Cardiac device infections: definition, classification, differential diagnosis, and management

Cardiac Implantable Electronic Devices Infection Assessment, Diagnosis and Management: A Review of the Literature

The use of increasingly complex cardiac implantable electronic devices (CIEDs) has increased exponentially in recent years. One of the most serious complications in terms of mortality, morbidity and financial burden is represented by infections involving these devices. They may affect only the generator pocket or be generalised with lead-related endocarditis. Modifiable and non-modifiable risk factors have been identified and they can be associated with patient or procedure characteristics or with the type of CIED. Pocket and systemic infections require a precise evaluation and a specialised treatment which in most cases involves the removal of all the components of the device and a personalised antimicrobial therapy. CIED retention is usually limited to cases where infection is unlikely or is limited to the skin incision site. Optimal re-implantation timing depends on the type of infection and on the results of microbiological tests. Preventive strategies, in the end, include antibiotic prophylaxis before CIED implantation, the possibility to use antibacterial envelopes and the prevention of hematomas. The aim of this review is to investigate the pathogenesis, stratification, diagnostic tools and management of CIED infections.

Clinical manifestations of device-related infective endocarditis in cardiac resynchronization therapy recipients

INTRODUCTION

The aim of the study was to analyse microbiological characteristics and clinical manifestations of cardiac device-related infective endocarditis (CDRIE) in cardiac resynchronization therapy (CRT) recipients, and to compare the diagnostic value of modified Duke (MDC) versus modified Duke lead criteria (MDLC; including to MDC local infection and pulmonary infection or embolism as major criteria).

MATERIAL AND METHODS

The study population comprised 765 consecutive CRT patients from a high-volume, tertiary care centre from 2002 to 2015. All patients were screened for CDRIE.

RESULTS

During a median follow-up of 1692 days (range: 457-3067) 5.36% of patients (n = 41) developed CDRIE, which was accompanied by CRT pocket infection in 17.1% (n = 7) and recurrent pulmonary infection or pulmonary embolism in 29.3% (n = 12). Fever was present in 95.1% of patients (n = 39), whereas blood cultures were positive in 65.9% (n = 27). Staphylococcus was the most prevalent pathogen in 59.3% (n = 16), Gram-negative bacteria in 25.9% (n = 7). Transoesophageal echocardiography showed intracardiac vegetations in 73.2% of patients (n = 30). Non-different pathogen types with the most common methicillin-sensitive Staphylococcus aureus were observed for early versus late CDRIE (endocarditis ≤ 6 vs. > 6 months from CRT or other device-related procedure). All 3 inflammatory markers (C-reactive protein, white blood cells, procalcitonin) were normal in 4.9% of patients (n = 2). MDC versus MDLC indicated definite CDRIE in 48.8% versus 80.5%, respectively (p = 0.003).

CONCLUSIONS

Fever is the most common symptom of CRT-related CDRIE, and transoesophageal echocardiography allows vegetations to be visualised in nearly 3/4 of patients with CDRIE. Although the most common pathogens were Staphylococci, Gram-negative bacteria accounted for a quarter of CDRIE. Modified Duke lead criteria proved superior to MDC.