Diagnosis of infective endocarditis

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.

Ultrastructure of a late-stage bacterial endocarditis valve vegetation

Infective endocarditis (IE) remains a severe illness with high mortality rate, despite advances in antibiotic therapy and cardiac surgery. If infectious bacteria and platelets are two key players of human IE vegetation developmental process, their interactions and respective roles in fully developed late-stage IE vegetations remain obscure. The objective of this study was to better understand the organization of the different components of the IE vegetation and to provide a detailed description of this vegetation ultrastructure. A late stage Staphylococcal endocarditic vegetation was provided from a 13 years teenager patient. After reception of the surgical piece, we carried out a histological study using routine methods, notably the hematoxylin-eosin-saffron staining. Labeling with the anti-CD 61 antibody was also carried out. In a second step, we used transmission electron microscopy to describe the different regions making up the vegetation. Our ultrastructural study revealed vegetation was clearly composed by three different regions and identified the specific location of the bacteria and platelets in the vegetation tissues. Histological analysis showed that platelets and Staphylococcus aureus were not co-localized. Electron microscopy study confirmed that S. aureus were found at distance from platelets, as well from immune cells, embedded in a biofilm and/or a necrotic area. These results reveal a development of a deep bacteria-only niche in vegetation, raising questions about medication access to these microorganisms. Vegetation composed of three regions: a region rich in bacteria incorporated into the necrotic tissue, the second region composed of fibrin filaments and the third region rich in platelets and free of bacteria.

Heart Infection Prognosis Analysis by Two-dimensional Spot Tracking Imaging

Cardiovascular death is one of the leading causes worldwide; an accurate identification followed by diagnosing the cardiovascular disease increases the chance of a better recovery. Among different demonstrated strategies, imaging on cardiac infections yields a visible result and highly reliable compared to other analytical methods. Two-dimensional spot tracking imaging is the emerging new technology that has been used to study the function and structure of the heart and test the deformation and movement of the myocardium. Particularly, it helps to capture the images of each segment in different directions of myocardial strain values, such as valves of radial strain, longitudinal strain, and circumferential strain. In this overview, we discussed the imaging of infections in the heart by using the two-dimensional spot tracking.

Twenty-Year Experience in the Diagnosis and Treatment of Infective Endocarditis

Aims

The aim of this study was to compare the etiology, clinical course, selected diagnostic methods and efficacy of the treatment used in patients with infective endocarditis (IE) in the nineteen eighties and nineties.

Material and Methods

The study group comprised 300 patients with infective endocarditis hospitalized in the Institute of Cardiology in Warsaw in the following years: from 1982 to 1987 (150 patients: 75 successive patients with IE on the prosthetic valve and 75 successive patients with IE on the native valve), as well as from 1990 to 2003 (150 patients: 75 successive patients with IE on the prosthetic valve and 75 successive patients with IE on the native valve).

Results

In the nineties, immunological symptoms, embolism formation and progressive heart failure were diagnosed decidedly more frequently. Early prosthetic valve endocarditis (PVE) (up to 60 days after operation) occurred significantly more frequently in the eighties. The quantity of negative blood cultures in PVE has not decreased, it is still observed in over 20% of cases. For 20 years the etiology of PVE has remained the same, the dominant pathogen remains Staphylococcus. The frequency of PVE caused by Streptococci has markedly reduced. In both the decades analyzed the etiology of native valve endocarditis (NVE) was similar. In the eighties Streptococcus was predominant. In successive years the number of infections caused by Staphylococci was the same as that caused by Streptococci.

Conclusions

The incidence of early PVE decreased in the nineties. More patients were treated surgically with lesser peri-operative mortality. A lower incidence of infective endocarditis on prosthetic valves caused by streptococci may signify better prophylaxis against infective endocarditis. Infective endocarditis with sterile blood cultures continues to occur frequently.

Infective endocarditis with uveitis: a rare case report

We report a case of a 51-year-old diabetic male who presented with a complaint of intermittent chills and fever that he had experienced for 10 days. No obvious respiratory tract, genitourinary tract, gastrointestinal tract, or skin lesions were observed. Blood culture data were positive for group B beta-streptococcus. Transthoracic and transesophageal echocardiography revealed vegetation in the anterior leaflet of the mitral valve. The patient was diagnosed with infective endocarditis (IE) and prescribed a parenteral antibiotic. Three days after admission, the patient complained of progressively blurred vision. Slit lamp examination found fine keratic precipitates and aqueous cells in the anterior chambers in both eyes, implying that the patient had uveitis. He was then prescribed a topical steroid for 4 months, and his vision improved gradually. This case is an important reminder that uveitis, not only endophthalmitis, can occur with IE. Treatment for one condition, if misapplied, may worsen the other.

Infective endocarditis presenting with Parinaud's dorsal midbrain syndrome

We present a case of vertical gaze palsy in a 13-year-old girl caused by underlying infective endocarditis, secondary to an infected navel piercing. This case illustrates that infective endocarditis does not always present with classic signs.

Recent trends in infective endocarditis: influence of case definitions

PURPOSE OF REVIEW

Infective endocarditis continues to pose major challenges in diagnosis and management despite advances in understanding the epidemiology, microbiology, and pathology of the disease. The purpose of this article is to provide a review of diagnosis, microbiology, and treatment of infective endocarditis, particularly as they are influenced by case definitions.

RECENT FINDINGS

Case definitions have a critical effect on the interpretation of trends in infective endocarditis, and recent studies have proposed more specific criteria. Studies have also addressed the appropriate use of echocardiography to assist in the diagnosis and management of infective endocarditis. Staphylococcus aureus has become an increasingly common cause of infective endocarditis, and the microbiology of nosocomial infective endocarditis is changing. Newer techniques are being used to aid in the identification of causal agents in blood culture-negative infective endocarditis. Antimicrobial guidelines for the treatment of infective endocarditis are readily available, including a proposal to avoid premature discharge of patients on outpatient antibiotic therapy. Additional studies have been conducted on combination antibiotic therapy, duration of treatment, dosing of aminoglycosides, alternative agents for gram-positive organisms, aspirin therapy, and surgical interventions.

SUMMARY

Recent trends in diagnosis, microbiology, and treatment of infective endocarditis are described, and case definitions play a critical role in their interpretation.

Innocent victim of a localised outbreak: legionella endocarditis

Legionella pneumophila endocarditis is extremely rare. The case of a fit 26 year old man who had previously undergone homograft aortic root replacement is reported. He was admitted with legionella pneumonia during the recent localised outbreak but went on to develop endocarditis. His aortic valve was replaced with a mechanical valve and he made an uneventful recovery. Public health issues and diagnosis in susceptible patients during localised outbreaks are discussed.