Although some observational studies suggest that the risk of throm- boembolism after cardioversion for atrial utter is low, even without anticoagulation, other studies have documented a similar risk of thromboembolism in patients after cardioversion for atrial utter and AF.140,162,163 This may be because AF and atrial utter often coexist. Recommendation 4.3. For patients with atrial utter undergo- ing elective or urgent pharmacologic or electri- cal cardioversion, we suggest that the same approach to thromboprophylaxis be used as for patients with atrial brillation undergoing cardioversion. 5.0 Practical Issues in the Management of VKA Therapy 5.1 Optimal Target INR Range For a full discussion of optimal target INR range with VKA therapy across a variety of indications, see Holbrook et al91 regarding evidence-based man- agement of anticoagulation in this guideline. With respect to patients with AF speci cally, several stud- www.chestpubs.org CHEST / 141 / 2 / FEBRUARY, 2012 SUPPLEMENT e569S and the Thrombosis Research Institute. She has also received support (travel and accommodation) to attend conferences from Astra- Zeneca and Boehringer Ingelheim GmbH. Dr Eckman has received a number of grants, including university grants for Using Decision Analytic Modeling to Guide the ACCP Guideline Development Process for Antithrombotic Therapy in Atrial Fibrilla- tion (Foundation for Informed Medical Decision Making; $185,000) and has the following industry grants: Cost-Effectiveness of Screening for Chronic Hepatitis C Infection (Merck/Schering- Plough; September 2012; $58,000) and Cost-Effectiveness of Screening for Chronic Hepatitis B Infection (Gilead Sciences Inc; $56,000). He served as a consultant for Savient Pharmaceuticals ($300). 