Prevention of recurrent deep-vein thrombosis

The aim of this review is to outline recent randomized controlled trials and strategies that have tested various methods that aim to reduce the risk of recurrent venous thromboembolism (VTE) after the completion of anticoagulant therapy. Aspirin reduced VTE recurrence by approximately 30% (hazard ratio [HR], 0.68; 95% confidence interval [CI] 0.51–0.90) without any increase in bleeding. Dabigatran was effective in reducing VTE (HR, 0.08; 95% CI, 0.02–0.25) but carried a lower risk of major or nonmajor clinically relevant bleeding than warfarin but a higher risk than placebo: 5.3% in the dabigatran group and 1.8% in the placebo group (HR, 2.92; 95% CI, 1.52–5.60). Rivaroxaban was effective in reducing VTE (HR, 0.18; 95% CI, 0.09–0.39) but carried a higher risk of major or nonmajor clinically relevant bleeding than placebo: 6.0% in the rivaroxaban group and 1.2% in the placebo group (HR, 5.19; 95% CI, 2.3–11.7). Apixaban at either treatment dose (5 mg) or a thromboprophylactic dose (2.5 mg) reduced the risk of recurrent VTE from 8.8% in the placebo group to 1.7% in the apixaban group (Relative risk reduction of 81%) (P < 0.001%) without increasing the rate of major bleeding. Sulodexide reduced the risk of recurrence (HR, 0.49; 95% CI 0.27–0.92), without any increase in bleeding risk. Residual thrombus and elevated D-dimer are markers for increased risk of recurrence. Their presence when combined with other risk factors enables one to stratify patients into high, intermediate, or low risk of recurrence of VTE. Other markers enable one to stratify patients into high, intermediate, and low risk for bleeding. On the basis of the balance of risks for recurrence and bleeding, one can advise patients on the need for secondary prevention and the most suitable medication.