Identification of high-risk subgroups in infective endocarditis and the role of echocardiography.

The outcome of infective endocarditis remains poor. It has an overall mortality of around 30%, rising in high-risk subgroups to 50% and 100%. The prognosis can be improved by identification of high-risk patients and special management. Patients with infective endocarditis are found to be at high risk for death or serious complications when one or more of the following factors exist: old age (especially > 60 years old), delayed diagnosis, staphylococcal infection, aortic valve endocarditis, large valvular vegetation, congestive heart failure, embolization in the central nervous system or coronary artery, prosthetic valve infection, recurrent events, and failed antibiotic therapy. These factors often coexist and interrelate with one another. Early diagnosis and active treatment are critical for a better clinical outcome. However, infective endocarditis is difficult to diagnose because of the atypical clinical manifestations and frequent negative results from blood culture. Echocardiography plays an indispensable role in the diagnosis and management of suspected or known infective endocarditis. By detecting and monitoring certain pathological changes associated with the disease, e.g. vegetation, abscess formation, or valvular destruction, echocardiography helps to diagnose the disease early, to identify patients at high risk, to monitor the patients, and to optimize the timing and mode of surgical intervention. Serious complications can thus be avoided or cured at an early stage and the prognosis significantly improved.