Introduction
The infection of cardiac implantable electronic devices (CIEDs) is a feared and devastating complication associated with a high morbidity, mortality and healthcare costs1,2. Removal of the infected device and extraction of the leads followed by prolonged administration of intravenous antibiotics are the core of the treatment. The incidence of CIEDs infection ranges from 0.5 to 2.2 % for permanent pacemakers and implantable cardiac defibrillators3,4. In the setting of bacteraemia, the risk for CEID infection depends on the offending species. Staphylococcus aureus carries a higher risk of device involvement as compared to gram negative bacilli except with Pseudomonas aeruginosa and Serratia marscecens 5,6. While diagnosis of CIED pocket infection can be generally confirmed by local inflammatory signs, the diagnosis of lead infection may be more challenging. To improve the diagnostic yield of CIED infection, the European Society of Cardiology and Heart Rhythm Society have suggested that the use of18 F-fluorodeoxyglucose (FDG)- PET/CT imaging might provide helpful evidence for inconclusive cases in their guidelines1,7. The uptake of18F-FDG, a glucose analogue, by the leukocytes has a high sensitivity in detecting infection using PET imaging and the combination of PET/CT imaging in recent systems provide the location of infectious foci with high spatial resolution8-10.
Leadless pacing system has been recently introduced for patients requiring ventricular pacing to overcome pocket and lead-related complications11. The updated results of the Micra Post-Approval Registry consistently showed the safety and the efficacy of leadless pacing with lower rates of complications including device infection as compared to a historical patients cohort with conventional permanent pacing12. Leadless pacemakers may be more resistant to bacterial seeding during bloodstream infection because of their intrinsic characteristics including a small surface area and encapsulation in the right ventricle11,13,14. In the present study, we report the incidence and outcome of bacteraemia in patients implanted with a Micra Transcatheter Pacing System (TPS) (Medtronic, Minneapolis, MN, US) in our institution. We also present18F-FDG PET/CT findings obtained in a patients sub-group.