Immunoglobulin G (IgG) anticardiolipin antibodies and recurrent cardiovascular events. A systematic review and Bayesian meta-regression analysis

Background: Anticardiolipin antibodies of the immunoglobulin G isotype (IgG aCL) have been suggested as risk factor for arterial and venous thrombosis. No conclusive data in patients with coronary artery disease (CAD) do exist. We investigate the risk of recurrent CAD according to the presence of IgG aCL. Methods: We performed a systematic review and meta-analysis to evaluate the risk of recurrent major adverse cardiac events (MACE) associated with the presence of IgG aCL in patients with CAD. MEDLINE and Cochrane databases were searched. We conducted a meta-analysis of the relative risk (RR) both at 12 and 24 months. Results: We included 11 eligible studies with a total of 2425 patients, 283 IgG aCL+ and 2142 IgG aCL-. The prevalence of IgG aCL + ranged from 6.1% to 43.3%. A total of 341 cardiac events were reported: 71 (25.1%) in IgG aCL+ and 270 (12.6%) in IgG aCL- patients. We found an increased risk of recurrent MACE in patients with high IgG aCL both at 12 (RR 2.17, 2.5-97.5%CI, 1.54-3.00) and 24 months (RR 2.11, 2.5-97.5%CI, 1.62-2.66). This association was even stronger in patients with juvenile CAD (i.e. < 50 years) at both 12 (RR 3.21, 2.5-97.5%CI, 1.74-5.41) and 24 months (RR 3.24, 2.5-97.5%CI, 1.84-5.21). Conclusion: Patients with CAD and elevated IgG aCL have a doubled risk of recurrent MACE at 12 and 24 months. The presence of aCL should be suspected in patients with recurrent CAD events or in patients with juvenile CAD.