How Long Should Warfarin Be Taken For Atrial Fibrillation After My Aortic Valve Surgery?

Hi In Oct 2018 I had aortic valve surgery. Since then I have had irregular heart beat. About 8 weeks ago I experience a issue with beats and was concerned and I reached out my Doctor. He put me on a weekly monitor and determined I was having 5 different fluctuations some benign but AF was now present. He put me on Amiodarone 200 mg and Warfarin 5 mg... He indicated if stable that he would take me off eventually. Presently, I appear stable. When is a reasonable time of being stable to ask off of warfarin? What are you thoughts?