Infective endocarditis caused by cardiac devices

The number of electronic cardiac devices, including pacemakers and cardioverter-defibrillators being implanted each year is increasing. As a result, there has been a 210% increase in the incidence of device infection between 1993 and 2008 in the USA. Cardiac device infective endocarditis (CDIE) is significant in that it is associated with a higher mortality rate than device infection without endocarditis.

Athan et al examined prospective data from the International Collaboration on Endocarditis-Prospective Cohort Study, collected from 61 centres in 28 countries over a 6-year period. All patients were hospitalised adults with definite endocarditis as defined by the modified Duke endocarditis criteria. The authors examined in-hospital and 1-year mortalities.

CDIE was diagnosed in 6.4% of patients with definite infective endocarditis. CDIE generally occurred in older patients (median age 71.2 years), was caused by staphylococci (66.6% of patients) and was associated with contact with healthcare services (45.8%). Some patients, 37.3%, also had coexisting valve involvement (especially the tricuspid valve). In-hospital and 1-year mortality rates were 14.7% and 23.2%, respectively. Removal of the device was associated with an increased chance of survival at 1 year (HR 0.42 when compared with patients who did not undergo device removal).