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The 6th International Symposium on Left Atrial Appendage: Highlights from the Annual Conference
The 6th International Symposium on Left Atrial Appendage (ISLAA) took place February 9-10, 2018 at the Westin Long Beach in Long Beach, California. ISLAA is a multidisciplinary cardiovascular educational symposium focused on the emerging science of the left atrial appendage (LAA). Once again, national and international researchers and experts shared a podium at ISLAA 2018 to discuss their experiences, innovative ideas, and continuing research. Among some of the noteworthy speakers were pioneers such as Dr. Andrea Natale, Dr. Samuel Asirvatham, and Dr. Saibal Kar. ISLAA offered informative presentations 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. In addition three live cases of left atrial appendage occlusion (LAAO), performed by Dr. Kar at Cedars-Sinai Hospital, were telecasted in-between sessions. The conference also included a lively exhibition of innovative technologies and cutting-edge tools from leading companies in the field.
Here we recap the main highlights of each session, including discussions on current clinical practice, constructive criticism raised, and future directions by each of the presenters who made ISLAA 2018 a success.
Fellows and Allied Health Professionals Conference
After Course Director Dr. Dhanunjaya Lakkireddy’s introduction of the 4th annual Fellows Boot Camp, Dr. Richard Wright began the session with a talk on imaging modalities for LAA visualization pre and post LAAO. He was followed by Dr. Shephal Doshi, who presented on the indications, challenges, and advancements thus far for cardiac resynchronization therapy (CRT). Next, Dr. Samuel Asirvatham described the different anatomical relationships and variations in the LAA and their impact on left atrial appendage closure (Figure 1).
Later, a workshop for fellows was held under the leadership of the above-mentioned speakers. The workshop started with the anatomical dissection of heart specimens, focused mainly on the LAA, under the guidance of Dr. Asirvatham (Figure 2). Multiple simulation labs were established, allowing the fellows to learn about different techniques of LAAO, transseptal punctures, and visualization of the LAA using transesophageal echocardiography (TEE). The fellow’s conference concluded with a reception.
Day 1
The conference then officially opened with Dr. Lakkireddy welcoming attendees from across the country and the world (Figure 3). ISLAA 2018 was covered extensively on social media platforms such as Facebook and Twitter. With live tweeting from speakers and the audience, the conference’s social media presence provided a great source of information for interested parties who could not attend.
Session 1
The first session focused on the anatomical aspects of LAAO and the use of different imaging modalities. Dr. Asirvatham opened the session with a discussion on LAA anatomy and close-by structures. He explained the importance of knowing these anatomical aspects about LAA for performing a LAAO procedure.
Next, Dr. Wright gave a presentation on pre- and post-procedural use of TEE to visualize and measure different dimensions of the LAA. He talked about the use of pre-procedural screening TEE to measure orifice diameter and exclude any thrombus in the LAA as being the most important factors to consider before pursuing LAAO in a patient.
This was followed by Dr. Sameer Gafoor’s talk on the utility of computed tomography (CT) imaging, pre and post procedure, for LAA exclusion. He went on to describe the advantages of coronary computed tomography angiography (CCTA) for imaging the LAA, which included but is not limited to, high spatial resolution, excellent three-dimensional relational depiction of the LAA and surrounding structures, as well as accurate measurements of maximal ostium diameter and depth of the LAA.
Next, Dr. Vivek Reddy joined the conference via Skype to present on the utility of intracardiac echo (ICE) for LAA closure. He began by discussing the implications for TEE, a current imaging standard for LAA closure. He then went on to cite some recent studies comparing TEE vs ICE, showing no difference in the procedural outcomes but a significant reduction in the time spent in the lab associated with the use of ICE.
Session 2
The next session began with a live case demonstration of WATCHMAN device (Boston Scientific) implantation by Dr. Kar from Cedars-Sinai Hospital.
This was followed by Dr. Lakkireddy’s talk on post-implant anticoagulation management, including current practices and the role of alternative regimens. He concluded by stating that the science of optimal “post-procedure oral anticoagulation therapy (OAT)” is still evolving, but that there is enough observational data, mainly from Europe, to support the use of modified post-procedure anticoagulation regimens in patients who are ineligible for OAT, and that NOACs are a reasonable alternative to warfarin as well.
Next, Dr. Vijay Swarup presented on the prevention, implications, and management of LAA closure device leaks. He noted that the key determinants of leaks are due to device sizing, orientation, and positioning. Additionally, he said that a flap-based technique has a theoretical advantage of a low incidence of leaks.
Lastly, Dr. Doshi talked about structural issues with the WATCHMAN device, and focused on areas of improvement in the future of device design. He described how the WATCHMAN FLX, which will soon be going into clinical trials, has tried to accommodate some of these features.
Session 3
Dr. Luigi Di Biase opened this session with his presentation on safe epicardial access. He started with the current indications and anatomical challenges for epicardial access, and went to on to describe the methods used to improve the safety of epicardial access procedures. He discussed the consistent technological improvements in the epicardial access tool box, especially the “access needle”, from the large Pajunk needle to a micropuncture needle with telescoping approach, to the EpiEP needle with fiberoptic pressure sensing at the tip, making epicardial access safer.
Dr. Randall Lee then presented a recorded case of LAA exclusion using the LARIAT Suture Delivery Device (SentreHEART, Inc.), going through each of the steps while explaining his rationale.
Next, Dr. Madhu Reddy gave a talk on pericarditis associated with epicardial access-dependent interventions, and how to prevent and/or manage this. He also shed some light on the utility of the pericardial drain to prevent accumulation of clinically significant pericardial effusions.
Session 4
This session started with a presentation by Dr. Maurice Buchbinder, who presented a recorded case demonstrating the challenges encountered while implanting a WATCHMAN device for LAAO, including a special focus on device embolization immediately upon release of the device. After this, Dr. Kar and his team presented another live demonstration of WATCHMAN device implantation.
This was followed by Dr. Lakkireddy, who provided insight on LAA occluder device embolization from a multicenter global registry. He concluded that the best way to manage LAAO device embolization is to prevent it.
Next, Dr. Thorsten Lewalter talked about the potential mechanisms and management of periprocedural LAA perforation. He mentioned that the risk of perforation is mostly during LAA angiography and sheath exchange with a stiff wire in LAA, but can rarely be associated with transseptal puncture. Once perforated, direct closure (by a cardiac surgeon) of the leak can be considered in rare cases, but immediate implantation of a LAA occluder can be lifesaving, especially if the surgeon is not readily available.
The session was concluded by Dr. Reda Ibrahim’s presentation on the management of a case of device embolization. He described the difference in retrieval techniques between devices, and what tools should be included in a device embolization toolbox.
Session 5
Dr. David Burkhardt opened this session with an excellent presentation on the management of leaks post-LAA ligation (both surgical and epicardial LARIAT). He noted that leaks, when present, lead to increased stroke risk; therefore, OAT or percutaneous closure using an ASD or coil closure is usually needed.
Next, Dr. Lee talked about the evolution of epicardial LAA exclusion techniques and devices. He mainly focused on the technological advances of the LARIAT Suture Delivery Device, and its safety profile over time. He also gave insight into the current status of the aMAZE trial.
This was followed by Dr. Andrea Natale’s presentation on the physiologic aspects of the LAA and the impact of LAA exclusion using the LARIAT on the some of these physiologic parameters. He also explored the impact of reservoir function of the LAA on left atrial function following LAA exclusion (Figure 4).
The last presentation of this session was by Dr. Lakkireddy, who talked about the role of LAA epicardial exclusion in the treatment of atrial fibrillation. He discussed the current state of non-paroxysmal AF ablation, as well as the current understanding of the role of LAA in arrhythmogenesis and how its isolation impacts the outcome. He concluded with a brief background and rationale behind the ongoing aMAZE trial.
Session 6
This session was dedicated to discussing challenging cases. The first case, presented by Dr. James Edgerton, was an 84-year-old female with LAA thrombus, which was the result of subtherapeutic INR while on warfarin. The patient was managed by continuing with an increased dose of warfarin.
Next, Dr. Brett Gidney presented a case refractory SVT, which was successfully terminated with LAA exclusion with the LARIAT Suture Delivery Device. This was followed by a case presentation by Dr. Ali Khoynezhad on LAA exclusion with the AtriClip (AtriCure, Inc.).
The final case of this session was presented by Dr. Ibrahim on LAA thrombus occurring intraoperatively, despite adequate anticoagulation, while preparing for AMPLATZER Cardiac Plug (ACP; Abbott) device implantation. He demonstrated the sandwich technique (using two devices) to close huge appendages with a clot in situ.
Day 2
Session 7
The first session of the day focused on ACP/AMPLATZER Amulet (Abbott) devices. The session started with a recorded case presentation by Dr. Apostolos Tzikas. He walked the audience through patient selection, pre-op workup, as well as tips and tricks of intraoperative device sizing and deployment of the Amulet device. He stressed the importance of deploying the ball of the device outside the appendage in the proximal part of the appendage or in the orifice of the pulmonary veins.
Next, Dr. Horst Sievert discussed LAA closure in patients undergoing TAVR. He presented data from a case series of 52 patients by Attinger-Toller et al,1 showing no significant differences in adverse events, clinical efficacy and mortality were noted. He concluded by discussing pros and cons of combining the procedure.
Dr. Jacqueline Saw then discussed the potential of the Amulet device to impinge on surrounding structures, and the importance of intraoperative device sizing to prevent this happening. She later discussed the pathophysiology, incidence, and implications of peri-device leaks, explaining the three common mechanisms for leaks: 1) ostial gap; 2) off-axis lobe; and 3) the sandwich technique. She recommended considering OAC or closure with a second device if leaks are larger than 3-5 mm.
Session 8
This session was dedicated to discussion about use of the AtriClip for LAA occlusion. Dr. Sacha Salzberg started by discussing the anatomical considerations for the AtriClip. He then presented long-term data on the AtriClip, which demonstrated safety and efficacy of the technique. He concluded that device-based closure techniques are superior to suturing, and stressed the importance of pre-procedural imaging.
Next, Dr. Gansevoort Dunnington presented a recorded case of LAAO with the AtriClip. He addressed common issues such as pericardial effusion, pericarditis, and anticoagulation management. Afterward, Dr. Christopher Gullett presented his views on post-procedural management after AtriClip placement. In his talk, he presented further data on the low thromboembolic events after AtriClip, and discussed the methodology of the ongoing ATLAS study. He explained that 15-50% of patients undergoing CABG might have post-operative atrial fibrillation and might benefit from a low-risk prophylactic AtriClip placement.
Session 9
This session focused on lesser-known LAAO devices. Dr. Jie Cheng first presented a recorded case demonstrating the LAAO using the LAmbre LAA Closure System (Lifetech Scientific). Following this, Dr. Sievert discussed the study design, endpoints, and outcomes of the available studies on the LAmbre LAA Closure System. He concluded by discussing the advantages of this device, including a unique anchoring mechanism to prevent device embolization, multiple sizes, and a provision for custom-made devices.
Next, Dr. Di Biase presented a recorded case of LAAO using the Sierra Ligation System (Aegis), and discussed how this unique technology is used when performing the procedure. He noted that the device is far from clinical practice, and data is lacking regarding procedural complications.
This was followed by Dr. Andrea Natale presenting his experience on the WaveCrest LAAO System (Coherex), describing the device design, mechanism, and a recorded case of the procedure.
Next, Dr. Sievert presented the current status and relevance of lesser-studied LAAO devices from PROLIPSIS, Occlutech, Cardia, and Acoredis. He briefly compared each device design and their potential role in the management of atrial fibrillation.
Session 10
This session focused on trial updates for existing LAAO devices. Dr. Kar started by presenting data from five-year outcomes of the PREVAIL and PROTECT AF trials. He showed that PROTECT AF met both the non-inferiority and superiority criterion when compared to coumadin at five years. Event rates of primary composite endpoint of ischemic stroke, hemorrhagic stroke, and CV/unexplained death in PROTECT AF were lower in the WATCHMAN arm when compared to coumadin. He also presented the results of the EWOLUTION trial, pointing out that the ischemic stroke rate with WATCHMAN is similar to that of the CHA2DS2-VASc matched cohort of coumadin.
Next, Dr. Lewalter presented data on LAAO in patients with contraindications to oral anticoagulation. His opening slides showed how contraindications to anticoagulation and risk of stroke are relative to each other. He discussed the results of the LAARGE registry, which reported on the real-world experience of LAAO in contraindicated patients. He also presented other ongoing trials in contraindicated patients and discussed the methodology of the CLOSURE-AF trial.
Dr. Lakkireddy then discussed currently available data for the ACP and Amulet devices. He presented data from the multicenter European ACP registry, which showed safety and efficacy of ACP in 1047 patients. He also noted the ~60% reduction of stroke and bleeding rates when compared to CHA2DS2-VASc and HAS-BLED matched controls. He then discussed methodology of the ongoing Amulet IDE study. He concluded by reporting on the outcomes of LAAO in a subgroup of patients with intracranial hemorrhage and gastrointestinal bleeding.
Following that, Dr. James Cox presented current data for device-based surgical LAAO. He presented upcoming devices that permit right-sided thoracoscopic surgical LAAO, and later discussed the methodology of the prospective randomized LAAOS III study, which will evaluate if LAA occlusion will reduce stroke in patients undergoing routine cardiac surgery.
Finally, Dr. Reddy discussed ongoing trials for the WaveCrest device. He first discussed the methodology of the randomized controlled WAVECREST 2 trial comparing the WaveCrest device with FDA-approved WATCHMAN device. He pointed out that the post-procedural regimen for the WaveCrest device included dual antiplatelet therapy for only three months. He then discussed the advantages of the device, including distal/proximal contrast injection and retractable anchors that help reposition the device.
Session 11
This session focused on the role of oral anticoagulants in 2018. The session started with a spirited debate between Dr. Rodney Horton and Dr. Di Biase on whether LAAO or oral anticoagulation is better for stroke prevention. Dr. Horton discussed some of the flaws associated with the PROTECT AF and PREVAIL study designs, and why a debate was necessary. He later presented data from these studies and discussed the favorable outcomes with WATCHMAN. He concluded by demonstrating the advantages of LAAO.
Dr. Di Biase also presented data from PROTECT AF and PREVAIL, pointing out how narrowly non-inferiority was met with the WATCHMAN group, primarily due to reduced intracranial bleeding rates with LAAO. He also discussed the better intracranial bleeding profiles seen with NOACs, and how there is no data comparing them with LAAO. He concluded by presenting data from a meta-analysis suggesting that NOACs might be better than LAAO when considering the overall complication profile.
Following the debate, Dr. Moussa Mansour spoke about transitioning LAAO from clinical trials to the real world. He started by presenting post-approval data on the WATCHMAN device, comparing their results to PROTECT AF and PREVAIL. He concluded that patient populations encountered in clinical practice might have a higher stroke risk and bleeding profiles, and post-procedural NOACs are feasible after LAAO.
Lastly, Dr. Reddy discussed what an ideal trial should look like when studying LAAO. He started by discussing other prominent trials including EWOLUTION and WASP. He then walked the audience through the ASAP-TOO trial, a well-designed randomized controlled trial studying the efficacy of LAAO in patients with contraindications to oral anticoagulation.
Session 12
Dr. Deering started this session with a brief overview of randomized controlled trial data comparing NOACs to warfarin. He noted that the absolute clinical benefits of NOACs are small when compared to warfarin, and that NOACs are neither non-inferior nor superior to warfarin. He concluded by stressing the importance of compliance, regardless of the agent used for anticoagulation.
Next, Dr. Mansour presented on NOACs and the need for LAA exclusion, presenting data on three key issues: 1) if NOACs are effective for stroke prevention; 2) if there is a risk of bleeding; and 3) If they are cost effective. He concluded that NOACs are better alternatives to warfarin. However, bleeding risks and non-compliance are still an issue. He emphasized that there is a need for effective means of stroke prevention without exposing the patient to bleeding events or requiring long-term anticoagulation.
Next, Dr. Gafoor presented data on triple therapy in patients with atrial fibrillation. The WOEST trial showed cumulative incidence of bleeding with triple therapy was 44% compared to 19.4% with dual therapy at 1 year after ACS. He concluded by providing alternatives to triple therapy in this patient population, including using a lower dose of NOACs, using clopidogrel over prasugrel or ticagrelor, and a lower INR target.
Dr. Subramaniam Krishnan then presented on non-LAA sources of thromboembolism. After presenting a case of thromboembolic stroke in a patient with left atrial septal pouch (LASP), he laid out the findings of smaller studies evaluating the incidence of thromboembolism in patients with LASP. He then discussed studies that showed a relationship between cryptogenic stroke and LASP. He concluded by determining that LASP is still an uncommon cause of thrombus.
Dr. Buchbinder concluded with a presentation on LAAO, offering several real-world scenarios in which LAAO would be vital. He presented data on peri-procedural complications and adverse event data on LAAO when compared to oral anticoagulation, showing superiority with LAAO. He discussed some of the limitations of anticoagulation, including compliance, cost, and bleeding rates. He presented a summary of the advantages of LAAO, and left the audience to decide if LAAO has reached the “prime time”.
Session 13
In the final session of the symposium, challenging cases were discussed by the faculty. Dr. Abdi Rasekh presented a case of concomitant atrial fibrillation ablation and LAAO. After an extensive discussion of pros and cons, he concluded that LAAO can be an important addition for improving success rates for paroxysmal atrial fibrillation ablation. Next, Dr. Doshi presented an interesting case of LAAO with the WATCHMAN device in a patient with a large appendage and spontaneous echo contrast, concerning for thrombus. Drs. Gafoor, Horton, and Edgerton then presented further cases on LAAO.
Dr. Lakkireddy then concluded the symposium, and the audience received a fair amount of time to ask clinical questions to the keynote speakers (Figure 5).
Dr. Di Biase also received the “Chicken Wing” award for his significant contribution to the field of LAA (Figure 6).
Overall, the sixth edition of this conference was a high-quality educational experience! The video sessions from this conference are available at www.islaasymposium.com. The seventh annual ISLAA conference is scheduled to take place at the Sheraton Overland Park Hotel in Kansas City on August 17-19, 2019.
Reference
- Attinger-Toller A, Maisano F, Taramasso M, et al. “One-stop shop”: Safety of combining transcatheter aortic valve replacement and left atrial appendage occlusion. JACC Cardiovasc Interv. 2016;9(14):1487-1495.
