Does extraction of cardiac implantable electronic devices improve outcome in patients with Staphylococcus aureus bacteraemia?

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.

Staphylococcus aureus bacteraemia, cardiac implantable electronic device, extraction, and the risk of recurrent infection; a retrospective population-based cohort study

BACKGROUND

Patients with cardiac implantable electronic device (CIED) and Staphylococcus aureus bacteraemia (SAB) are at risk of having CIED infection, pocket infection or endocarditis. To avoid treatment failures, guidelines recommend that the CIED should be extracted in all cases of SAB butrecent studies indicate low extraction rates and low risk of relapse. The aim of the study was to describe a Swedish population-based cohort of patients with CIED and SAB, the rate of extraction, and treatment failure measured as recurrent SAB.

METHODS

Patients identified to have SAB in the Karolinska Laboratory database, serving a population of 1.9 million, from January 2015 through December 2019 were matched to the Swedish ICD and Pacemaker Registry. Patients with CIED and SAB were included. Clinical data were collected from medical records.

RESULTS

A cohort of 274 patients was identified and 38 patients (14%)had the CIED extracted. Factors associated with extraction were lower age, lower Charlson comorbidity index, shorter time since CIED implantation, and non-nosocomial acquisition, but not mortality. No patient was put on lifelong antibiotic treatment. Sixteen patients (6%) had a recurrent SAB within one year, two in patients subjected to extraction (5%) and 14 in patients not subjected to CIED-extraction (6%). Three of the 14 patients were found to have definite endocarditis during the recurrent episode.

CONCLUSIONS

Despite a low extraction rate, there were few recurrences. We suggest that extraction of the CIED might be omitted if pocket infection, changes on the CIED, or definite endocarditis are not detected.

Risk of Cardiac Implantable Electronic Device Infection in Patients with Bloodstream Infection: Microbiologic Effect in the Era of Positron Emission Tomography-Computed Tomography

PURPOSE OF REVIEW

Bloodstream infection (BSI) in patients with cardiac implantable electronic devices (CIEDs) is common and can prompt challenges in defining optimal management. We provide a contemporary narrative review of this topic and propose a pathogen-dependent clinical approach to patient management.

RECENT FINDINGS

BSI due to staphylococci, viridans group streptococci, and enterococci is associated with an increased risk of underlying CIED infection, while the risk of CIED infection due to other organisms is poorly defined. There is growing evidence that positron emission tomography-computed tomography may be helpful in some patients with BSI and underlying CIED. Twenty studies were included to examine the impact of microbiologic findings on the risk of CIED infection among patients with BSI. Diagnosis of CIED infection in patients with BSI without pocket findings is often difficult, necessitating the use of novel diagnostic tools to help guide the clinician in subsequent patient management.

Molecular Epidemiology of Bulgarian Clinically Significant Staphylococcus aureus Isolates

Severe infections due to highly virulent and resistant Staphylococcus aureus pose a serious health threat in Bulgaria and worldwide. The purpose of this study was to explore the clonal spread of recent clinically significant methicillin-susceptible S. aureus (MSSA) isolates from inpatients and outpatients treated in three university hospitals in Sofia, Bulgaria, during the period 2016-2020 and evaluate the relationship between their molecular epidemiology, virulence profiling, and antimicrobial resistance. A total of 85 isolates (invasive and noninvasive) were studied using RAPD analysis. Ten major clusters (A-K) were identified. The first major cluster A (31.8%) was found to be predominant during 2016 and 2017 and was widespread in two hospitals, unlike its case in the following years, when it was found to be replaced by newer cluster groups. All MSSA members of the second most common cluster F (11.8%) were recovered from the Military Medical Academy, mainly during 2018-2020, and were determined to be susceptible to all other groups of antimicrobials, except for penicillins without inhibitors because they harboured the blaZ gene. The newer cluster I, with 9.4% of the isolates absent in 2016-2017, showed significantly higher virulence and macrolide resistance (42.9%) due to ermB and ermC. All the isolated MSSA in groups F and I were nosocomial and mostly invasive. In conclusion, this 5-year study demonstrates the molecular epidemiology of MSSA infections in three Bulgarian hospitals. Findings can be helpful for the understanding of staphylococcal infection distribution in hospital settings and their prevention.

Staphylococcus aureus bacteremia and cardiac implantable electronic devices in a county hospital setting: a population-based retrospective cohort study

BACKGROUND

Due to a high incidence of cardiac implantable electronic device-associated infective endocarditis (CIED-IE) in cases of Staphylococcus aureus bacteremia (SAB) and high mortality with conservative management, guidelines advocate device removal in all subjects with SAB. We aimed to investigate the clinical course of SAB in patients with a CIED (SAB+CIED) in a Swedish county hospital setting and relate it to guideline recommendations.

METHODS

All CIED carriers with SAB, excluding clinical pocket infections, in the County of Västmanland during 2010-2017 were reviewed retrospectively.

RESULTS

There were 61 cases of SAB+CIED during the study period, and CIED-IE was diagnosed in 13/61 (21%) cases. In-hospital death occurred in 19/61 (31%) cases, 34/61 (56%) cases were discharged with CIED device retained, and 8/61 (13%) cases were discharged after device removal. Subjects dying during hospitalization were elderly and diseased. No events was seen if the CIED was removed. Among four discharged cases with conservatively managed CIED-IE one relapse occured. Among 30 cases discharged with retained CIED and no evidence of IE, 22/30 (73%) cases had an uneventful follow-up, whereas adverse events secondary to overlooked CIED-IE were likely in 1/30 (3%) cases and could not be definitely excluded in additionally 4/30 (13%) cases.

CONCLUSIONS

During the study period, management became more active and prognosis improved. The heterogeneity within the population of SAB+CIED suggests that a management strategy based on an individual risk/benefit analysis could be an alternative to mandatory device removal.