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 United States.  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 (ICE-PCS), collected from 61 centers in 28 countries over a six 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 mortality.

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 health care services (45.8%).  37.3% of patients also had co-existing valve involvement (especially the tricuspid valve).  In-hospital and one-year mortality rates were 14.7% and 23.2%, respectively.  Removal of the device was associated with an increased chance of survival at one year (hazard ratio 0.42 when compared to patients who did not undergo device removal).

Conclusion:

Patients with cardiac device infective endocarditis have high rates of mortality and concomitant valve infection.  Early device removal is indicated to improve survival at one year.

• Athan E, Chu VH, Tattevin P et al.  Clinical Characteristics and Outcome of Infective Endocarditis Involving Implantable Cardiac Devices.  JAMA 2012;307:1727-1735.