Left Atrial Appendage Occlusion Guided by Intracardiac Echocardiography from the Right Ventricular Outflow Tract

The mainstay of treatment for prevention of thromboembolic events in patients with atrial fibrillation remains systemic anticoagulation. In recent years, left atrial appendage occlusion (LAAO) devices have provided an alternative option. LAAO has traditionally been performed using transesophageal echocardiography (TEE) and fluoroscopic guidance.1.Masson JB Kouz R Riahi M et al.Transcatheter left atrial appendage closure using intracardiac echocardiographic guidance from the left atrium.Can J Cardiol. 2015; 31 (doi: 10.1016/j.cjca.2015.04.031): 1497.e7-1497.e14Google Scholar Recently, intracardiac echocardiography (ICE) has been used to guide implantation, avoiding the need for general anesthesia, reducing procedure time, and improving patient satisfaction2.Saw J Intracardiac echocardiography for endovascular left atrial appendage closure.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.07.002): 2207-2210Google Scholar ICE-catheter positioning can vary, though the largest published studies have positioned the catheter in the right atrium (RA), coronary sinus (CS) or left atrium (LA).3.Berti S Paradossi U Meucci F et al.Periprocedural intracardiac echocardiography for left atrial appendage closure: a dual-center experience.JACC Cardiovasc Interv. 2014; 7 (doi: 10.1016/j.jcin.2014.04.014): 1036-1044Google Scholar, 4.Korsholm K Jensen JM Nielsen-Kudsk JE Intracardiac echocardiography from the left atrium for procedural guidance of transcatheter left atrial appendage occlusion.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.06.057): 2198-2206Google Scholar, 5.Enriquez A Saenz LC Rosso R et al.Use of intracardiac echocardiography in interventional cardiology: working with the anatomy rather than fighting it.Circulation. 2018; 137 (doi: 10.1161/CIRCULATIONAHA.117.031343): 2278-2294Google Scholar Overall procedural success is high when imaging the left atrial appendage (LAA) from the RA, however the catheter angle and distance from the appendage can prohibit complete visualization, accurate measurements, and the ability to assess peri-prosthetic leaks. Catheter placement in the CS alleviates several of these issues, though it is not always accessible with ICE and carries with it an increased risk of perforation.2.Saw J Intracardiac echocardiography for endovascular left atrial appendage closure.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.07.002): 2207-2210Google Scholar The LA position allows optimal image acquisition, but is technically more complex and requires a second transseptal puncture.1.Masson JB Kouz R Riahi M et al.Transcatheter left atrial appendage closure using intracardiac echocardiographic guidance from the left atrium.Can J Cardiol. 2015; 31 (doi: 10.1016/j.cjca.2015.04.031): 1497.e7-1497.e14Google Scholar,4.Korsholm K Jensen JM Nielsen-Kudsk JE Intracardiac echocardiography from the left atrium for procedural guidance of transcatheter left atrial appendage occlusion.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.06.057): 2198-2206Google Scholar We sought to improve upon these limitations through demonstrating the feasibility of ICE-guided LAAO from the right ventricular outflow tract (RVOT) position. A series of 13 consecutive patients underwent LAAO with the Amulet LAA occluder (ACP-2, Abbott, IL, USA) using ICE guidance from the RVOT position. Pre-procedural cardiac computed tomography scan was used to visualize the LAA and rule out LA thrombus. Only conscious sedation was administered, avoiding the need for general anesthesia. Intra-procedurally, ICE was performed using a 9-French ViewFlex ICE catheter (Abbott) placed in the left femoral vein through an 11-French introducing sheath. The ICE catheter was advanced via the inferior vena cava into the RA and torqued to visualize the tricuspid valve. The catheter was then flexed anteriorly and advanced through the tricuspid valve into the right ventricle, followed by release of flexion and advancement into the RVOT. ICE imaging was used to guide transseptal puncture (RA position), measure the landing zone diameter for device sizing (RVOT position), guide catheter movement and assess for procedural complications (Figure 1). IRB approval for research of our LAAO database for outcomes based research was obtained but due to the retrospective nature of the study informed consent was waived. All 13 patients planned for ICE-guided LAAO underwent attempted device placement and were included in the analysis. Twenty-three percent of the patients were women and the mean patient age was 76.7 ± 11.9 years. The most frequent indication for device placement was a history of bleeding while on anticoagulation (85%), and 60% of patients had a previous ischemic stroke or transient ischemic attack (TIA) (Table 1).1.Masson JB Kouz R Riahi M et al.Transcatheter left atrial appendage closure using intracardiac echocardiographic guidance from the left atrium.Can J Cardiol. 2015; 31 (doi: 10.1016/j.cjca.2015.04.031): 1497.e7-1497.e14Google Scholar,3.Berti S Paradossi U Meucci F et al.Periprocedural intracardiac echocardiography for left atrial appendage closure: a dual-center experience.JACC Cardiovasc Interv. 2014; 7 (doi: 10.1016/j.jcin.2014.04.014): 1036-1044Google Scholar,4.Korsholm K Jensen JM Nielsen-Kudsk JE Intracardiac echocardiography from the left atrium for procedural guidance of transcatheter left atrial appendage occlusion.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.06.057): 2198-2206Google Scholar,6.Matsuo Y Neuzil P Petru J et al.Left atrial appendage closure under intracardiac echocardiographic guidance: feasibility and comparison with transesophageal echocardiography.J Am Heart Assoc. 2016; 5 (doi: 10.1161/JAHA.116.003695): 1-6Google ScholarTable 1.Baseline and procedural characteristics.(N = 13)Procedural characteristicsEchocardiography imagingICE PAProcedural success12 (92)Procedure time, min66 (55–78)Fluoroscopy time, min12 (11–18)Contrast volume, mL128 (112–173)Major complications0Patient characteristicsAge, yrs76.7 ± 11.9Female (%)3 (23)Congestive heart failure2 (15)Diabetes mellitus1 (8)Ischemic stroke or TIA8 (62)Prior bleeding11 (85)Left ventricular ejection fraction, %55 (53–55)Note. Values are mean ± SD, n (%), or median (IQR); IQR, interquartile range; TIA, transient ischemic attack. Open table in a new tab Note. Values are mean ± SD, n (%), or median (IQR); IQR, interquartile range; TIA, transient ischemic attack. The Amulet was successfully placed in 12 of 13 patients (92%), which approximates the success rate observed through ICE guidance from the LA position (89–94%).1.Masson JB Kouz R Riahi M et al.Transcatheter left atrial appendage closure using intracardiac echocardiographic guidance from the left atrium.Can J Cardiol. 2015; 31 (doi: 10.1016/j.cjca.2015.04.031): 1497.e7-1497.e14Google Scholar,4.Korsholm K Jensen JM Nielsen-Kudsk JE Intracardiac echocardiography from the left atrium for procedural guidance of transcatheter left atrial appendage occlusion.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.06.057): 2198-2206Google Scholar Unsuccessful placement in one patient was due to the inability to safely advance the sheath into the mouth of the LAA which had an anterior take-off—imaging in the patient was satisfactory. Compared to published procedure times by Korsholm et al.4.Korsholm K Jensen JM Nielsen-Kudsk JE Intracardiac echocardiography from the left atrium for procedural guidance of transcatheter left atrial appendage occlusion.JACC Cardiovasc Interv. 2017; 10 (doi: 10.1016/j.jcin.2017.06.057): 2198-2206Google Scholar using TEE (116 min; IQR 94–143) and ICE in the LA position (87 min; IQR 77–106), we report the shortest total procedure time with RVOT ICE placement (66 min; IQR 55–78). Despite the reduced procedure time, fluoroscopy time (ICE RVOT 12 min; IQR 11–18 vs. ICE LA 15 min; IQR 11–19 vs. TEE 14 min; IQR 10–22) was similar between cohorts. However, contrast volume (ICE RVOT 128 mL; IQR 112–173 vs. ICE LA 60 mL; IQR 47–71 vs. TEE 70 mL; IQR 55–82) was higher in the ICE RVOT cohort. All patients underwent same day discharge without complication and no patients had peri-device leaks on follow-up imaging. Though small, our single center cohort of ICE-guided LAAO is the first study to evaluate the feasibility and procedural characteristics of ICE catheter placement in the RVOT. These results suggest a potential procedural advantage of ICE guidance over TEE in regard to the risk of general anesthesia, procedure duration, and patient satisfaction while maintaining similar procedural success. The RVOT location provides comparable image quality to LA placement, while avoiding a second transseptal puncture and reducing the procedural complexity and complication risk. Accordingly, RVOT-ICE placement may represent an acceptable technique for ICE-guided LAAO and an incremental advancement in improving procedural efficacy. The authors report no conflicts of interest.