Management of Antithrombotic Agents During Surgery or Other Kinds of Medical Procedures With Bleeding: The MARK Study

Background Optimal management of antithrombotic agents during surgery has yet to be established. We performed a prospective multicenter observational study to determine the current status of the management of antithrombotic agents during surgery or other medical procedures with bleeding (MARK [Management of Antithrombotic Agents During Surgery or Other Kinds of Medical Procedures With Bleeding] study) in Japan. Methods and Results The participants were 9700 patients who received oral antithrombotic agents and underwent scheduled medical procedures with bleeding at 59 National Hospital Organization institutions in Japan. Primary outcomes were thromboembolic events, bleeding events, and death within 2 weeks before and 4 weeks after the procedures. We investigated the relationships between each outcome and patient demographics, comorbidities, type of procedure, and management of antithrombotic therapy. With respect to the periprocedural management of antithrombotic agents, 3551 patients continued oral antithrombotic agents (36.6%, continuation group) and 6149 patients discontinued them (63.4%, discontinuation group). The incidence of any thromboembolic event (1.7% versus 0.6%,