Left atrial appendage occlusion guided by procedural fluoroscopy only: When and how to perform?

Abstract

Left atrial appendage occlusion (LAAO) hasdemonstrated to be equivalently effective in the prevention ofstroke and systemic embolism in nonvalvular atrial fibrillation comparable to warfarin and direct oral anticoagulants by randomized trials,1–3 with additional benefits of preventing/reducing the occurrence of disabling/fatal stroke, and decreasing mortality during long-term follow-up.4 There are mainly three types of LAAO devices, based on three different principles, including plug, pacifier, and ligation. The devices implanted by the endocardial approach are generally performed under transesophageal echocardiography (TEE) guidance with general anesthesia or deep sedation, or under intracardiac echocardiography or fluoroscopy alone with local anesthesia.5 The various modalities suit different clinical practices. It is important to evaluate the efficacy and safety of available technology. TEE with general anesthesia or intracardiac echocardiography with local anesthesia for the devices is well documented.6 Fluoroscopy alone with local anesthesia is mainly selected for the firstgeneration Amplatzer Cardiac Plug and second-generation Amulet,7 while few studies reported for the Watchman8 or LAmbre device.9 In the issue of PACE, Wang et al., reported a single-center prospective pilot study for the efficacy and safety of LAAO of the Watchman or LAmbre device guided by fluoroscopy only with local anesthesia.10 The study included 97 patients (50 in the Watchman group and 47 in the LAmbre group) after excluding nine patients unsuitable for LAAO. TEE was introduced for preprocedural and post-procedural imaging as recommended,5 while not used during operation. The procedure of transseptal puncture, diameter of the landing zone, position of the device, and peri-device leak were guided by fluoroscopy or angiography only. A well-performed LAAO is the basis of gaining a net clinical benefit of the patient. The study, thoughwithout direct comparisonwith other technology, yielded a high procedural success rate (97.9%), while the rate of the pericardial effusion that occurred in the early 20 cases of the Watchman group was 2.1%. The TEE among 94 patients (96.9%) at 3 months documented, any peri-device leak occurred in 17.5% and ≥5 mm in 0.0%; zero cases presented device-related thrombosis. During the 22.0 ± 11.1 months follow-up, two patients experienced ischemic stroke, and zero patients experienced major bleeding events. The performance of key indexes regarding success rate, peri-device leak, thrombus formation, device embolization, and stroke events was similar to other reported studies of Watchman11 or LAmbre device.12 The rate ofmajor complications was relatively higher in theWatchman group (4.1%) than theNCDRLAAOregistry,11 whichmaybe associated with the operators’ lack of experience since it occurred in the initial 20 cases as the authors explained.10 It is of concern that fluoroscopy alone may result in patients suffering more radiation and contrast exposure. A study reported similar fluoroscopy timeand total contrastmedium to the results of TEE guidance by a systematic review.12 It was reported;8 however, the fluoroscopy-alone group had a higher fluoroscopy time compared with the TEE-guided group, with short procedural time and low hospitalization cost. The first head-to-head study comparing the efficacy and safety of the Watchman and Amplatzer devices, guided by TEE with general anesthesia and fluoroscopy alone with local anesthesia respectively, demonstrated comparable results, which indicates the need to compare the different modalities of LAAO. There are some fluoroscopyalone LAAO studies reporting the usage of the Watchman or LAmbre device.8,9 Hence the next step is to establish a step-by-step approach like the AMPLATZER Amulet device. A randomized trial comparing the fluoroscopy alone to the TEE or intracardiac echocardiography is required. There are some limitations in this study. First, the patients were relatively younger and with no history of renal dysfunction, hence may have a good tolerance to contrast medium; second, the operators have extensive experience in catheter ablation, which could have further reduced procedural complications, procedural time and fluoroscopy time needed; third, the fluoroscopy was unable to find the thrombus formation during the procedure, therefore proper periprocedural imaging, achievement of targeted activated clotting time, and strict anticoagulation regimen were vital to prevent deviceassociated thrombus formation; fourth, the value of preprocedural TEE or cardiac computed tomography angiography for the decision of device selection and procedural fluoroscopy only approach, and the ideal views of angiography to assess the positioning of different types of devices and the peri-device leak need to be further studied. In conclusion, although this is a pilot study, it proposes that fluoroscopy alone with local anesthesia is an alternative modality for patients less tolerant to general anesthesia or as a more feasible and efficient option in an experienced center. Further head-to-head comparisons between different LAAOmodalities are required.