Temporal and Microbiological Analysis of Cardiac Implantable Electrical Device Infections - A Retrospective Study

Incidence of Staphylococcus aureus Bacteremia in Patients Following Implantation of Cardiac Implantable Electronic Devices: A Danish Nationwide Cohort Study

Background

Staphylococcus aureus bacteremia (SAB) is a high-risk condition associated with high morbidity and mortality. In the presence of cardiac implantable electronic devices (CIEDs), SAB may cause or clinically indicate device infection. We aimed to estimate the 10-year absolute risk of SAB in adult Danish first-time CIED carriers. Secondary aims included identification of risk factors associated with SAB.

Methods

A registry-based study utilizing Danish nationwide registers and including consecutive Danish patients undergoing first CIED implantation between 2000 and 2020 was conducted. The primary outcome was first-time SAB after CIED implantation.

Results

A total of 87 257 patients with first CIED implantation in the study period were identified (median age, 75 years; 62.6% were male; median follow-up, 3.8 years). Patients with pacemakers (PMs) were older and with more noncardiovascular comorbidities compared to patients with implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy devices with or without defibrillator capacity (CRTs). In total, 1366 patients (1.6%) developed SAB. The 10-year absolute risk (95% confidence interval) of SAB was 2.0% (1.9%-2.1%) for PM, 2.6% (2.2%-3.1%) for ICD, and 3.7% (3.0%-4.5%) for CRT. A multivariable Cox analysis identified hemodialysis (hazard ratio [HR], 8.51), SAB before CIED (HR, 2.76), liver disease (HR, 2.35), and carrying a CRT device (HR, 1.68) among the covariates associated with increased risk of SAB.

Conclusions

The absolute risk of SAB in Danish CIED carriers increased with more advanced CIED systems. The risk was highest within the first 3 months after CIED implantation and increased with the presence of certain covariates including renal dialysis, SAB before CIED, male sex, and advancing age.

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.

Risk of Cardiac Implantable Electronic Device Infection after Early versus Delayed Lead Repositioning

(1) Background: Early reintervention increases the risk of infection of cardiac implantable electronic devices (CIEDs). Some operators therefore delay lead repositioning in the case of dislocation by weeks; however, there is no evidence to support this practice. The aim of our study was to evaluate the impact of the timing of reoperation on infection risk. (2) Methods: The data from consecutive patients undergoing lead repositioning in two European referral centers were retrospectively analyzed. The odds ratio (OR) of CIED infection in the first year was compared among patients undergoing early (≤1 week) vs. delayed (>1 week to 1 year) reoperation. (3) Results: Out of 249 patients requiring CIED reintervention, 85 patients (34%) underwent an early (median 2 days) and 164 (66%) underwent a delayed lead revision (median 53 days). A total of nine (3.6%) wound/device infections were identified. The risk of infection was numerically lower in the early (1.2%) vs. delayed (4.9%) intervention group yielding no statistically significant difference, even after adjustment for typical risk factors for CIED infection (adjusted OR = 0.264, 95% CI 0.032-2.179, p = 0.216). System explantation/extraction was necessary in seven cases, all being revised in the delayed group. (4) Conclusions: In this bicentric, international study, delayed lead repositioning did not reduce the risk of CIED infection.

Surgical Management of Cardiac Implantable Electronic Device Complications in Patients Unsuitable for Transvenous Lead Extraction

BACKGROUND

Although surgical approaches for infected or failing cardiac implantable electronic device (CIED) leads are more invasive than transvenous approaches, they are still required for patients considered unsuitable for transvenous procedures. In this study, surgical management with transvenous equipment for CIED complications was examined in patients unsuitable for transvenous lead extraction.

METHODS AND RESULTS

We retrospectively examined 152 consecutive patients who underwent CIED extraction between April 2009 and December 2021 at the Department of Cardiovascular Surgery, Nippon Medical School. Nine patients (5.9%; mean [±SD] age 61.7±16.7 years) who underwent open heart surgery were identified as unsuitable for the isolated transvenous approach. CIED types included 5 pacemakers and 4 implantable cardioverter-defibrillators; the mean [±SD] lead age was 19.5±7.0 years. Indications for surgical management according to Heart Rhythm Society guidelines included failed prior to transvenous CIED extraction (n=6), intracardiac vegetation (n=2), and severe lead adhesion (n=1). Transvenous CIED extraction tools were used in all patients during or before surgery. Additional surgical procedures with CIED extraction included epicardial lead implantation (n=4) and tricuspid valve repair (n=3). All patients were discharged; during the follow-up period (mean 5.7±3.7 years), only 1 patient died (non-cardiac cause).

CONCLUSIONS

Surgical procedures and transvenous extraction tools were combined in the removal strategy for efficacious surgical management of CIED leads. Intensive surgical procedures were safely performed in patients unsuitable for transvenous extraction.