Antibodies to cardiolipin in young survivors of myocardial infarction: an association with recurrent cardiovascular events.

Antibodies to cardiolipin were measured in 62 survivors of myocardial infarction under age 45 at 3, 12, and 36 months after the acute event. 13 patients (21%) had raised anticardiolipin antibody levels on at least two of the three sampling occasions. Risk-factor profiles and coronary angiographic findings did not differ between the anticardiolipin-positive group and the rest of the patients. No correlation was found between cardiolipin and anti-DNA antibody levels. 8 of the 13 patients with raised anticardiolipin antibody levels experienced additional cardiovascular events during a follow-up of 36-64 months after the first myocardial infarction: cerebral infarction developed in 2, arterial occlusion of the lower limb in 2, new myocardial infarction in 3, pulmonary emboli in 1, and deep-vein thrombosis in 1. These 8 patients had cardiolipin antibody titres of 5 times the mean for voluntary blood donors. Antibodies to cardiolipin are common in young post-infarction patients and should be interpreted as markers of high risk for recurrent cardiovascular events.