion are echocardiography or also an a to and This variable the A and is LA a in a and is by most a or in the contrast under in and of the LAA not the LA. decision on is based on with echocardiography and TOE on the of the in the LAA and during the is for echocardiography to and exclude to are not of on the of an first of the patient with of the heart have been echocardiography is the most to assess residual flow in the and thrombus formation on the of or is by The of a follow-up TOE between or follow-up i.e. the of large residual flow the LAA or as a for In the AF Left Atrial for in Patients with Atrial TOE was performed at and 1 The the of the first two was based on changes in to the i.e. and were TOE the of occlusion of the or residual flow of by at and A with the a of for 1 and for to TOE was performed at variable between and patients with and to the AF it is to the of the as it as a to changes in In other patients are with it to to of and is It is to a TOE at to after most events including and thrombi were so at the The of additional TOE at is In case of a embolic a TOE is as is the case a TOE a or a thrombus on the on flow is a common in patients with the There is that this to thrombo-embolic thrombi may in the LAA as a of low flow In of patients of the AF this was during TOE at This to at the The of patients flow of in patients with flow the was not devices have residual flow the of the the LAA further on treatment in patients with to the on is the role of in and echocardiography is to LAA occlusion during the procedure and for but clear has been of cardiac particularly of the LA and LAA and the is required for on LAA be with and with as a to LAA occlusion with other performed for an or with LA for an electrophysiologist be required to be of LA and the of LAA in to the be of the LAA in of and The is also based the to LAA in to the technique and the of the Left atrial appendage a role for the of the most occlusion The success of the procedure is related to the of and of to the including the supporting the The has to be in of the of the A for success is a an independent The by the includes specific and the of the that a for of a specific the in addition to the in patient for the procedure and during be for the of the often on and the of including This also as patient and and and of major events including including with of the and at or during or The addition of on is but not at their first are to be at their by the procedure is performed under general and TOE an and an specific in supporting LAA occlusion be of the and also be with well to and to events and for the procedure not only a but a of the procedure and of the role of of the to in surgery in LAA occlusion is not but for to a with cardiac surgery be with a of to the In of the number of LAA occlusion there is a need to the number of of patient and and the of of are from the and the in randomized to success and with the are based on with to to the that not patients with AF and to OAC or with with OAC are for LAA there is a need for to patient In this studies be including with of with at and studies are there is also a need for large of LAA large among the different and are the This of and with to as or of and of the the of and to and group of different and to be in LAA occlusion for of LAA or of of LAA occlusion of atrial fibrillation heart heart heart other AF CHADS2 score CHA2DS2-VASc score score to the for of bleeding and of bleeding of spontaneous bleeding other or bleeding of of of the LAA and LAA for during the procedure and stroke ischaemic stroke with mitral valve vascular embolism at and of TOE follow-up at and 1 at thrombi follow-up at and stroke ischaemic stroke vascular embolism of or of of LAA occlusion of atrial fibrillation heart heart heart other AF CHADS2 score CHA2DS2-VASc score score to the for of bleeding and of bleeding of spontaneous bleeding other or bleeding of of of the LAA and LAA for during the procedure and stroke ischaemic stroke with mitral valve vascular embolism at and of TOE follow-up at and 1 at thrombi follow-up at and stroke ischaemic stroke vascular embolism of as in for of LAA or of of LAA occlusion of atrial fibrillation heart heart heart other AF CHADS2 score CHA2DS2-VASc score score to the for of bleeding and of bleeding of spontaneous bleeding other or bleeding of of of the LAA and LAA for during the procedure and stroke ischaemic stroke with mitral valve vascular embolism at and of TOE follow-up at and 1 at thrombi follow-up at and stroke ischaemic stroke vascular embolism of or of of LAA occlusion of atrial fibrillation heart heart heart other AF CHADS2 score CHA2DS2-VASc score score to the for of bleeding and of bleeding of spontaneous bleeding other or bleeding of of of the LAA and LAA for during the procedure and stroke ischaemic stroke with mitral valve vascular embolism at and of TOE follow-up at and 1 at thrombi follow-up at and stroke ischaemic stroke vascular embolism of as in studies the longer have been In only was after the stroke was by the CHADS2 score for patients with to from studies including a of patients follow-up of and the stroke were and the based on the CHADS2 score and follow-up follow-up of the stroke or ischaemic remained by the CHADS2 score from patients with or mortality and the of and stroke were and associated with a small risk of major the to be effective in the stroke risk or OAC in patients with AF when compared with of stroke risk in a and with the with the AF, atrial are and is not with the AF, atrial are and is not with the was in patients have been and from patients with of The the and of this in thrombo-embolic events compared with The is the only LAA occlusion that has been in randomized its and in patients with non-valvular The AF was to assess the of the The first follow-up of but on are of OAC at and after of Although there was a higher of events in the group in the due to