The 4th International Symposium on Left Atrial Appendage: Updates in the Science of the Left Atrial Appendage

The 4th International Symposium on Left Atrial Appendage (ISLAA), sponsored by the ISLAA Foundation, was held March 11-12, 2016 in New York City. ISLAA is supported by the University of Kansas Hospital, Texas Cardiac Arrhythmia Institute, Cedars-Sinai Hospital, Mayo Clinic, and Mount Sinai Hospital.

ISLAA is a multispecialty cardiovascular educational symposium focused on the frontier science of the LAA. With more than 240 attendees, the interest in this topic was evident. Over a period of two days, ISLAA offered informative presentations from leaders in the field on the anatomical, physiological, and pathological aspects of the LAA, as well as new therapeutic strategies of stroke prophylaxis including cardiac devices for LAA exclusion. Five of the top LAA experts in the world, Drs. Dhanunjaya Lakkireddy, Andrea Natale, Saibal Kar, Vivek Reddy, and David Holmes, directed this high-quality program.

This symposium addressed gaps in knowledge and competence through didactic lecture, panel discussions, debate, and discussion of live case studies. The symposium was divided into 13 sessions. The talks were intentionally kept short to cover a majority of practical topics in this rapidly growing field. The highlights of this year’s symposium were the live cases and the intense discussion on practical topics between the panelists at the end of each session. Four live cases were performed by experts in the field to demonstrate optimal technique, tips and tricks, and problem solving. This symposium was designed for physicians, advanced practice registered nurses, nurses, and allied health professionals in the fields of electrophysiology, cardiology, family, and internal medicine.

Under the leadership of Drs. Lakkireddy and Natale, a fellows course also took place on March 10, which enabled hands-on experience with heart dissection, case-based learning, and lectures on atrial and ventricular ablation and advanced mapping technology. Fellows from around the country joined in this unique educational opportunity.

Day 1

The day started with the course director Vivek Reddy, MD welcoming the audience and giving a brief outline of the conference.

Session 1:
The first session was focused on understanding anatomy, physiology, and morphology of the LAA. Dr. Luigi Di Biase set the pace with a comprehensive presentation on anatomy and morphology of the LAA. Course director Dr. Lakkireddy followed this presentation with a detailed and functional understanding of the LAA. Neurohormonal function of the LAA is currently a hot topic. This function is mediated via atrial natriuretic peptide and eventually, via renin-angiotensin-aldosterone axis. Whether LAA exclusion can alter this function and reverse or prevent detrimental effects of the renin-angiotensin axis was the focus of his discussion. He also explored the impact of reservoir function of the LAA on left atrial function following LAA exclusion.

Next, Dr. Natale presented evidence behind the arrhythmogenic role of the LAA, which is an under-recognized trigger site of atrial fibrillation (AF). He presented data supporting the role of the LAA in initiation and maintenance of certain cases of longstanding persistent AF and atrial tachycardia. He further corroborated this hypothesis by presenting data from the LAALA-AF Registry. According to this study, epicardial mechanical isolation of the LAA (LARIAT Suture Delivery Device, SentreHEART, Inc.) resulted in increased freedom from AF. However, he stressed that a high dose of isoproterenol infusion is necessary to accurately identify LAA triggers.

Session 2:
Session 2 was focused on the Amplatzer Amulet ACP (St. Jude Medical) for LAA occlusion. This device received the CE Mark in January 2013, and is currently under investigation in the U.S. Dr. Apostolos Tzikas started the session by explaining design, indications, and practical advantages of the device. He further explained differences between the first- and second-generation devices.

This talk was followed by a prerecorded case presented by Dr. Thorsten Lewalter, who explained indications, preparation, and device selections. Dr. Lewalter highlighted the utility of different echocardiographic views in proper selection and placement of the device, and provided a useful checklist of essential points for post-deployment evaluation.

Dr. Moussa Mansour then presented his views on managing post-procedural anticoagulation and antiplatelet therapy in regards to devices. He pointed out that clinical data in this area is limited. So far, no randomized studies have been conducted. However, 2 important studies addressing this issue have recently been conducted. He concluded that most patients treated with this device can be managed with single or dual antiplatelet therapy. Thrombus formation on the device is rare, which can be successfully managed with a short course of OAC.

Following this, Dr. Lars Sondergaard presented on post-procedural leaks with ACP devices and potential implications. He classified leaks according to size (mild, moderate, major, and severe), and presented cases to explain grading of these leaks. He suggested potential ways to prevent and handle this issue.

Session 3:
This session was dedicated entirely to the WATCHMAN device (Boston Scientific). Dr. Shephal Doshi started by discussing the device and the access system for proper implantation. He stressed that a thorough understanding of the tools is essential for proper placement of the device and avoidance of preventable complications. He went over different device delivery sheaths and implications in guiding proper device position. 

Course co-director Dr. Saibal Kar presented a step-by-step approach for properly navigating and deploying the device. He went over how to properly size and select the device, and gave important pointers for appropriate location for the transseptal puncture and sheath selection. 

These talks were followed by live cases from the Mount Sinai EP lab by course co-director Dr. Reddy and his colleague, Dr. Srinivas Dukkipati. Dr. Reddy explained each step of the procedure as well as the rationale behind them. He stressed that proper planning during transseptal puncture is critical for proper placement of the device. It is essential that transseptal puncture be inferior and posterior for optimal placement of the device. Several key components of the LAA occlusion procedure using the WATCHMAN were discussed, as well as helpful “tricks” shown to the audience.

Following the live cases, Dr. Vijay Swarup presented his tips for post-procedural care after a successful WATCHMAN implant. He presented recommended protocol for the timing of follow-up imaging and post-procedural anticoagulation. He also shared a few practical tips to differentiate true peri-procedural leaks from the artifact. Warfarin is the recommended anticoagulation agent for 45 days after the implant. He also shared his experience on the use of NOACs in this post-procedural period.

Dr. David Holmes then presented his expert opinion on post-procedural leaks associated with the WATCHMAN device. He highlighted different mechanisms and significance of the leaks with different devices. With the help of current available data, he concluded that leaks are infrequent and not associated with higher thromboembolic events.

Session 4:
This session was focused on understanding the LARIAT Suture Delivery Device (SentreHEART, Inc.) and implantation techniques. Dr. Jie Cheng started the session by explaining the LARIAT device and other useful tools in detail. He discussed the current LARIAT system and how the newer system (LARIAT+) differs. LARIAT+ is larger in size (45 mm) to facilitate closure of larger LAA, a SofTIP guide cannula with a braided shaft, and a radiopaque marker on the snare.

Dr. Randall Lee then addressed the issue of pericardial access, a critical step for the LARIAT device. He demonstrated various techniques to achieve a ‘dry’ pericardial access. He further suggested that use of a telescoping micropuncture technique (long micropuncture), but not the traditional Pajunk needle (spinal needle) technique, is the correct approach to access pericardial space for LARIAT cases.

Next, Dr. Christopher Ellis presented his tips for avoiding complications related to transseptal access. He identified warning signs in which the operator should anticipate difficult transseptal access and be prepared to handle them. He strongly suggested that ICE or TEE be used for transseptal access for LAA closure. He also suggested that rotations of sheath or the LARIAT+ should be kept to a minimum to avoid complications.

Session 5:
Dr. Reda Ibrahim discussed the right candidates for a WATCHMAN device, reviewing recently published CMS guidelines to answer this question. 

Next, Dr. Reddy and Dr. Dukkipati presented 2 more live WATCHMAN cases from Mount Sinai. Following this, Dr. Jacqueline Saw showed the audience how to locate and retrieve an embolized device. She presented current incidence, indicators, and predictors of device embolization, and offered a case-based summary of different retrieval techniques.

Risk of complications during the WATCHMAN procedure is significantly improved with increased operator experience. Dr. Mansour presented an informative talk on how to predict and prevent major complications associated with the WATCHMAN.

Session 6:
Dr. Ellis started the session by identifying the best candidates for the LARIAT device. He suggested that in addition to patients who have absolute contraindications to anticoagulation, patients who have unsuitable anatomy for the WATCHMAN device should be considered for the LARIAT device. Furthermore, selected patients with longstanding persistent AF undergoing catheter ablation should also be considered for the LARIAT.

Next, Dr. Suneet Mittal presented on FDA Safety Alerts and what they mean to clinical practice. He also identified predictors for complications and how an operator can avoid them.

Following this talk, Dr. Abdi Rasekh presented a pre-recorded LARIAT case. Finally, Dr. Douglas Gibson presented current views on LARIAT-associated leaks. His evaluation was similar to that of Dr. Holmes. Leaks associated with the LARIAT, like that of the WATCHMAN, do not translate to stroke. However, data are lacking on this topic. He also suggested that leaks could be closed with an Amplatzer Septal Occluder or Amplatzer Vascular Plug if needed.

Day 2

The day started with LAA research presentations by fellows from EP, interventional, and cardiothoracic surgery, with Dr. Di Biase moderating the session. 

Session 7:
Session 7 focused on the role of various imaging modalities in LAA occlusion. Dr. Jayant Nath started by discussing the utility of various imaging techniques in evaluation of borderline LAA thrombus cases. He delineated the roles of different echocardiography, CT scan, and MRI techniques to differentiate between thrombus and spontaneous echo contrast, commonly known as ‘sludge’ or ‘echo’. Practical tips to handle this tricky situation were presented to the audience.

Next, Dr. Swaminatha Gurudevan went into great detail about the role of transesophageal echocardiogram (TEE) in different LAA occlusion therapies. Multiplanar TEE remains a gold standard procedure for proper placement of an LAAO device. He demonstrated how TEE can be helpful during different stages of the procedure. The highlight of his talk was his demonstration on obtaining long and short axis of LAA for proper sizing of the WATCHMAN device. His illustration demonstrating organization of the operating room for these procedures was instructive to physicians starting a new LAAO program.

Dr. Lee then reviewed the role of the CT scan in planning LAA exclusion. He demonstrated how proper planning can be helpful for a successful deployment of the LARIAT device, as well as to prevent complications.

In the next session, Dr. Horst Sievert discussed upcoming technologies for 3D printing and its potential in further advancement of appendology. Three-dimensional printing is useful in understanding anatomy and for planning appropriate selection of devices and employment strategies. He also demonstrated the role of 3D printing in development of new devices.

The panel discussion for this session addressed how to manage patients with pre-existing thrombus. The experts presented their views and experiences on this critical issue. Session chair Dr. Di Biase concluded by emphasizing that due to complexity, a team approach between electrophysiologists, non-invasive cardiologists, and interventionalists is critical.

Session 8:
This session was dedicated to discussing different surgical options for LAA occlusion. The first speaker was Dr. Basel Ramlawi, who discussed the pros and cons of a video-assisted thoracoscopic approach (VATS) versus a minithoracotomy for LAAO. His talk included videos and photos of how to exclude the LAA during a VATS and minithoracotomy. He also presented steps taken during the procedure to avoid injury to the left circumflex artery and other complications. He briefly presented studies being conducted using these 2 methods. He concluded that the surgical approach to exclude the LAA is the best option for patients who have a contraindication to anticoagulation and are at high risk for bleeding. He also presented preliminary long-term data of the AtriClip device (AtriCure), which demonstrated safety and efficacy of the technique.

Next, Dr. James Edgerton presented his expertise on post-procedural management of the AtriClip. He pointed out that evidence-based data are seriously lacking in addressing this issue. He compared his current practice with other prominent faculties in this field. He addressed common issues such as pericardial effusion, pericarditis, anticoagulation management, and the need for imaging. He stressed that there is no need for anticoagulation after a successful surgical LAAO.

After that, Dr. Ali Khoynezhad presented his views on robotic surgical techniques and their role in a currently growing percutaneous LAAO market. He briefly mentioned different surgical approaches for the management of AF, including the Cox-Maze IV procedure and AtriClip device. He presented a video demonstrating robotic technique, and described why the chance of aortic dissection is higher with this technique and is not optimal at this moment. He concluded his presentation by stating that the AtriClip is safe, effective, cost-effective, and should be an essential part of the LAAO armamentarium.

During the following panel discussion, session moderator Dr. Lakkireddy presented the scenario of not performing a follow-up imaging procedure and missing a thrombus. The surgeons on the panel vehemently defended their stance on the basis of their collective experience of approximately 60,000 patients. The panel discussed various surgical options for LAAO for patients with pre-existing thrombus.

Session 9: 
This session was dedicated to upcoming but lesser-known LAA occlusion devices. Dr. Sievert first presented video cases demonstrating the Lifetech LAmbre device. Following this, Dr. Kar presented his experience with the WaveCrest device (Coherex Medical). Both speakers presented on device design, mechanisms, and the limited available data with these novel devices.

Dr. Doshi presented the current status of lesser studied LAAO devices such as the Prolipsis, Occlutech, PFM Medical, and AEGIS, to name a few. He briefly outlined device design, uniqueness, and their potential role in the management of AF. He has an optimistic outlook that there will be more to be offered in this growing branch of electrophysiology.

In the concluding panel discussion, Dr. Samuel Asirvatham engaged the panelists in discussing the “nitty-gritty” of these device placements, and comparing them with existing technologies. 

Session 10: 
This session focused on trial updates for existing LAAO devices. Dr. Reddy started by providing updates pertaining to the WATCHMAN device. He discussed various data from the PREVAIL and PROTECT AF trials and EWOLUTION Registry. He also presented information on cost-effectiveness of the WATCHMAN device, highlighting that despite an initial increase in cost with the WATCHMAN device, it is dominant to NOACs after 5 years and to warfarin after 7 years. He also warned that cross analysis between different studies is hazardous in regards to comparing NOACs vs LAA occlusion. 

Next, Dr. Lee presented on the design and current status of the AMAZE trial, the first randomized prospective, multicenter trial involving the LARIAT. This trial will be reported in 2 stages: the first will focus on safety, and the second part will focus on efficacy. 

Dr. Tzikas then discussed currently available data for the Amplatzer. He presented data from the multicenter European ACP registry data, which showed safety and efficacy in 1047 patients. He discussed the astonishing reduction in rebleeding and ischemic stroke due to the ACP device in patients with previous IC bleeding of up to 89% and 75%, respectively. A similar reduction was also observed in patients with renal disease and patients >75 years. The first clinical IDE study for the ACP device is expected to start in Q4 of 2016.

Following that, Dr. Ramlawi presented historical and current data of surgical LAAO. He presented current status of open suture ligation, staple ligation, and direct surgical LAA closure. He raised concerns of recanalization and incomplete closure with these techniques. He emphasized the need for LAA exclusion with the AtriClip by presenting unpublished data from his own experience. He also presented the study design of the ATLAS study, evaluating the use of the AtriClip device to decrease complications associated with post-operative AF.

Session 11: 
This session focused on the role of oral anticoagulants in 2016. Dr. Larry Chinitz discussed data involving NOACs in AF, including from landmark trials such as the RE-LY, ROCKET AF, ARISTOTLE, and ENGAGE trials. He also presented current data from follow-up studies of these landmark studies and other real-world studies. He pointed out that all NOACs are substrate for P-glycoprotein metabolism and are susceptible to drug-drug interactions. He strongly advocated for NOACs to be considered as a first-line agent over warfarin. He also suggested that selection of NOACs should be based on individual patient characteristics. 

Dr. Di Biase furthered Dr. Chinitz’s talk by providing an algorithm on how to select one NOAC over another. He presented a network analysis comparing different NOACs with one another. With data from this study and other studies, he suggested that NOAC prescriptions should be individualized. He further discussed use of NOACs for special situations such as valvular heart disease, mechanical heart valve, chronic kidney disease, and the peri-AF ablation period.

Dr. Asirvatham addressed the most feared issue associated with NOACs: bleeding risk. He presented different ways of managing major bleeding episodes in an emergency. He also presented data on specific antidotes to NOACs, namely andexanet alfa (for factor Xa inhibitors) and idarucizumab (for dabigatran). He emphasized that unlike idarucizumab, andexanet alfa needs to continuously be infused to antagonize rebound factor Xa activity. 

Following that, Dr. Natale made a case that LAAO can be a viable option to the warfarin-ineligible population. He presented a series of surgical and non-surgical data supporting his conclusion. He suggested that the LAAO device can provide a significant benefit to this population and should strongly be considered. However, he cautioned against blindly using it in all patients. Considering the issues related to device implant and associated complications, he suggested that proper patient selection be performed. 

Another feared bleeding complication associated with OACs is GI bleeding. Dr. Lakkireddy presented on the role of octreotide therapy in microvascular GI bleeding. He suggested that the risk of GI bleed is 1-2% depending upon which medication is used. This risk is further compounded when used with other antiplatelet agents. He presented data on NOAC use in warfarin-ineligible patients, and noted that 48% of patients had repeat bleeding with GI bleeding as the most common cause. In addition, 30-40% of patients will have recurrence despite local GI therapy. To help these patients, he presented data on use of octreotide in patients with unexplained lower GI bleed while on NOACs. In this study, octreotide therapy fared better. He concluded by saying we should explore the role of adjuvant medications such as octreotide in patients at risk of GI bleeding. 

During the panel discussion for this session, the panelists discussed how to manage pericardial effusion and tamponade in a periablation procedure while on NOACs. Dr. Asirvatham stressed that FFP, cryoprecipitate, and factor VII have no role in reversal of NOACs. They further discussed the timing and need for surgery in cases for different types of cardiovascular perforation. Most of the panelists suggested that endocardial closure should be considered over surgical options for certain pericardial tears in appropriate cases. 

Session 12: 
This session was focused on practical issues pertaining to LAAO therapies.

Dr. Dukkipati presented his experience and shared practical tips on how to build a successful LAA referral program. He defined ways to educate patients and relevant health care professionals about LAA therapies. He outlined various sources to identify potentially eligible patients via internal and external referral pathways. He suggested that an LAAO program should be tailored on an individual basis for that particular institute.

Next, Dr. Brian Whisenant presented on regulatory and reimbursement issues related to LAAO. He highlighted key points from the recently published CMS NCD decision memo. He also demonstrated an app for calculating stroke and bleeding risk with and without anticoagulation therapy. By providing different examples in the use of patients, he suggested that this tool should be used cautiously. He also voiced his dissatisfaction on certain points in the current CMS NCD decision memo, and their implication for practice. 

Dr. Swarup then presented a multidisciplinary approach for the management of patients undergoing LAAO. He described the skill sets needed for successful placement of a LAAO device. He also discussed data from the CMS NCD decision memo, and highlighted the need for a non-interventional physician for regulatory requirements and shared decision making. He presented a list of stakeholders for the preparation of the procedure. He concluded that a cohesive multidisciplinary team of medical professionals is needed for the formation of a successful LAAO program. 

Dr. David Wilber presented on how to design a trial for LAA exclusion in warfarin-ineligible patients. He argued the need for a viable option for anticoagulation in patients with contraindication to OAC, and suggested that patients who are deemed ineligible for OAC because of high bleeding risk or previous bleeding episodes are also at high risk of thromboembolism. An alternate option to LAAO should be strongly considered. He presented ongoing trial data addressing this issue, and identified issues and challenges to perform a randomized multicenter trial. 

The session concluded with a lively discussion between panelists about what an ideal trial should look like, and if a trial comparing LAAO with NOACs is practical. 

Session 13:
In this final session, challenging cases were presented by the faculty. Dr. Holmes presented an interesting case of inferior epigastric artery dissection extending to the common femoral artery, which was worsened by bridging with enoxaparin. Dr. Reddy presented a case delineating the importance of a proper site for transseptal puncture, as well as tips and tricks of WATCHMAN device placement in a ‘chicken wing’ LAA. Panelists further discussed selection of appropriate sheaths for WATCHMAN placement. Dr. Edgerton presented different techniques and pitfalls associated with thoracoacopic LAA closure. After that, Dr. Kar presented a case of ACP placement that was found to be partially dislodged at 45-day follow-up TEE, which was retrieved percutaneously with the help of a snare. He attributed it to oversizing of the device. 

At the end of this session, Dr. Reddy concluded the symposium by thanking the attendees and sponsors. 

The audience received a fair amount of time to ask clinical questions to the keynote speakers. Additionally, several members of the audience shared their own thoughtful insights on the management of LAA exclusion devices. Overall, the fourth edition of this conference was a high-quality educational experience! 

The video sessions from this conference will soon be available at www.islaasymposium.com. The fifth edition of the ISLAA conference is scheduled for March 3-4, 2017 in Austin, Texas. 

What is the true value of education? 

As LAA closure procedures gain momentum and with CMS approval for reimbursement pending, this procedure will come to the forefront of clinical practice in a big way. Even factoring a conservative 10% of AF patients that are at high risk for stroke and recurrent bleed, we still have many patients that will benefit from this therapy. The onus is on the operators and their teams to be fully educated in the field. Without any doubt, ISLAA seems to provide a very comprehensive knowledge base that one needs to be proficient. Industry and physician organizations should recognize this effort, and partner with ISLAA to spread the message and enable all those who aspire to be involved in this space to be fully educated prior to starting their program. Manufacturers should encourage their potential users to embrace education as a key component to their skills acquisition. This will pave the way for a well-equipped operator with a thorough knowledge base and the necessary resources to ensure safe implementation of a new technology for the most optimal outcomes. The huge gap between the initial clinical trial data from experienced operators to real-life experience during the post-market phase can be significantly reduced by engaging new operators in thorough education. LAA closure devices are no different. A review of the recent MAUDE database clearly suggests the need for such an approach.