Recurrent venous thromboembolism: association with thrombin generation and d-dimer

In patients with a first event of venous thromboembolism (VTE) clinicians must decide when to stop anticoagulation, evaluating the risk of recurrent thrombosis.

The aim of this study was to evaluate the association between recurrent VTE and d-dimer and thrombin generation.

Analyses were performed in 1895 individuals of the Multiple Environmental and Genetic Assessment of Risk Factors for Venous Thrombosis (MEGA) case-control study, followed up for recurrent VTE. The cumulative incidence of recurrent VTE, incidence rates, and hazard ratios were estimated by Cox proportional hazard regression models, to obtain rates and risks of VTE for different levels of d-dimer and thrombin generation.

Three classes of risk of recurrent VTE were shown: low risk for patients with low d-dimer and thrombin generation (incidence rate, 1.20/100 patient years; 95% confidence interval [CI], 0.75-1.62), intermediate risk for patients with either high d-dimer and low thrombin generation (2.31; 95% CI, 1.97-2.66) or low d-dimer and high thrombin generation (2.89; 95% CI, 0.06-5.73), and high risk for patients with high d-dimer and thrombin generation (4.70; 95% CI, 3.31-6.09).In the subgroup of patients with unprovoked VTE (n = 539), the 3 levels of risk of recurrent VTE were confirmed: low risk in patients with low d-dimer and thrombin generation (incidence rates per 100 patient years, 1.36; 95% CI, 0.42-2.30); intermediate risk in patients with high d-dimer (3.89; 95% CI, 3.07-4.70) and high risk in patients with high d-dimer and thrombin generation (9.80; 95% CI, 5.28-14.33).

The combination of these 2 tests allows identification of patients with high risk of recurrent VTE who could benefit from long-term anticoagulation.