Douglas Gibson

Early safety and efficacy of percutaneous left atrial appendage suture ligation: results from the U.S. transcatheter LAA ligation consortium

BACKGROUND Transcatheter left atrial appendage (LAA) ligation may represent an alternative to oral anticoagulation for stroke prevention in atrial fibrillation. OBJECTIVES This study sought to assess the early safety and efficacy of transcatheter ligation of the LAA for stroke prevention in atrial fibrillation. METHODS This was a retrospective, multicenter study of consecutive patients undergoing LAA ligation with the Lariat device at 8 U.S. sites. The primary endpoint was procedural success, defined as device success (suture deployment and <5 mm leak by post-procedure transesophageal echocardiography), and no major complication at discharge (death, myocardial infarction, stroke, Bleeding Academic Research Consortium bleeding type 3 or greater, or cardiac surgery). Post-discharge management was per operator discretion. RESULTS A total of 154 patients were enrolled. Median CHADS2 score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism [doubled]) was 3 (interquartile range: 2 to 4). Device success was 94%, and procedural success was 86%. A major complication occurred in 15 patients (9.7%). There were 14 major bleeds (9.1%), driven by the need for transfusion (4.5%). Significant pericardial effusion occurred in 16 patients (10.4%). Follow-up was available in 134 patients at a median of 112 days (interquartile range: 50 to 270 days): Death, myocardial infarction, or stroke occurred in 4 patients (2.9%). Among 63 patients with acute closure and transesophageal echocardiography follow-up, there were 3 thrombi (4.8%) and 13 (20%) with residual leak. CONCLUSIONS In this initial multicenter experience of LAA ligation with the Lariat device, the rate of acute closure was high, but procedural success was limited by bleeding. A prospective randomized trial is required to adequately define clinical efficacy, optimal post-procedure medical therapy, and the effect of operator experience on procedural safety.

Catheter Ablation of Atrial Fibrillation in Octogenarians: Safety and Outcomes

AF Ablation in Octogenarians. Introduction: Radiofrequency catheter ablation (RFCA) is an effective treatment for atrial fibrillation (AF), although studies evaluating the role of RFCA have largely excluded elderly patients. We report the safety and outcomes of RFCA of AF in octogenarians.

Short and long-term outcomes of percutaneous left atrial appendage suture ligation: Results from a US multicenter evaluation

BACKGROUND Published studies of epicardial ligation of left atrial appendage (LAA) have reported discordant results. OBJECTIVE The purpose of this study was to delineate the safety and efficacy of LAA closure with the LARIAT device. METHODS This is a multicenter registry of 712 consecutive patients undergoing LAA ligation with LARIAT at 18 US hospitals. The primary end point was successful suture deployment, no leak by intraprocedural transesophageal echocardiography (TEE), and no major complication (death, stroke, cardiac perforation, and bleeding requiring transfusion) at discharge. A leak of 2-5 mm on follow-up TEE was the secondary end point. RESULTS LARIAT was successfully deployed in 682 patients (95.5%). A complete closure was achieved in 669 patients (98%), while 13 patients (1.8%) had a trace leak (<2 mm). There was 1 death related to the procedure. Ten patients (1.44%) had cardiac perforation necessitating open heart surgery, while another 14 (2.01%) did not need surgery. The risk of cardiac perforation decreased significantly after the introduction of a micropuncture (MP) needle for pericardial access. Delayed complications (pericarditis requiring >2 weeks of treatment with nonsteroidal anti-inflammatory drugs/colchicine and pericardial and pleural effusion after discharge) occurred in 34 (4.78%) patients, and the risk decreased significantly with the periprocedural use of colchicine. Follow-up TEE (n = 480) showed a leak of 2-5 mm in 6.5% and a thrombus in 2.5%. One patient had a leak of >5 mm. CONCLUSION LARIAT effectively closes the LAA and has acceptable procedural risks with the evolution of the use of the micropuncture needle for pericardial access and the use of colchicine for mitigating the postinflammatory response associated with LAA ligation and pericardial access.

Worldwide Experience with the Robotic Navigation System in Catheter Ablation of Atrial Fibrillation: Methodology, Efficacy and Safety

Worldwide Survey on Robotic AF Ablation. Introduction: The Hansen Robotic system has been utilized in ablation procedures for atrial fibrillation (AF). However, because of the lack of tactile feedback and the rigidity of the robotic sheath, this approach could result in higher risk of complications. This worldwide survey reports a multicenter experience on the methodology, efficacy, and safety of the Hansen system in AF ablations.

Bleeding Outcomes after Left Atrial Appendage Closure Compared with Long-Term Warfarin A Pooled, Patient-Level Analysis of the WATCHMAN Randomized Trial Experience

OBJECTIVES The purpose of this study was to compare the relative risk of major bleeding with left atrial appendage (LAA) closure compared with long-term warfarin therapy. BACKGROUND LAA closure is an alternative approach to chronic oral anticoagulation for the prevention of thromboembolism in patients with atrial fibrillation (AF). METHODS We conducted a pooled, patient-level analysis of the 2 randomized clinical trials that compared WATCHMAN (Boston Scientific, Natick, Massachusetts) LAA closure with long-term warfarin therapy in AF. RESULTS A total of 1,114 patients were included, with a median follow-up of 3.1 years. The overall rate of major bleeding from randomization to the end of follow-up was similar between treatment groups (3.5 events vs. 3.6 events per 100 patient-years; rate ratio [RR]: 0.96; 95% confidence interval [CI]: 0.66 to 1.40; p = 0.84). LAA closure significantly reduced bleeding >7 days post-randomization (1.8 events vs. 3.6 events per 100 patient-years; RR: 0.49; 95% CI: 0.32 to 0.75; p = 0.001), with the difference emerging 6 months after randomization (1.0 events vs. 3.5 events per 100 patient-years; RR: 0.28; 95% CI: 0.16 to 0.49; p < 0.001), when patients assigned to LAA closure were able to discontinue adjunctive oral anticoagulation and antiplatelet therapy. The reduction in bleeding with LAA closure was directionally consistent across all patient subgroups. CONCLUSIONS There was no difference in the overall rate of major bleeding in patients assigned to LAA closure compared with extended warfarin therapy over 3 years of follow-up. However, LAA closure significantly reduced bleeding beyond the procedural period, particularly once adjunctive pharmacotherapy was discontinued. The favorable effect of LAA closure on long-term bleeding should be considered when selecting a stroke prevention strategy for patients with nonvalvular AF. (WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy [PREVAIL]; NCT01182441).

Use of non-warfarin oral anticoagulants instead of warfarin during left atrial appendage closure with the Watchman device

BACKGROUND In the stroke prevention trials of left atrial appendage closure with the Watchman device (Boston Scientific), a postimplantation antithrombotic regimen of 6 weeks of warfarin was used. OBJECTIVE Given the clinical complexity of warfarin use, the purpose of this study was to study the relative feasibility and safety of using non-warfarin oral anticoagulants (NOACs) instead of warfarin during the peri- and initial postimplantation periods after Watchman implantation. METHODS This was a retrospective multicenter study of consecutive patients undergoing Watchman implantation and receiving peri- and postprocedural NOACs or warfarin. Transesophageal echocardiography or chest computed tomography was performed between 6 weeks and 4 months postimplant to assess for device-related thrombosis. Bleeding and thromboembolic events also were evaluated at the time of follow-up. RESULTS In 5 centers, 214 patients received NOACs (46% apixaban, 46% rivaroxaban, 7% dabigatran, and 1% edoxaban) in either an uninterrupted (82%) or a single-held-dose (16%) fashion. Compared to a control group receiving uninterrupted warfarin (n = 212), the rates of periprocedural complications, including bleeding events, were similar (2.8% vs 2.4%, P = 1). At follow-up, the rates of device-related thrombosis (0.9% vs 0.5%, P = 1), composite of thromboembolism or device-related thrombosis (1.4% vs 0.9%, P = 1), and postprocedure bleeding events (0.5% vs 0.9%, P = .6) also were comparable between the NOAC and warfarin groups. CONCLUSION NOACs proved to be a feasible peri- and postprocedural alternative regimen to warfarin for preventing device-related thrombosis and thromboembolic complications expected early after appendage closure with the Watchman device, without increasing the risk of bleeding.

2D and 3D TEE evaluation of an early reopening of the LARIAT epicardial left atrial appendage closure device

2D and 3D TEE evaluation of an early reopening of the LARIAT epicardial left atrial appendage closure device Luigi Di Biase, MD, PhD, FHRS, J. David Burkhardt, MD, FHRS, Douglas N. Gibson, MD, FHRS, Andrea Natale, MD, FHRS From the Texas Cardiac Arrhythmia Institute, St. David’s Medical Center, Austin, Texas, Albert Einstein College of Medicine at Montefiore Hospital, New York, New York, Department of Biomedical Engineering, University of Texas, Austin, Texas, Department of Cardiology, University of Foggia, Foggia, Italy, and Interventional Electrophysiology, Scripps Clinic, San Diego, California.

Left atrial thrombus formation after successful left atrial appendage ligation: case series from a nationwide survey.

Percutaneous left atrial appendage (LAA) exclusion can be performed using endocardial occlusion devices or an endoepicardially placed suture delivery device (1-3). Thrombus formation on endocardial occlusion devices (Watchman, Boston Scientific, Marlborough, Massachusetts; or Amplatzer Cardiac Plug [ACP], St. Jude Medical, St. Paul, Minnesota) (1,2) has been attributed to platelet aggregation in the setting of a foreign body in the left atrium (LA). With the percutaneous endoepicardial ligation technique (Lariat, SentreHEART, Redwood City, California), there is no foreign body left behind, and the risk of thrombus formation should be insignificant. This study describes the clinical course of LA thrombi after the Lariat procedure in 19 patients. We conducted a nationwide survey of physicians performing procedures with the Lariat device in the United States to identify patients who developed LA thrombus after the procedure. Our study cohort comprised patients found to have LA thrombus post-procedure. Post-procedure surveillance imaging was not uniform across centers. Most patients underwent transesophageal echocardiogram (TEE)/computed tomography at 1 to 3 months post-procedure. Anticoagulation/antiplatelet therapy was initiated immediately after detection of LA thrombus. We collected demographic, clinical, and pre-procedural imaging characteristics of patients. Procedural variables and clinical course of patients after thrombus detection were recorded. Statistical analyses were performed using SPSS version 19.0 for Windows (SPSS, Inc., Chicago, Illinois). A total of 47 operators participated in the survey. Routine post-procedure imaging was performed by 44 (93.6%) operators. Three (6.4%) operators performed imaging only if clinically indicated. Routine post-procedure follow-up imaging was performed at 1 to 3 months and 3 to 6 months by 80% and 40% of the operators, respectively. Of the 964 patients who underwent the procedure, 19 (2%) had an LA thrombus. Table 1 lists some patient characteristics and includes follow-up data of the 19 patients. TABLE 1 Patient Characteristics and Follow-Up (n = 19) LA thrombus was detected within 90 days in 15 (79%) patients. TEEs performed in the first 6 months were negative for thrombi in 2 patients with clots discovered >200 days after the procedure. Eighteen patients received oral anticoagulants after detection of LA thrombus, whereas 1 patient received antiplatelet therapy. Thrombus remained unchanged at 90 days in the latter patient, requiring a switch to rivaroxaban. Serial TEEs were performed until thrombus resolution. Oral anticoagulation was discontinued in 16 patients after clot resolution, whereas 3 patients with unresolved thrombi remained on anticoagulation (30, 58, and 80 days, respectively). None of the patients had clinical evidence of stroke or peripheral embolism during follow-up. Our study highlights that the risk of LA thrombus formation with the device is low (2%). Most (79%) cases were detected within the first 90 days. Prompt initiation of anticoagulation can lead to thrombus resolution. This is the first investigation to describe the clinical course of LA thrombus post-procedure in a large cohort of patients receiving the Lariat device. In a clinical study involving 89 patients, no case of LA thrombus was detected on the 30-day post-procedure TEE. However, 1 patient had an LA thrombus away from the site of occlusion at 1-year follow-up (3). Our study is consistent in that, although uncommon, an LA thrombus can develop after the procedure. The pathophysiology of LA thrombus formation after the Lariat procedure remains unclear. Focal endocardial damage and inflammation around the LAA orifice secondary to tissue compression from the Lariat suture, causing edema and ischemic necrosis around the ligation site, can increase the propensity for LA thrombus formation. In our study, 17 of 19 (89%) patients developed a thrombus at the ligation site. Currently, there are no clear guidelines on LA thrombus surveillance after LAA ligation. We strongly support a follow-up TEE 30 to 90 days post-procedure. Given that the risk of thrombus formation is greatest during the first 3 months post-procedure, it may be appropriate for patients to receive antiplatelet or anticoagulant therapy during this period. The risk of LA thrombus in the absence of anticoagulation use post-procedure is low and is more frequently seen during the first 3 months after LAA ligation. Periodic imaging studies are essential for early detection of an LA thrombus. With prompt initiation of anticoagulation and close supervision, an LA thrombus can be managed safely.

Visualization of lesion transmurality and depth of necrosis using an ablation catheter that incorporates ultrasound imaging: A small step or a major leap forward on the road to a more durable catheter ablation procedure for treatment of atrial fibrillation?

d t t d t Percutaneous catheter ablation has revolutionized the care of patients with atrial fibrillation. Pulmonary vein isolation has become the cornerstone of most ablation procedures for the treatment of atrial fibrillation following the observation by Haissaguerre et al that pulmonary veins were a frequent source of ectopic beats initiating atrial fibrillation. Pulmonary vein isolation may be combined with linear ablation or ablation of other targets for treatment of persistent or longstanding persistent atrial fibrillation. Pulmonary vein electrical reconnection to the left atrium is not uncommon and may be the primary reason for procedure failure among patients with paroxysmal atrial fibrillation. Pulmonary vein reconnections also have been demonstrated to be important triggers in patients with persistent atrial fibrillation undergoing repeat ablation. Recovery of conuction across linear ablation lesions is also likely to play a ole in procedure failure among patients with persistent trial fibrillation. With current technology, some tissue that is ablated recovers electrical activity. Any technology that could safely increase the probability that ablated tissue would remain ablated would be an important contribution. One reason for recovery of electrical activity may be that the original ablation lesion may not have produced transmural necrosis and subsequent scar. In this issue of Heart Rhythm, Wright et al report the results of an important ody of work that attempts to address this issue. In this roundbreaking piece of work, Wright et al designed and ested novel ablation catheters and electrodes that incorpoate ultrasound into the catheter tip for visualization of esion formation. The authors effectively demonstrated that n ablation catheter incorporating ultrasound visualization f lesion depth can accurately predict lesion transmurality

Device-Related Thrombus After Left Atrial Appendage Closure: Incidence, Predictors, and Outcomes

Background: In patients with atrial fibrillation, left atrial appendage closure with the Watchman device prevents thromboembolism from the left atrial appendage; however, thrombus may form on the left atrial face of the device, and then potentially embolize. Herein, we studied the incidence, predictors, and clinical outcome of device-related thrombus (DRT) using a large series of clinical trial cohorts of patients undergoing Watchman implantation. Methods: We studied the device arms of 4 prospective Food and Drug Administration trials: PROTECT-AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) (n=463); PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) (n=269); CAP (Continued Access to PROTECT AF registry) (n=566); and CAP2 (Continued Access to PREVAIL registry) (n=578). Surveillance transesophageal echocardiographs were performed at 45 days and 12 months in all patients, and also at 6 months in the randomized control trials. We assessed both the incidence of DRT during these transesophageal echocardiographs (and other unscheduled transesophageal echocardiographs), and clinical outcomes of postprocedure stroke or systemic embolism (SSE) and adjusted for CHA2DS2-VASC and HAS-BLED scores. Results: Of 1739 patients who received an implant (7159 patient-years follow-up; CHA2DS2-VASc=4.0), DRT was seen in 65 patients (3.74%). The rates of SSE with and without DRT were 7.46 and 1.78 per 100 patient-years (adjusted rate ratio, 3.55; 95% confidence interval [CI], 2.18–5.79; P<0.001), and ischemic SSE rates were 6.28 and 1.65 per 100 patient-years (adjusted rate ratio, 3.22; 95% CI, 1.90–5.45, P<0.001). On multivariable modeling analysis, the predictors of DRT were as follows: history of transient ischemic attack or stroke (odds ratio [OR], 2.31; 95% CI, 1.26–4.25; P=0.007), permanent atrial fibrillation (OR, 2.24; 95% CI, 1.19–4.20; P=0.012); vascular disease (OR, 2.06; 95% CI, 1.08–3.91; P=0.028); left atrial appendage diameter (OR, 1.06 per mm increase; 95% CI, 1.01–1.12; P=0.019); left ventricular ejection fraction (OR, 0.96 per 1% increase; 95% CI, 0.94–0.99; P=0.009). DRT and SSE both occurred in 17 of 65 patients (26.2%). Of the 19 SSE events in these patients with DRT, 9 of 19 (47.4%) and 12 of 19 (63.2%) occurred within 1 and 6 months of DRT detection. Conversely, after left atrial appendage closure, most SSEs (123/142, 86.62%) occurred in patients without DRT. Conclusions: After left atrial appendage closure with Watchman, DRT (≈3.7%) is not frequent but, when present, is associated with a higher rate of stroke and systemic embolism.