Efficacy of Short Term Dabigatran Etexilate Followed by Aspirin Monotherapy After LAA (Left Atrial Appendage) Device Closure (the DEA-LAA Study).

Single arm, prospective unblinded study on post Watchman LAA closure device implant anti-coagulation management at a primary center (Vanderbilt Medical Center) and up to 5 additional high volume LAA implant centers. This trial will be designed to evaluate the use of dabigatran for 90 days post implantation of an LAA closure device (Watchman LAA Closure Device, Boston Scientific Inc.).

The drug will be initiated on the morning following device implantation, taken BID per package insert dosing and until follow-up 90-day post implant TEE. Aspirin monotherapy will be utilized in conjunction at 81 mg for up to 12 months, after which the patients will be exited from the study and further treatment decisions will be made by the following physician (see Schedule of Study Procedures at end of protocol). The objective of this trial is to evaluate safety and efficacy of a 90-day period of dabigatran etexilate following LAA closure to prevent device associated thrombus, while minimizing adverse bleeding by eliminating the need for clopidogrel.

This is a single arm pilot study with the option (pending collaboration with additional funding source) to expand to a full single arm non-inferiority trial design with 80% power to detect a 1.4% difference with the non-inferiority margin 1% in absolute rate of DAT (control rate 3.9%).

Prospective, non-randomized single arm study. Comparison will be made to historical controls based on published one year DAT rates from PROTECT-AF, PREVAIL clinical trials, and EWOLUTION, and ACP/Amulet registries.

Echocardiography (TEE) will be performed at 90 days (3 months, +/- 2-week window), and again at 1-year post implant (+/- 4 weeks). Selected images will be interpreted by echo lab at coordinating center in an anonymous fashion (patient data de-identified). Ideal imaging will incorporate 0, 45, 90 and 135 degree angled views on the device at follow up.

Drug will be dispensed as part of the clinical trial supplied from the sponsor and each patient will receive a complete 90 days' supply up front. They will have a drug visit on the day of TEE with the research coordinator to hand back any remaining dabigatran, with clear instruction to stop the drug and only take ASA following confirmation of closure on TEE (no peri-device leak on Doppler of \>5mm). A decision to continue anti-coagulation post closure 90day TEE will be made by the physician discretion based on TEE findings. If thrombus is found at the 90 days TEE, anti-coagulation may be extended another 6 weeks with repeat TEE imaging to confirm clot resolution at the discretion of the investigator. In the unlikely event of embolization or Doppler leak \>5mm, decision on extending anti-coagulation, or re-implanting a device will be made by the following physician.