The APPEND-CT registry is an investigator-driven multicenter retrospective observational database intended to compile cardiac CT follow-up data after Watchman FLX device implantation and function as a platform for answering clinical and research questions within LAAC follow-up. The derived studies should support therapeutic decision-making, improve risk-stratification in LAAC and help generate hypotheses for potential future clinical intervention trials.

An investigator-driven multicenter retrospective observational database enrolling patients from high-volume North American and European centers. The database will include Watchman FLX implanted patients with a minimum of one follow-up cardiac CT performed within 45-120 days post-procedure. Additional timepoints may be entered. Cardiac CT scans are to be uploaded and will be analyzed by the core-lab at Aarhus University Hospital.

Investigator-reported findings will be systematically reported to the database. This includes information on baseline characteristics, preprocedural planning, implantation details, discharge medication, follow-up imaging and clinical endpoints of interest.

As a minimum, investigator-reported endpoints will be collected from patient registries at one-year follow-up by site-investigators. Endpoints of interest include ischemic stroke, systemic embolism, major bleeding, mortality, device-related thrombosis, pericardial effusion, vascular complications, and device migration.

Inclusion Criteria:

• Watchman FLX LAAO
• A minimum of one follow-up cardiac CT performed within 30-120 days post-procedure.
• A minimum of one year clinical follow-up data

Watchman FLX implanted patients with a minimum of one early follow-up cardiac CT.

Patient data will be registered under a pseudonymous registry-ID and will not be personally identifiable.