Background: The relationship between invasive medical devices and infective endocarditis (IE) has not been comprehensively assessed. We describe our experience of patients with IE, with particular attention to the role of pre-existing intravascular catheters and implanted cardiac devices in the pathogenesis.
Methods: We performed a retrospective review of hospital records over a 10-y period (1997-2007), and included patients with 'definite' or 'possible' IE as per the modified Duke criteria. The complete electronic medical record was reviewed for the presence of intravascular devices prior to the onset of IE, including intravascular catheters and implanted cardiac devices (defibrillators and pacemakers).
Results: We identified 155 patients with IE. Infection involved a native valve in 124 (80%) patients and a prosthetic valve in 15 (9.7%). In the remaining 16 (10.3%) patients, infection was attributed to an implanted cardiac device. The most commonly identified source of infection was a central venous catheter, accounting for 17.4% of patients, followed by an implanted cardiac device in 10.3% of patients. Staphylococcus aureus was the most commonly isolated organism in catheter-associated IE and cardiac device-associated IE (31.9% and 62.5%, respectively). Thirty-five (22.5%) patients died within 90 days. Mortality was 31.9% in patients with IE caused by methicillin-resistant S. aureus (MRSA).
Conclusions: Intravascular catheters and cardiac implantable devices are common sources of infection leading to IE, and the intracardiac devices themselves often become infected, with MRSA as the predominant pathogen.