Negative D-dimer Not Sufficient to Stop Anticoagulation in Men

Background : Patients with unprovoked VTE have high recurrence risk if anticoagulation is stopped after initial treatment. How to determine the need for long- term anticoagulation is unclear. D- dimer results have been proposed as a risk stratification tool, with low values suggesting lower risk of recurrence. Aims : To evaluate risk of recurrent VTE in patients with first unprovoked proximal DVT or PE and negative D- dimer test on anticoagulants and 1 month after stopping. Methods : After 3 to 7 months of anticoagulation, 410 patients had D- dimer levels on and at 1 month off anticoagulation. If both were negative patients remained off anticoagulation and were followed for median of 5.0 years; longest duration of follow up 7.5 years. Primary outcome was symptomatic recurrent VTE. We describe time to first recurrent VTE, the overall rate of recurrent VTE, and assessed changes in recurrence rates over time. Results : In 319 patients remaining off anticoagulants, recurrent VTE was 5.1% (60/319) per patient- year (95% CI 3.6 to 6.5); 7.5% per patient- year (95% CI 5.5 to 10.0) in men, 3.8% per patient- year (95% CI 2.0 to 6.6) in women with VTE not associated with estrogens, and 0.4% per patient- year (95% CI 0.0 to 2.3) in women with estrogen associated VTE (p\u3c 0.001 for 3- group comparison). The cumulative risk of recurrence at 5 years was 21.5% (95% CI 16.4 to 26.5) overall, 29.7% (95% CI 22.1 to 37.3) for men, 17.0% (95% CI 8.1 to 25.9) for non- estrogen women, and 2.3% (95% CI 0.0 to 6.8) for estrogenwomen. Annualized rate of recurrent VTE in non- anticoagulated patients was 7.8% in year 1, 7.5% in year 2, 2.9% in year 3, 3.8% in year 4, 2.1% in year 5 and 1.9% in year 6 or later. Conclusions : Negative D- dimer results in men with unprovoked VTE are not associated with low rates of recurrent VTE over time. (Table Presented)