Purpose: Anticardiolipin antibodies may be associated with recurrent thromboembolic events in patients with myocardial infarction or stroke. We sought to determine the prevalence of anticardiolipin antibodies in patients with peripheral arterial disease and their association with subsequent thromboembolic events and mortality.
Methods: We ascertained anticardiolipin antibodies using a standardized enzyme-linked immunosorbent assay (immunoglobulin G [IgG] anticardiolipin > or =15 GPL units or IgM anticardiolipin > or =15 MPL units) in 232 patients with peripheral arterial disease and 100 control subjects. Patients were observed to determine overall and cardiovascular mortality, and incident thromboembolic events.
Results: IgG anticardiolipin antibodies were significantly more common in the patients with peripheral arterial disease (36 of 232 [16%]) than in the controls (7 of 100 [7%], P = 0.03). During a median follow-up of 3.5 years, 3 of the 232 patients were lost to follow-up and 56 (24%) died. Overall mortality was significantly greater in the IgG anticardiolipin-positive patients (16 of 35 [46%]) compared with those who were IgG anticardiolipin-negative (40 of 194 [21%], P = 0.0003), largely due to an increase in cardiovascular mortality among the IgG anticardiolipin-positive patients. In a multivariate proportional hazards analysis, IgG anticardiolipin antibodies were an independent risk factor for overall mortality (hazard ratio [HR] = 2.1, 95% confidence interval [CI]: 1.2 to 4.0) and cardiovascular mortality (HR = 4.4, 95% CI: 1.6 to 12).
Conclusions: IgG anticardiolipin antibodies are common in patients with peripheral arterial disease and are associated with an increased risk of overall and cardiovascular mortality.