Diagnostic Accuracy of 18FDG-PET-CT for Pacing or Defibrillation Lead Infection

With aging of the general population and broadening indications, the number of pacemaker recipients is steadily increasing. The incidence of infections of the implanted material, a dreaded major complication, is also rising. The diagnosis is evident in presence of an abscessed pocket, cutaneous breakthrough of the pulse generator or vegetations attached to the lead. On the other hand, a proportion of patients present with less specific clinical manifestations and a pacemaker recipient may be recurrently hospitalized for an infectious disorder of unknown origin despite detailed investigations. Without proof of lead infection, removal of the system without confirmation of its infection is usually proposed, despite the known morbidity and mortality associated with the extraction procedure (0.5 to 2%). Positive culture of the leads implies that the leads were involved in the infectious process. In recent years, 18FDG-PET-CT scan has made promising contributions in different areas including imaging to detect infection at different organ sites. Absence of hyperfixation of the lead, identified by 18FDG-PET/CT scan may be an accurate sign of absence of pacing system infection.

The extraction of intracardiac implanted material, when it is indicated by the current standard strategy, may result in negative bacteriological cultures in 10 to 25% of patients, even when they did not receive antibiotics before extraction.

The hypothesis of the study is that a new strategy adding 18FDG-PET-CT to the current strategy may avoid or reduce these false-positives.

Therefore it is hypothesized that the sensitivity of 18FDG-PET-CT will be high enough to avoid unnecessary extractions of uninfected leads, resulting in a high negative predictive value of the new diagnostic strategy incorporating 18FDG-PET-CT. The present study aims at providing valid estimates of diagnostic accuracy parameters of 18FDG-PET-CT, especially its sensitivity.

For this clinical study, firstly, 18FDG-PET-CT exam will be performed in patients, with suspicion of pacing or defibrillation lead infection, hospitalized in cardiology unit; secondarily, an intervention for the extraction of the intra-cardiac material, under general anesthesia, will be practiced and then a bacteriological culture for extracted material will be required.

The end of study visit is complete the last day of material extraction. The follow up will last 2 to 7 days.