In the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, in which many patients in the rhythm control arm did not receive anticoagulation, patients in a rhythm control strategy had a similar risk of stroke compared with patients in a rate control strategy (see also section 4.1.1).125 There are several RCTs of catheter ablation vs AAD therapy in patients with AF, typically those who have failed rst-line therapy with AADs.126-132 All trials found a signi cant reduction in AF recurrence at 1 year of follow-up. However, AF recurrence in the catheter ablation arms ranged from 11% to 44% at 1 year. The studies rarely reported on stroke outcomes, and all were underpowered to address this question. Given the results of the AFFIRM trial, the lack of longer-term follow-up data from catheter ablation RCTs regarding AF recurrence rates, and poor reporting of stroke outcomes, it would be pru- dent to base decisions about long-term antithrom- botic therapy on a patient s underlying risk for stroke as recommended in section 2.1, and not on their underlying rhythm. Recommendation 3.4. For patients with AF being managed with a rhythm control strategy (pharmacologic or cath- eter ablation), we suggest that antithrombotic therapy decisions follow the general risk-based recommendations for patients with AF in sec- tion 2.1, regardless of the apparent persistence of normal sinus rhythm (Grade 2C). 3.5 Patients With Atrial Flutter Many patients with persistent atrial utter have periods of atrial utter alternating with periods of AF.133,134 The prevalence of thrombus in the body of the atria and atrial appendage on TEE in patients with atrial utter ranges from 1% to 21%.135-138 There are few data from longitudinal studies assessing the risk of thromboembolism with well-documented sustained atrial utter. 