Patient flow and when APA testing was performed. At enrollment, all patients were receiving anticoagulants. At 1 month, patients with a positive D-dimer at enrollment remained on anticoagulants. At 7 months, patients with a positive D-dimer at enrollment or 1 month were receiving anticoagulants, and patients with a negative D-dimer at enrollment and at 1 month were not receiving anticoagulants.