What Lies Beneath Left Atrial Appendage Occlusion : Know Your Enemy

The purpose of this study was to assess the safety and efficacy of left atrial appendage (LAA) closure in nonvalvular atrial fibrillation (AF) patients ineligible for warfarin therapy. The PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that LAA closure with the Watchman device (Boston Scientific, Natick, Massachusetts) was noninferior to warfarin therapy. However, the PROTECT AF trial only included patients who were candidates for warfarin, and even patients randomly assigned to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation. A multicenter, prospective, nonrandomized study was conducted of LAA closure with the Watchman device in 150 patients with nonvalvular AF and CHADS₂ (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥1, who were considered ineligible for warfarin. The primary efficacy endpoint was the combined events of ischemic stroke, hemorrhagic stroke, systemic embolism, and cardiovascular/unexplained death. The mean CHADS₂ score and CHA₂DS₂-VASc (CHADS₂ score plus 2 points for age ≥75 years and 1 point for vascular disease, age 65 to 74 years, or female sex) score were 2.8 ± 1.2 and 4.4 ± 1.7, respectively. History of hemorrhagic/bleeding tendencies (93%) was the most common reason for warfarin ineligibility. Mean duration of follow-up was 14.4 ± 8.6 months. Serious procedure- or device-related safety events occurred in 8.7% of patients (13 of 150 patients). All-cause stroke or systemic embolism occurred in 4 patients (2.3% per year): ischemic stroke in 3 patients (1.7% per year) and hemorrhagic stroke in 1 patient (0.6% per year). This ischemic stroke rate was less than that expected (7.3% per year) based on the CHADS₂ scores of the patient cohort. LAA closure with the Watchman device can be safely performed without a warfarin transition, and is a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation. (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology [ASAP]; NCT00851578). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Aims Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk patients with non-valvular atrial fibrillation. The objective of the multicentre EWOLUTION registry was to obtain clinical data on procedural success and complications, and long-term patient outcomes, including bleeding and incidence of stroke/transient ischaemic attack (TIA). Here, we report on the peri-procedural outcomes of up to 30 days. Methods and results Baseline/implant data are available for 1021 subjects. Subjects in the study were at high risk of stroke (average CHADS2 score: 2.8 ± 1.3, CHA2DS2-VASc: 4.5 ± 1.6) and moderate-to-high risk of bleeding (average HAS-BLED score: 2.3 ± 1.2). Almost half of the subjects (45.4%) had a history of TIA, ischaemic stroke, or haemorrhagic stroke; 62% of patients were deemed unsuitable for novel oral anticoagulant by their physician. The device was successfully deployed in 98.5% of patients with no flow or minimal residual flow achieved in 99.3% of implanted patients. Twenty-eight subjects experienced 31 serious adverse events (SAEs) within 1 day of the procedure. The overall 30-day mortality rate was 0.7%. The most common SAE occurring within 30 days of the procedure was major bleeding requiring transfusion. Incidence of SAEs within 30 days was significantly lower for subjects deemed to be ineligible for oral anticoagulation therapy (OAT) compared with those eligible for OAT (6.5 vs. 10.2%, P = 0.042). Conclusion Left atrial appendage closure with the WATCHMAN device has a high success rate in complete LAAC with low peri-procedural risk, even in a population with a higher risk of stroke and bleeding, and multiple co-morbidities. Improvement in implantation techniques has led to a reduction of peri-procedural complications previously limiting the net clinical benefit of the procedure.

The purpose of this study was to investigate the frequency and clinical impact of incomplete left atrial appendage (LAA) sealing and consequent peri-device residual blood flow in patients undergoing percutaneous LAA closure with the Watchman device (Atritech, Inc., Plymouth, Minnesota). During percutaneous LAA closure for stroke prophylaxis, the geometric variability of the LAA ostium may result in an incomplete seal of the LAA. On the one hand, this could enhance thrombus formation and embolization of thrombi around the device into the circulation; on the other hand, the relatively small size of these leaks may preclude clinically relevant embolizations. Patients randomly assigned to device implantation in the PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial were analyzed. Transesophageal echocardiography was performed at 45 days, 6 months, and 12 months. Per the study protocol, patients discontinued warfarin therapy if the 45-day Transesophageal echocardiogram revealed either minimal or no peri-device flow (jet ≤5 mm width). The impact of peri-device flow severity, defined as minor, moderate, or major ( 3 mm, respectively) on the composite primary efficacy endpoint (stroke, systemic embolism, and cardiovascular death) is expressed as hazard ratio (HR) with 95% confidence interval (CI). Transesophageal echocardiography follow-up revealed that 32.0% of implanted patients had at least some degree of peri-device flow at 12 months. The HR of the primary efficacy endpoint per 1 mm larger per-device flow was 0.84 (95% CI: 0.62 to 1.14; p = 0.256). Compared to patients with no peri-device flow, the HRs were 0.85 (95% CI: 0.11 to 6.40), 0.83 (95% CI: 0.33 to 2.09), and 0.48 (95% CI: 0.11 to 2.09) for minor, moderate, and major peri-device flow, respectively (p = 0.798). Compared to patients with no peri-device flow who discontinued warfarin, the HR for patients with any peri-device flow and continuing warfarin was 0.63 (95% CI: 0.14 to 2.71; p = 0.530). These data indicate that residual peri-device flow into the LAA after percutaneous closure with the Watchman device was common, and is not associated with an increased risk of thromboembolism. This finding should be interpreted with caution as the low event rate decreases the confidence of this conclusion. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.