The Fourth Left Atrial Appendage Occlusion Study: (LAAOS-4)

Brief description of study

The purpose of the LAAOS-4 study is to determine if closure of the left atrial appendage using a closure device called the WATCHMAN™, in addition to taking oral anticoagulant medications, is more effective at reducing strokes and blood clots in your body, than taking oral anticoagulant medications on their own.

The comparison being tested in this study is whether or not having a WATCHMAN™ Device implanted will help in preventing strokes and blood clots in people taking anticoagulant medication, compared to people taking anticoagulant medication without a device.

One group of participants will receive the WATCHMAN™ Device (called the “Anticoagulation and Device” or “Device” group), and the other group will not receive the device (called the “Anticoagulation” group). Both groups will continue to take anticoagulant medications prescribed by their regular doctor.

Participants will be randomly divided (like a flip of a coin) into one of the two groups to be compared in this study:

  • Anticoagulation and Device Group: This group will undergo WATCHMAN™ Device implantation.
  • Anticoagulation Group: This group will not have the device implanted but will continue their anticoagulation medications for the duration of the study.


Clinical Study Identifier: s24-00056
ClinicalTrials.gov Identifier: NCT05963698
Principal Investigator: Larry A Chinitz.
Other Investigator: Anthony Aizer.


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