Rheumatologists may soon be able to leverage several new aPL tests in APS diagnosis and risk calculation. The most promising of these is the test for phosphatidylserine-dependent antiprothrombin antibodies. Other tests, such as for antibodies to domain I of β2GPI, are being investigated. Unfortunately, there are not yet any official recommendations for these.
Prevention
Dr. Erkan also updated the audience on primary and secondary thrombosis prevention, noting, “It’s easy because there’s no update.” He reiterated that, in the case of primary thrombosis prevention, risk stratification is critical. The ideal strategy should stratify risk based upon aPL profile, age, traditional cardiovascular risk factors, venous thrombosis risk factors and systemic autoimmune disease. Any non-aPL thrombosis risks should be investigated regularly and eliminated and/or treated rigorously.
Although the effectiveness of low-dose aspirin is not supported by randomized controlled data, Dr. Erkan explained that “aspirin can be effective, based on all retrospective studies.” Therefore, he recommends that general cardiovascular disease guidelines play a role in decision making for low-dose aspirin therapy. He added, however, “In my practice, aspirin is not an automatic reaction to a positive aPL result.”
Likewise, when it comes to secondary thrombosis prevention, rheumatologists should stratify risk and regularly investigate non-aPL thrombosis risk factors, eliminating and/or treating them rigorously. Randomized, controlled trials do not support the use of high-intensity (international normalized ratio 3–4) anticoagulation for these patients; however, it may be considered in patients at very high risk of thrombosis.
Dr. Erkan also pointed out that the necessity of lifelong anticoagulation for every APS patient is not well established; discontinuation of anticoagulation may be considered in APS patients with a single venous thrombosis occurring with a clear thrombosis trigger, such as birth control pills.
CAPS Guideline
Dr. Erkan provided the audience with an update on the clinical practice guideline recently submitted—but not yet published—on the diagnosis and management of catastrophic APS (CAPS), a project funded by the European Rare Practices Initiative and guided by methodologists from McMaster University, Canada. He called CAPS “a very difficult topic” and emphasized the importance of early and aggressive treatment. Standard treatment includes anticoagulation plus corticosteroids plus intravenous immunoglobulin (IVIG)/plasma exchange, possibly with rituximab.
DOACs & More
In the remainder of his talk, Dr. Erkan discussed the role of direct oral anticoagulants (DOACs), such as rivaroxaban, apixaban, adoxaban and dabigatran, in the management of APS. He shared the 15th International Congress on aPL Task Force on Treatment Trends Recommendation, which was that “insufficient evidence exists to make recommendations at this time regarding DOAC use in APS.” Thus, Dr. Erkan recommended against the use DOACs in APS until the results of controlled trials using clinical outcome measures are available.