Reevaluación del diagnóstico y el tratamiento de las infecciones de dispositivos de electroestimulación cardiaca mediante [18F]FDG-PET/TC / Reappraisal of [18F]FDG-PET/CT for diagnosis and management of cardiac implantable electronic device infections

Introducción y objetivos: El papel de la tomografía por emisión de positrones/tomografía computarizada con 18F-fluorodesoxiglucosa ([18F]FDG-PET/CT) en las infecciones de los dispositivos de electroestimulación cardiaca (DEC) requiere una evaluación más precisa. El objetivo del trabajo es determinar su rendimiento en cada región topográfica del DEC, su capacidad en la diferenciación de infecciones locales aisladas y sistémicas, la utilidad de la captación de bazo y médula ósea (MO) para diferenciar entre infecciones locales y sistémicas y su potencial utilidad en el seguimiento de las infecciones de los DEC. Métodos: Estudio retrospectivo unicéntrico de 54 casos de infección de DEC y 54 controles durante 2014-2021. Se estudió el rendimiento diagnóstico en cada región topográfica del DEC. Se evaluó la combinación de la [18F]FDG-PET/CT con el ecocardiograma transesofágico (ETE) para diagnosticar infecciones sistémicas, el papel de la actividad en MO y bazo y su posible utilidad para guiar la duración de la antibioterapia crónica cuando no se retira el DEC. Resultados: Se incluyeron 13 (24%) infecciones locales aisladas y 41 (76%) infecciones sistémicas. En general, la [18F]FDG-PET/CT mostró un 100% de especificidad y el 85% de sensibilidad, que fue del 79% en el bolsillo, el 57% en el cable subcutáneo, el 22% en el cable endovascular y del 10% en el cable intracardiaco. En las infecciones sistémicas, la [18F]FDG-PET/CT en combinación con ETE aumentó el diagnóstico definitivo del 34 al 56% (p=0,04). Los casos con bacteriemia mostraron hipermetabolismo del bazo (p=0,05) y la MO (p=0,04). Se obtuvo una [18F]FDG-PET/CT de seguimiento de 13 pacientes sin extracción del DEC. No hubo recaídas al suspender la antibioterapia crónica en 6 casos con [18F]FDG-PET/CT negativa. Conclusiones: La sensibilidad de la [18F]FDG-PET/CT para evaluar infecciones locales es mayor que en infecciones sistémicas y aumenta en las sistémicas en combinación con ETE...(AU)

Introduction and objectives: The role of [18F]FDG-PET/CT in cardiac implantable electronic device (CIED) infections requires better evaluation, especially in the diagnosis of systemic infections. We aimed to determine the following: a) the diagnostic accuracy of [18F]FDG-PET/CT in each CIED topographical region, b) the added value of [18F]FDG-PET/CT over transesophageal echocardiography (TEE) in diagnosing systemic infections, c) spleen and bone marrow uptake in differentiating isolated local infections from systemic infections, and d) the potential application of [18F]FDG-PET/CT in follow-up. Methods: Retrospective single-center study including 54 cases and 54 controls from 2014 to 2021. The Primary endpoint was the diagnostic yield of [18F]FDG-PET/CT in each topographical CIED region. Secondary analyses described the performance of [18F]FDG-PET/CT compared with that of TEE in systemic infections, bone marrow and spleen uptake in systemic and isolated local infections, and the potential application of [18F]FDG-PET/CT in guiding cessation of chronic antibiotic suppression when completed device removal is not performed. Results: We analyzed 13 (24%) isolated local infections and 41 (76%) systemic infections. Overall, the specificity of [18F]FDG-PET/CT was 100% and sensitivity 85% (79% pocket, 57% subcutaneous lead, 22% endovascular lead, 10% intracardiac lead). When combined with TEE, [18F]FDG-PET/CT increased definite diagnosis o fsystemic infections from 34% to 56% (P=.04). Systemic infections with bacteremia showed higher spleen (P=.05) and bone marrow metabolism (P=.04) than local infections. Thirteen patients without complete device removal underwent a follow-up [18F]FDG-PET/CT, with no relapses after discontinuation of chronic antibiotic suppression in 6 cases with negative follow-up [18F]FDG-PET/CT. Conclusions: The sensitivity of [18F]FDG-PET/CT for evaluating CIED infections was high in local infections but much lower in systemic infections...(AU)

Reappraisal of [18F]FDG-PET/CT for diagnosis and management of cardiac implantable electronic device infections.

INTRODUCTION AND OBJECTIVES: The role of [18F]FDG-PET/CT in cardiac implantable electronic device (CIED) infections requires better evaluation, especially in the diagnosis of systemic infections. We aimed to determine the following: a) the diagnostic accuracy of [18F]FDG-PET/CT in each CIED topographical region, b) the added value of [18F]FDG-PET/CT over transesophageal echocardiography (TEE) in diagnosing systemic infections, c) spleen and bone marrow uptake in differentiating isolated local infections from systemic infections, and d) the potential application of [18F]FDG-PET/CT in follow-up. METHODS: Retrospective single-center study including 54 cases and 54 controls from 2014 to 2021. The Primary endpoint was the diagnostic yield of [18F]FDG-PET/CT in each topographical CIED region. Secondary analyses described the performance of [18F]FDG-PET/CT compared with that of TEE in systemic infections, bone marrow and spleen uptake in systemic and isolated local infections, and the potential application of [18F]FDG-PET/CT in guiding cessation of chronic antibiotic suppression when completed device removal is not performed. RESULTS: We analyzed 13 (24%) isolated local infections and 41 (76%) systemic infections. Overall, the specificity of [18F]FDG-PET/CT was 100% and sensitivity 85% (79% pocket, 57% subcutaneous lead, 22% endovascular lead, 10% intracardiac lead). When combined with TEE, [18F]FDG-PET/CT increased definite diagnosis o fsystemic infections from 34% to 56% (P=.04). Systemic infections with bacteremia showed higher spleen (P=.05) and bone marrow metabolism (P=.04) than local infections. Thirteen patients without complete device removal underwent a follow-up [18F]FDG-PET/CT, with no relapses after discontinuation of chronic antibiotic suppression in 6 cases with negative follow-up [18F]FDG-PET/CT. CONCLUSIONS: The sensitivity of [18F]FDG-PET/CT for evaluating CIED infections was high in local infections but much lower in systemic infections. However, accuracy increased when [18F]FDG-PET/CT was combined with TEE in endovascular lead bacteremic infection. Spleen and bone marrow hypermetabolism could differentiate bacteremic systemic infection from local infection. Although further prospective studies are needed, follow-up [18F]FDG-PET/CT could play a potential role in the management of chronic antibiotic suppression therapy when complete device removal is unachievable.

Alternative Nuclear Imaging Tools for Infection Imaging.

PURPOSE OF REVIEW: Cardiovascular infections are serious disease associated with high morbidity and mortality. Their diagnosis is challenging, requiring a proper management for a prompt recognition of the clinical manifestations, and a multidisciplinary approach involving cardiologists, cardiothoracic surgeons, infectious diseases specialist, imagers, and microbiologists. Imaging plays a central role in the diagnostic workout, including molecular imaging techniques. In this setting, two different strategies might be used to image infections: the first is based on the use of agents targeting the microorganism responsible for the infection. Alternatively, we can target the components of the pathophysiological changes of the inflammatory process and/or the host response to the infectious pathogen can be considered. Understanding the strength and limitations of each strategy is crucial to select the most appropriate imaging tool. RECENT FINDINGS: Currently, multislice computed tomography (MSCT) and nuclear imaging (18F-fluorodeoxyglucose positron emission tomography/computed tomography, and leucocyte scintigraphy) are part of the diagnostic strategies. The main role of nuclear medicine imaging (PET/CT and SPECT/CT) is the confirmation of valve/CIED involvement and/or associated perivalvular infection and the detection of distant septic embolism. Proper patients' preparation, imaging acquisition, and reconstruction as well as imaging reading are crucial to maximize the diagnostic information. In this manuscript, we described the use of molecular imaging techniques, in particular WBC imaging, in patients with infective endocarditis, cardiovascular implantable electronic device infections, and infections of composite aortic graft, underlying the strength and limitations of such approached as compared to the other imaging modalities.

Defibrillator generator replacements in patients with left ventricular assist device support: The risks of hematoma and infection.

BACKGROUND: The majority (89%) of left ventricular assist device (LVAD) patients have an implantable cardioverter-defibrillator (ICD) in place. Due to the advances of modern-day LVAD therapy, more patients are on support for longer. This inevitably leads to more LVAD patients facing ICD generator battery depletion. Until now, there are insufficient data regarding periprocedural risks of generator replacements in a high-risk group like the LVAD cohort. METHODS: A retrospective, single-center analysis of pocket-related outcomes of all ICD generator replacements in LVAD and Non-LVAD patients between January 2014 and December 2018. The primary outcome was the combined endpoint of clinically significant pocket hematoma and/or cardiac implantable electronic device (CIED) infection in the first 6 months after ICD generator exchange. The clinically significant hematoma was defined as hematoma requiring reoperation, prolongation of hospitalization, or interruption of anticoagulation. The cumulative incidence function was calculated for the primary endpoint. RESULTS: Two hundred seventy-seven patients underwent ICD generator exchange in our clinic in this time. Of these, 251 patients had a complete 6-month follow-up regarding clinically significant pocket hematomas and pocket infections. One hundred ninety patients had no LVAD, and 61 patients were on LVAD support. The rate of the primary combined endpoint clinically significant pocket hematoma and/or CIED infection was 3.5 times higher in LVAD patients compared to the non-LVAD cohort (event rate 39.14 vs 11.07 per 100 patient-years, p = 0.048). Clinically significant pocket hematomas necessitating revision occurred nearly 4 times more often in the LVAD group (p = 0.042). Pocket device infection rates were around 16 times higher in LVAD patients compared to non-LVAD patients (p = 0.002). CONCLUSIONS: Compared to Non-LVAD patients, LVAD patients exhibit a relevant higher rate of clinically significant pocket hematoma and CIED infection after ICD generator exchange. This information should additionally be considered in the decision-making process regarding the indication for ICD generator exchange.

Cardiac Implantable Electronic Device Infections; Long-Term Outcome after Extraction and Antibiotic Treatment.

BACKGROUND: The aim of the study was to examine the treatment outcome for patients with cardiovascular implantable electronic device (CIED) infections after extraction. METHODS: Patients who underwent CIED extractions due to an infection at Karolinska University Hospital 2006-2015 were analyzed. RESULTS: In total, 165 patients were reviewed, 104 (63%) with pocket infection and 61 (37%) with systemic infection. Of the patients with systemic infection, 34 and 25 patients fulfilled the criteria for definite and possible endocarditis, respectively. Complications after extraction occurred only in one patient. Reimplantation was made after a mean of 9.5 days and performed in 81% of those with pocket infection and 44.3% in systemic infection. Infection with the new device occurred in 4.6%. The mean length of hospital stay for patients with pocket infection was 5.7 days, compared to 38.6 days in systemic infection. One-year mortality was 7.7% and 22.2% in pocket infection and systemic infection, respectively. Patients with Staphylococcus aureus infection had a higher mortality. CONCLUSIONS: In this study, the majority of the patients had a pocket CIED infection, with a short hospital stay. Patients with a systemic infection, and S. aureus etiology, had a prolonged hospital stay and a higher mortality.

Differences in laser lead extraction of infected vs. non-infected leads.

We investigated the effect of systemic infection or lead endocarditis on the complexity and the success of laser lead extraction (LLE) procedures. Medical records of all patients undergoing LLE between January 2012 and March 2017 were screened with regard to information on systemic infection or lead endocarditis. We treated 184 patients using high-frequency 80 Hz laser sheaths in patients with lead implant duration of ≥ 12 months. Indications for lead extraction were systemic infection and lead endocarditis in 52 cases (28.3%), local infection in 74 cases (40.2%), lead dysfunction in 37 cases (20.1%) and other indications in 21 cases (11.4%). 386 leads were scheduled for LLE: 235 (60.9%) pacing, 105 (27.2%) ICD and 46 (11.9%) CS leads. The mean time from initial lead implantation (systemic infection 96.8 ± 74.7 months vs. 102.1 ± 82.6 non-infected: months; p = 0.4155) and ratio of ICD leads (26.8 vs. 27.4%; p = 0.3411) did not differ significantly between the two groups. Complete procedural success was significantly higher in the systemic infection group (100 vs. 94.7%; p = 0.0077). The mean laser treatment (60.2 ± 48.7 vs. 72.4 ± 61.5 s; p = 0.2038) was numerically lower in the infection group, while fluoroscopy time (9.3 ± 7.6 vs. 12.8 ± 10.3 min; p = 0.0275) was significantly lower in this group. Minor and major complications were low in both groups and did not reveal any statistically significant difference (infected group: one minor complication; pocket hematoma, non-infected: three major complications; emergent sternotomy due to pericardial tamponade). No extraction related mortality was observed. The presence of systemic infection or lead endocarditis in LLE procedures allows for higher complete procedural success. When compared with LLE of non-infected leads, the infected leads require less laser and fluoroscopy times. Due to the scarcity of minor and major complications in general, no statistical significance was found in that regard.

International survey of knowledge, attitudes, and practices of cardiologists regarding prevention and management of cardiac implantable electronic device infections.

BACKGROUND: Cardiovascular implantable electronic devices (CIEDs) can be life-saving. However, complications from CIED infection can be life-threatening, often requiring device removal. Despite publication of CIED infection management guidelines, there remains marked variation in clinical practice. OBJECTIVE: To better understand and quantify these differences, we conducted a multinational survey of practitioners of CIED management. METHODS: An electronic survey was sent to Heart Rhythm Society members, spanning 70 countries across six continents. All responses were collected anonymously. RESULTS: 227 out of 3,600 (6.3%) responded to the survey. The majority of surveys were completed by practitioners from the United States (168; 68.3%) and 53.8% of these practiced in academic medical centers. The large majority (92.7%) of sites had protocols to ensure appropriate timing of prophylactic antibiotics. Superficial (incisional) site infections were treated with antibiotics alone 52.5% of the time (consistent with guidelines); in contrast, deep pocket infections were treated with antibiotics (with device removal) in accordance to guidelines only 37.4% of the time. Almost all providers (98.7%) were inclined to perform complete hardware removal in cases of CIED-related endocarditis. In contrast, 82.2% of survey participants suggested complete CIED system removal in patients with an occult Gram-positive bacteremia, 65.5% with occult Gram-negative bacteremia, and 59.3% with prolonged bacteremia due to a source other than CIED. CONCLUSIONS: These data suggest wide variability in clinical practice in managing CIED infection with significant deviations from published guidelines. There is critical need to increase awareness and develop institutional protocols to ensure adherence with evidence-based guidelines to optimize outcomes.

The Changing Epidemiology of Infective Endocarditis in the Twenty-First Century.

PURPOSE OF THE REVIEW: Infective endocarditis (IE) is a relatively infrequent infectious disease. It does, however, causes serious morbidity, and its mortality rate has remained unchanged at approximately 25%. Changes in IE risk factors have deeply impacted its epidemiology during recent decades but literature from low-income countries is very scarce. Moreover, prophylaxis guidelines have recently changed and the impact on IE incidence is still unknown. RECENT FINDINGS: In high-income countries, the proportion of IE related to prior rheumatic disease has decreased significantly and has been replaced proportionally by cases related to degenerative valvulopathies, prosthetic valves, and cardiovascular implantable electronic devices. Nosocomial and non-nosocomial-acquired cases have risen, as has the proportion caused by staphylococci, and the median age of patients. In low-income countries, in contrast, rheumatic disease remains the main risk factor, and streptococci the most frequent causative agents. Studies performed to evaluate impact of guidelines changes' have shown contradictory results. The increased complexity of cases in high-income countries has led to the creation of IE teams, involving several specialties. New imaging and microbiological techniques may increase sensitivity for diagnosis and detection of IE cases. In low-income countries, IE remained related to classic risk factors. The consequences of prophylaxis guidelines changes are still undetermined.