Demographics, Clinical Characteristics, Microbiological Findings, and Risk Factors of 66 Patients with Cardiac Implantable Electronic Devices Infection

Background: Cardiac implantable electronic device (CIED) infection is a significant complication associated with implantable cardiac devices, resulting in considerable morbidity, mortality, and financial burden. In recent years, the rate of CIED implantation has increased, leading to a corresponding rise in CIED infections. Objectives: This study investigates the demographics, comorbidities, clinical presentations, microbiological findings, and complications associated with CIED infections. Methods: This cross-sectional retrospective study was conducted at Tehran Heart Center and Imam Khomeini Hospital, Tehran, Iran, from March 2017 to March 2023. A total of 66 patients with confirmed CIED infections participated in the study. Patients aged 18 years or older who were admitted with CIED infection were included. The patients' demographic characteristics, predisposing factors, clinical presentations, echocardiographic findings, and laboratory results were recorded. Descriptive analysis was performed using mean ± standard deviation and frequencies (percentages). Statistical analysis was conducted using SPSS software, version 18, for Windows (SPSS Inc., Chicago, Illinois, USA). Results: Between March 2017 and March 2023, 66 patients with confirmed CIED infections participated in the study. The cohort consisted of 53 males (80.3%) and 13 females (19.7%), with a mean age of 59.67 ± 13.59 years. Most patients (91%) exhibited signs of pocket site infection. The occurrence rates for various presentations were as follows: Device lead or generator erosion at 24.2% (16 patients), fever at 19.7% (13 patients), bacteremia at 7.6% (5 patients), and CIED-related infective endocarditis at 10.6% (7 patients). Among the patients, 25 (37.9%) had negative cultures, while positive cultures were identified in 41 patients. The most frequent causative microorganisms were coagulase-negative staphylococci (CONS) and Staphylococcus aureus. Conclusions: Due to the high prevalence of culture-negative CIED infection and the low sensitivity of laboratory findings such as leukocytosis, anemia, and elevated erythrocyte sedimentation rates (ESR) in CIED infection patients, diagnosing CIED infection can be challenging in cases where pocket site inflammatory changes or device erosion is absent. In these cases, the diagnosis should be confirmed with a combination of clinical findings, microbiologic techniques, echocardiography, new imaging modalities such as 18 FDG-PET/CT, and the physician's clinical judgment.