Outcome and microbiological findings of patients with cardiac implantable electronic device infection.

Introduction: Infections associated with cardiac implantable electronic devices (CIEDs) are a multifactorial disease that leads to increased morbidity and mortality.

Objective: The aim was to analyze patient-, disease- and treatment-related characteristics including microbiological and bacterial spectrum according to survival status and to identify risk factors for 1- and 3-year mortality in patients with local and systemic CIED infection.

Methods: In a retrospective cohort study, we analyzed data from patients with CIED-related local or systemic infection undergoing successful transvenous lead extraction (TLE). Survival status as well as incidence and cause of rehospitalization were recorded. Microbiology and antibiotics used as first-line therapy were compared according to mortality. Independent risk factors for 1- and 3-year mortality were determined.

Results: Data from 243 Patients were analyzed. In-hospital mortality was 2.5%. Mortality rates at 30 days, 1- and 3 years were 4.1%, 18.1% and 30%, respectively. Seventy-four (30.5%) patients had systemic bacterial infection. Independent risk factors for 1-year mortality included age (OR 1.05 [1.01-1.10], p = 0.014), NT-proBNP at admission (OR 4.18 [1.81-9.65], p = 0.001), new onset or worsened tricuspid regurgitation after TLE (OR 6.04 [1.58-23.02], p = 0.009), and systemic infection (OR 2.76 [1.08-7.03], p = 0.034), whereas systemic infection was no longer an independent risk factor for 3-year mortality. Staphylococcus aureus was found in 18.1% of patients who survived and in 25% of those who died, p = 0.092. There was a high proportion of methicillin-resistant strains among coagulase-negative staphylococci (16.5%) compared to Staphylococcus aureus (1.2%).

Conclusions: Staphylococci are the most common causative germs of CIED-infection with coagulase-negative staphylococci showing higher resistance rates to antibiotics. The independent risk factors for increased long-term mortality could contribute to individual risk stratification and well-founded treatment decisions in clinical routine. Especially the role of tricuspid regurgitation as a complication after TLE should be investigated in future studies.