Thyrotropin testing in recent-onset atrial fibrillation

The letter by Schreiber calls into question the methodology and presentation of our data on the results of thyroid screening in 726 patients with recent-onset atrial fibrillation.1This article attempted to determine the yield of routine screening in this population with a discussion of the resultant utility and cost implications. The first concern revolves around patient selection for the Canandian Registry of Atrial Fibrillation study.1Indeed, patients with transient atrial fibrillation surrounding cardiac surgery or other procedures warrant attention, but the purpose of this database was to establish the natural history of atrial fibrillation with current therapy in a patient population at significant risk for recurrent atrial fibrillation. These data do not necessarily generalize to all patients with atrial fibrillation, the management of which must be tailored to the individual clinical presentation. Second, Table 2 suggests that 18 patients had previous hyperthyroidism (6 taking thyroxine) and 44 patients