Current Challenges in the Management of Infective Endocarditis

Predictors of infective endocarditis associated in-hospital mortality in Ayder Comprehensive Specialized Hospital, Tigray, North Ethiopia: Microbiological,clinical features, and management profiles

BACKGROUND

Infective endocarditis (IE) is a continuously evolving disease with a high mortality rate despite different advances in treatment. In Ethiopia, there is a paucity of data regarding IE. Therefore, this study is aimed at assessing IE-related in-hospital mortality and characterization of IE patients based on their microbiological, clinical features, and management profiles in the Ayder Comprehensive Specified Hospital (ACSH).

METHODS

We conducted a hospital-based prospective follow-up study with all consecutive sampling techniques for suspected infective endocarditis patients admitted to ACSH from January 2020 to February 2022. Echocardiography was performed, and three sets of blood samples for blood culture were taken as per the standard protocol. We also performed isolation of microbial etiologies and antimicrobial susceptibility tests. The data was analyzed using STATA version 16. Stepwise logistic regression was run to identify predictors of in-hospital mortality. Effects were measured through the odds ratio at the 5% level of significance.

RESULTS

Seventy-four cases of suspected infective endocarditis were investigated; of these, 54 episodes fulfilled modified Duke's criteria. Rheumatic heart disease (RHD) (85.2%) was the most common underlying heart disease. Murmur (94.4%), fever (68.5%), and pallor (57.4%) were the most common clinical findings. Vegetation was present in 96.3% of episodes. Blood culture was positive only in 7 (13%) episodes. Complications occurred in 41 (75.9%) cases, with congestive heart failure being the most common. All patients were managed medically, with no surgical intervention. The in-hospital mortality was 14 (25.9%). IE-related in-hospital mortality was significantly associated with surgery recommendation and myalgia clinical symptoms.

CONCLUSION

IE occurred relatively in a younger population, with RHD as the most common underlying heart disease. There was a high rate of culture-negative endocarditis, and the majority of patients were treated empirically. Mortality was high. The establishment of cardiac surgery and strengthening microbiology services should be given top priority.

Contemporary surgical management of infective endocarditis of the aortic root

Infective endocarditis involving the aortic root is associated with a high degree of morbidity and mortality. Native aortic root infections can develop from aggressive organisms or from delays in diagnosis or definitive care, whereas prosthetic valve infections commonly result in extensive destruction of the aortic root and neighboring structures. Early detection, tailored antibiotic therapy, thoughtful pre-operative planning, and multidisciplinary heart team management are the keys to optimizing patient outcomes. Aggressive and complete surgical debridement are mandatory prior to aortic root reconstruction. Surgical experience and patient-centered decision making are critical in selecting the optimal reconstructive strategy for the aortic root and adjacent structures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01604-6.

An Unusual Case of Cryoglobulinemic Vasculitis and Acute Disseminating Encephalomyelitis in a 21-Year-Old Caucasian Male

Cryoglobulinemic vasculitis and acute disseminated encephalomyelitis (ADEM) are characterized by damage to either blood vessels or grey matter. For both diseases, infections can be an etiology. In cryoglobulinemic vasculitis, the initial insult causes damage to the glomerulus, and in the case of ADEM, damage leads to a central nervous system demyelinating disorder. Infective endocarditis can be associated with both diseases and can be challenging to diagnose. Individuals on antibiotics may present with negative blood cultures, making underlying infective endocarditis difficult to diagnose. In this report, we describe a 21-year-old male who presented to the hospital after an assault with splenic laceration and was subsequently found to have infective endocarditis associated with cryoglobulinemic vasculitis and ADEM.

Phage-antibiotic synergy against daptomycin-nonsusceptible MRSA in an ex vivo simulated endocardial pharmacokinetic/pharmacodynamic model

Phage-antibiotic combinations (PAC) offer a potential solution for treating refractory daptomycin-nonsusceptible (DNS) methicillin-resistant Staphylococcus aureus (MRSA) infections. We examined PAC activity against two well-characterized DNS MRSA strains (C4 and C37) in vitro and ex vivo. PACs comprising daptomycin (DAP) ± ceftaroline (CPT) and a two-phage cocktail (Intesti13 + Sb-1) were evaluated for phage-antibiotic synergy (PAS) against high MRSA inoculum (109 CFU/mL) using (i) modified checkerboards (CB), (ii) 24-h time-kill assays (TKA), and (iii) 168-h ex vivo simulated endocardial vegetation (SEV) models. PAS was defined as a fractional inhibitory concentration ≤0.5 in CB minimum inhibitory concentration (MIC) or a ≥2 log10 CFU/mL reduction compared to the next best regimen in time-kill assays and SEV models. Significant differences between regimens were assessed by analysis of variance with Tukey's post hoc modification (α = 0.05). CB assays revealed PAS with Intesti13 + Sb-1 + DAP ± CPT. In 24-h time-kill assays against C4, Intesti13 + Sb-1 + DAP ± CPT demonstrated synergistic activity (-Δ7.21 and -Δ7.39 log10 CFU/mL, respectively) (P < 0.05 each). Against C37, Intesti13 + Sb-1 + CPT ± DAP was equally effective (-Δ7.14 log10 CFU/mL each) and not significantly different from DAP + Intesti13 + Sb-1 (-Δ6.65 log10 CFU/mL). In 168-h SEV models against C4 and C37, DAP ± CPT + the phage cocktail exerted synergistic activities, significantly reducing bio-burdens to the detection limit [2 log10 CFU/g (-Δ7.07 and -Δ7.11 log10 CFU/g, respectively)] (P < 0.001). At 168 h, both models maintained stable MICs, and no treatment-emergent phage resistance occurred with DAP or DAP + CPT regimens. The two-phage cocktail demonstrated synergistic activity against two DNS MRSA isolates in combination with DAP + CPT in vitro and ex vivo. Further in vivo PAC investigations are needed.

Vasculitis and cerebral hemorrhage due to Streptococcus gordonii infectious endocarditis: A case report

Infective endocarditis is an infection of the heart with systemic consequences, both infectious and non-infectious. Infective endocarditis can affect several systems, one of which is the central nervous system. The most common form of presentation is ischemic stroke; however, intracranial hemorrhage can occur due to immune-mediated damage to the vessel wall. The former further complicates cardiac surgical procedures when necessary. We present here the case of a 21-year-old male patient, with no personal medical history, who presented with intracranial hemorrhage due to a vasculitis phenomenon, caused by Streptococcus gordonii infective endocarditis. The patient underwent emergency drainage of the intracranial hemorrhage and minimally invasive valve surgery in 17 days, with satisfactory postoperative recovery and follow-up.

Endovascular aspiration of native tricuspid valve vegetation using INARI catheter in a patient with methicillin-sensitive Staphylococcus aureus endocarditis

A middle-aged man presented to the hospital with chief complaint of worsening chest pain and shortness of breath. He was found to have methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia, acute hypoxic respiratory failure secondary to MSSA pneumonia and septic emboli. The patient underwent a transesophageal echocardiogram which revealed a large, mobile tricuspid valve vegetation secondary to endocarditis. The patient was initially managed conservatively with intravenous antibiotics and supportive measures. However, his respiratory status worsened due to persistence of a large tricuspid valve vegetation which progressed to bilateral septic pulmonary emboli with peripheral cavitary lesions identified on follow-up CT of the chest. In order to debulk the large tricuspid vegetation, the patient successfully underwent endovascular mechanical aspiration of tricuspid valve vegetation utilizing the 20-Fr INARI curved Flowtriever (INARI Medical, CA) catheter. This case highlights a new, minimally invasive technique and device employed in treating native valve vegetations caused by endocarditis as an alternative approach to surgery.

Multimodality Imaging Diagnosis in Infective Endocarditis

Imaging is an important tool in the diagnosis and management of infective endocarditis (IE). Echocardiography is an essential examination, especially in native valve endocarditis (NVE), but its diagnostic accuracy is reduced in prosthetic valve endocarditis (PVE). The diagnostic ability is superior for transoesophageal echocardiography (TEE), but a negative test cannot exclude PVE. Both transthoracic echocardiography (TTE) and TEE can provide normal or inconclusive findings in up to 30% of cases, especially in patients with prosthetic devices. New advanced non-invasive imaging tests are increasingly used in the diagnosis of IE. Nuclear medicine imaging techniques have demonstrated their superiority over TEE for the diagnosis of PVE and cardiac implantable electronic device infective endocarditis (CIED-IE). Cardiac computed tomography angiography imaging is useful in PVE cases with inconclusive TTE and TEE investigations and for the evaluation of paravalvular complications. In the present review, imaging tools are described with their values and limitations for improving diagnosis in NVE, PVE and CIED-IE. Current knowledge about multimodality imaging approaches in IE and imaging methods to assess the local and distant complications of IE is also reviewed. Furthermore, a potential diagnostic work-up for different clinical scenarios is described. However, further studies are essential for refining diagnostic and management approaches in infective endocarditis, addressing limitations and optimizing advanced imaging techniques across different clinical scenarios.

Leptospirosis-Induced Septic Shock and Multi-Organ Dysfunction Syndrome: A Complex Case of Zoonotic Infection in a Young Female Patient

Leptospirosis, a zoonotic infection caused by the Leptospira bacteria, can manifest with varying clinical severities, ranging from subclinical disease to severe multiorgan failure. This progression to severe multiorgan failure, also known as multi-organ dysfunction syndrome (MODS), is a life-threatening condition characterized by the dysfunction of two or more organ systems. Often, MODS is a consequence of events triggered by underlying pathologies, such as severe infections, including those caused by Leptospira. Here, we present a case report of a 29-year-old female patient who initially sought care for increased temperature, fatigue, diarrhea, and vomiting. The patient exhibited signs of septic shock (SS). Her medical history raised suspicion of multiple potential sources of infection. She experienced cat scratch several days before admission, accompanied by an enlarged inguinal lymph node and a history of frequent interaction with animals, as well as freshwater exposure, which prompted investigations into various zoonotic infections. Empiric treatment was started, and, subsequently, after several days, Leptospira titer came back positive. Over the hospitalization course, the patient developed multi-organ failure, which was attributed to the underlying Leptospira infection. The complexity and severity of the patient's condition underscore the far-reaching impact of leptospirosis in precipitating a spectrum of systemic complications culminating in multiorgan failure. The treatment interventions yielded successful outcome, and the patient recovered in one month. This case report highlights the difficulties in diagnosing and treating patients with multiple possible sources of infection. it emphasizes the need for a careful history-taking and high level of suspicion for zoonotic infections in patients with a history of animal exposure and clinical symptoms suggestive of infectious diseases.

ASSESS-IE: a Novel Risk Score for Patients with Infective Endocarditis

Mortality in patients with infective endocarditis (IE) remains high. The existing risk scores are relatively complex with limited clinical application. This study was conducted to establish a new risk model to predict in-hospital and 6-month mortality in IE patients. A total of 1549 adult patients with definite IE admitted to Guangdong Provincial People's Hospital (n=1354) or Xiamen Cardiovascular Hospital (n=195) were included. The derivation cohort consisted of 1141 patients. The score was developed using the multivariate stepwise logistic regression analysis for in-hospital death. Bootstrap analysis was used for validation. Discrimination and calibration were evaluated by the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test. Six risk factors were used as score parameters (1 point for each): aortic valve affected, previous valve replacement surgery, severe heart failure, elevated serum direct bilirubin, moderate-severe anemia and acute stage. The predictive value and calibration of the ASSESS-IE score for in-hospital death were excellent in the derivation (area under the curve [AUC]=0.781, p<0.001; Hosmer-Lemeshow p=0.948) and validation (AUC=0.779, p<0.001; Hosmer-Lemeshow p=0.520) cohorts. The score remained excellent in bootstrap validation (AUC=0.783). The discriminatory ability of the ASSESS-IE score for in-hospital (AUC: 0.781 vs. 0.799, p=0.398) and 6-month mortality (AUC: 0.778 vs. 0.814, p=0.040) were similar with that of Park's score which comprised 14 variables. The ASSESS-IE risk score is a new and robust risk-stratified tool for patients with IE, which might further facilitate clinical decision-making.

A rare Serratia marcescens-associated acute endocarditis of a tricuspid valve in an intravenous drug user : A case report and literature review

Serratia marcescens is a gram-negative bacillus that is an opportunistic agent in respiratory tract infections, urinary tract infections, and septicemia. It is rarely also a cause of infective endocarditis which follows a rapid and devastating course, typically in persons with history of intravenous drug use (IDU). This article reports a fatal case of a 27-year-old patient with a known history of IDU, who presented with clinical symptoms concerning right-sided endocarditis as well as signs of acute respiratory distress syndrome. Finally, a detailed review of the literature is provided concerning the acute endocarditis of a tricuspid valve, especially associated with Serratia marcescens infection.

Novel putative biomarkers for infective endocarditis by serum proteomic analysis: a comprehensive review of literature

Infective endocarditis (IE) is a challenging condition with high mortality. Prompt detection of IE has become essential for early and immediate management. The authors aimed to comprehensively review the existing literature on novel putative biomarkers for IE through serum proteomic analysis. The literature reveals high levels of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) levels in IE with staphylococcal etiology, valvular lesions, and when combined with cardiac troponin I (cTnI), had a more significant value for risk stratification. A higher pro-ADM level, copeptin, NT-proBNP, and the monocyte-to-high-density lipoprotein cholesterol ratio (MHR) all impacted mortality during the hospital stay. The biomarker matrix metalloproteinase-9 was utilized to predict new-onset embolic events in patients, thus serving as a predictive marker. Procalcitonin was an important diagnostic marker in IE complicated with severe infection. Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interferon-γ, cTnI, and NT-proBNP were also discovered to be useful as prognostic indicators. Early diagnosis and appropriate treatment are possible using antiphospholipid antibodies as a diagnostic test for definite IE. It is also concluded that antineutrophilic cytoplasmic antibody positive individuals with IE had a lengthier hospital stay. These noninvasive biomarkers can identify patients at risk and provide appropriate and early clinical management. NT-proBNP, Cystatin C, troponins, IL-6, IL-8, S100A11, and AQP9 are examples of possible markers that appear promising for further research. In conclusion, large-scale validation studies should study these biomarkers further to establish their use in clinical settings.

Risk factors of prolonged intensive care unit stay following cardiac surgery for infective endocarditis

INTRODUCTION

Prolonged intensive care unit (ICU) stay is common in serious patients undergoing cardiac surgery. Prolonged ICU stay is associated with increased mortality and worse prognosis. This study was conducted to determine the risk factors for prolonged ICU stay after cardiac surgery for infective endocarditis (IE) and we try to decrease the operative risk of mortality and morbidity of cardiac surgery for IE.

METHODS

The retrospective study of patients with IE undergoing cardiac surgery between January 2006 and November 2022 at our hospital was performed.

RESULTS

896 patients undergoing cardiac surgery were divided into group of ICU stay ≤ 3d (n = 416) and group p of ICU stay > 3d (n = 480). There were 48 operative deaths (5.4%). Univariable and multivariable analyses showed that factors are associated with prolonged ICU stay following cardiac surgery for IE, including male (P < .001), age (P < .001), weight (P = .009), vegetation length (P < .001), paravalvular leak (P < .001), aortic cross-clamp time (P < .001), cardiopulmonary bypass (CPB) time (P < .001), mechanical ventilation time (P < .001), hospitalized time postoperative (P = .032), creatinine of serum before surgery (P < .001), creatinine of serum 24h after surgery (P = .005), creatinine of serum 48h after surgery (P < .001), fluid balance on operation day (P < .001), postoperative acute kidney injury (P < .001), left ventricular end diastolic dimension (LVEDD) preoperative (P < .001), LVEDD postoperative (P < .001), chest drainage (P = .032), frozen plasma (P = .016), preoperative aortic insufficiency (P < .001), and packed red cells (P < .001).

CONCLUSIONS

In our study, shortness of ICU stay and optimization of pre-, peri-, and postoperative factors that can shorten ICU stay, therefore, contribute to a better postoperative outcome and leads to lower rates of mortality and morbidity.

DNA and histones impair the mechanical stability and lytic susceptibility of fibrin formed by staphylocoagulase

Background

Staphylocoagulase (SCG) is a virulence factor of Staphylococcus aureus, one of the most lethal pathogens of our times. The complex of SCG with prothrombin (SCG/ProT) can clot fibrinogen, and SCG/ProT-induced fibrin and plasma clots have been described to show decreased mechanical and lytic resistance, which may contribute to septic emboli from infected cardiac vegetations. At infection sites, neutrophils can release DNA and histones, as parts of neutrophil extracellular traps (NETs), which in turn favor thrombosis, inhibit fibrinolysis and strengthen clot structure.

Objectives

To characterize the combined effects of major NET-components (DNA, histone H1 and H3) on SCG/ProT-induced clot structure, mechanical and lytic stability.

Methods

Recombinant SCG was used to clot purified fibrinogen and plasma. The kinetics of formation and lysis of fibrin and plasma clots containing H1 or core histones+/-DNA were followed by turbidimetry. Fibrin structure and mechanical stability were characterized with scanning electron microscopy, pressure-driven permeation, and oscillation rheometry.

Results

Histones and DNA favored the formation of thicker fibrin fibers and a more heterogeneous clot structure including high porosity with H1 histone, whereas low porosity with core histones and DNA. As opposed to previous observations with thrombin-induced clots, SCG/ProT-induced fibrin was not mechanically stabilized by histones. Similarly to thrombin-induced clots, the DNA-histone complexes prolonged fibrinolysis with tissue-type plasminogen activator (up to 2-fold). The anti-fibrinolytic effect of the DNA and DNA-H3 complex was observed in plasma clots too. Heparin (low molecular weight) accelerated the lysis of SCG/ProT-clots from plasma, even if DNA and histones were also present.

Conclusions

In the interplay of NETs and fibrin formed by SCG, DNA and histones promote structural heterogeneity in the clots, and fail to stabilize them against mechanical stress. The DNA-histone complexes render the SCG-fibrin more resistant to lysis and thereby less prone to embolization.

Safety and Efficacy of a Single Procedure of Extraction and Reimplantation of Infected Cardiovascular Implantable Electronic Device (CIED) in Comparison with Deferral Timing: An Observational Retrospective Multicentric Study

(1) Background: Infections are among the most frequent and life-threatening complications of cardiovascular implantable electronic device (CIED) implantation. The aim of this study is to compare the outcome and safety of a single-procedure device extraction and contralateral implantation versus the standard-of-care (SoC) two-stage replacement for infected CIEDs. (2) Methods: We retrospectively included 66 patients with CIED infections who were treated at two Italian hospitals. Of the 66 patients enrolled in the study, 27 underwent a single procedure, whereas 39 received SoC treatment. All patients were followed up for 12 months after the procedure. (3) Results: Considering those lost to follow-up, there were no differences in the mortality rates between the two cohorts, with survival rates of 81.5% in the single-procedure group and 84.6% in the SoC group (p = 0.075). (4) Conclusions: Single-procedure reimplantation associated with an active antibiofilm therapy may be a feasible and effective therapeutic option in CIED-dependent and frail patients. Further studies are warranted to define the best treatment regimen and strategies to select patients suitable for the single-procedure reimplantation.

Prosthetic Mitral Valve Endocarditis Complicated by Left Ventricular Pseudoaneurysm

Left ventricular pseudoaneurysm is a rare complication that can result from mitral valve replacement. Proper follow-up imaging can help to detect this potentially fatal complication and identify areas of concern. Infective endocarditis following mitral valve replacement can occur and further lead to the development of a pseudoaneurysm. We describe a case of left ventricular aneurysm in the setting of infective endocarditis following mitral valve replacement and present radiologic images from various modalities detailing the major findings.

A Case of Infective Endocarditis Treated With Homeopathy Medicine

Infective endocarditis is a deadly disease, associated with high mortality and morbidity. We present a case of a 14-year-old boy with antibiotic-resistant infective endocarditis who was treated with classical homeopathy. The case is analyzed according to the general reactivity of the organism and the Levels of Health theory.

Native valve, prosthetic valve, and cardiac device-related infective endocarditis: A review and update on current innovative diagnostic and therapeutic strategies

Infective endocarditis (IE) is a life-threatening microbial infection of native and prosthetic heart valves, endocardial surface, and/or indwelling cardiac device. Prevalence of IE is increasing and mortality has not significantly improved despite technological advances. This review provides an updated overview using recent literature on the clinical presentation, diagnosis, imaging, causative pathogens, treatment, and outcomes in native valve, prosthetic valve, and cardiac device-related IE. In addition, the experimental approaches used in IE research to improve the understanding of disease mechanisms and the current diagnostic pipelines are discussed, as well as potential innovative diagnostic and therapeutic strategies. This will ultimately help towards deriving better diagnostic tools and treatments to improve IE patient outcomes.

Surgical Treatment of Infective Endocarditis, Complicated with Splenic Abscesses

Infectious endocarditis (IE) represents an inflammation of the heart endothelium usually as a result of bacterial colonization after trauma. Splenic abscess is a rare and dangerous extracardiac manifestation of IE. An expert multidisciplinary collaboration is necessary for the diagnosis and treatment strategy of this high-risk and challenging disease. Valvuloplasty and splenectomy are the mainstay of radical treatment and offer excellent long-term results. We present two cases with infectious endocarditis, complicated with splenic abscesses, which were successfully operated in the Department of Cardiac Surgery.

Pathogenesis, Diagnosis, Antimicrobial Therapy, and Management of Infective Endocarditis, and Its Complications

Infective endocarditis in the adult is life-threatening. Bacterial endocarditis is an inner infection lining the heart muscle (endocardium). The scientific study of the causes of diseases is known as etiology. The agents that cause disease fall into five groups: bacteria, viruses, protozoa, fungi, and helminths (worms). Risk factors are past heart defects, damaged or abnormal heart valves, new valves after surgery, chronic hemodialysis, and immunosuppressed state (chemotherapy, HIV, etc.). Infective endocarditis is categorized into two clinical forms: bacterial acute and subacute endocarditis. Acute bacterial endocarditis is usually caused by staphylococci (staph) and streptococci (strep). And occasionally by listeria and brucella bacterial strains. Invasive medical technology has increased the responsibility of healthcare-associated infective endocarditis (HAIE). Microscopy of the disease is the chronic aggressive cells in the deeper zone of nonspecific, composed of fibrin and platelets covering colonies of bacteria. Tuberculous valvular endocarditis due to mycobacterium tuberculosis is a rare clinical entity. Syphilitic endocarditis is pathologically the cutaneous lesions of secondary syphilis. It is caused by infection with the microorganismTreponema pallidum. Fungal endocarditis is a rare and fatal condition. They are infected with fungi such as Candida albicans, Histoplasma capsulatum, and Aspergillus species. Fatal endocarditis associated with Q fever (query fever). Q fever is a chronic or prolonged disease caused by the rickettsial-like bacillus Coxiella burnetii, a rare form of rickettsia in the endocarditis. Varicella-zoster virus (VZV) infection causes chronic and repeated febrile illness. They are followed by pharyngitis, malaise, and a vesicular rash. Chronic Q fever usually manifests as endocarditis or hepatitis. The therapy given to simplify the complications is antimicrobial therapy. The medicines prescribed are ampicillin, cefazolin, ceftazidime, gentamicin, vancomycin, metronidazole, and tobramycin. High medicinal antibiotics are used to control the spread of infective endocarditis.

A Rare Case of Endocarditis and Mycotic Pseudoaneurysm of the Left Ventricle Caused by Escherichia coli Following Transcatheter Aortic Valve Replacement

Infective endocarditis caused by gram-negative enteral bacteria is very rare. Herein, we report the first case of infective endocarditis complicated by a paravalvular mycotic pseudoaneurysm of the left ventricle caused by Escherichia coli post transcatheter aortic valve replacement, highlighting the diagnostic workup, multimodality imaging, and treatment options.

Unusual Presentation of Infective Endocarditis Following a Prostatic Urethral Lift

Infective endocarditis is a serious inflammation of the inner lining of the heart. It is caused by pathogens entering the bloodstream and infecting the endocardium. We demonstrate a unique presentation of infective endocarditis following a prostatic urethral lift. The low index of suspicion and atypical symptoms prevented early diagnosis of the disease, leading to life-threatening complications and valve replacement surgery. Understanding unusual presentations of infective endocarditis can increase the index of suspicion in outpatient settings, leading to early diagnosis and preventing fatal complications.

Characteristics of patients with infective endocarditis and no underlying cardiac conditions

BACKGROUND

Infective endocarditis (IE) typically occurs in patients with underlying cardiac conditions (UCC). Little is known about IE in patients without UCC. We aimed to describe the clinical, microbiological and imaging characteristics, management, and in-hospital mortality of IE patients without UCC.

METHODS

We analysed the data of patients with definite IE included in an observatory between 1st January 2009 and 31st December 2019. We described patients without UCC compared to those with UCC.

RESULTS

Of 1502 IE patients, 475 (31.6%) had no UCC. They were younger (median 64.0 [19.0-101.0] vs. 70.0 [18.0-104.0] years, p < .001), more often on chronic haemodialysis (5.5% vs. 2.7%, p = .008), and had more often malignancy (22.5% vs. 17.3%, p = .017), immune deficiency (10.3% vs. 6.4%, p = .008), and an indwelling central venous line (14.5% vs. 7.0%, p < .001). They more often developed cerebral complications (34.7% vs. 27.5%, p = .004) and extracerebral embolism (48.6% vs. 36.1%, p < .001). Causative microorganisms were less often coagulase negative staphylococci (5.9% vs. 10.8%, p = .002) or enterococci (10.3% vs. 15.0%, p = .014) and more often group D streptococci (14.1% vs. 10.0%, p = 0.020). Vegetations were more common (92.8% vs. 77.0%, p < 0.001) and larger (14.0 [1.0-87.0], vs. 12.0 [0.5-60.0] mm, p = 0.002). They had more valve perforation or valve regurgitation (67.4% vs. 53.0%, p < 0.001) and underwent valve surgery more often (53.5% vs. 36.3%, p < 0.001). In-hospital mortality did not significantly differ between groups.

CONCLUSION

Patients with IE and no UCC were younger than those with UCC, had specific comorbidities and portals of entry, and a more severe disease course.

A Patient’s Six-Month Journey From Low Sodium to Blue Toes to Stroke: Non-infective Thrombotic Endocarditis Due to Non-small Cell Lung Cancer

We report a patient's journey with a four-year history of hypertension (HTN) and hyperlipidemia (HLD), stable on beta-blocker and statin, monitored every six months by alternating visits between her cardiologist and primary care physician (PCP) in North Carolina (NC). Six months before relocating to New York (NY) she had been informed about incidental severe hyponatremia during her last outpatient visit, the need for repletion with sodium chloride tablets, and the critical importance of prompt follow-up to rule out malignancy by starting with a chest X-ray. She opted not to follow instructions, continued cigarettes, and decided to spend the summer season with her son in NY. Six months after being told of her low sodium, she presented to our NY hospital with an acute, painful right foot blue toe syndrome. During the ischemic right foot evaluation, she was discovered to have adenocarcinoma of the right lung (stage 4) and a normal transthoracic echocardiogram (TTE). Heparin was initiated and thromboembolectomy with an endovascular bovine patch to revascularize the foot was successful, and post-procedure apixaban was started.

Hyponatremia was attributed to the syndrome of inappropriate antidiuretic hormone release (SIADH) secondary to non-small cell lung cancer (NSCLC). The serum sodium was stabilized, and the patient was discharged with a plan for outpatient follow-up with the cardiologist and oncologist within two weeks for hypertension, hyperlipidemia, hyponatremia, and management of stage 4 NSCLC. During her cardiology follow-up, 10 days after discharge, complaints of mild dyspnea on exertion (DOE) prompted an ECG (electrocardiogram) that revealed new T wave inversions in leads V3-6, and the patient was readmitted for non-ST elevation myocardial infarction (NSTEMI) evaluation. On day one of the readmission troponins were negative with normal ejection fraction (EF) on TTE and an acute 2 g/dl hemoglobin (Hb) drop with melena. This led to discontinuation of anticoagulation, initiation of intravenous (IV) pantoprazole, and endoscopy (EGD) which revealed gastritis. On the third day, she developed sudden expressive aphasia. Computed tomography (CT) of the head did not show any bleed but same-day magnetic resonance imaging (MRI) demonstrated multiple evolving acute infarcts. Transesophageal echocardiogram (TEE) demonstrated two large, mobile masses on the mitral valve consistent with vegetative endocarditis. Cultures for bacteria, fungi, and evaluation for organisms associated with culture-negative acute bacterial endocarditis/subacute bacterial endocarditis were unrevealing, thus confirming malignancy-associated non-infectious thrombotic endocarditis or non-bacterial thrombotic endocarditis (NBTE).

Gastrointestinal (GI) bleeding ceased, and the patient initially started on a heparin drip and transitioned to enoxaparin as lifelong anticoagulation for malignancy-associated NBTE. She recovered neurologically and was given pembrolizumab. At her recent 15-month visit she continued to have no residual neurological impairments, however, new positron emission tomography (PET) detected metastasis to the liver, lung, and adrenals which prompted evaluation for hospice care. We, therefore, emphasize the need for timely diagnosis of NBTE and prompt initiation of anticoagulation in suitable patients to prevent complications such as in our patient. Additionally, hyponatremia secondary to SIADH in NSCLC is a poor prognostic indicator of overall survival. 

Infective Endocarditis: New Challenges in a Classic Disease

Infective endocarditis is a relatively rare, but deadly infection, with an overall mortality of around 20% in most series. Clinical manifestations have evolved in response to significant epidemiological shifts in industrialized nations, with a move toward a nosocomial or health-care-related pattern, in older patients, with more episodes associated with prostheses and/or intravascular electronic devices and a predominance of staphylococcal and enterococcal etiology.Diagnosis is often challenging and is based on the conjunction of clinical, microbiological, and imaging information, with notable progress in recent years in the accuracy of echocardiographic data, coupled with the recent emergence of other useful imaging techniques such as cardiac computed tomography (CT) and nuclear medicine tools, particularly ¹⁸F-fluorodeoxyglucose positron emission/CT.The choice of an appropriate treatment for each specific case is complex, both in terms of the selection of the appropriate agent and doses and durations of therapy as well as the possibility of using combined bactericidal antibiotic regimens in the initial phase and finalizing treatment at home in patients with good evolution with outpatient oral or parenteral antimicrobial therapies programs. A relevant proportion of patients will also require valve surgery during the active phase of treatment, the timing of which is extremely difficult to define. For all the above, the management of infective endocarditis requires a close collaboration of multidisciplinary endocarditis teams.

Infective endocarditis treated in a secondary hospital: epidemiological, clinical, microbiological characteristics and prognosis, with special reference to patients transferred to a third level hospital

OBJECTIVE

To analyse the clinical and epidemiological characteristics and mortality-related factors of patients admitted to a secondary hospital with Infective Endocarditis (IE).

METHODS

Observational study of a cohort of patients who have been diagnosed with IE in a secondary hospital and evaluated in accordance with a pre-established protocol.

RESULTS

A total of 101 cases were evaluated (years 2000-2017), with an average age of 64 years and a male-to-female ratio of 2:1. 76% of the cases had an age-adjusted Charlson comorbidity index of >6, with 21% having had a dental procedure and 36% with a history of heart valve disease. The most common microorganism was methicillin-susceptible S. aureus (36%), with bacterial focus of unknown origin in 54%. The diagnostic delay time was 12 days in patients who were transferred, compared to 8 days in patients who were not transferred (p=0.07); the median surgery indication delay time was 5 days (IQR 13.5). The in-hospital mortality rate was 34.6% and the prognostic factors independently associated with mortality were: cerebrovascular events (OR 98.7%, 95% CI, 70.9-164.4); heart failure (OR 27.3, 95% CI, 10.2-149.1); and unsuitable antibiotic treatment (OR 7.2, 95% CI, 1.5-10.5). The mortality rate of the patients who were transferred and who therefore underwent surgery was 20% (5/25).

CONCLUSIONS

The onset of cerebrovascular events, heart failure and unsuitable antibiotic treatment are independently and significantly associated with in-hospital mortality. The mortality rate was higher than the published average (35%); the diagnostic delay was greater in patients for whom surgery was indicated.

Investigating the anti-streptococcal biofilm effect of ssDNA aptamer-silver nanoparticles complex on a titanium-based substrate

Streptococcus mutans is a commensal and opportunistic pathogen that causes several diseases by forming a biofilm in humans and animals in many areas such as nasopharyngeal, cardiac valves, lungs, and oral cavity. Biofilms are very important in prosthetic infections associated with medical implants. The use of nanoparticles is one of the evolving fields in biofilm targeting. Silver nanoparticles can be used for biofilm targeting due to their inherent antimicrobial properties. Hybridization of nanoparticles with small molecules increases their biological properties and makes them multifunctional. The present investigation aimed to design an appropriate silver nanoparticles–aptamer complex that binds to the surface receptors of streptococcal strains. For this reason, silver nanoparticles with particle sizes in a range of 50 to 70 nm were synthesized and connected to a designed aptamer with a streptavidin–biotin linker. Then, the effect of the complex was investigated on the S. mutans biofilm formed on the surface of a medical-grade titanium substrate. The silver nanoparticles–aptamer complex at a concentration of 100 μg mL⁻¹ after 48 h inhibited 43% of the biofilm formation and degraded 63% of the formed biofilm. Also, the cell availability reached 96% and the complex was stable in cell medium culture for 360 min. It was concluded that this complex could be a good candidate for removing the formed biofilms on the surface of titanium implants.

Silver nanoparticles attached to the specific aptamer forStreptococcus mutans, can significantly remove the biofilm of this bacterium attached to the surface of the titanium implant.

Linezolid for infective endocarditis: A structured approach based on a national database experience

Current data on the frequency and efficacy of linezolid (LNZ) in infective endocarditis (IE) are based on small retrospective series. We used a national database to evaluate the effectiveness of LNZ in IE.This is a retrospective study of IE patients in the Spanish GAMES database who received LNZ. We defined 3 levels of therapeutic impact: LNZ < 7 days, LNZ high-impact (≥ 7 days, > 50% of the total treatment, and > 50% of the LNZ doses prescribed in the first weeks of treatment), and LNZ ≥ 7 days not fulfilling the high-impact criteria (LNZ-NHI). Effectiveness of LNZ was assessed using propensity score matching and multivariate analysis of high-impact cases in comparison to patients not treated with LNZ from the GAMES database matched for age-adjusted comorbidity Charlson index, heart failure, renal failure, prosthetic and intracardiac IE device, left-sided IE, and Staphylococcus aureus. Primary outcomes were in-hospital mortality and one-year mortality. Secondary outcomes included IE complications and relapses.From 3467 patients included in the GAMES database, 295 (8.5%) received LNZ. After excluding 3 patients, 292 were grouped as follows for the analyses: 99 (33.9%) patients in LNZ < 7 days, 11 (3.7%) in LNZ high-impact, and 178 (61%) in LNZ-NHI. In-hospital mortality was 51.5%, 54.4%, and 19.1% respectively. In the propensity analysis, LNZ high-impact group presented with respect to matched controls not treated with LNZ higher in-hospital mortality (54.5% vs 18.2%, P = .04). The multivariate analysis showed an independent relationship of LNZ use with in-hospital mortality (odds ratio 9.06, 95% confidence interval 1.15--71.08, P = .03).Treatment with LNZ is relatively frequent, but most cases do not fulfill our high-impact criteria. Our data suggest that the use of LNZ as definitive treatment in IE may be associated with higher in-hospital mortality.

Time to abandon ampicillin plus gentamicin in favour of ampicillin plus ceftriaxone in Enterococcus faecalis infective endocarditis? A meta-analysis of comparative trials

Background

Current guidelines recommend either ampicillin plus ceftriaxone (AC) or amoxicillin/ampicillin plus gentamicin (AG) with an equivalent class IB recommendation in Enterococcus faecalis endocarditis. However, previous observational studies suggest that AC might be favourable in terms of adverse events.

Objectives

To investigate whether AC is non-inferior to AG, and if it is associated with less adverse events.

Methods

In June 2021, a systematic literature search using the databases PubMed/MEDLINE, CDSR, CENTRAL, CCAs, EBM Reviews, Web of Science and LILACS was conducted by two independent reviewers. Studies were considered eligible if (P) patients included were ≥ 18 years of age and had IE with E. faecalis, (I) treatment with AC was compared to (C) treatment with AG and (O) outcomes on in-hospital mortality, nephrotoxicity and adverse events requiring drug withdrawal were reported. Odds ratios and 95% confidence intervals were calculated using random-effects models with the Mantel–Haenszel method, the Sidik–Jonkman estimator for τ² and the Hartung–Knapp adjustment.

Results

Treatment with AC was non-inferior to AG, as depicted by no significant differences in-hospital mortality, 3-month mortality, relapses or treatment failure. Furthermore, AC was associated with a lower prevalence of nephrotoxicity (OR 0.45 [0.26–0.77], p = 0.0182) and drug withdrawal due to adverse events (OR 0.11 [0.03–0.46], p = 0.0160) than AG.

Conclusions

Treatment with AC was non-inferior to treatment with AG, and it was associated with a reduced prevalence of nephrotoxicity and drug withdrawal due to adverse events. Thus, combination therapy with AC appears favourable over AG in patients with E. faecalis IE.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01971-3.

Challenges and solutions in polymer drug delivery for bacterial biofilm treatment: A tissue-by-tissue account

To tackle the emerging antibiotic resistance crisis, novel antimicrobial approaches are urgently needed. Bacterial communities (biofilms) are a particular concern in this context. Biofilms are responsible for most human infections and are inherently less susceptible to antibiotic treatments. Biofilms have been linked with several challenging chronic diseases, including implant-associated osteomyelitis and chronic wounds. The specific local environments present in the infected tissues further contribute to the rise in antibiotic resistance by limiting the efficacy of systemic antibiotic therapies and reducing drug concentrations at the infection site, which can lead to reoccurring infections. To overcome the shortcomings of systemic drug delivery, encapsulation within polymeric carriers has been shown to enhance antimicrobial efficacy, permeation and retention at the infection site. In this Review, we present an overview of current strategies for antimicrobial encapsulation within polymeric carriers, comparing challenges and solutions on a tissue-by-tissue basis. We compare challenges and proposed drug delivery solutions from the perspective of the local environments for biofilms found in oral, wound, gastric, urinary tract, bone, pulmonary, vaginal, ocular and middle/inner ear tissues. We will also discuss future challenges and barriers to clinical translation for these therapeutics. The following Review demonstrates there is a significant imbalance between the research focus being placed on different tissue types, with some targets (oral and wound biofims) being extensively more studied than others (vaginal and otitis media biofilms and endocarditis). Furthermore, the importance of the local tissue environment when selecting target therapies is demonstrated, with some materials being optimal choices for certain sites of bacterial infection, while having limited applicability in others.

Exploring the Interplay Between Oral Diseases, Microbiome, and Chronic Diseases Driven by Metabolic Dysfunction in Childhood

Oral childhood diseases, such as caries and gingivitis, have much more than a local impact on the dentition and tooth surrounding tissues, which can affect systemic conditions. While the mouth is frequently exposed to microbial stressors that can contribute to an inflammatory state in the entire body, chronic disorders can also interfere with oral health. Sharing common risk factors, a dynamic interplay can be driven between 1. dental caries, gingivitis, and type I diabetes mellitus, 2. early childhood caries and obesity, and 3. caries and cardiovascular diseases. Considering that there are ~2.2 billion children worldwide and that childhood provides unique opportunities for intervention targeting future health promotion, this review is of prime importance and aimed to explore the relationship between the oral microbiome and oral chronic diseases driven by metabolic dysfunction in childhood.