How I treat patients with hereditary antithrombin deficiency

Abstract

This issue’s How I Treat article offers valuable insights to clinicians caring for patients with congenital antithrombin deficiency and is likely to be especially helpful for clinicians who only see a few cases in their career.

Primary prophylaxis of venous thromboembolic disease with direct oral anticoagulants in patients with severe inherited thrombophilia

“…Shortly after her birth, she underwent aortic coarctation surgery, which was complicated by cardiogenic shock and thrombus formation in the descending aorta and left subclavian artery. Considering her personal and family thrombosis history and in agreement with international guidelines, 1 she was referred to us for genetic screening in 2006, which revealed the same mutation in the AT gene as in her mother. Her AT level was measured at 42%, based on a functional chromogenic assay.…”

“…To date, this patient has not presented with any further venous or arterial thrombotic events, in spite of not being administered any anticoagulant therapy. However, she has been advised to avoid contraceptives containing estrogen and was informed about the necessity of thromboprophylaxis in high‐risk situations, such as surgery, pregnancy, or long‐distance flights, as recommended in the literature 1 …”

“…Notably, the risk of thrombosis associated with AT deficiency depends on the defect type, with patients affected by a homozygous AT type II heparinbinding site defect bearing the highest risk. 1 Given their high VTE risk, we now consider conducting primary prophylaxis with a lowdose DOAC (eg, rivaroxaban 10 mg once daily or apixaban 2.5 mg twice daily) for individuals exhibiting AT deficiency with a positive VTE family history, yet without any personal VTE events in the past. This preventive approach is, nonetheless, not supported by published evidence.…”

“…Overall, individuals with AT deficiency display a greater risk of developing VTE than the general population, their relative risk of developing a first VTE being the highest among all inherited thrombophilia, 2 and especially high compared to other conditions predisposing to arterial or venous thrombosis (Table 1). Notably, the risk of thrombosis associated with AT deficiency depends on the defect type, with patients affected by a homozygous AT type II heparin‐binding site defect bearing the highest risk 1 . Given their high VTE risk, we now consider conducting primary prophylaxis with a low‐dose DOAC (eg, rivaroxaban 10 mg once daily or apixaban 2.5 mg twice daily) for individuals exhibiting AT deficiency with a positive VTE family history, yet without any personal VTE events in the past.…”

Direct Oral Anticoagulants in Antithrombin Deficiency: Initial Experience in a Single Center

“…Recently, a paper on the treatment of venous thromboembolism (VTE) in patients with hereditary antithrombin (AT) deficiency was published. 1 One of the issues the authors address is the use of direct oral anticoagulants (DOACs) and the duration of anticoagulation therapy in this specific patient population. Currently, clinical evidence on the use of DOACs in these patients is lacking.…”