###Human: If I have had open heart surgery, how long should I take warfarin? ###Assistant: Hi. It depends upon the cause for which the surgery is being done, and what open heart surgery is being done. And if you have any indication for long-term anticoagulation like atrial fibrillation (abnormal heartbeat). I can provide you more insights only after knowing the complete details. Revert back to a cardiologist online for further help -->