Clinical features and outcomes of cardiovascular implantable electronic device infections due to staphylococcal species

Cardiovascular Implantable Electronic Device Infections: A Contemporary Review

Infections associated with cardiac implantable electronic devices (CIEDs) are increasing and are a cause of significant morbidity and mortality. This article summarizes the latest updates with respect to the epidemiology, microbiology, and risk factors for CIED-related infections. It also covers important considerations regarding the diagnosis, management, and prevention of these infections. Newer technologies such as leadless pacemakers and subcutaneous implantable cardioverters and defibrillators are discussed.

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.

Prevention and Management of Cardiac Implantable Electronic Device Infections: State-of-the-Art and Future Directions

Cardiac implantable electronic device (CIED) infection is an increasingly common complication of device therapy. CIED infection confers significant patient morbidity and health care expenditure, hence it is essential that clinicians recognise the contemporary strategies for predicting, reducing and treating these events. Recent technological advances-in particular, the development of antimicrobial envelopes, leadless devices and validated risk scores-present decision-makers with novel strategies for managing this expanding patient population. This review summarises the key issues facing CIED patients and their physicians, and explores the supporting evidence for the latest therapeutic developments in this field.

Risk of cardiac device-related infection in patients with late-onset bloodstream infection. Analysis on a National Cohort

OBJECTIVES

To determine the incidence of cardiac device-related infection (CDRI) among patients with cardiac device (CD) during late-onset bloodstream infection (BSI) and to identify the risk factors associated with CDRI.

METHODS

Patients with a CD (cardiac implantable electronic devices -CIED- and/or prosthetic heart valve -PHV-) and late-onset-BSI (>1 year after the CD implantation/last manipulation) were selected from the PROBAC project, a prospective, observational cohort study including adult patients with bacteraemia consecutively admitted to 26 Spanish hospitals from October 2016 to March 2017. Multivariate analyses using logistic regression were performed to identify the risk factors associated with CDRI.

RESULTS

317 BSI from patients carrying a CD were registered, 187 (56.2%) were late-onset-BSI. A total of 40 (21.4%) CDRI were identified during late-onset-BSI. The CDRI cumulative incidence in Gram-positive-BSI was 41.8% (38/91), with S. aureus, Enterococcus spp. and viridans streptococci showing the greatest percentages: 40% (12/30), 42% (11/26) and 75% (6/8), respectively. Independent predictors of CDRI were an unknown source of infection (OR: 2.88 [CI 95%:1.18-7.06], p=0.02), Gram-positive-aetiology (23.1 [5.23-102.1], p<0.001) and persistent bacteraemia (4.81 [1.21-19], p=0.03). In an exploratory analysis, S. aureus (3.99 [1.37-11.65], p=0.011), Enterococcus spp. (5.21 [1.76-15.4], p=0.003) and viridans streptococci (28.7 [4.71-173.5], p<0.001) aetiology were also found to be risk factors for CDRI.

CONCLUSIONS

CDRI during late-onset-BSI is a frequent phenomenon. Risk of CDRI differs among species, happening in almost half of the Gram-positive-BSI. An unknown source of the primary infection, Gram-positive-aetiology -especially S. aureus, Enterococcus spp. and viridans streptococci-, and persistent bacteraemia were identified as risk factors for CDRI.

Staphylococcus aureus and Neutrophil Extracellular Traps: The Master Manipulator Meets Its Match in Immunothrombosis

Over the past 10 years, neutrophil extracellular traps (NETs) have become widely accepted as an integral player in immunothrombosis, due to their complex interplay with both pathogens and components of the coagulation system. While the release of NETs is an attempt by neutrophils to trap pathogens and constrain infections, NETs can have bystander effects on the host by inducing uncontrolled thrombosis, inflammation, and tissue damage. From an evolutionary perspective, pathogens have adapted to bypass the host innate immune response. Staphylococcus aureus (S. aureus), in particular, proficiently overcomes NET formation using several virulence factors. Here we review mechanisms of NET formation and how these are intertwined with platelet activation, the release of endothelial von Willebrand factor, and the activation of the coagulation system. We discuss the unique ability of S. aureus to modulate NET formation and alter released NETs, which helps S. aureus to escape from the host's defense mechanisms. We then discuss how platelets and the coagulation system could play a role in NET formation in S. aureus-induced infective endocarditis, and we explain how targeting these complex cellular interactions could reveal novel therapies to treat this disease and other immunothrombotic disorders.

Influence of the type of pathogen on the clinical course of infectious complications related to cardiac implantable electronic devices

The specific role of the various pathogens causing cardiac implantable electronic devices-(CIEDs)-related infections requires further understanding. The data of 1241 patients undergoing transvenous lead extraction because of lead-related infective endocarditis (LRIE-773 patients) and pocket infection (PI-468 patients) in two high-volume centers were analyzed. Clinical course and long-term prognosis according to the pathogen were assessed. Blood and generator pocket cultures were most often positive for methicillin-sensitive Staphylococcus aureus (MSSA: 22.19% and 18.13% respectively), methicillin-sensitive Staphylococcus epidermidis (MSSE: 17.39% and 15.63%) and other staphylococci (11.59% and 6.46%). The worst long-term prognosis both in LRIE and PI subgroup was in patients with infection caused by Gram-positive microorganisms, other than staphylococci. The most common pathogens causing CIED infection are MSSA and MSSE, however, the role of other Gram-positive bacteria and Gram-negative organisms is also important. Comparable, high mortality in patients with LRIE and PI requires further studies.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

Therapy and outcomes of cardiac implantable electronic devices infections

Cardiac implantable electronic device (CIED) infection causes significant morbidity and mortality without appropriate treatment. It can present as incisional infection, pocket infection, systemic CIED infection, or occult bacteraemia. Complete percutaneous CIED extraction (excepted in case of incisional infection) and appropriate antibiotic therapy are the two main pillars of therapy. Device reimplantation, if needed, should be delayed sufficiently to allow control of the infection. Here, we address the differences in prognosis according to the clinical scenario and the different treatment options.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

The emergence of Staphylococcus aureus as the primary cause of cardiac device-related infective endocarditis

BACKGROUND

Increasing use of cardiovascular implantable electronic devices (CIED), as permanent pacemakers (PPM), implantable cardioverter defibrillators (ICD), or cardiac resynchronization therapy (CRT), is associated with the emergence of CIED-related infective endocarditis (CIED-IE). We aimed to characterize CIED-IE profile, temporal trends, and prognostic factors.

METHODS

CIED-IE diagnosed at Rennes University Hospital during years 1992-2017 were identified through computerized database, and included if they presented all of the following: (1) clinical signs of infection; (2) microbiological documentation through blood and/or CIED lead cultures; (3) lead or valve vegetation, or definite IE according to Duke criteria. Data were retrospectively extracted from medical charts. The cohort was categorized in three periods: 1992-1999, 2000-2008, and 2009-2017.

RESULTS

We included 199 patients (51 women, 148 men, median age 73 years [interquartile range, 64-79]), with CIED-IE: 158 PPMs (79%), 24 ICD (12%), and 17 CRT (9%). Main pathogens were coagulase-negative staphylococci (CoNS: n = 86, 43%), Staphylococcus aureus (n = 60, 30%), and other Gram-positive cocci (n = 28, 14%). Temporal trends were remarkable for the decline in CoNS (P = 0.002), and the emergence of S. aureus as the primary cause of CIED-IE (24/63 in 2009-2017, 38%). Factors independently associated with one-year mortality were chronic obstructive pulmonary disease (COPD: hazard ratio 3.84 [1.03-6.02], P = 0.03), left-sided endocarditis (HR 2.25 [1.09-4.65], P = 0.03), pathogens other than CoNS (HR 3.16 [1.19-8.39], P = 0.02), and CIED removal/reimplantation (HR 0.41 [0.20-0.83], P = 0.01).

CONCLUSIONS

S. aureus has emerged as the primary cause of CIED-IE. Left-sided endocarditis, COPD, pathogens other than CoNS, and no CIED removal/reimplantation are independent risk factors for one-year mortality.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID), and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially lifesaving treatments for a number of cardiac conditions but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased health care costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well-recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, antibacterial envelopes, prolonged antibiotics post-implantation, and others. When compared with previous guidelines or consensus statements, the present consensus document gives guidance on the use of novel device alternatives, novel oral anticoagulants, antibacterial envelopes, prolonged antibiotics post-implantation, as well as definitions on minimum quality requirements for centres and operators and volumes. The recognition that an international consensus document focused on management of CIED infections is lacking, the dissemination of results from new important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a Novel 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

Cardiovascular Implantable Electronic Device Infection and New Insights About Correlation Between Pro-inflammatory Markers and Heart Failure: A Systematic Literature Review and Meta-Analysis

Introduction: Surgical approaches to treat patients with abnormal pro-inflammatory parameters remain controversial, and the debate on the correlation between hematological parameter alteration in cardiac implantable electronic device (CIED) infection and the increase in mortality continues.

Methods: We performed a systematic review using the PubMed, Scopus, and Cochrane Library databases. Twenty-two articles from May 2007 to April 2020 were selected and divided according to the following topics: prevalence of microbes in patients with CIED infection; characteristics of patients with CIED infection; comparison between patients who underwent and did not undergo replantation after device extraction; and correlation between alteration of hematological parameters and poor prognosis analysis.

Results: Epidemiological analysis confirmed high prevalence of male sex, staphylococcal infection, and coagulase-negative staphylococci (CoNS). The most common comorbidity was heart failure. Complete removal of CIED and antimicrobial therapy combination are the gold standard. CIED replacement was associated with higher survival. High preoperative white blood cell count and C-reactive protein levels increased the risk of right ventricular failure (RVF) development. Increased red blood cell distribution width (RDW) value or decreased platelet count was correlated with poor prognosis. No correlation was noted between preoperative leukocytosis and CIED infection.

Discussion: A relevant correlation between leukocytosis and RVF was observed. Heart failure may be related to high RDW values and decreased platelet count. Data on the correlation between hematological parameter alteration and poor prognosis are missing in many studies because of delayed implantation in patients showing signs of infection.

Risk Factors for Repeat Infection and Mortality After Extraction of Infected Cardiovascular Implantable Electronic Devices

OBJECTIVES

This study sought to investigate the factors associated with repeat infection following lead extraction procedures.

BACKGROUND

Although lead extraction is an essential therapy for patients with cardiovascular implantable electronic device (CIED) infection, repeat infection still occurs in some patients.

METHODS

The authors reviewed data for consecutive patients who underwent extraction of infected CIEDs from August 2003 to May 2019. Repeat infection was defined as infective endocarditis, sepsis with no alternative focus, or pocket infection after extraction of infected CIEDs.

RESULTS

Extraction of infected CIEDs was performed in 496 patients. The most commonly implicated pathogen was Staphylococcus aureus (188 patients). In 449 patients (90.5%), all leads were completely extracted using only transvenous techniques. Thirty-three patients (6.7%) underwent surgical lead extraction, and 14 (2.8%) had retained leads or lead components. After a median follow-up of 352 [40 to 1,255] days after CIED extraction, 144 patients (29.0%) died. Repeat infection occurred in 47 patients (9.5%) with the median time from the extraction to repeat infection of 103 [45 to 214] days. In multivariable analysis, presence of a left ventricular assist device, younger age at extraction, and S. aureus infection were independent predictors of repeat infection. Additionally, chronic kidney disease, congestive heart failure, presence of septic emboli, S. aureus infection, and occurrence of major complications were independent predictors of increased mortality.

CONCLUSIONS

Patients with S. aureus infection have a high risk of repeat infection and poor prognosis after CIED extraction. Repeat infection is also predicted by younger age and the presence of a left ventricular assist device, whereas mortality was predicted by congestive heart failure, chronic kidney disease, and septic emboli.

Clinical Presentation, Timing, and Microbiology of CIED Infections: An Analysis of the WRAP-IT Trial

OBJECTIVES

This study characterized the microbiology of major cardiac implantable electronic device (CIED) infections that occurred during the WRAP-IT (Worldwide Randomized Antibiotic Envelope Infection Prevention Trial) study.

BACKGROUND

The WRAP-IT study offers a unique opportunity for further understanding of the pathogens involved in major CIED infections in a prospective dataset, with implications for clinical practice and infection management.

METHODS

A total of 6,800 patients randomized 1:1 to receive an antibacterial envelope or not (control subjects) were included in this analysis. Patient characteristics, infection manifestation (pocket vs. systemic), and infection microbiology were evaluated through all follow-up (36 months). Data were analyzed using Cox proportional hazards regression.

RESULTS

A total of 3,371 patients received an envelope, and 3,429 patients were control subjects. Major CIED infection occurred in 32 patients who received an envelope and 51 control subjects (36-month Kaplan-Meier estimated event rate, 1.3% and 1.9%, respectively; p = 0.046). A 61% reduction in major pocket infection was observed within 12 months of the procedure in the envelope group (hazard ratio: 0.39, 95% confidence interval: 0.21 to 0.73; p = 0.003). Among 76 patients with major infections who had a sample taken, causative pathogens were identified in 47 patients. Staphylococcus species were the predominate pathogen (n = 31) and envelope use resulted in a 76% reduction in Staphylococcus-related pocket infections (n = 4 vs. 17; p = 0.010). Envelope use was not associated with delayed onset of pocket infections and did not affect the presentation of infections.

CONCLUSIONS

Antibacterial envelope use resulted in a significant reduction of major CIED pocket infections and was particularly effective against Staphylococcus species, the predominant cause of pocket infections. (Worldwide Randomized Antibiotic Envelope Infection Prevention Trial [WRAP-IT]; NCT02277990).

Diagnosis and management of subcutaneous implantable cardioverter-defibrillator infections based on process mapping

BACKGROUND

Infection is a well-recognized complication of cardiovascular implantable electronic device (CIED) implantation, including the more recently available subcutaneous implantable cardioverter-defibrillator (S-ICD). Although the AHA/ACC/HRS guidelines include recommendations for S-ICD use, currently there are no clinical trial data that address the diagnosis and management of S-ICD infections. Therefore, an expert panel was convened to develop consensus on these topics.

METHODS

A process mapping methodology was used to achieve a primary goal - the development of consensus on the diagnosis and management of S-ICD infections. Two face-to-face meetings of panel experts were conducted to recommend useful information to clinicians in individual patient management of S-ICD infections.

RESULTS

Panel consensus of a stepwise approach in the diagnosis and management was developed to provide guidance in individual patient management.

CONCLUSION

Achieving expert panel consensus by process mapping methodology in S-ICD infection diagnosis and management was attainable, and the results should be helpful in individual patient management.

Salvage of Threatened Cardiovascular Implantable Electronic Devices: Case Series and Review of Literature

BACKGROUND

The treatment of infected or exposed cardiac pacing and defibrillator devices is controversial. The conservative and widely accepted management calls for removal of the device and leads with immediate or delayed replacement of new components in a new site. Lead extraction carries a 2% major complication risk. In this article, we describe our experience with device salvage techniques and review the current literature.

METHODS

This is a retrospective case series of consecutive patients with infected, exposed, or at-risk implanted cardiac devices that were treated with aggressive surgical debridement, local pocket irrigation, and revision. A comprehensive review of the literature regarding device infection management was performed.

RESULTS

Ten patients with threatened devices were identified. Surgical revision with the aim to salvage the device was successful in 8 (80%) of 10 cases. Seventeen retrospective publications were reviewed. All indicate success with attempted salvage surgery, but heterogeneity of data limits formal meta-analysis and prevents management recommendations.

CONCLUSIONS

Cardiac pacing and defibrillator devices with low-grade infection or threatened exposure may be salvaged without explantation. Despite the lack of clear management guidelines or data, plastic surgeons may be asked to assist in the management of threatened cardiac devices. Further prospective trials are required to evaluate the safety, efficacy, and cost-effectiveness of attempted implant salvage.

The never-ending story of CIED infection prevention: Shall we WRAP-IT and go?

CIED infection is perceived as substantial, ranging from 1% to 4% in literature depending on different studies and on the population profile, and can appear either as surgical site or endovascular infection or both. Several factors have been found to be associated to CIED infection, that can be summarized as patient-related (clinical profile, associated comorbidities, ongoing treatment as anticoagulants and immunosuppressants), Procedure-related (complexity of CIED surgery, type of surgery, previous pocket exploration), and center-/operator-related (center/operator volume). Thus, it is difficult to disentangle the extent of benefit that any intervention may offer to decrease this threatened complication, owing to its multifaceted complexity. The recently completed PADIT and WRAP-IT trials have significantly improved our knowledge in this field (nearly 20 000 patients enrolled), reporting an infection rate of 1% to 1.2% in control-arm patients and a 20% to 67% infection decrease when incremental antibiotic prophylaxis is added on top of optimized preventative strategies. Observational registries highlighted that participation in a prospective survey of CIED infection dramatically decrease infection rate by optimization of antisepsis protocols and operator awareness, that explains the low event rate observed in PADIT and WRAP-IT. While this consideration prompts each center to engage into a proactive infection prevention program, it makes a point in favor of antibiotic prophylaxis delivered locally in 7 days or more, as enabled by TYRX in the WRAP-IT trial. However, care sustainability (the number needed to treat in the most favorable WRAP-IT scenario is 100) suggests further analysis to understand the settings (patient- or procedure-related) most likely to benefit by such an enhanced prevention strategy.

Cardiovascular Implantable Electronic Device Infections

Infections associated with cardiac implantable electronic devices are increasing and are associated with significant morbidity and mortality. This article reviews the epidemiology, microbiology, and risk factors for acquisition of these infections. The complex diagnostic and management strategies associated with these serious infections are reviewed with an emphasis on recent updates and advances, as well as existing controversies. Additionally, the latest in preventative strategies are reviewed.

The Risk of Cardiac Device-Related Infection in Bacteremic Patients Is Species Specific: Results of a 12-Year Prospective Cohort

BACKGROUND

The species-specific risk of cardiac device-related infection (CDRI) among bacteremic patients is incompletely understood.

METHODS

We conducted a prospective cohort study of hospitalized patients from October 2002 to December 2014 with a cardiac device (CD) and either Staphylococcus aureus bacteremia (SAB) or Gram-negative bacteremia (GNB). Cardiac devices were defined as either prosthetic heart valves (PHVs), including valvular support rings, permanent pacemakers (PPMs)/automatic implantable cardioverter defibrillators (AICDs), or left ventricular assist devices (LVADs).

RESULTS

During the study period, a total of 284 patients with ≥1 CD developed either SAB (n = 152 patients) or GNB (n = 132 patients). Among the 284 patients, 150 (52.8%) had PPMs/AICDs, 72 (25.4%) had PHVs, 4 (1.4%) had LVADs, and 58 (20.4%) had >1 device present. Overall, 54.6% of patients with SAB and 16.7% of patients with GNB met criteria for definite CDRI (P < .0001). Multivariable logistic regression analysis revealed that 3 bacterial species were associated with an increased risk for CDRI: Staphylococcus aureus (odds ratio [OR] = 5.57; 95% confidence interval [CI], 2.16-14.36), Pseudomonas aeruginosa (OR = 50.28; 95% CI, 4.16-606.93), and Serratia marcescens (OR = 7.75; 95% CI, 1.48-40.48).

CONCLUSIONS

Risk of CDRI among patients with bacteremia varies by species. Cardiac device-related infection risk is highest in patients with bacteremia due to S aureus, P aeruginosa, or S marcescens. By contrast, it is lower in patients with bacteremia due to other species of Gram-negative bacilli. Patients with a CD who develop bacteremia due to either P aeruginosa or S marcescens should be considered for diagnostic imaging to evaluate for the presence of CDRI.

Cardiac device infection: Review based in the experience of a single center

INTRODUCTION

The incidence of cardiac implantable electronic device infections has increased significantly over the years and they are associated with significant morbidity and mortality. The epidemiology in the Central region of Portugal is not known.

OBJECTIVE AND METHODS

To characterize cardiac implantable electronic device infections through a retrospective study of 3158 patients admitted to our center between January 2008 and September 2014 and to review the subject in the light of the current state of the art.

RESULTS

The infection rate was 1.48% (pacemakers 1.21%, cardiac defibrillator/resynchronization devices 5.40%). The study population consisted of 47 patients with a mean age of 65±19 years, predominantly male (72.3%). Infections were mainly of pacemakers, the main device implanted in our population (n=2954), and most occurred late after first implantation. Clinically, most patients presented with fever and local inflammation. Blood cultures identified mainly Gram-positive microorganisms. Empiric antibiotic therapy with vancomycin was instituted in all patients, associated with gentamicin in 57%. The device was extracted in the majority of cases (72%). During follow-up (32±22 months) eight patients died (17%), seven of cardiovascular cause (15%), and seven were readmitted with device infection (15%).

CONCLUSIONS

Our rate of infection was low, similar to other published series, with a higher rate in cardiac defibrillator/resynchronization devices. After standard treatment with antibiotic therapy and device extraction, the prognosis was good.

Automated implantable cardioverter defibrillator lead infection in a patient with previous superior vena cava thrombosis

We present a case of a 44-year-old woman who presented with cough, pleuritic chest pain and fever leading to a diagnosis of pneumonia±pulmonary embolism. She had a history of familial hypertrophic obstructive cardiomyopathy (HOCM), for which an automated implantable cardioverter defibrillator (AICD) had been implanted, and a subsequent superior vena cava (SVC) thrombus, for which she was anticoagulated with warfarin. On admission, blood cultures grew a coagulase-negative Staphylococcus. CT pulmonary angiogram and transoesophageal echocardiography (TOE) were performed and revealed large vegetations adherent to the AICD leads with complete occlusion of the SVC. The infected leads were the source of sepsis. Open surgery was planned. For cardiopulmonary bypass, the venous cannula was inserted in the inferior vena cava (IVC) and a completely bloodless field was obtained in the right atrium allowing for the extraction of the AICD leads completely, along with the adherent vegetations from within.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Clinical manifestations of lead-dependent infective endocarditis: analysis of 414 cases

It is important to identify clinical manifestations of lead-dependent infective endocarditis (LDIE), as it begins insidiously with the slow development of nonspecific symptoms. Clinical data from 414 patients with the diagnosis of LDIE according to Modified Duke Lead Criteria (MDLC) were analyzed. Patients with LDIE had been identified in a population of 1,426 subjects submitted to transvenous lead extraction (TLE) in the Reference Clinical Cardiology Center in Lublin between 2006 and 2013. The symptoms of LDIE and pocket infection were detected in 62.1 % of patients. The mean duration of LDIE symptoms prior to referral for TLE was 6.7 months. Fever and shivers were found in 55.3 % of patients, and pulmonary infections in 24.9 %. Vegetations were detected in 67.6 % of patients, and positive cultures of blood, lead, and pocket in 34.5, 46.4, and 30.0 %, respectively. The most common pathogens in all type cultures were coagulase-negative staphylococci (CNS), with Staphylococcus epidermidis domination; the second most common organism was Staphylococcus aureus. 76.3 % of patients were treated with empirical antibiotic therapy before hospitalization due to TLE. In the laboratory tests, the mean white blood cell count was 9,671 ± 5,212/μl, mean erythrocyte sedimentation rate 43 mm, C-reactive protein (CRP) 46.3 mg/dl ± 61, and procalcitonin 1.57 ± 4.4 ng/ml. The multivariate analysis showed that the probability of LDIE increased with increasing CRP. The diagnosis of LDIE based on MDLC may be challenging because of a relatively low sensitivity of major criteria, which is associated with early antibiotic therapy and low usefulness of minor criteria. The important clinical symptoms of LDIE include fever with shivering and recurrent pulmonary infections. The most specific pathogens were Staphylococcus epidermidis and Staphylococcus aureus. Laboratory tests most frequently revealed normal white blood cell count, relatively rarely elevated procalcitonin level, and significantly increased erythrocyte sedimentation rate (ESR) and CRP. This constellation of signs should prompt a more thorough search for LDIE.

Clinical characteristics of infections in humans due to Staphylococcus epidermidis

Staphylococcus epidermidis is the most common cause of primary bacteremia and infections of indwelling medical devices. The ability to cause disease is linked to its natural niche on human skin and ability to attach and form biofilm on foreign bodies. This review focuses on the S. epidermidis clinical syndromes most commonly encountered by clinicians and future potential treatment modalities.

Trends in antibiotic resistance in coagulase-negative staphylococci in the United States, 1999 to 2012

Coagulase-negative staphylococci (CoNS) are important bloodstream pathogens that are typically resistant to multiple antibiotics. Despite the concern about increasing resistance, there have been no recent studies describing the national prevalence of CoNS pathogens. We used national resistance data over a period of 13 years (1999 to 2012) from The Surveillance Network (TSN) to determine the prevalence of and assess the trends in resistance for Staphylococcus epidermidis, the most common CoNS pathogen, and all other CoNS pathogens. Over the course of the study period, S. epidermidis resistance to ciprofloxacin and clindamycin increased steadily from 58.3% to 68.4% and from 43.4% to 48.5%, respectively. Resistance to levofloxacin increased rapidly from 57.1% in 1999 to a high of 78.6% in 2005, followed by a decrease to 68.1% in 2012. Multidrug resistance for CoNS followed a similar pattern, and this rise and small decline in resistance were found to be strongly correlated with levofloxacin prescribing patterns. The resistance patterns were similar for the aggregate of CoNS pathogens. The results from our study demonstrate that the antibiotic resistance in CoNS pathogens has increased significantly over the past 13 years. These results are important, as CoNS can serve as sentinels for monitoring resistance, and they play a role as reservoirs of resistance genes that can be transmitted to other pathogens. The link between the levofloxacin prescription rate and resistance levels suggests a critical role for reducing the inappropriate use of fluoroquinolones and other broad-spectrum antibiotics in health care settings and in the community to help curb the reservoir of resistance in these colonizing pathogens.

Predictors of mortality in patients with cardiovascular implantable electronic device infections

Infection reduces survival in cardiovascular implantable electronic device (CIED) recipients. However, the clinical predictors of short- and long-term mortality in patients with CIED infection are not well understood. We retrospectively reviewed all patients with CIED infection who were admitted to Mayo Clinic from January 1991 to December 2008. Survival data were obtained from the medical records and the United Sates Social Security Index. The purported risk factors for short-term (30-day) and long-term (>30-day) mortality were analyzed using univariate and multivariate models. Overall, 415 cases of CIED infection were identified during the study period. The mean follow-up duration for the 243 patients who were alive at the last follow-up visit was 6.9 years. In a multivariate model, heart failure (odds ratio 9.31, 95% confidence interval 2.08 to 41.67), corticosteroid therapy (odds ratio 4.04, 95% confidence interval 1.40 to 11.60), and presentation with CIED-related infective endocarditis (odds ratio 5.60, 95% confidence interval 2.25 to 13.92) were associated with increased short-term mortality. The factors associated with long-term mortality in the multivariate model included patient age (hazard ratio 1.20, 95% confidence interval 1.06 to 1.36), heart failure (hazard ratio 2.01, 95% confidence interval 1.42 to 2.86), metastatic malignancy (hazard ratio 5.99, 95% confidence interval 1.67 to 21.53), corticosteroid therapy (hazard ratio 1.97, 95% confidence interval 1.22 to 3.18), renal failure (hazard ratio 1.94, 95% confidence interval 1.37 to 2.74), and CIED-related infective endocarditis (hazard ratio 1.68, 95% confidence interval 1.17 to 2.41). In conclusion, these data suggest that the development of CIED-related infective endocarditis and the presence of co-morbid conditions are associated with increased short- and long-term mortality in patients with CIED infection.