Secondary prophylaxis of venous thromboembolism (VTE) with low dose apixaban or rivaroxaban in major-thrombophilia carriers.

Direct oral anticoagulants (DOACs) are widely used for treatment and secondary prophylaxis of venous thromboembolism (VTE) and represent the gold standard for VTE secondary prophylaxis, with low-intensity DOACs administration becoming increasingly used worldwide in such scenario. Albeit widespread DOACs usage there are few literature data regarding their efficacy and safety in major thrombophilia carriers and almost no data is available for low intensity apixaban and rivaroxaban as secondary VTE prophylaxis in such patients. The aim of our study is to evaluate and confront the efficacy and safety of low-dose DOACs for VTE secondary prophylaxis, in major thrombophilia carriers vs patients at high risk of VTE recurrence for other reasons. We retrospectively evaluated patients who required long-term anticoagulant secondary prophylaxis to prevent recurrent VTE, treated with apixaban 2.5 mg BID or rivaroxaban 10 mg daily and that were screened for thrombophilia. The examined patients were 339. Baseline characteristics such as sex, age, obesity rate, smoking, number of previous VTEs and comorbidities (such as cardiovascular diseases, diabetes, mild CKD) were equally distributed in either group. The median low-dose DOACs administration time was 19.20 months (IQR 12.17-35.67). During low-dose DOACs treatment, 13 (3.8%) VTE recurrences were observed; 14 bleeding events were registered (4,1%), with no major bleeding (MB), 6 clinically relevant non major bleeding (CRNMB) (1.8%) and 8 minor bleeding (2.3%). No statistically significant difference in the rate of VTE recurrence and/or bleeding events emerged between major thrombophilia carriers and non-major thrombophilia carriers. In multivariate analysis increased risk of VTE recurrence was found for patients with cardiovascular comorbidities (HR 4.00 - p = 0.034) and for patients with more than one previous VTE episode (HR 5.14 - p = 0.034). Our data suggest that low-dose DOACs may be effective and safe in secondary VTE prophylaxis for carriers of major thrombophilia with no increase in VTE recurrence and/or bleeding risk.