A randomized, controlled trial found no benefit for the use of low-dose aspirin in APS patients. A meta-analysis found low-dose aspirin helps prevent a first arterial thrombosis, but not venous thrombosis.
“Our recommendation at this point is to [prescribe] low-dose aspirin [for] patients who have a high-risk profile—say they’re triple positive or [have] a very strong lupus anticoagulant [with or without the] presence of other thrombotic risk factors,” Dr. Sammaritano said. “This [decision] becomes very much a discussion between the physician and the patient, so the patient understands there’s no clear way to assess the benefit of [low-dose aspirin therapy]. But you can certainly talk to them about the relative risks in terms of bleeding.”
In patients with lupus, the recommendation for low-dose aspirin is stronger, she said.
Patients who are pregnant and have APS are routinely followed during pregnancy and anticoagulated for six to 12 weeks post-pregnancy, after which treatment is stopped. But Dr. Sammaritano noted a role for further treatment may exist. “If I have patients with obstetric APS, especially who have a high-risk profile, I routinely suggest they continue low-dose aspirin,” she said.
For secondary prevention of unprovoked venous thrombosis, she recommends lifelong warfarin, with a moderate goal of a 2.0 to 3.0 international normalized ratio. But she cautioned the literature on this approach is not clear. Her recommendation is based on a trial in which a high-intensity warfarin group was compared with a moderate-intensity group. The high-intensity group had subtherapeutic levels of the drug about half the time and, therefore, the comparison was less than optimal.2
“It’s a little bit hard to be 100% convinced this, in fact, proves moderate intensity is as effective [as high intensity],” Dr. Sammaritano said.
To prevent recurrent arterial thromboses, the most telling data come from a Japanese study of 20 patients from a cohort that fits the profile of a patient most clinicians will likely see. On average, the study patients were younger than 50, she said. The non-stroke survival was 25% in the aspirin group compared with 74% in the combination warfarin and aspirin group.3
Her recommendation for these patients is lifelong warfarin with an international normalized ratio goal of 3.0 to 4.0, or low-dose aspirin with a moderate warfarin goal of a 2.0 to 3.0 international normalized ratio.
Dr. Sammaritano said she is frequently asked whether direct oral anticoagulants have a role in such patients. Understandably so, she said, because the treatments are convenient. But the 2018 TRAPS study of rivaroxaban vs. warfarin in high-risk patients—all triple positive—was stopped early after the cumulative incidence of death, thromboembolism and major bleeding in the rivaroxaban group outpaced the warfarin group.4
