This clinical trial is focused on studying the effects of certain medications on patients who have experienced perioperative atrial fibrillation after undergoing noncardiac surgery. Atrial fibrillation is a condition where the heart beats irregularly, which can sometimes occur after surgery. The medications being studied are known as non-vitamin K oral anticoagulants (NOACs), which help prevent blood clots. The specific medications included in this study are Apixaban, Edoxaban, Rivaroxaban, and Dabigatran. These medications are taken orally, meaning they are swallowed in the form of tablets or capsules.

The purpose of the study is to compare the effects of these NOACs with no anticoagulation treatment on preventing certain health issues. These issues include non-hemorrhagic stroke, which is a type of stroke not caused by bleeding in the brain, and systemic embolism, which is when a blood clot travels through the bloodstream and causes blockages. The study also looks at vascular mortality, which refers to deaths related to blood vessel problems, and other conditions like heart attacks and blood clots in the veins.

Participants in the study will be randomly assigned to receive either one of the NOACs or no anticoagulation treatment. The study will last for a period of up to 120 days, during which the health of the participants will be monitored to see how well the medications work in preventing the mentioned health issues. The goal is to gather information that could help improve treatment options for patients who experience atrial fibrillation after surgery.