Cardiac and Pulmonary Manifestations in the Antiphospholipid Syndrome

Publisher Summary This chapter focuses on the main cardiac and pulmonary features related to the presence of antiphospholipid antibodies (aPL). Patients suffering from systemic lupus erythematosus (SLE) with antiphospholipid antibodies (aPL) show a significantly higher prevalence of valvular defects than from those without these antibodies. In addition, almost 89% of patients with SLE and valvular disease have been found to have aPL, compared to 44% of patients without valvular involvement. The primary APS valvular lesion consists mainly of superficial or intravalvular fibrin deposits and its subsequent organization such as vascular proliferation, fibroblast infiltration, fibrosis, and calcification. Thickening of the valve leaflets is the most common lesion detected by echocardiography in both SLE and primary APS patients. The mitral valve is involved most commonly, followed by aortic valve involvement. Mitral regurgitation is the most common haemodynamic dysfunction, occurring in 22% and 26% of all patients with primary APS and SLE, respectively and aortic regurgitation is less common, occurring in 6% and 10%, respectively. In patients with SLE, aPL have been reported to correlate with the markers of lipid peroxidation, suggesting that increased oxidative stress could be a trigger of these antibodies. The prevalence of aCL in patients with myocardial infarction seems to be between 5% and 15% and widespread cardiac dysfunction may be present in some patients with normal valves and coronary arteries.