Anticardiolipin antibodies and acute myocardial infarction in non-systemic lupus erythmatosus patients: A controlled prospective study

PURPOSE: To examine the prevalence of anticardiolipin antibodies (ACLA) in relatively young patients with acute myocardial infarction (MI) and their role in subsequent coronary and thromboembolic events in the post-MI period. PATIENTS AND METHODS: In 124 relatively young survivors (aged 65 or younger) of acute MI, ACLA were measured in a controlled prospective study on admission and 3 months later. Myocardial reinfarction and thromboembolic events during a mean follow-up period of 19 +/- 3 months were diagnosed by standard tests. RESULTS: Seventeen (14%) of the 124 patients were ACLA positive (either IgM or IgG) upon admission compared with 2 out of 76 (3%) of the control group matched for age and coronary risk factors (P <0.01). The levels of ACLA remained unchanged in all but 1 patient 3 months later. During the follow-up period the rate of thromboembolic events and myocardial reinfarction was significantly higher in the ACLA-positive patients as compared with the ACLA-negative group: 41% versus 4% (P <0.0001) and 35% versus 10% (P <0.05), respectively. Using logistic regression, high titer of ACLA was found to be the only independent risk factor for subsequent thromboembolic events or myocardial reinfarction after acute MI. CONCLUSIONS: High prevalence of ACLA was found in relatively young survivors of acute MI. The presence of ACLA is a marker for increased risk of subsequent myocardial reinfarction and thromboembolic events after acute MI.