Page 10 - Journal of Structural Heart Disease Volume 2, Issue 1

Review Article
Figure 1. Amplatzer cardiac plug (ACP) device. The ACP device is a self-expanding nitinol mesh connected to a polyester disk through a central waist. The soft lobe mesh is deformable and deploys distally with anchors that insert into the LAA. This main- tains device stability within the LAA. The disk covers the ostium of the LAA sealing it (image courtesy of St. Jude Medical, Inc.).
antiplatelet therapy for 1 to 3 months followed by as- pirin alone for at least 5 months. Data for this device are limited and consist mainly of small, observational studies in patients not able to take anticoagulation. Initial trials in Europe demonstrated a high rate of procedural success, with 96% of patients successfully implanted in 137 patients [34]. Serious complications were reported in 10 patients (7%), including ischemic stroke, device embolization, and serious pericardial e usion. Data from the Asia Paci c experience and Canadian experience have demonstrated a similar high rate of implant success and similar rate of pro- cedural complications [35, 36]. Thrombus formation on the device has been reported [37-39]. The ACP device has CE mark approval but is not approved in the United States at this time. The new ACP 2 device has been implanted with reported improvements in design including an imbedded threaded insert to de- crease thrombus formation [40]. In the United States, a large, randomized, controlled trial of the ACP device compared to oral anticoagulation was recently halted
4 in likely anticipation of still pending FDA approval of
the WATCHMAN device [41]. WATCHMAN
The WATCHMAN device (Boston Scienti c, Natick, Massachusetts, USA) is the most studied LAA closure device currently in use. It consists of a self-expanding nitinol frame with porous polyethylene terephthal- ate membrane on the face of the device (Figure 2). The device is delivered through the femoral vein into the left atrium via transseptal access. A 14 French access sheath is carefully maneuvered into the LAA body. The device is loaded into the distal sheath and unsheathed with removal of the access sheath while maintaining distal position of the WATCHMAN device within the LAA. The device is secured in position with xation barbs present along the sides of the device which engage the endocardium.
This device has CE mark approval. It is the rst and only LAA closure device to receive FDA approved in the United States. It was evaluated in a large, random- ized, controlled trial in patients with nonvalvular AF who were eligible for warfarin therapy and high risk for thromboembolism. The WATCHMAN Left Atrial Appendage system for Embolic Protection in Patients With Atrial Fibrillation (PROTECT AF) enrolled 707 pa- tients who were candidates for long-term anticoag- ulation and had nonvalvular AF [42]. The PROTECT AF study was a multicenter non-inferiority trial that randomized patients in a 2:1 fashion to either LAA occlusion with the WATCHMAN device or to warfarin therapy. Patients 18 years old or older with nonval- vular AF were eligible for enrollment with a CHADS2 score greater than or equal to 1 (i.e., at least one of the following: congestive heart failure, hypertension, age greater than 75 years old, diabetes mellitus, pre- vious stroke or transient ischemic attack [43]). Exclu- sion criteria for the trial included contraindication to aspirin or warfarin, comorbidities other than AF that required chronic warfarin use, LAA thrombus, pat- ent foramen ovale with atrial septal aneurysm and a right-to-left shunt, mobile atheroma, and symp- tomatic carotid disease. Patients randomized to the device arm were placed on warfarin and aspirin for 45 days postimplantation. Device arm patients then underwent repeat TEE at 45 days of follow up. War-
Journal of Structural Heart Disease, February 2016
Volume 2, Issue 1:1-14