Recent progress in the understanding of infective endocarditis.

OPINION STATEMENT: Infective endocarditis is an uncommon cardiac condition but is associated with significant morbidity and mortality despite advancements in diagnosis and treatment. Recent epidemiologic changes in this disease have resulted in additional challenges for treatment and improving outcome. Health care-associated infection is a growing cause of endocarditis, and the predominance of Staphylococcus aureus infection is associated with increased co-morbid medical conditions, lower rate of surgical intervention, and worse outcome. In order to reduce the high rate of complications and mortality related to endocarditis, attention to the role of antibiotic prophylaxis has been given by major cardiology societies including the American College of Cardiology, American Heart Association, and European Society of Cardiology. These recent guidelines have reduced the role of prophylaxis due to the unclear benefit, but uncertainty remains for certain pre-disposing cardiac lesions. Earlier diagnosis of endocarditis or improved prognostic tests may also reduce the complications of endocarditis by allowing earlier treatment with antibiotics or surgery, and a number of recent, preliminary studies have investigated biomarkers for improving its diagnosis or better prediction of adverse outcome. In patients with complications of endocarditis (heart failure, severe valvular regurgitation, intracardiac abscess or fistula, recurrent emboli, large vegetation or refractory infection), surgery is recommended because outcome is recognized to be poor with medical treatment alone. Recent studies of surgery for infective endocarditis have shown low operative mortality rates, particularly for patients with hemodynamic stability and non-emergent status, and a survival benefit over medical therapy alone for many of these complications. In patients with S. aureus endocarditis, surgery is less commonly performed due to co-morbid conditions, but has been shown to improve outcome and should be considered more aggressively. A growing number of studies have suggested that early surgery during the active phase of infection can be performed at low risk of operative mortality and recurrence of endocarditis, even in patients with cerebral infarction. Additional studies are needed to define the influence of surgical timing on outcome, and its potential benefit in lower-risk patients with endocarditis.