Antiphospholipid antibodies, both anticardiolipin and lupus anticoagulant, are common in SLE. We asked, in a prospective cohort, whether these antibodies are predictive of atherosclerosis and/or coronary artery disease.
Methods: Three hundred eighty patients, 92% female, 49% Caucasian, 51% African-American, mean age 46.4+/-12.3 years are followed quarterly, with assessment of both anticardiolipin and lupus anticoagulant (dRVVT). These patients underwent both helical CT and carotid duplex.
Results: Both the lupus anticoagulant and anticardiolipin are predictive of later venous or arterial thrombosis. Twenty years after diagnosis, SLE patients with the lupus anticoagulant (LA) have a 50% chance of a venous thrombotic event. Myocardial infarction occurs significantly more often in those with LA 22% vs. 9%, p=0.04. Neither anticardiolipin nor LA are associated with carotid IMT, carotid plaque, nor coronary calcium by helical CT. In aCL positive patients carotid IMT was 0.57+/-0.01 vs. 0.58+/-0.01 in aCL negative patients (p=NS); carotid plaque 0.47+/-0.13 vs. 0.32+/-0.10 (p=NS); and coronary calcium 65.4+/-37.4 vs. 65.4+/-30.2 (p=NS). In LA positive patients, carotid IMT was 0.59+/-0.03 vs. 0.59+/-0.02 in LA negative patients (p=NS); carotid plaque 0.07+/-0.02 (SE) vs. 0.80+/-0.02 (SE) (p=0.06); and coronary calcium 28.1+/-3.7 (SE) vs. 85.7+/-2.6 (SE) (p=NS).
Conclusion: Antiphospholipid antibodies are not associated with subclinical atherosclerosis (carotid IMR, carotid plaque, helical CT coronary calcium), but are associated with actual thrombotic sequelae (myocardial infarction).