Perspective:

The following are 10 points to remember about the ninth edition of the Antithrombotic Therapy and Prevention of Thrombosis Guidelines:

1. For patients sufficiently healthy to be treated as outpatients, the guidelines suggest initiating vitamin K antagonist (VKA) therapy with warfarin 10 mg daily for the first 2 days, followed by dosing based on international normalized ratio (INR) measurements rather than starting with the estimated maintenance dose.

2. For patients with VKA-associated major bleeding, the guidelines suggest rapid reversal of anticoagulation with four-factor prothrombin complex concentrate rather than with plasma.

3. For long-distance travelers at increased risk of venous thromboembolism (VTE) (including previous VTE, recent surgery or trauma, active malignancy, pregnancy, estrogen use, advanced age, limited mobility, severe obesity, or known thrombophilic disorder), the guidelines suggest frequent ambulation, calf muscle exercise, or sitting in an aisle seat if feasible and against the use of aspirin or anticoagulants to prevent VTE.

4. In patients who require temporary interruption of a VKA before surgery, the guidelines recommend stopping VKAs approximately 5 days before surgery instead of stopping VKAs a shorter time before surgery.

5. In patients with acute DVT of the leg, the guidelines recommend early initiation of VKA (e.g., same day as parenteral therapy is started) over delayed initiation, and continuation of parenteral anticoagulation for a minimum of 5 days and until the INR is 2.0 or above for at least 24 hours.

6. In patients with a proximal deep vein thrombosis (DVT) of the leg provoked by surgery, the guidelines recommend treatment with anticoagulation for 3 months over: 1) treatment of a shorter period (Grade 1B), 2) treatment of a longer time-limited period (e.g., 6 or 12 months) (Grade 1B), or 3) extended therapy.

7. In patients with acute pulmonary embolism associated with hypotension (e.g., systolic blood pressure <90 mm Hg) who do not have a high bleeding risk, the guidelines suggest systemically administered thrombolytic therapy over no such therapy.

8. In patients with acute PE associated with hypotension and who have: 1) contraindications to thrombolysis, 2) failed thrombolysis, or 3) shock that is likely to cause death before systemic thrombolysis can take effect (e.g., within hours), if appropriate expertise and resources are available, the guidelines suggest catheter-assisted thrombus removal over no such intervention.

9. For patients with atrial fibrillation, including those with paroxysmal atrial fibrillation, for recommendations in favor of oral anticoagulation, the guidelines suggest dabigatran 150 mg twice daily rather than adjusted-dose VKA therapy (target INR range, 2.0-3.0).

10. In patients with cryptogenic stroke and patent foramen ovale or atrial septal aneurysm, the guidelines recommend aspirin (50-100 mg/d) over no aspirin.