• ABSTRACT
    • The eighth edition (AT8) of the American College of Chest Physicians (ACCP) Antithrombotic Therapy and Prevention of Thrombosis Guideline, published in June 2008, was a comprehensive presentation of primary studies and detailed discussions of rationale for recommendations. This resulted in an approximately 900-page Chest Supplement publication. Updating the guidelines in a succinct fashion posed a formidable challenge for the ninth edition (AT9), published in February 2012. The strategy adopted for AT9 was to publish an Executive Summary of the recommendations in a 50-page document in the Chest supplement highlighting the changes, with online publication of the full version. Major innovative changes include a recognition of the value of estimating the risk reductions in symptomatic, as opposed to asymptomatic (venographically), detected venous thrombosis, using nonconflicted methodologists as topic editors, new insights into evidence, and increasing emphasis on what is known about patients' values and preferences that have served to improve this edition of the guidelines. This review provides a summary of the updates of the guidelines for anticoagulation therapy and prevention of thrombosis. The AT9 recommendations are presented with, if included, the AT8 recommendations in parenthesis for comparison purposes.