Anticoagulation withdrawal in antiphospholipid syndrome: a retrospective matched-control study

Background/Purpose Long-term anticoagulation is the standard treatment for thrombotic antiphospholipid syndrome (APS). However, in daily practice, the question of withdrawing anticoagulation may arise, without any evidence-based recommendations. This study aimed to assess outcomes in APS patients after anticoagulation withdrawal. Methods Thrombotic APS patients followed in our centre, whose anticoagulation was withdrawn after APS diagnosis, were retrospectively selected, and were match-controlled with patients under anticoagulation, based on sex, age, APS clinical phenotype and disease duration. Results Thirty cases with anticoagulation withdrawal were included. Median follow-up was 51 months (12-124). The risk of thrombotic relapse was higher in cases compared to controls (7.3% versus 1.5% patient-year ( p = 0.01); hazard ratio 4.8; 95% confidence interval (1.4-16.7)). Male gender, anti-β2GP1 and triple positivity at inclusion were predictive factors for thrombotic relapse. Conversely, aspirin prescription was a protective factor against relapses. Persistence of LA, anti-β2GP1 and triple positivity over time were associated with a higher risk of thrombosis and aPL disappearance with a lower risk. Conclusion In our study, anticoagulation withdrawal was associated with an increased risk of thrombotic relapse. Our findings emphasize the influence of anti-β2GP1 and triple positivity persistence over time on the risk of relapse and the benefit of aspirin prescription when anticoagulation has been withdrawn.