Which of the following is the most common complication of asymptomatic atrial fibrillation?

In choosing to treat a patient who has atrial fibrillation with oral anticoagulants, the balance of risks and benefits needs to be considered. Assessment of patients for these risk factors can be used to decide who should be treated with warfarin. There is a fourfold increase in the risk of stroke in patients with atrial fibrillation. CHADS2 is a modified stroke risk classification that integrates the above schemes. Congestive hea failure (C), hypeension (H), age greater than 75 years (A) and diabetes (D) are each assigned one point. Patients with previous stroke (S) are assigned two points. The CHADS2 risk assessment assists in determining the approach to antithrombotic treatment Anticoagulants are the treatment of choice in patients with atrial fibrillation and prior stroke or transient ischemic attack (TIA). Ref: 1. Taylor R.D., Asinger R.W. (2009). Chapter 29. Long-Term Anticoagulation for Cardiac Conditions. In M.H. Crawford (Ed), CURRENT Diagnosis & Treatment: Cardiology, 3e. 2. Easton JD et al. Apixaban compared with warfarin in patients with atrial fibrillation and previous stroke or transient ischaemic attack: A subgroup analysis of the ARISTOTLE trial. Lancet Neurol 2012;11:503.