Antiphospholipid antibodies in patients with coronary artery disease: new cardiac risk factors?

Antiphospholipid antibodies (aPL) have been implicated in the pathogenesis of coronary artery disease (CAD). We evaluated the presence of aPL in patients with chest pain/acute coronary syndromes (ACS) to determine if aPL were associated with the presence and severity of CAD, adverse outcomes, and other coronary risk factors. Patients with chest pain/ACS were evaluated for aPL prior to diagnostic and therapeutic investigations. Coronary angiograms were graded according to the severity of disease. Risk factors, including family histories, were assessed and patients were followed for adverse outcomes. To date, 232 patients (116 M, 116 F, mean age 63 years) with a mean follow-up of 9 months were studied. Thirty-seven percent (86/232) were positive for one or more aPL. More women, 49/86 (57%), were aPL positive versus men, 37/86 (43%). The presence of aPL appeared associated with both presence and severity of CAD (P = 0.176 women; P = 0.163 men). In patients undergoing procedures (angioplasty, stent, bypass), aPL was significantly associated with both an increase in adverse cardiac outcomes (P = 0.045) and extracardiac thrombotic events (P = 0.033). Anti-beta2 glycoprotein-1 (abeta2GP1) was the most frequent aPL, occurring in 68.5% of aPL-positive patients with CAD. Anticardiolipin antibody (aCL) occurred in only 7.4%. IgM isotypes were the most frequent for all categories of aPL (range 55-90%). Family history of antiphospholipid syndrome (APS)-related events was more significant in aPL-positive than aPL-negative individuals (P = 0.027).

Anti-beta 2-glycoprotein I and antiphosphatidylserine antibodies are predictors of arterial thrombosis in patients with antiphospholipid syndrome.

The predictive value (PV) and association of 4 antiphospholipid antibodies with clinical manifestations of the antiphospholipid syndrome (APS) were evaluated in 90 patients with systemic lupus erythematosus (SLE) and 100 with APS. Patients with APS were classified into arterial thrombosis, venous thrombosis, and pregnancy morbidity subgroups. IgG, IgM, and IgA anticardiolipin (aCL), antiphosphatidylserine (aPS), anti-beta 2-glycoprotein I (anti-B2GPI), and antiprothrombin (aPT) antibodies were determined by enzyme-linked immunosorbent assay. Individually, anti-B2GPI and aPS antibodies had the strongest PV for APS (86.4%-94.1%; P < .001) in patients with SLE. The PV for APS reached 100% when 2 or more antibodies were present. Similarly, anti-B2GPI and aPS antibodies had a stronger PV and association for arterial thrombosis (87%-95%; P < .001) compared with venous thrombosis (80%-92%; P = .01). Weak PV and association with pregnancy morbidity were seen with all antibodies. These results suggest an important pathogenic role of anti-B2GPI antibodies in arterial thrombosis. In addition, anti-B2GPI and aPS antibodies seem to provide the best diagnostic value for the laboratory assessment of APS.