Prevalence of anti-phospholipid syndrome among patients aged less than 65 years with acute myocardial infarction

Background. The antiphospholipid antibody syndrome (AAS), which is characte rized by thromboembolic events and/or fetal loss and/or low platetelt count associated with antiphospholipid antibodies, may evolve with acute myocard ial infarction (AMI). The presence of AAS among young patients with AMI ran ges from 14% to 21%, and this condition implies specific therapeutic attitu des as new thrombotic events may occur, according to some authors. Materials and methods. A prospective study was undertaken with 25 patients aged greater than or equal to 65 years with AMI that were admitted to our i nstitution during one year who were compared with control patients with sim ilar risk factors. IgG and IgM anticardiolipin antibodies (ACA) were measur ed in the first 24 hours since the onset of AMI symptoms and three months l ater. Results. The follow-up ranged from three months to one year. Among patients , ACA positivity in the two measurements was higher (12%) than that observe d in the control group (5%) (p = 0.36). ACA positivity on two occasions was not a risk factor for new thrombotic events. Conclusion. ACA positivity is higher among AMI patients (measured early and at three months) than among the general population although the presence o f such antibodies does not increase the risk for new post-infarction thromb otic events.