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.

Microbiological diagnosis in cardiac implantable electronic device infections detected by sonication and next-generation sequencing.

BACKGROUND: Device-related infection (DRI) is a severe complication of treatment with cardiac implantable electronic devices. Identification of the causative pathogen is essential for optimal treatment, but conventional methods often are inadequate. OBJECTIVE: The purpose of this study was to improve microbiological diagnosis in DRI using sonication and next-generation sequencing analysis. The primary objective was identification of causative pathogens. The secondary objective was estimation of the sensitivity of different microbiological methods in detecting the causative pathogen. METHODS: Consecutive patients with clinical signs of DRI between October 2016 and January 2019 from 3 tertiary centers in Denmark were included in the study. Patients underwent a diagnostic approach, including blood cultures and perioperative collection of microbiological samples (pocket swab, pocket tissue biopsies, generator, and leads). Conventional culturing was performed, and device components were sonicated and examined with an amplicon-based metagenomic analysis using next-generation sequencing. The results were compared with a reference standard-identified causative pathogen. RESULTS: In 110 patients with clinical signs of pocket (n = 50) or systemic DRI (n = 60), we collected 109 pocket swabs, 220 pocket tissue biopsies, 106 generators, 235 leads, and a minimum 1 set of blood cultures from 102 patients. Combining all findings, we identified the causative pathogen in 95% of cases, irrespective of DRI type. The usability of each microbiological method differed between DRI types. In pocket DRI, next-generation sequencing analysis of generators achieved sensitivity of 90%. For systemic DRI, blood cultures reached sensitivity of 93%. CONCLUSION: Using a strategy including sonication and next-generation sequencing, we identified the causative pathogen in 95% of DRI. Sensitivity of microbiological methods differed according to the type of DRI.

Detection of Vancomycin-Resistant Enterococcus faecium Endocarditis After Clearance of Vancomycin-Sensitive Enterococcus faecium Bacteremia.

Vancomycin-resistant enterococcal (VRE) bacteremia is associated with higher mortality rates and longer hospitalizations than vancomycin-sensitive enterococcal (VSE) bacteremia. A 67-year-old man with a right psoas abscess and pacemaker-associated tricuspid valve endocarditis in September 2020 grew VSE Enterococcus faecium from blood cultures that cleared after administration of intravenous vancomycin and gentamicin. Subsequently, he underwent tricuspid valve repair, pacemaker removal, and partial lead extraction. Valve and postoperative blood cultures grew VRE E. faecium, which cleared after administration of intravenous daptomycin. One VSE and two VRE isolates were collected and sequenced. All isolates belonged to E. faecium multilocus sequence type ST17 and were closely related, having <20 mutations in pairwise genome comparisons. Vancomycin resistance was due to the acquisition of a plasmid-encoded VanA operon. None of the isolates encoded the virulence factors asa1, gelE, cylA, or hyl; all encoded a homologue of efaAfm. VSE E. faecium, but not VRE E. faecium isolates, encoded a glucose transporter gene mutation. Two VRE E. faecium isolates formed more robust biofilms than the VSE E. faecium isolate (p < 0.001). The VRE E. faecium isolates, which generated larger biofilms than the VSE E. faecium isolate, could have remained protected in the heart valve and only caused bacteremia when disrupted during cardiac surgery. This study demonstrates that bacteria detected in the bloodstream of patients with endocarditis may not fully represent the organisms adherent to the cardiac valves or indwelling devices.

Pacemaker infection and endocarditis due to Parvimonas micra: A case report and systematic review.

Infective endocarditis caused by Parvimonas micra is rare. Its clinical features are presented in this systematic review. We also describe the case of an 82-year-old man with infective endocarditis and pacemaker infection due to P. micra. There are some reports of recurrence during antimicrobial therapy; hence, careful follow-up is necessary.

Clinical utility of sonication for diagnosing infection and colonization of cardiovascular implantable electronic devices.

Our study aimed to evaluate the sensitivity of the sonication tool for the microbiological diagnosis of cardiovascular implantable electronic device infections (CIEDIs). The extracted cardiac implants of 52 patients were assessed: 19 with CIEDI and 33 with elective generator replacement or revision without clinical infection. Sonication fluid culture of explanted CIEDs yielded higher numbers of microorganisms than pocket tissue or swab cultures. The sensitivity of sonication fluid culture was significantly higher than that of pocket swab and tissue culture for microbiological diagnosis of CIEDI. The microorganisms isolated most frequently via sonication of explanted CIEDs were Gram-positive cocci (70%), of which 50% was coagulase-negative Staphylococcus. Sonication fluid culture detected colonization in 36.4% of the non-infected patients. Sonication fluid culture represents a promising diagnostic strategy with increased sensitivity compared to conventional culture methods for microbiological diagnosis of cardiac devices associated with infection and colonization.

Cost-Effectiveness Analyses of an Absorbable Antibacterial Envelope for Use in Patients at Increased Risk of Cardiac Implantable Electronic Device Infection in Germany, Italy, and England.

OBJECTIVES: To model the cost-effectiveness of the TYRX Absorbable Antibacterial Envelope when used in patients at increased risk of cardiac implantable electronic device (CIED) infection in the context of 3 European healthcare systems: Germany, Italy, and England. METHODS: A decision tree model with a lifetime horizon was populated using data from the Worldwide Randomized Antibiotic Envelope Infection Prevention Trial, a large multicenter randomized controlled trial. Use of the antibacterial envelope adjunctive to standard of care was compared to standard of care infection prevention alone. Patients in the model were divided into subgroups based on presence of factors known to increase infection risk. RESULTS: The antibacterial envelope had the most favorable cost-effectiveness profile when patients had previously experienced CIED infection, had a history of immunosuppressive therapy, or had a Prevention of Arrhythmia Device Infection Trial (PADIT) score indicating high risk of infection (scores ≥6) at cost-effectiveness thresholds of €50 000 in Germany (assumed in the absence of an official threshold), €40 000 in Italy, and £30 000 in England. Probabilistic sensitivity analysis indicated that the antibacterial envelope was likely to be cost-effective in patients with other risk factors (including replacement of high power CIEDs, generator replacement with lead modification, and PADIT scores indicating intermediate risk of infection) when used with some device types and in some countries. CONCLUSIONS: The absorbable antibacterial envelope was associated with cost-effectiveness ratios below European benchmarks in selected patients at increased risk of infection, suggesting the envelope provides value for European healthcare systems by reducing CIED infections.

Hyaluronic acid-based antibacterial hydrogels constructed by a hybrid crosslinking strategy for pacemaker pocket infection prevention.

In this study, we developed an injectable antibacterial hydrogel based on hyaluronic acid (HA) and chlorhexidine (CHX) for cardiovascular implantable electronic device (CIED) infection treatment. To balance stability and moldability, the HA scaffold was pre-crosslinked by 1,4-butanediol diglycidyl ether (BDDE) and then ground to form an HA microgel (CHA). Then, the antibacterial agent CHX was further crosslinked in the CHA microgel through electrostatic interactions between CHA and CHX to obtain hybrid crosslinked hydrogels (CHA/CHX). These hydrogels exhibited shear-thinning/self-recovery behavior, allowing easy injection into the CIED pocket and good matching with the pocket shape without extra space requirements, which represents an improvement on previously reported methods. In vitro and in vivo antibacterial tests showed that the CHA/CHX hydrogels had both good biocompatibility and very effective antibacterial action. The above results indicated that the CHA/CHX hydrogels would be an excellent candidate for CIED pocket infection treatment.

[Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves]. / Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Reduced bacterial adhesion with parylene coating: Potential implications for Micra transcatheter pacemakers.

INTRODUCTION: Infections of cardiac implantable electronic devices remain a prevalent health concern necessitating the advent of novel preventative strategies. Based on the observation that bacterial infections of the Micra transcatheter pacemaker device are extremely rare, we examine the effect of parylene coating on bacterial adhesion and growth. METHODS: Bacterial growth was compared on polyurethane coated, bare, or parylene coated titanium surfaces. Eight test samples per bacterial species and material combination were incubated with Staphylococcus Aureus or Pseudomonas aeruginosa for 24 hours and then assayed for bacterial growth. The surface contact angle was also characterized by measuring the angle between the tangent to the surface of a liquid droplet made with the surface of the solid sample. RESULTS: The mean bacterial colony counts were significantly reduced for both parylene coated titanium versus bare samples (3.69 ± 0.27 and 4.80 ± 0.48 log[CFU/mL] respectively for S. aureus [P < .001] and 5.51 ± 0.27 and 6.08 ± 0.11 log[CFU/mL] respectively for P. aeruginosa [P < .001]), and for parylene coated titanium versus polyurethane samples (4.27 ± 0.42 and 5.40 ± 0.49 log[CFU/mL] respectively for S. aureus [P < .001] and 4.23 ± 0.42 and 4.84 ± 0.32 log[CFU/mL] respectively for P. aeruginosa [P = .006]). Parylene coated titanium samples had a higher contact angle compared with bare titanium, but lower compared with polyurethane (mean contact angle 87.5 ± 3.1 degrees parylene, 73.3 ± 3.7 degrees titanium [P < .001 vs parylene], and 94.8 ± 3.7 degrees polyurethane [P = .002 vs parylene]). CONCLUSIONS: Parylene coating significantly reduced the ability of bacteria to grow in colony count assays suggesting that this could contribute to the reduction of bacterial infections of Micra transcatheter pacemakers.

Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas / Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value (SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.

Propionibacterium acnes Pacemaker Endocarditis in a Patient With a Redundant Loop of the Ventricular Lead: PET/CT Findings.

A 59-year-old man with a pacemaker who was admitted for evaluation of fever was found to have a redundant loop of the ventricular lead and a vegetation attached to it. An FDG PET/CT revealed a focus of FDG uptake at the ventricular lead loop. Surgical extraction of the pacemaker device confirmed a Propionibacterium acnes pacemaker endocarditis. We hypothesize that the redundant loop of the ventricular lead induced a chronic mechanical stress both to the tricuspid valve and to the lead itself, facilitating the bacterial colonization of the lead.

The predictors and economic burden of early-, mid- and late-onset cardiac implantable electronic device infections: a retrospective cohort study in Ontario, Canada.

The rate of cardiac implantable electronic device (CIED) infection is increasing with time. We sought to determine the predictors, relative mortality, and cost burden of early-, mid- and late-onset CIED infections. We conducted a retrospective cohort study of all CIED implantations in Ontario, Canada between April 2013 and March 2016. The procedures and infections were identified in validated, population-wide health-care databases. Infection onset was categorized as early (0-30 days), mid (31-182 days) and late (183-365 days). Cox proportional hazards regression was used to assess the mortality impact of CIED infections, with infection modelled as a time-varying covariate. A generalized linear model with a log-link and γ distribution was used to compare health-care system costs by infection status. Among 17 584 patients undergoing CIED implantation, 215 (1.2%) developed an infection, including 88 early, 85 mid, and 42 late infections. The adjusted hazard ratio (aHR) of death was higher for patients with early (aHR 2.9, 95% CI 1.7-4.9), mid (aHR 3.3, 95% CI 1.9-5.7) and late (aHR 19.9, 95% CI 9.9-40.2) infections. Total mean 1-year health costs were highest for late-onset (mean Can$113 778), followed by mid-onset (mean Can$85 302), and then early-onset (Can$75 415) infections; costs for uninfected patients were Can$25 631. After accounting for patient and procedure characteristics, there was a significant increase in costs associated with early- (rate ratio (RR) 3.1, 95% CI 2.3-4.1), mid- (RR 2.8, 95% CI 2.4-3.3) and late- (RR 4.7, 95% CI 3.6-6.2) onset infections. In summary, CIED infections carry a tremendous clinical and economic burden, and this burden is disproportionately high for late-onset infections.

Lead Removal Without Extraction Tools: A Single-Center Experience.

INTRODUCTION: Indications for cardiac devices have been increasing as well as the need for lead extractions as a result of infections, failed leads and device recalls. Powered laser sheaths, with a global trend towards the in-creasingly technological tools, meant to improve the procedure's outcome but have economic implications. OBJECTIVE: The aim of this study is to demonstrate the experience of a Bra-zilian center that uses simple manual traction in most lead removals per-formed annually, questioning the real need for expensive and technically challenging new devices. METHODS: This retrospective observational study included 35 patients who had a transvenous lead extraction in the period of a year between January 1998 and October 2014 at Hospital de Messejana Dr. Carlos Alberto Studart Gomes, in Fortaleza, CE, Brazil. Data were collected through a records review. They were evaluated based on age, type of device, dwelling time, indication for removal, technique used and immediate outcomes. RESULTS: The median dwelling time of the devices was 46.22 months. Infec-tion, lead fracture and device malfunction were the most common indica-tions. Simple traction was the method of choice, used in 88.9% of the pro-cedures. Manual traction presented high success rates, resulting in com-plete removal without complications in 90% of the cases. CONCLUSION: This article suggests that lead extraction by simple manual traction can still be performed effectively in countries with economic diffi-culties as a first attempt, leaving auxiliary tools for a second attempt in case of failure or contraindications to the simple manual traction technique.

Cardiovascular implantable electronic device infections due to enterococcal species: Clinical features, management, and outcomes.

BACKGROUND: Enterococcal cardiovascular implantable electronic device (CIED) infections are not well characterized. METHODS: Data from the Multicenter Electrophysiologic Device Infection Cohort, a prospective study of CIED infections, were used for descriptive analysis of adults with enterococcal CIED infections. RESULTS: Of 433 patients, 21 (4.8%) had enterococcal CIED infection. Median age was 71 years. Twelve patients (57%) had permanent pacemakers, five (24%) implantable cardioverter defibrillators, and four (19%) biventricular devices. Median time from last procedure to infection was 570 days. CIED-related bloodstream infections occurred in three patients (14%) and 18 (86%) had infective endocarditis (IE), 14 (78%) of which were definite by the modified Duke criteria. IE cases were classified as follows: valvular IE, four; lead IE, eight; both valve and lead IE, six. Vegetations were demonstrated by transesophageal echocardiography in 17 patients (81%). Blood cultures were positive in 19/19 patients with confirmed results. The most common antimicrobial regimen was penicillin plus an aminoglycoside (33%). Antibiotics were given for a median of 43 days. Only 14 patients (67%) underwent device removal. There was one death during the index hospitalization with four additional deaths within 6 months (overall mortality 24%). There were no relapses. CONCLUSIONS: Enterococci caused 4.8% of CIED infections in our cohort. Based on the late onset after device placement or manipulation, most infections were likely hematogenous in origin. IE was the most common infection syndrome. Only 67% of patients underwent device removal. At 6 months follow-up, no CIED infection relapses had occurred, but overall mortality was 24%.

Lead removal without extraction tools: a single-center experience

Abstract Introduction: Indications for cardiac devices have been increasing as well as the need for lead extractions as a result of infections, failed leads and device recalls. Powered laser sheaths, with a global trend towards the in-creasingly technological tools, meant to improve the procedure's outcome but have economic implications. Objective: The aim of this study is to demonstrate the experience of a Bra-zilian center that uses simple manual traction in most lead removals per-formed annually, questioning the real need for expensive and technically challenging new devices. Methods: This retrospective observational study included 35 patients who had a transvenous lead extraction in the period of a year between January 1998 and October 2014 at Hospital de Messejana Dr. Carlos Alberto Studart Gomes, in Fortaleza, CE, Brazil. Data were collected through a records review. They were evaluated based on age, type of device, dwelling time, indication for removal, technique used and immediate outcomes. Results: The median dwelling time of the devices was 46.22 months. Infec-tion, lead fracture and device malfunction were the most common indica-tions. Simple traction was the method of choice, used in 88.9% of the pro-cedures. Manual traction presented high success rates, resulting in com-plete removal without complications in 90% of the cases. Conclusion: This article suggests that lead extraction by simple manual traction can still be performed effectively in countries with economic diffi-culties as a first attempt, leaving auxiliary tools for a second attempt in case of failure or contraindications to the simple manual traction technique.

Diagnostic Impact of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and White Blood Cell SPECT/Computed Tomography in Patients With Suspected Cardiac Implantable Electronic Device Chronic Infection.

BACKGROUND: Cardiac implantable electronic devices (CIEDs) chronic infection diagnosis is challenging because the clinical presentation is frequently misleading and echocardiography may be inconclusive. The aim of this study was to evaluate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (CT) and radiolabeled white blood cells single photon emission CT/CT in a cohort of patients who underwent both scans for suspicion of CIED infection and inconclusive routine investigations. METHODS: Forty-eight consecutive patients with suspicion of CIED infection who underwent both 18F-fluorodeoxyglucose positron emission tomography/CT and white blood cell single photon emission CT/CT in a time span ≤30 days were retrospectively included. The final diagnosis of CIED infection by the endocarditis expert team was based on the modified Duke-Li classification at the end of follow-up. 18F-Fluorodeoxyglucose positron emission tomography/CT and white blood cell single photon emission CT/CT scans were independently analyzed blinded to the patients' medical record. RESULTS: In the overall study population, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were respectively 80%, 91%, 80%, and 91% for 18F-fluorodeoxyglucose positron emission tomography/CT and 60%, 100%, 100%, and 85% for white blood cell single photon emission CT/CT. Addition of a positive nuclear imaging scan as a major criterion markedly improved the Duke-Li classification at admission. Semiquantitative parameters did not allow to discriminate between definite and rejected CIED infection. Prolonged antibiotic therapy before imaging tended to decrease the sensitivity for both techniques. CONCLUSIONS: Nuclear imaging can improve the diagnostic performances of the Duke-Li score at admission in a selected population of patients with suspected CIED infection, particularly when the infection was initially graded as possible. Whenever possible, imaging should be performed before or early after antibiotic initiation.

Surgical extraction of a giant intracardiac lead vegetation and epicardial pacemaker reimplantation in a pacemaker-dependent hemodialysis patient.

A 57-year old male with a dual-chamber pacemaker and 40-year history of hemodialysis and autoinflammatory disease developed a large, 35 × 35 mm intracardiac vegetation on the right ventricular pacing lead. As this mass was large enough to occlude the tricuspid valve orifice, transvenous lead extraction was deemed unsuitable. Instead, an urgent surgical extraction of the whole pacemaker system, including leads and vegetation, was conducted under cardiopulmonary bypass. In light of a high risk of recurrent blood infection, a new dual-chamber pacing system was then immediately re-established using epicardial pacing leads on the right atrium and ventricle instead of transvenous electrodes. This case of a rare, giant intracardiac lead vegetation lacked most known causal factors, except for renal failure, but a possibly immunosuppressed cardiac microenvironment due to long-term steroid therapy may have been an important influencing factor.