Anticoagulation Interruptus Not Without Risk

The need to withhold anticoagulation in patients requir-ing elective surgery poses a particularly importantchallenge when the risk of thrombosis and thrombo-embolism is high. In spite of the increasing use of prosthetic heart valves and the increasing prevalence of atrial fibrillation in the aging population, Kovacs et al1 make the important point in this issue of Circulation that there is a paucity of information in the literature to guide the clinician to optimal care. This observation motivated the design of the prospective study they report. Patients ’ anticoagulation therapy was discontinued before surgery. There were 3 reporting phases: preoperative, intraoperative, and postoperative. See p 1658 In the preoperative phase, warfarin was stopped 5 days before the procedure and replaced with dalteparin, a low-molecular-weight heparin administered at a dose of 200 IU/kg on the mornings of the third and second days before th