The risk of infective endocarditis after cardiac surgical and interventional procedures.

The risk of infective endocarditis after cardiac surgery relates mainly to the risk of infective endocarditis on prosthetic valves. The frequency of prosthetic infective endocarditis varies according to the criteria used in the literature, ranging from 0.4 to 1.3% for early infective endocarditis, with an annual linear risk of late infective endocarditis of 0.5%. This figure seems to be independent of either the type or the location of prostheses, but it does nevertheless increase if more than one valve has been replaced. The most commonly isolated microorganisms in early infective endocarditis are staphylococci. The bacteriological findings in late prosthetic infective endocarditis are similar to those seen in the native disease. The portal of entry is more easily identified in early than in late infective endocarditis (50%). The risk of infective endocarditis in surgically treated congenital heart disease is very low when the patient has a left-to-right shunt or valvar stenosis; it increases amongst patients with tetralogy of Fallot and patients with complex cyanotic congenital heart disease, mainly when there is a residual ventricular septal defect or prior palliative surgery. The risk of infective endocarditis in patients with intracavitary electrodes such as pacemakers and defibrillators, after the interventional procedure itself and after heart transplant, is very 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 congenital heart diseases.