If the patient was already on anticoagulation, or has high bleeding risk, then mechanical occlusion is a no brainer.

However, although mechanical occlusion is very appealing, I do not know if we have strong enough data for this "very scenario" (i.e., document LAA clot!), where device occlusion shows superiority over "reliable" oral anticoagulation alone.

Although we may rank this patient's CHADS2-VASCR risk of 1000! (just kidding), because we visualized the beast sitting in LAA by TEE, there may be many examples of these in real-life that come and go without us documenting them by TEE and treated with just anticoagulation and did fine.

In fact, in the late nineties and early 2000s, even before mechanical occlusion was available we treated these cases caught by TEE by oral anti-coaulgations alone, in some cases we repeated TEE in several weeks to make sure clot is gone, again no strong data to support that, all LOE "C".