Prevalence and outcome of bacterial endocarditis in patients with implantable cardiac device infections

ABSTRACT

Cardiac device infection [CDI] is a devastating complication of permanent pacemaker [PPM] or implantable cardioverter-defibrillators [ICD]. The incidence and outcome of endocarditis among patients with CDI is not well defined. The aim of this study was to report our experience in the prevalence, clinical presentations, and management of bacterial endocarditis [BE] among patients with CDI in a tertiary care cardiac center over a 25-year period. A total of 2630 cardiac devices implanted in a cohort of 2367 patients over 25 years were studied. Of these, 117 [4.4%] patients presented with CDI. Clinical, bacteriologic and both transthoracic [TTE] and transoesophageal echocardiographic [TEE] assessment were done. Of the 117 patients with CDI [90 males, age range 18-82 yrs, mean = 63 +/- 6 yrs], 87 [74%] had redo procedures [battery replacement in 50, repositioning of leads in 12, device extrusion in 15 or evacuation of significant haematoma in 10 patients]. Of these 87 patients, 65 had -re-implants on the same day of explantation. In 30 patients [26%] no apparent cause of PI was identified. Of the 117 patietns with CDI, 30 patients [26% of CDI and 1.1% of total procedures] had device-related BE with vegetations having appeared in all patients by TEE [15 DDD, 9VVI, 3 CRT and 3 ICD]. The clinical presentations were prolonged fever in 25 patients [83%], significant pulmonary hypertension with thrombo-embolism in 3 patients [10%], severe sepsis and multi-organ failure in 2 patients [6%]. Twenty-eight patients [93%] had positive blood cultures [S aureus in 23 [77%] and enterococci in 5]. There were only 2 patients with negative blood cultures. Device lead vegetations were evident in 20 patients [>10 mm diameter in 13 patients]. Ten patients presented with only right heart valve vegetations. Of the 30 BE patients, 28 [93%] had PI while 2 patients had no apparent cause but frequent intravenous injections [one drug addict and one on regular haemodialysis]. Of the 20 patients with lead endocarditis, 15 had their leads removed surgically with re-implantation of either epicardial [6 patients] or endocardial leads [9 patients]. Fifteen patients had only medical treatment with proper antibiotics [5 patients with lead BE and all 10 patients with valvular BE]. Four patients [13%] died; all had their devices implanted on same day of explanation. Cardiac device redo procedures are major risk factors for CDI, especially with re-implantation on the same day. Device related BE carries a serious morbidity and mortality, yet surgical removal of the whole system in the management of choice. Blood stream bacteraemia is a potential risk factor in patients with cardiac devices and warrants prophylaxis against BE