What is the treatment for a patient who has had a venous thrombosis and elevated levels of aPL abs (secondary venous thrombosis prevention)?
Two prospective trials ( N Engl J Med 349:1133, 2003; J Thromb Haemost 3:848, 2005) have shown that after initial heparin therapy transitioning to moderate intensity warfarin therapy (INR: 2 to 3) is sufficient to prevent further venous clots. Because the risk of recurrent thrombosis without therapy is between 44% and 69%, most individuals will require lifelong anticoagulation. However, patients who had a provoked DVT (without a pulmonary embolus) due to a reversible risk factor (surgery, cast, estrogen therapy, pregnancy, immobilization) may be considered for withdrawal of anticoagulation after 6 months if the proximal venous clot has resolved on ultrasound and D-dimer is normal (controversial). Patients in the high-risk group (triple positive aPL abs, high-titer aPL abs or LA, previous history of clot, SLE, hereditary thrombophilia) should have lifelong anticoagulation even if the DVT was caused by mitigating factors.
