The LAAO Registry dataset, comprised of approximately 300 data elements, was created by a panel of experts using available American College of Cardiology (ACC), Heart Rhythm Society (HRS), and Society for Cardiovascular Angiography and Interventions (SCAI) societal overview document guidance, data elements and definitions, previous trial data elements, and other evidentiary sources. Protected Health Information (PHI), such as social security number, is collected. The intent for collection of PHI is to allow for complete follow-up and tracking of the patient, to assist data managers in correcting data collection errors and improving data quality, for future registry interoperability and the potential for future generation of patient-level drill downs in Quality and Outcomes Reports (see section 11, Data Analysis and Statistical Considerations). Registry sites can opt out of transmitting direct identifiers to the National Cardiovascular Data Registry (NCDR), so inclusion of direct identifiers in the registry is at the discretion of the registry site. When using the NCDR web-based data collection tool, direct identifiers are entered but a partition between the data collection process and the data warehouse maintains the direct identifiers separate from the analysis datasets. The minimum level of PHI transmitted to the ACC when a participant opts out of submitting direct identifiers meets the definition of a Limited Dataset as such term is defined by the Health Insurance Portability and Accountability Act of 1996.