Clinical Research Directory

DOAC Versus VKA in Patients With Non-high-risk APS : Prospective Cohort Study

Antiphospholipid syndrome (APS) is a thrombotic disease requiring prolonged anticoagulation. Direct oral anticoagulants (DOACs) are indicated as 1st-line therapy in venous thrombosis, compared with VKAs, due to their easier handling and lower bleeding risk for equivalent efficacy. In APS, VKAs are still the reference treatment. However, DOACs are generally introduced in the acute phase of venous, before the diagnosis of APS. VKA have the disadvantage of numerous food and drug interactions, and therefore require close monitoring of INR, at least once a month. Because they are easier to use than VKAs, and the risk of bleeding is lower, patients are often reluctant to switch from DOACs to VKA. Studies have shown that APS patients with high thrombotic risk (positivity of all three antiphospholipid tests, history of arterial or small vessels thrombosis or cardiac valve damage) have an increased thrombotic risk during DOACs vs. VKA treatment. Since 2020, the ISTH guidelines have suggested avoiding DOACs in high-risk APS, but suggest continuing theim in other patients if they were introduced for venous thrombosis and if follow-up on DOACs is reassuring. In the case of high-risk APS patients, the relay is therefore systematic. For non-high-risk patients (the majority), there are no data to justify systematic switch. Given the quality-of-life advantages of DOACs over VKAs, patients are not always in favor of changing their anticoagulant therapy, especially if they have been on it for many years with good tolerability. For these reasons, a number of patients with non-high-risk APS remain on DOACs. Nevertheless, the limited data available on the efficacy of DOACs in non-high-risk patients are of low level of evidence and contradictory. In 2020, a literature review of non-high-risk SAPL patients treated with DOACs reported that 8.6% of them experienced thrombotic recurrence within 12 months, with no possible comparison with VKAs. A recent retrospective study with 96 patients reported that 15.4% of patients treated with DOACs had a recurrence, compared to 5.3% on VKAs. However, this difference was not statistically significant (p=0.15) due to a clear lack of power. The objective is to determine the frequency of thrombotic recurrences and to compare it according to the type of oral treatment, anti-Xa versus VKA, in non-high-risk APS, through a cohort study with prospective follow-up. The patient's usual antithrombotic treatment, DOAC and VKA, will be continued unchanged.

OBServaToIre interNational Des Patients AnTiphospholipidEs traités Par Anticoagulants Oraux Directs

This registry will make it possible to collect large-scale data on SAPL patients, particularly those treated with DOACs, in order to better assess the frequency of thrombotic and hemorrhagic events in this population of "non-high-risk" thrombotic SAPL patients treated with DOACs. The results will help refine treatment recommendations and could form the basis of future clinical trials. In this study, there will be no modification of the usual care and no additional follow-up. Follow-up will be carried out during the patient's usual visits in the context of his or her pathology, the frequency of which will be left to the discretion of the usual physician. No additional consultations/hospitalizations/examinations will be carried out as part of the study. Data normally recorded in the medical record will be collected over a 5-year period, in line with standard patient follow-up.

On-X Aortic Prosthetic Heart Valve Low Dose Warfarin Post Approval Clinical Registry Study

The purpose of the proposed study is to assess the occurrence of bleeding, valve-related thromboembolism and valve thrombosis with the On-X Aortic Prosthetic Heart Valve when targeted at an International Normalized Ratio (INR) level of 1.8 (1.5-2.0 range) during a 5-year follow-up period. The objective will be to compare adverse event rates for patients in subgroups as listed below targeted at 1.8 (range 1.5 to 2.0) per On-X instructions for use to rates from the previous IDE trial (G050208).