THE RISK OF INFECTIVE ENDOCARDITIS AFTER CARDIAC SURGICAL AND INTERVENTIONAL PROCEDURES

The risk of infective endocarditis after cardiac surgery relates mainl y to the risk of infective endocarditis on prosthetic valves. The freq uency of prosthetic infective endocarditis varies according to the cri teria used in the literature, ranging from 0.4 to 1.3% for early infec tive endocarditis, with an annual linear risk of late infective endoca rditis of 0.5%. This figure seems to be independent of either the type or the location of prostheses, but it does nevertheless increase if m ore than one valve has been replaced. The mast commonly isolated micro organisms in early infective endocarditis are staphylococci. The bacte riological findings in late prosthetic infective endocarditis are simi lar to those seen in the native disease. The portal of entry is more e asily identified in early than in late infective endocarditis (50%). T he risk of infective endocarditis in surgically treated congenital hea rt disease is very low when the patient has a left-to-right shunt or v alvar stenosis; it increases amongst patients with tetralogy of Fallot and patients with complex cyanotic congenital heart disease, mainly w hen there is a residual ventricular septal defect or prior palliative surgery. The risk of infective infective endocarditis in patients with intracavitary electrodes such as pacemakers and defibrillators, after the interventional procedure itself and after heart transplant, is ve ry low. This leads us to conclude that antibiotic prophylaxis is only warranted in those patients with a prosthetic valve and after surgical treatment of tetralogy of Fallot and other complex cyanotic congenita l heart diseases.