Non-infected lead-associated masses were detected in 24% of patients without infection suspicion, persisting in 42% at 6 months, with no adverse clinical outcomes.
Non-infected lead-associated masses are frequently detected by TEE on intracardiac devices (>20% prevalence) and do not appear to be associated with adverse clinical events at 1 year, suggesting they should not automatically be interpreted as infection.
Abstract Background Cardiac implantable electronic device (CIED) infections are associated with significant morbidity and mortality. While infections often present with lead vegetations, non-infected lead associated masses (LAMs), such as thrombi or fibrotic tissue, can mimic infective endocarditis on imaging. Distinguishing between infected and non-infected lead masses is crucial for guiding appropriate management, as device extraction carries risks. Purpose To assess the prevalence of non-infected LAMs in patients with intracardiac devices, including changes over a six-month period. Method The study was a prospective observational study performed at two large tertiary centers with outpatient care for patients with pacemakers/ICDs. Patients booked for routine follow-up for their device between 2018-2022 were screened for inclusion. Patients were excluded if the device was less than 3 months old, if they had esophageal disease contraindicating transesophageal echocardiography (TEE) or if there was clinical suspicion of infection. A TEE with focus on intracardiac leads was performed at baseline and repeated after 6 months. All echocardiograms were assessed separately by 2 experienced cardiologists for presence of LAMs. Any disagreements were adjudicated by a third reader. Patients were followed by chart review for an additional year for any relevant outcomes including embolism, endocarditis or death. Results In total, 101 patients were included (age 68 yeas (SD 9.8), 81 male (80%)) and had TEE performed. The majority had a pacemaker (n = 65, 64%) while the remaining had an ICD (n = 36, 36%). The median time from lead implantation was 5.0 years (IQR 1.6-9.8). A total of 65 patients (65%) were being treated with antithrombotic drugs at inclusion. At baseline, LAMs were detected in 24 of 100 patients (24%). A total of 84 (84%) patients had a follow-up TEE after 6 months, on which 17 (20%) patients had LAMs. The prevalence of LAMs on the follow-up scan in patients who had LAMs on the baseline scan was 10 (42%), while 12 patients (50%) who had LAMs on the baseline scan had a follow-up scan without LAMs and 2 patients (8%) did not have a repeat scan. An additional 7 patients (8%) had new LAMs on follow-up scan. There were no significant differences in baseline characteristics, prevalence of antithrombotic drugs, type of device and detection of a LAMs on TEE. After 1 year of follow-up, there were no occurrences of symptomatic embolic events or endocarditis and 1 patient who did not have LAMs on a scan had died. Conclusion In patients without clinical suspicion of device infection, LAMs were detected in more than 20% of patients, regardless of device-type or treatment with antithrombotic drugs. After 6 months, 42% of patients still had LAMs. There was no clinical impact of detected LAMs. These findings suggest echocardiographic detection of LAMs does not necessarily indicate infection, which should be considered when diagnosing CIED infection.
Pries-Heje et al. (2025) studied this question. Non-infected lead-associated masses were detected in 24% of patients without infection suspicion, persisting in 42% at 6 months, with no adverse clinical outcomes.