Measurement of D-dimer concentrations may help clinicians predict who is at high risk of recurrent venous thromboembolism (VTE) after stopping anticoagulant therapy. Recurrent VTE occurs in as many as 30% of patients who discontinue therapy. Those at highest risk include patients who are male, are obese (>30 kg/m2), and had a proximal (vs distal) deep vein thrombosis. A recent prospective study of 608 patients evaluated the rate of recurrence after 3 months of oral anticoagulant therapy. Therapy was stopped after 3 months, then D-dimer levels were measured a month later. Patients with normal levels (n = 385) did not resume therapy. Patients with high levels (n = 223) were randomized to resume therapy or remain off anticoagulants. After an average of 1.4 years of follow-up, recurrence rates were 6.2% in the group with normal levels, 1.9% in the group that resumed therapy, and 15% in the group with high levels who remained off therapy. The authors concluded that high D-dimer levels predict high risk of recurrent VTE, and this risk can be minimized by restarting warfarin therapy.
Long-term therapy with anticoagulants lowers recurrent VTE risk but is associated with a 1% to 3% risk of major bleeding. Identifying patients with a low risk of recurrence is important in order to safely discontinue therapy as soon as possible. Current recommendations for a first episode of unprovoked VTE call for 6 to 12 months of therapy. The results of this study suggest that use of the D-dimer test may provide an alternate approach to therapy, although further evaluation is necessary to confirm safety and efficacy.
Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.
One study linked multiple pregnancies to an increased risk of developing atrial fibrillation later in life, and another investigated the association between premature delivery and cardiovascular disease.
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