Our Reader Score[Total: 0 Average: 0] A recent study in the Annals of Internal Medicine investigated the frequency of antiphospholipid antibodies in first-time heart attack patients. Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of autoantibodies that attack phospholipid proteins, including cardiolipin and β2-glycoprotein. APS can lead to blood clot formation in