Antiphospholipid Syndrome and Cardiovascular Disease.

Antiphospholipid syndrome (APS) is an acquired systemic autoimmune thrombo-inflammatory disorder characterized by venous, arterial, and microvascular thrombosis and/or pregnancy morbidity in the setting of persistent antiphospholipid antibodies. Cardiovascular disease in APS extends well beyond classic thrombosis and includes ischemic stroke, myocardial infarction, venous thromboembolism, valvular heart disease, pulmonary embolism, accelerated atherosclerosis, and microvascular ischemic injury. Mechanistically, APS is increasingly understood as a disorder of immunothrombosis, in which antiphospholipid antibodies-particularly anti-β2-glycoprotein I antibodies-promote endothelial dysfunction, tissue factor expression, platelet activation, complement amplification, and neutrophil extracellular trap formation. In parallel, oxidized low-density lipoprotein-β2-glycoprotein I immune complexes may link autoimmunity with plaque formation and atherothrombosis. Clinical cardiovascular risk is shaped not only by antibody profile, including lupus anticoagulant positivity, double/triple positivity, and high titers, but also by traditional atherosclerotic risk factors, systemic lupus erythematosus, hematologic manifestations, and prior thrombotic phenotype. Recent advances in classification, particularly the 2023 American College of Rheumatology/European League Against Rheumatism criteria, better capture macrovascular, microvascular, and valvular domains relevant to cardiovascular practice, although classification should not substitute for diagnosis. For secondary prevention, vitamin K antagonist therapy remains the cornerstone of thrombotic APS management. Randomized trials of direct oral anticoagulants have demonstrated excess recurrent thrombosis, especially arterial events, in high-risk APS.