Contribution of PET imaging to mortality risk stratification in candidates to lead extraction for pacemaker or defibrillator infection: a prospective single center study

PURPOSE: 18F-FDG PET/CT is an emerging technique for diagnosis of cardiac implantable electronic devices infection (CIEDI). Despite the improvements in transvenous lead extraction (TLE), long-term survival in patients with CIEDI is poor. The aim of the present study was to evaluate whether the extension of CIEDI at 18F-FDG PET/CT can improve prediction of survival after TLE.

METHODS: Prospective, monocentric observational study enrolling consecutive candidates to TLE for a diagnosis of CIEDI. 18F-FDG PET/CT was performed in all patients prior TLE.

RESULTS: There were 105 consecutive patients with confirmed CIEDI enrolled. An increased 18F-FDG uptake was limited to cardiac implantable electrical device (CIED) pocket in 56 patients, 40 patients had a systemic involvement. We had nine negative PET in patients undergoing prolonged antimicrobial therapy (22.5 ± 14.0 days vs. 8.6 ± 13.0 days; p = 0.005). Implementation of 18F-FDG PET/CT in modified Duke Criteria lead to reclassification of 23.8% of the patients. After a mean follow-up of 25.0 ± 9.0 months, 31 patients died (29.5%). Patients with CIED pocket involvement at 18F-FDG PET/CT presented a better survival independently of presence/absence of systemic involvement (HR 0.493, 95%CI 0.240-0.984; p = 0.048). After integration of 18F-FDG PET/CT data, absence of overt/hidden pocket involvement in CIEDI and a (glomerular filtration rate) GFR < 60 ml/min were the only independent predictors of mortality at long term.

CONCLUSIONS: Patient with CIEDI and a Cold Closed Pocket (i.e., a CIED pocket without skin erosion/perforation nor increased capitation at 18F-FDG PET/CT) present worse long-term survival. Patient management can benefit by systematic adoption of pre-TLE 18F-FDG PET/CT through improved identification of CIED related endocarditis (CIEDIE) and hidden involvement of CIED pocket.