Anticardiolipin antibodies and recurrent coronary events - A prospective study of 1150 patients

Background-The association of anticardiolipin (aCL) antibodies with coronar y artery disease has been shown in several studies but remains controversia l. We evaluated the association of aCL and anti-beta(2)-glycoprotein I (a b eta(2)GPI) antibodies with the risk of recurrent cardiac events in postinfa rction patients. Methods and Results-The study population consisted of 1150 patients with ac ute myocardial infarction, Levels of IgG and IgM aCL and a beta(2)GPI antib odies were determined on sera collected before hospital discharge. There we re 131 recurrent cardiac events (nonfatal myocardial infarctions or cardiac deaths) over a mean follow-up period of 24.6 months. Patients with elevate d IgG aCL antibodies had a higher event rate than patients with low levels (P = 0.05). Multivariate Cox analysis after adjustment for relevant clinica l covariates showed that elevated levels of IgG aCL (hazard ratio = 1.63; P = 0.01) and low levels of IgM aCL (hazard ratio of 1.76; P = 0.02) antibod ies contribute independent risks for recurrent cardiac events. Patients wit h elevated Ige aCL and low IgM aCL antibody levels had a 3-fold higher risk of recurrent cardiac events than patients with low IgG aCL and elevated Ig M aCL antibody levels (P < 0.001), There was no significant association of the a beta(2)GPI antibodies with recurrent cardiac events. Conclusions-In postinfarction patients, elevated IgG aCL and low IgM aCL an tibodies are independent risk factors for recurrent cardiac events. Patient s with both elevated IgG aCL and low IgM aCL antibodies have the highest ri sk. These findings shed additional light on the mechanistic role of aCL ant ibodies in coronary artery disease in patients without autoimmune diseases.