Introduction: Lower extremity deep vein thrombosis (DVT) and pulmonary embolism represents the third cause of cardiovascular disease, after acute myocar-dial infarction and stroke. It is necessary to establish wheather DVT was provoked or not by a certain factor, due to prognostic and therapeutic implications. The risk of recurrence in unprovoked DVT is 11% at 1 year and 40% at 10 years, without knowing very well the factors that mostly contribute to the recurrence. The treatment of DVT consists of low molecular weight he-parins (LMWH), antivitamin K (AVK) and direct oral anticoagulants (DOACs). DOACs were proved to be non-inferior to AVK in what efficacy and recurrence is concerned, with a superior safety profile. There aren’t in literature to many data about relapsed unprovoked DVT under all DOACs properly administered.

Methods: I will present the case of a 67 years old male, normal weighted, non-smoker, without known disease, who had recurrent deep vein thrombosis of legs under properly administrated anticoagulants, from october 2016 until february 2019. Meanwhile the patient had no risk factors for DVT, no significant thrombophilia and no cancer. For the first unprovoked DVT episode (left popliteal vein) the patient had rivaroxaban 6 months. At 1 month control after stopping rivaroxaban, there was a residual thrombus in the popliteal vein and D-Dimer level was within normal limits. The second DVT episode (left superficial femural vein: SFV) appeared at 9 months after stopping rivaroxaban. We had adminis-tred LMWH for 14 days, then we indicated dabigatran. At 6 months control under dabigatran the patient had a new DVT, in the right SFV. At patient wish we re-started rivaroxaban. We repetead cancer screening and made the thrombophilia profile (withou any major thrombophilia, only homozygote genotype + MTHFR C677T).

Results: After 2 months of properly administrated ri-varoxaban, we identified a new DVT in the left com-mon femural vein (CFV) and we changed rivaroxaban with apixaban. We have repetead the anticancer scre-ening (thoraco-abdominal computer thomography: non secretant suprarenalian incidentaloma). After 3 months under apixaban, the patient had a left exter-nal iliac vein thrombosis, rethrombosis of the left CFV and SFV, with aleft post thrombostic syndrome. For 3 months we have recommended LMWH, than AVK, wi-thout any thrombosis in the next 3 months.

Discutions: It is believed that DVT recurence under properly administrated anticoagulant treatment is gre-ater in cancer patients and in those with antiphospoli-pid syndrome. For our patient we did not detected any active cancer durind 2 years course, and due to high costs and the administration route, after 3 months of LMWH the patients wanted to give him pills instead of injections, so we switch to AVK. In a study published in 2018, the DOACs were directly compared with war-farin for the chronic phase of DVT treatment. DOACs were proved to have the same safety and efficacy profile as warfarin, the cancer was an independent risk factor for bleeding and rethrombosis in the warfarin treated group, not in the DOACs treated group. For our pa-tient we have experienced DVT reccurrence under all 3 DOAcs properly administretead available in Roma-nia. He refused to continue LMWH for more than 3 months, the only alternative left being AVK. According to data available in literature AVK have a geater risk of bleeding and rethrombosis than DOACs.

Conclusions: Repetitive, unprovoked DVT under pro-perly administrated anticoagulant treatment is very rare and assumes great therapeutic and prognostic challan-ges. For our knowledge it is the first case described in literature, of reccurrent DVT under all 3 DOACs.