Nosocomial cardiac infections

Abstract

The most important nosocomial cardiac infections include nosocomial infective endocarditis on native and prosthetic valves, and nosocomial infections related to transvenous permanent pacemakers, implantable cardioverter-defibrillators and left ventricular assist devices. Although representing rare complications, they are of great importance because they are associated with high morbidity and mortality. Most of them are encountered in older-age groups, related to nosocomial invasive procedures performed within the preceding four to eight weeks of hospital admission. Nosocomial bacteraemia associated with infected central intravascular devices, genitourinary or gastrointestinal tract surgery and instrumentation, breaks in sterile surgical techniques at the implantation of prosthetic valves and cardiac devices as well as wound and skin infections, represent the most important risk factors. Staphylococcus aureus in native valve endocarditis and S. epidermidis in the presence of foreign bodies are the main implicated pathogens. However, because of the steeply increasing incidence of candidaemia in tertiary hospitals, nosocomial cardiac infections caused by Candida spp. have also been steadily increasing over the last decades. Diagnosis of nosocomial cardiac infections, particularly in the presence of foreign bodies, is often difficult because of the severity of patients' co-morbid illnesses and the co-existence of several risk factors. Diagnosis should be based on positive blood cultures and transoesophageal echocardiographic findings in febrile high-risk patients. Therapy necessitates a combination of antibiotics and surgical removal of foreign bodies. Prophylaxis should mainly target the prevention and/or appropriate treatment of bacteraemias secondary to infected intravascular devices, as well as application of prophylaxis guidelines whenever invasive hospital-based procedures are performed in high-risk individuals.