“Role of D-Dimer in One Year Recurrence of Venous Thromboembolism after Completed Anticoagulation Treatment” Following A First Idiopathic Deep Vein Thrombosis

After oral anticoagulant therapy (OAT) withdrawal, the recurrence of risk is greatest in the first year and gradually diminishes, while the increased bleeding risk may offset the benefits of prolonged OAT. the benefits of extending anticoagulation should be balanced against the risk of bleeding . D-dimer assay and measurement of residual thrombosis on ultrasonography, so-called residual vein obstruction (RVO) were proposed to be effective in selecting patients with idiopathic DVT Materials and methods: This single center prospective study was conducted in patients with a first episode of symptomatic proximal DVT, detected by compression ultrasonography (CUS), and who received OAT for at least 3 months. Follow-up was extended from Oct. 2011, to Aug. 2013. After enrollment, patients were re-evaluated at 1st, 6th and 12th months of their follow-up. At the first and 30-day visits, venous blood samples were taken for D-dimer test. All enrolled patients without RVT were stopped OAT. At each follow-up visit, we examined patients and inquired about health status, clinical symptoms or signs of recurrent VTE, bleeding, post-thrombotic manifestations, adherence to treatment, and concomitant analgesic or anti-inflammatory therapy. The end point outcomes were VTE recurrence or complete of this survey follow-ups. Results: A total of 68 eligible patients were enrolled. Four patients (two patients need to using long-term oral anticoagulation, and another two patients for lost to their first follow-up) were excluded. D-dimer and CUS at first was normal in 28 patients (44%) while the remaining 36 patients had abnormal D-dimer but normal CUS while both groups were not consuming their anticoagulant. Total follow-up was 52.5 patient-years. Median follow-up was 11 months (95% CI: 6–17 months). A minimum follow-up of 12 months was available in 44 patients (68%). During follow-up, three recurrent events were recorded (4.6% of patients – 95% CI: 3–7%). All Recurrent events were ipsilateral DVT. Among these index cases, all had an abnormal D-dimer at either T0 and/or T1. The recurrence rate was higher in males than in females (8.6% vs. 2.2%) with an abnormal D-dimer at T0 and/or T1 with a multivariate hazard ratio of 2.1 (95% 1.2–7; p=0.04). Patients older than 65 years had a higher rate of events than younger patients (2/ 12: (16%); 95% CI: 4–24% Vs. 1/ 52: (2%); 95% CI: 0.05–3%) and hazard ratio was about 3.8; (95% CI: 1.95–8.4 p= 0.04). Patients with recurrences had higher mean D-dimer at both T0 and T1 when compared with those without recurrences but the difference was significant only for D-dimer at T1. During follow-up, two patients died (3%). Conclusion: In our cohort of DVT patients, the annual risk of recurrence with an abnormal D-dimer, either during or at one month after VKA withdrawal, was 4.6% which is much lower to the annual risk of recurrence in most studies with idiopathic and provoked VTE. The benefits of extending anticoagulation should be balanced against the risk of bleeding. So according to these results of D-Dimer assay before withdrawal of OAT, this test is helpful for OAT withdrawal decision making.