Over the last decade there has been a remarkable increase in cardiovascular implantable electronic device (CIED) utilization; in the United States alone 235,567 new and 101,042 replacement pacemakers and 133,262 new and 73,217 replacement implantable cardioverter-defibrillators (ICD) were implanted in 2009. Much of this growth has been driven by the broadened utilization of the ICD, which now accounts for over a third of all CIEDs being placed. Delay from presentation to hardware removal stems from failure to recognize the presence of an infection or mistaken attribution of an infection to another source is thought to increase the risk of adverse outcome for those with CIED infection. A high index of suspicion is essential for early diagnosis and should trigger blood culture, antibiotic therapy, and, in those with bacteremia or who have been on antibiotics prior to a negative culture, transesophageal echocardiography (TEE).
There is increasing evidence that fluorodeoxyglucose marked by fluorine-18 (18F-FDG) positron emission tomography (PET) co-registered with computed tomography (CT) is useful for the detection and localization of infection including infective endocarditis.
A retrospective study was conducted of all patients with proven or suspected infected CIEDs who were referred to the Cleveland Clinic for system removal from January 2002 through March 2007. A total of 412 patients (age 68 ± 15 years) were included. The majority of patients (241 [59%]) presented with localized infection involving the device pocket. The remaining 171 patients (41%) presented with endovascular infection but no evidence of inflammation of the device pocket. Of the total 414 pathogens isolated, 366 (88%) were aerobic gram positive organisms, of which 90% were Staphylococcus species, and almost half of these were methicillin resistant. In-hospital mortality was 4.6% (19 patients). Only 2 deaths were extraction related. One-year mortality was 17%. CIED infections are most often caused by Staphylococcus species, half of which are methicillin resistant. Percutaneous lead and device removal along with antibiotic therapy are effective as primary interventions. The overall relapse rate is 1.9%, and the relapse rate among patients who had re-implantation during the same hospitalization is 2.6%.
Further reading: 1. Editorial by J. Brinker in JACC Vol. 59, No. 18, May 1, 2012:1626–8
2. Cleveland clinic experience (Tarakji et al. Heart Rhythm 2010; 7: 1043–1047).
Case compiled with the help of Wissam Alajaji M.D., third year Cardiology fellow, American university of Beirut Medical center.