CHICAGO – Patients with a first MI were nearly nine times more likely to have detectable IgG antiphospholipid antibodies than were matched controls in a cross-sectional cohort study, Elisabet Svenungsson, MD, PhD, reported at the annual meeting of the American College of Rheumatology.
Her case-control study included 805 Swedish patients tested for antiphospholipid antibodies 6-10 weeks after experiencing their first MI and an equal number of age-, sex-, and location-matched controls. Prior to their MIs, none of the patients had been diagnosed with antiphospholipid syndrome, which requires both positive antiphospholipid antibodies and a vascular thrombotic event or obstetric morbidity.
A positive test for IgG anti-cardiolipin antibody was present in 10.9% of the first-MI patients, compared with 0.9% of controls. Similarly, 10.4% of acute MI patients and 0.9% of controls were positive for anti-beta2-glycoprotein-1 antibodies. Most patients who tested positive for one were positive for both. Thus, it’s possible that IgG antiphospholipid antibody positivity is an important silent risk factor that’s present in 1 in 10 MI patients, according to Dr. Svenungsson, professor of rheumatology at the Karolinska Institute in Stockholm.
If these results are confirmed and expanded upon in additional studies, testing for antiphospholipid antibodies could become part of the routine care in patients with an acute MI. Those who test positive would meet the criteria for antiphospholipid syndrome and qualify for long-term oral anticoagulation to reduce their elevated risk of further vascular events, she explained in this video interview.
The study was published in Annals of Internal Medicine simultaneously with the presentation at the ACR annual meeting (Ann Int Med. 2018 Oct 23. doi: 10.7326/M18-2130).
SOURCE: Grosso G et al. Arthritis Rheumatol. 2018;70(Suppl 10): Abstract 855.