[Infectious endocarditis: the right time for surgery].

Valve repair is often required to maintain haemodynamic performance in patients with infectious endocarditis. Localizations on the aortic valve are frequent and lead to rapid, often severe, deterioration, especially when the valve ring and the septum are also infected. Conduction disorders and rupture of the abscess into the heart cavities are formal indications for surgery. Mitral regurgitation requires surgical repair less often and has a slower clinical course. The tricuspid valve generally tolerates infection well and surgery is only exceptionally indicated. An emergency situation due to heart failure occurring simultaneously with valve damage (ruptured mitral chordae) and moderate regurgitation, can most often be managed medically. Inversely, surgery is required when blood cultures are persistently positive and sepsis remains uncontrolled after 8 days of adapted antibiotics. Surgery is entertained when the risk of emboli is established echographically, although growth on valves is not in itself sufficient. Most operated cases also involve an initial embolic event. Conservative surgery (mitral or tricuspid plasty) should always be performed to avoid the long-term complications of prostheses: valve dysfunction (disinsertion or thrombosis), bacterial resistance, risk of embolism especially for mechanical valves, risk of brain haemorrhage related to anticoagulant therapy. When endocarditis develops on a prosthesis early after implantation reoperation is usually required, especially when certain organisms (yeasts, Staphylococcus aureus) are involved. Haemodynamic performance and bacterial resistance dominate the decision making processes which must be adapted to each individual case. Once the decision for surgery has been made, the operation should not be delayed in the hope a longer antibiotic course will be effective since prognosis worsens rapidly if the haemodynamic situation is allowed to deteriorate.