Abstract 2000: Evaluation of Follow-Up Echocardiographic Assessment after Percutaneous Placement of the WATCHMAN Left Atrial Appendage Occlusion System for Embolic Protection in Patients with Atrial Fibrillation
Background: Stroke is the third leading cause of death in the U.S. Studies have revealed that the left atrial appendage (LAA) is the most common site for thrombi development. Although chronic anticoagulation with warfarin therapy is effective in decreasing events, there are numerous drug and dietary interactions and associated bleeding risks. The WATCHMAN LAA occluder device is an innovative device designed to prevent the embolization of thrombi that may form in the LAA. PROTECT AF is a multicenter, prospective randomized study enrolling patients with non-valvular, persistent, or permanent AF.
Methods: Transesophageal Echocardiography (TEE) was performed at baseline, implant, 45 day, 6 month, and 12month intervals. During implantation, TEE provided guidance for device placement and event monitoring. Subsequent follow-up imaging provided LAA and device anatomic and functional characteristics. All echo analysis was performed at a central core echo lab. Functional measurement of the LAA included pulsed and tissue dopper velocity imaging. Additional images of cardiac structure was also routinely evaluated including pulmonary veins and valvular competency.
Results: To date 94 of 96 patients have been successfully implanted with the WATCHMAN device. 161 baseline, procedural, and follow-up TEEs were evaluated. At baseline, mean LAA velocity was 38.9±19cm/sec which decreased to 26.9±21cm/sec at 45 days (p<.05). Tissue Doppler Imaging (TDI) in the medial aspect of the LAA averaged 9.3±5cm/s and decreased to 7.4±4.0cm/s at 45 days (p<.05). TEE aided in visualization of device implantation in all patients and after device implantation, mean device depth was 1.0 ± 0.7cm. Immediately after implantation of device, 26 (16%) of patient had flow around the device. At 45 day Follow-up, flow around the device was detected in 31 patients (NS from implantation). At 6 month follow-up, flow around the device was detected in 14 patients (3 measured greater than 3mm in size).
Conclusions: TEE helps to identify baseline, procedural and follow-up characteristics after device implantation. Further study will determine whether the WATCHMAN device is a potential effective alternative to chronic anticoagulation for the treatment of atrial fibrillation.