Non-vitamin K antagonist oral anticoagulants in patients with severe inherited thrombophilia: a series of 33 patients.

: The aim of the study was to investigate whether treatment with non-vitamin K antagonist oral anticoagulants (NOACs) is effective and well tolerated in real-life patients following venous thromboembolism (VTE) associated with severe inherited thrombophilia. We evaluated 33 consecutive patients with severe inherited thrombophilia, defined as the presence of deficiencies in protein C, protein S, or anti-thrombin, homozygous factor V Leiden and prothrombin G20210A mutations, or combined defects. The patients were recruited from March 2010 to December 2015 and followed till July 2016. Rivaroxaban was used in 23 patients (70%), whereas dabigatran and apixaban were used in 4 patients each. During a median 21 (range 8-34) months' follow-up, three recurrent VTE episodes (9%) were observed. Deep vein thrombosis recurred after 6 months on rivaroxaban in a protein S-deficient 32-year-old woman who had heavy menstrual bleeding resulting in interruptions of therapy. A long journey preceded deep vein thrombosis recurrence after 12 months of rivaroxaban use in a 59-year-old obese man homozygous for prothrombin 20210A mutation. The third recurrent VTE following anticoagulation withdrawal prior to surgery and during hospitalization was observed in a 56-year-old woman with protein S deficiency and heterozygous factor V Leiden. The three patients continued use of NOACs, apixaban, dabigatran, and rivaroxaban, respectively. This largest real-life series of patients with severe thrombophilia receiving NOACs indicates that such patients could be safely and effectively treated with NOACs. Lower efficacy was observed in protein S deficiency. Recurrent VTE was mostly related with nonadherence, which highlights an important role of regular intake of NOACs in high-risk patients.