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Evidence summaries

Antiplatelet and Anticoagulant Agents for Secondary Prevention of Stroke and other Thromboembolic Events in People with Antiphospholipid Syndrome

Rivaroxaban compared with standard-dose warfarin appears to increase the risk of stroke and may not alter other outcomes (any thromboembolic events, major bleeding, mortality) for secondary prevention of recurrent thrombosis in people with antiphospholipid syndrome. Level of evidence: "B"

Comment: The quality of evidence is downgraded by imprecise results (wide confidence intervals).

Summary

A Cochrane review [Abstract] 1 included 8 studies with a total of 811 subjects with antiphospholipid syndrome (APS). The duration of intervention ranged from 180 days to a mean of 3.9 years.

  • Rivaroxaban vs. warfarin (3 studies, n=425): There were no differences in any thromboembolic event (including death) and major bleeding, but an increased risk of stroke (RR 14.13, 95% CI 1.87 to 106.8). One of the studies reported a small benefit of rivaroxaban in terms of quality of life at 180 days measured as health state on visual analogue scale (MD 7 mm, 95% CI 2.01 to 11.99), but not measured as health utility on a scale from 0 to 1 (MD 0.04, 95% CI -0.02 to 0.10).
  • High-dose warfarin (target INR of 3.1 to 4.0) vs. standard warfarin (target INR of 2.0 to 3.0) (2 studies, n=223): There were no differences in the rates of any thrombotic events (RR 2.22, 95% CI 0.79 to 6.23) or major bleeding (RR 0.74, 95% CI 0.24 to 2.25) between the groups. Minor bleeding analyzed using the RR and any bleeding using the HR were more frequent in patients receiving high-intensity warfarin compared to the standard therapy (RR 2.55, 95% CI 1.07 to 6.07; and HR 2.03, 95% CI 1.12 to 3.68).
  • Standard dose warfarin plus single antiplatelet agent (aspirin 100 mg/d) vs. standard dose warfarin (1 study, n=82): One high-risk-of-bias study showed an increased risk of any thromboembolic event with combined treatment (RR 2.14, 95% CI 1.04 to 4.43) and reported on major bleeding with 5 cases in the combined treatment group and 1 case in the standard-dose warfarin group (RR 7.42, 95% CI 0.91 to 60.7).
  • Standard-dose vitamin K antagonist (VKA) plus antiplatelet agent (aspirin 100 mg/d) vs. single antiplatelet agent (aspirin 100 mg/d): Two high-risk-of-bias studies did not provide any conclusive evidence regarding the effects of those drugs.
  • Warfarin plus antiplatelet vs. dual antiplatelet therapy (1 study, n=40): the RR of the risk of stroke over 3 years of observation was 5.00 (95% CI 0.26 to 98.0).
  • Dual antiplatelet vs. single antiplatelet therapy (1 study, n=40): RR for stroke during one year of observation was 0.14 (95% CI 0.01 to 2.60).

Clinical comments

Note

Date of latest search:

    References

    • Bala MM, Celinska-Lowenhoff M, Szot W et al. Antiplatelet and anticoagulant agents for secondary prevention of stroke and other thromboembolic events in people with antiphospholipid syndrome. Cochrane Database Syst Rev 2020;(10):CD012169. [PubMed]. [PubMed]

Primary/Secondary Keywords