Eugene M. Tan

Outcomes in Patients With Cardiovascular Implantable Electronic Device Infection Managed With Chronic Antibiotic Suppression

Background. Most cardiovascular implantable electronic device (CIED) recipients are elderly, have multiple comorbid conditions, and are at increased risk of CIED infection (CIEDI). Current guidelines recommend complete device removal in patients with CIEDI to prevent relapse and mortality. However, comorbidities or other factors may preclude device removal, thus prompting a nonsurgical approach that includes chronic antibiotic suppression (CAS). There are limited data on outcomes of patients receiving CAS for CIEDI. Methods. We retrospectively screened 660 CIEDI cases from 2005 to 2015 using electronic health records and a CIEDI institutional database and identified 48 patients prescribed CAS. Primary outcomes were infection relapse and survival. Results. The median age was 78 years, and 73% (35/48) were male. The median Charlson comorbidity index was 4. Common pathogens were coagulase-negative staphylococci (21%, 10/48) and methicillin-sensitive Staphylococcus aureus (19%, 9/48). At 1 month after hospitalization, 25% (12/48) of patients had died, of whom only 1 initiated CAS; 67% (8/12) of these had staphylococcal infections. Of the 37 patients who initiated CAS, the most common antimicrobials were trimethoprim-sulfamethoxazole, penicillin, and amoxicillin (22%, 8/37 each). Estimated median overall survival was 1.43 years (95% confidence interval, 0.27-2.14), with 18% (6/33 survivors) developing relapse within 1 year. Of the 6 patients who relapsed, 2 (33%) subsequently underwent CIED extraction. Conclusion. CAS is reasonable in select patients who are not candidates for complete device removal for attempted cure of CIEDI. Nevertheless, 1-month mortality in our sample of CAS-eligible patients was high and reflective of high rates of comorbid conditions.

Erysipelothrix rhusiopathiae bloodstream infection – A 22‐year experience at Mayo Clinic, Minnesota

Erysipelothrix rhusiopathiae is a facultatively anaerobic Gram‐positive bacillus found mostly in swine, fish and sheep. E. rhusiopathiae classically causes cutaneous eruptions in butchers, fish handlers and veterinarians. Based solely on case reports, 90% of E. rhusiopathiae bloodstream infections (BSI) have been associated with infective endocarditis (IE). To assess the true frequency of IE in E. rhusiopathiae BSI as well as other clinical associations, we performed a retrospective cohort analysis of E. rhusiopathiae BSI at Mayo Clinic. This is a single‐centre, retrospective study conducted between 1/1/1994 and 20/6/2016 at Mayo Clinic in Rochester, MN. Medical records were reviewed for demographics, E. rhusiopathiae BSI, anti‐microbial susceptibilities, incidence of IE, patient comorbidities, intensive care unit (ICU) admission and duration of antibiotics. Five cases of E. rhusiopathiae BSI were identified. Risk factors included animal exposures, immunosuppression, diabetes and kidney disease. All cases involved penicillin‐sensitive strains and high‐grade BSI. Four cases showed no signs of IE on transesophageal echocardiogram. All patients recovered fully with intravenous antibiotics. Our retrospective review illustrates that E. rhusiopathiae can cause invasive BSI in the absence of IE and that the previously reported 90% association between BSI and IE may be overestimated due to reporting bias. E. rhusiopathiae should be suspected in any patient with Gram‐positive bacilli in blood cultures and the aforementioned risk factors. A limitation of our study was the low sample size, and future studies may involve multicentre collaborations and the use of polymerase chain reaction (PCR) or serologic testing to increase the number of diagnoses..