Long-term use of HCQ and low dose aspirin may work to reduce cardiovascular events.
Hydroxychloroquine appears to reduce the risk of thrombosis over the long term in patients who have systemic lupus erythematosus.
Combining hydroxychloroquine with aspirin long term in patients with lupus seems to further reduce the risk.
Cardiovascular disease and, in particular, accelerated atherosclerosis causes significant morbidity and mortality in patients with systemic lupus erythematosus, researchers noted. Prevention of cardiovascular disease through prophylaxis of clotting is a major focus of treatment in lupus, especially in patients who have antiphospholipid antibody, lupus anticoagulant, or isolated persistent anticardiolipin antibody positivity.
Low-dose aspirin and hydroxychloroquine currently are advocated for prevention of thrombosis, but study authors pointed out that when the protective effects start and how long they are sustained is not known.
No other long-term studies have looked at hydroxychloroquine and primary thromboprophylaxis in patients with systemic lupus erythematosus.
Serena Fasano and fellow researchers in Italy examined how cumulative doses of hydroxychloroquine alone and combined with aspirin affect thrombosis risk in patients with systemic lupus erythematosus and presented their findings in a recent Journal of Rheumatology article.
This retrospective observational cohort study enrolled 189 patients with systemic lupus erythematosus. Non-lethal thrombotic events occurred in 5.2% of subjects, including 1 stroke, 5 transient ischemic attacks, and 4 myocardial infarctions. No deaths were attributed to cardiovascular events in the study.
• 27.5% of subjects had been treated with high-dose steroids, which has been reported to contribute to atherosclerosis.
• 82% of subjects were prescribed hydroxychloroquine at 6 mg/kg; the median treatment period was 5 years.
• The rate of cardiovascular events was similar in patients treated with both aspirin and hydroxychloroquine and in those treated with aspirin alone.
• Patients with systemic lupus erythematosus were more likely to be free from cardiovascular events when treated with aspirin and a greater than 600 g cumulative dose of hydroxychloroquine (a standard daily dose over 5 years) than patients treated with aspirin alone or a lower dose of hydroxychloroquine (chi= 4.01, p=0.045).
• Patients who experienced cardiovascular events had significantly higher blood pressure and were antiphospholipid antibody positive. In addition, antiphospholipid antibody positivity and high blood pressure were associated with an increased risk of thrombosis (HR, 17.96, 95% CI, 1.48-217.61, and HR, 18.05, 95% CI, 1.64-98.76, respectively).
Implications for physicians
• Long-term treatment with the antimalarial drug hydroxychloroquine is safe in patients with systemic lupus erythematosus.
• A cumulative dose of hydroxychloroquine > 600 g taken for 5 years or more independently and significantly reduced the risk of cardiovascular events in patients with systemic lupus erythematosus.
• The combination of hydroxychloroquine and low dose aspirin appears to work synergistically to reduce the risk of thrombosis and cardiovascular events in patients with systemic lupus erythematosus.
No funding sources were disclosed.
Serena Fasano, Lucianna Pierro, Ilenia Pantano, et al. “Longterm Hydroxychloroquine Therapy and Low-dose Aspirin May Have an Additive Effectiveness in the Primary Prevention of Cardiovascular Events in Patients with Systemic Lupus Erythematosus.” J Rheumatol. 2017;44:1032-1038. doi: 10.3899/jrheum.161351. Epub 2017 May 15.