Non-typhoidal Salmonella enteritidis prosthetic valve endocarditis

In this case, we present a rare cause of prosthetic valve endocarditis. A man in his 80s presented to the emergency department with fever and diarrhoea. The patient underwent a transcatheter aortic valve replacement 17 years earlier. A negative PCR result in faeces for Salmonella and positive blood cultures with Salmonella gave rise to the suspicion of an intravascular Salmonella infection, which was confirmed with a positron emission tomography. Due to the low prevalence of Salmonella endocarditis, there is no consensus on the most effective treatment. Guidelines recommend early surgery and long-term antimicrobial treatment in endocarditis with Gram-negative bacteria. In this case, surgery was not deemed feasible given the patient his advanced age and multiple comorbidities. Despite treatment with intravenous antibiotics, the patient succumbed to progression of endocarditis 37 days after admission.

Metagenomic analysis of oral plaques and aortic valve tissues reveals oral bacteria associated with aortic stenosis

OBJECTIVES

Bacteria derived from the oral cavity enter the bloodstream and cause the onset of various systemic diseases, including heart valve disease. However, information on the oral bacteria involved in aortic stenosis is limited.

MATERIALS AND METHODS

We comprehensively analyzed the microbiota in aortic valve tissues collected from aortic stenosis patients using metagenomic sequencing and investigated the relationships between the valve microbiota, the oral microbiota, and oral cavity conditions.

RESULTS

Metagenomic analysis revealed the presence of 629 bacterial species in five oral plaques and 15 aortic valve clinical specimens. Patients were classified into two groups (A and B) according to their aortic valve microbiota composition using principal coordinate analysis. Examination of the oral conditions of the patients showed no difference in the decayed/missing/filled teeth index. Bacteria in group B tend to be associated with severe disease, and the number of bacteria on the dorsum of the tongue and the positive rate of bleeding during probing were significantly higher in this group than in group A. The pathophysiology of aortic stenosis may be related to the presence of oral bacteria such as Streptococcus oralis and Streptococcus sanguinis following bacteremia.

CONCLUSIONS

Systemic inflammation in severe periodontitis may be driven by the oral microbiota, supporting the indirect (inflammatory) association between oral bacteria and aortic stenosis.

CLINICAL RELEVANCE

Appropriate oral hygiene management may contribute to the prevention and treatment of aortic stenosis.

Bacteremia Caused by Neisseria elongata in an Infective Endocarditis Patient: Case Report and Review of Literature

BACKGROUND

Neisseria elongata (N. elongate) is a strictly aerobic and gram-negative rod bacterium which is a constituent of the commensal bacterial flora in the pharynx. Infection caused by Neisseria elongata is rarely reported. Here we describe a case of endocarditis in a patient after aortic mechanical valve replacement caused by N. elon-gate in China.

METHOD

A 30-year-old man suffered infective endocarditis after aortic mechanical valve replacement. Blood cultures were positive and the organism was identified as Neisseria elongata by MALDI-TOF MS as well as the 16S rRNA sequencing.

RESULT

The patient was treated with ofloxacin and meropenem. He was successfully treated with the 6-week course of antibiotic therapy.

CONCLUSIONS

N. elongate endocarditis is rarely reported. Our report expands the range of infection caused by N. elongate.

Double-Valve Heart Disease and Glomerulonephritis Consequent to Abiotrophia defectiva Endocarditis

Abiotrophia defectiva, a nutritionally deficient streptococcus, is a rare cause of infective endocarditis. It has been associated with hemophagocytic syndrome. We present the first case of A. defectiva infective endocarditis that led to antineutrophil cytoplasmic antibody-associated glomerulonephritis. The patient was a 55-year-old man whose endocarditis affected the mitral and aortic valves. His course was complicated by atrial fibrillation, stroke, and glomerulonephritis. He was successfully treated with antibiotics and dual valve replacement.

Bordetella hinzii: An Unexpected Pathogen in Native Valve Endocarditis

Bordetella hinzii's route of transmission to human hosts and its pathogenicity remain unclear. Only a few cases have established this species as an opportunistic zoonotic disease. We introduce the first reported case of native aortic valve endocarditis presenting with fulminant aortic valve insufficiency that responded to conventional medical and surgical treatment. The patient did not have predisposing factors to this unusual infection. This case may provide a better understanding of the disease process, transmission, and pathogenicity of Bordetella hinzii.

Tick-borne pathogens Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii and Rickettsia spp. may trigger endocarditis

BACKGROUND

Infections caused by tick-borne pathogens such as Bartonella spp., Borrelia burgdorferi s.l., Coxiella burnetii, and Rickettsia spp. are capable of causing serious lesions of the mitral and aortic valves, leading to a need for valve replacement.

OBJECTIVES

The aim of the study was to determine whether such cases are sporadic or frequent. An additional goal was to establish effective diagnostic methods to detect these infections.

MATERIAL AND METHODS

The study involved 148 patients undergoing valve replacement. Blood samples were drawn for serological testing. Samples of the removed mitral and aortic valves were tested with polymerase chain reaction and immunohistochemical staining.

RESULTS

Specific antibodies to Bartonella spp. were detected in 47 patients (31.7%) and in 1 of the healthy controls (1%) (p < 0.05). Antibodies to B. burgdorferi spirochetes were found in 18 of the patients (12.2%) and in 6 blood donors from the control group (5.8%) (p < 0.1). Antibodies to Rickettsia spp. were detected in 12 (8.1%) and to C. burnetii phase I and II antigens in the serum of 1 patient. All the participants in the control group were seronegative to C. burnetii and Rickettsia spp. antigens. Polymerase chain reaction (PCR) tests for detection of Bartonella spp., B. burgdorferi s.l., C. burnetii and Rickettsia spp. DNA in the valve samples were all negative. Inflammation foci with mononuclear lymphoid cells in the aortic and mitral valves were seen in sections stained with hematoxiline and eozine. In sections dyed using the indirect immunofluorescence method with hyperimmune sera, Bartonella spp. and Rickettsia spp. were found.

CONCLUSIONS

The results obtained indicate that laboratory diagnostics for patients with heart disorders should be expanded to include tests detecting tick-borne zoonoses such as bartonelloses, Lyme borreliosis, rickettsioses and Q fever.

Compassionate Use of Cefiderocol as Adjunctive Treatment of Native Aortic Valve Endocarditis Due to Extremely Drug-resistant Pseudomonas aeruginosa

Serious infections such as endocarditis due to extremely drug-resistance gram-negative bacteria are an increasing challenge. Here, we present successful adjunctive use of cefiderocol for a patient with persistently bacteremic healthcare-associated native aortic valve endocarditis due to an extended-spectrum beta-lactamase-positive Pseudomonas aeruginosa susceptible in vitro only to colistin, following failure of conventional therapeutic options.

Adjunctive dabigatran therapy improves outcome of experimental left-sided Staphylococcus aureus endocarditis

Background

Staphylococcus aureus is the most frequent and fatal cause of left-sided infective endocarditis (IE). New treatment strategies are needed to improve the outcome. S. aureus coagulase promotes clot and fibrin formation. We hypothesized that dabigatran, could reduce valve vegetations and inflammation in S. aureus IE.

Methods

We used a rat model of severe aortic valve S. aureus IE. All infected animals were randomized to receive adjunctive dabigatran (10 mg/kg b.i.d., n = 12) or saline (controls, n = 11) in combination with gentamicin. Valve vegetation size, bacterial load, cytokine, cell integrins expression and peripheral platelets and neutrophils were assessed 3 days post-infection.

Results

Adjunctive dabigatran treatment significantly reduced valve vegetation size compared to controls (p< 0.0001). A significant reduction of the bacterial load in aortic valves was seen in dabigatran group compared to controls (p = 0.02), as well as expression of key pro-inflammatory markers keratinocyte-derived chemokine, IL-6, ICAM-1, TIMP-1, L-selectin (p< 0.04). Moreover, the dabigatran group had a 2.5-fold increase of circulating platelets compared to controls and a higher expression of functional and activated platelets (CD62p⁺) unbound to neutrophils.

Conclusion

Adjunctive dabigatran reduced the vegetation size, bacterial load, and inflammation in experimental S. aureus IE.

Infective Endocarditis Due to Bartonella Quintana in a Patient with Biological Aortic Prosthesis

BACKGROUND

Bartonella quintana is a facultative intracellular bacterium and the causative agent of trench fever. The disease was reported during the World Wars in pre-antibiotic era and is associated with louse infestation and poor hygiene conditions. Bartonella bacteraemia may result in endocarditis mostly in people with existing heart valve abnormalities.

CASE REPORT

We report a case of endocarditis caused by B. quintana in a 77-year-old woman with previous valvulopathy. This active endocarditis case was characterized by aortic root involvement 5 years after surgical aortic valve replacement. Although the initial serological tests had induced to a presumptive diagnosis of Q fever, B. quintana infection was confirmed by PCR and sequencing. Detection of Bartonella DNA in valvular and abscess specimens was determinant to confirm Bartonella infection in the absence of other associated risk factors.

CONCLUSIONS

Bartonella infection should be considered in patients with pre-existing valvular disease and with a blood culture-negative endocarditis.

The Duke minor criterion "predisposing heart condition" in native valve infective endocarditis - a systematic review

BACKGROUND The term “predisposition” is used as an indication of antimicrobial prophylaxis to prevent infective endocarditis and as a criterion for diagnosing infective endocarditis according to the modified Duke criteria. The criterion for diagnosing infective endocarditis in native valves is not well defined. OBJECTIVES To identify conditions that increase the risk for infective endocarditis in native valves, for the diagnosis of infective endocarditis according to the modified Duke criteria. In parallel, we compared the results with the year of patient inclusion for each study and echocardiographic techniques. RESULTS Our systematic review included 207 studies published from January 1970 to August 2015. Studies that focused on mitral valve prolapse (112 studies), prior infective endocarditis (96) and bicuspid aortic valve (78) provided the most data. However, only six (5.3%), three (3.1%) and one (1.3%) of these studies, respectively, used analytical statistical methods. Three (2.7%), two (2.1%) and one (1.3%), respectively, were graded as good quality studies. Odds ratios (ORs) for developing infective endocarditis were 3.5–8.2 for mitral valve prolapse, and 2.2 and 2.8 for prior infective endocarditis. The hazard ratio for developing infective endocarditis was 6.3 for bicuspid aortic valve. The mean prevalence proportion of infective endocarditis in patients with these three heart conditions were 8.5% (mitral valve prolapse), 8.3% (prior infective endocarditis) and 8.8% (bicuspid aortic valve). The proportions of publications prior to the publication of the modified Duke criteria were 81.8, 75.6 and 74%, respectively. Evolution of the imaging method and echocardiographic technique was estimated to be considerable for mitral valve prolapse. The literature review on aortic valve stenosis (46 studies), mitral valve insufficiency (41) and aortic valve insufficiency (39) provided two analytical studies for aortic stenosis. One study was graded as good quality and reported a hazard ratio 4.9. The mean prevalence of these heart conditions in patients with infective endocarditis were 7.3, 19.9 and 10.2%, respectively. The proportions of publications prior to the publication of the modified Duke criteria were 78, 75.6 and 79.5%, respectively. The evolution of both the echocardiographic technique and the categorisation of valve disease severity was considerable for all three entities. CONCLUSIONS The evidence for native valve heart conditions predisposing to infective endocarditis is mainly based on studies with only descriptive statistics published prior to the release of the modified Duke criteria. Mitral valve prolapse, prior infective endocarditis and bicuspid aortic valve are frequently cited as predisposing heart conditions for infective endocarditis. The evolution in echocardiographic techniques over the past decades and its influence on diagnosis was considerable for mitral valve prolapse, aortic stenosis, mitral insufficiency and aortic insufficiency.

A Double Whammy: Lactobacillus acidophilus Bacteremia and Subsequent Lactobacillus rhamnosus Prosthetic Valve Infective Endocarditis in an Elderly Diabetic Patient

The clinical significance of the relatively avirulent organ- ism, Lactobacillus, has been debated in the past. At times misdiagnosed as a contaminant, Lactobacillus has uncommonly been reported to cause intra-abdominal abscesses, peritonitis, meningitis, bacteremia, pneumonia and endocarditis, especially in the population of patients with underlying comorbid conditions including malignancy, diabetes, recent surgery or organ transplantation. We report a case of a 74-year-old male with Lactobacillus bacteremia leading to prosthetic valve infective endocarditis complicated by an aortic root abscess. He was managed with IV antibiotic therapy, ultimately penicillin G, and aortic valve replacement, and completely recovered after a period of rehabilitation. Several factors that predispose to Lactobacillus bacteremia were identified in our patient. This case further supports the proposition that Lactobacillus is not always a contaminant; when pathogenic, underlying disease conditions should be investigated.

Complex regional pain syndrome type II arising from a gunshot wound (GSW) associated with infective endocarditis and aortic valve replacement

A 34-year-old man with a history of gunshot wound (GSW) to the right upper chest developed secondary aortic valve endocarditis (AVE) and was treated with an artificial valve placement (AVP). Three months after, he presented to an outpatient pain management clinic right arm pain and was diagnosed with complex regional pain syndrome type II (CRPS II). The patient underwent a diagnostic sympathetic ganglion block, before undergoing endoscopic thoracic sympathectomy surgery. Successful outcomes revealed decreased pain, opioid utilisation and improved tolerance to therapy and activities of daily living. To our knowledge, this is the first case reporting CRPS II arising from a GSW complicated by AVE followed by AVP, which emphasises how unforeseen syndromes can arise from the management of seemingly unrelated pathology. This case demonstrates the importance of timely and proper diagnosis of uncharacterised residual pain status post-trauma and differential diagnosis and management of chronic pain syndromes.

An Interesting Case of Recurrent Pyelonephritis

A 35-year-old male presented with repeated episodes of fever and abdominal pain of 3-month duration. He had been hospitalized twice with similar complaints in the past 3-month. He was diagnosed as pyelonephritis and managed with intravenous antibiotics. However, fever recurred after ten days of discharge from the hospital. With these complaints, he was referred to the Department of Medicine, AIIMS, New Delhi. After evaluation, he was diagnosed as pyelonephritis with right sided consolidation and was started on broad spectrum antibiotics. After a transient initial improvement, his dyspnea worsened, fever recurred and he developed a tender submandibular abscess. Further evaluation for the actual focus of infection, revealed a small mass attached to the right coronary aortic cusp on transthoracic ECHO. Diagnosis of native Aortic valve endocarditis was made and suitably treated. The patient became afebrile on the 8th day of therapy and was discharged after 20-day. He is doing well on subsequent follow-up.

A Fish Mouth Appearing Perforation of the Native Aortic Valve Due to Streptococcus infantarius subspecies coli

Infective endocarditis due to Streptococcus infantarius with the subspecies (subsp.) coli is infrequently encountered in healthy humans. This entity is associated with hepatobiliary malignancies and colorectal neoplasia. Here, we report on a unique case of endocarditis associated with S. infantarius subsp. coli in an 80-year-old male with no known risk factors of the infective endocarditis.

Outpatient parenteral antimicrobial therapy for infective endocarditis in patients over 80 years

OBJECTIVE

The incidence of infective endocarditis is progressively increasing, especially in elderly patients. Outpatient parenteral antibiotic therapy (OPAT) is being an excellent alternative for treatment, but advanced age is one of the relative contraindications. The aim of this study is to compare the characteristics and prognosis of patients less or more than 80 years, treated with OPAT.

METHODS

One hundred and ninety four patients were included between 1996 and 2015, 31 of them older than 80 years.

RESULTS

The most frequently affected valve is the aortic one, mainly native valves. Most used antibiotics are ceftriaxone, ampicillin, cloxacillin and daptomycin. Differences in surgery (39.9% vs 9.7%, p=0.001) and use of infusion pump (55.2% vs 35.5%; p= 0.044) were observed, under 80 years and older respectively. No differences in readmissions and mortality were observed.

CONCLUSIONS

OPAT could be considered an effective alternative for appropriately-selected elderly patients with infective endocarditis.

Prosthetic Aortic Valve Endocarditis Without Evidence of Vegetation

Despite significant technological advances, the diagnosis of infective endocarditis (IE) remains a major challenge, and the condition continues to be associated with significant morbidity and mortality. Valvular vegetations have long been the diagnostic and pathologic hallmarks of IE. However, IE can be diagnosed even in the absence of vegetations using the modified Duke criteria. Vegetation-negative endocarditis is rare, and to the present authors' knowledge no cases of septic emboli in the absence of valvular vegetations have been reported. Herein is reported a case of prosthetic aortic valve endocarditis associated with both clinical and radiologic evidence of septic emboli, but in the absence of vegetations on both repeated transesophageal echocardiography and pathologic evaluation. This case highlights the importance of maintaining a high clinical suspicion and a low threshold for the surgical replacement of a possibly infected valve, in patients that meet other clinical criteria for IE, even in the absence of detectable valvular vegetations.

Fungal Endocarditis Due to Aspergillus oryzae: The First Case Reported in the Literature

Infective endocarditis (IE) is a severe disease with high mortality and morbidity. Prosthetic valve endocarditis is a life-threatening complication which can occur in less than 10% of patients with valve prosthesis. A fungal etiology of IE is rare and accounts for only 2-4% of all case of endocarditis, but is associated with a higher mortality and morbidity. Herein is reported the first case of fungal endocarditis of aortic valve prosthesis due to Aspergillus oryzae in a 67-year-old caucasian man who nine years previously underwent mitral and aortic valve replacement with mechanical prostheses, and tricuspid annuloplasty for acute IE due to Enterococcus spp. Seven months previously, the patient also underwent a redo cardiac procedure to replace a mitral valve prosthesis with a new mechanical device due to a leakage. Aspergillus oryzae showed impressive growth with strong and unexpected virulence in both local and systemic settings.

Infective Endocarditis of the Aortic Valve with Anterior Mitral Valve Leaflet Aneurysm

Mitral valve leaflet aneurysm is a rare and potentially devastating complication of aortic valve endocarditis. We report the case of a 48-year-old man who had endocarditis of the native aortic valve and a concomitant aneurysm of the anterior mitral valve leaflet. Severe mitral regurgitation occurred after the aneurysm perforated. The patient showed no signs of heart failure and completed a 6-week regimen of antibiotic therapy before undergoing successful aortic and mitral valve replacement. In addition to the patient's case, we review the relevant medical literature.

Malplacement of a Pacemaker Lead — A Rare Cause for Aortic Valve Endocarditis

Infective endocarditis of native valves following pacemaker implantation is rare but can be associated with serious complications, approaching a mortality of up to 25%. 1 Recent publications report a frequency of pacemaker related endocarditis between 0.5 and 7%. 2 Due to anatomical reasons the tricuspid valve is mostly affected in these patients, with involvement of the left heart valves usually secondary. We report an incidence of native aortic valve endocarditis due to a misplaced pacemaker lead into the left heart.

Fungal Endocarditis: An Autopsy Study

Between 1990 and 2002, 237 hearts were examined at autopsy, including 16 with infective endocarditis; 6 showed fungal endocarditis. The preceding pathology was chronic rheumatic heart disease in 2 patients, one of whom had undergone double valve replacement, 2 patients had been treated for acute lymphoblastic leukemia, and one had protein-energy malnutrition. The underlying cause was unknown in one case. The organisms isolated were Aspergillus in 3 patients, Zygomycota in 1, Candida in 1, and both Candida tropicalis and Aspergillus in 1 patient. Immunosuppressed states are a cause of fungal endocarditis in India, although chronic rheumatic heart disease is the preceding pathology in the majority of patients.

Rapid molecular diagnosis of infective aortic valve endocarditis caused by Coxiella burnetii

We describe a case of Q-fever endocarditis with severe destruction of the aortic valve with perivalvular abscess formation and cardiac failure. The patient needed urgent operative treatment and postoperative critical care. All specimens sent for microbiological examination were negative. Molecular analysis, including fluorescence in situ hybridization of aortic valve tissue combined with PCR and sequencing, led to the correct diagnosis and to appropriate anti-infective treatment. The patient subsequently recovered from complex cardiovascular surgery. This is the first report on Q-fever endocarditis that was rapidly diagnosed using these methods.

The value of transthoracic and transesophageal echocardiography for the diagnosis of the native aortic infective endocarditis valve complications: a case report and literature review

Despite its current limitations transthoracic echocardiography is still widely used for the anatomical and functional evaluation of patients with infective endocarditis. However, all these limitations can be overcome by using transesophageal echocardiography. We present the case of a 42-year-old male patient, diagnosed with aortic valve infective endocarditis, whose transthoracic echocardiography showed only a cusp vegetation and aortic regurgitation, but raised the suspicion of periannular complications. The transesophageal echocardiography revealed a circular aortic root abscess and a ventricular septal defect with left-to-right shunt, and consequently leads to a complete different surgical tactical approach. The patient was urgently referred for surgery due to the rapid deterioration of the hemodynamic status, and had a good outcome on the short-term follow-up.

Complicated Infective Endocarditis of a Mechanical Aortic Valve due to Propionibacterium acnes

Propionibacterium acnes is known to be a causative microorganism in low-grade and late prosthetic valve endocarditis. Here, the case is reported of a late, apparently culture-negative endocarditis of an aortic mechanical prosthesis, diagnosed to be caused by P. acnes after pan-bacterial polymerase chain reaction (PCR) on the explanted mechanical prosthetic valve. This endocarditis was complicated by an aortic root abscess; after surgical resection a ventricular septal defect (VSD) with overt right ventricular and multiple organ failure occurred. Low suspicion, the failure of routine blood culture to grow P. acnes and erroneous interpretation of P. acnes as contamination, frequently delay the correct diagnosis and treatment of this condition. Hence, although infection with P. acnes is usually indolent, abscess formation and a need for surgery are common.

Bioprosthetic Aortic Valve Endocarditis in Association with Enterococcus durans

Enterococci are common organisms associated with endocarditis, but infection by Enterococcus durans is very rare. To our knowledge, only 3 cases have been reported in the medical literature, and all 3 have involved native valves. Here we publish the first reported case (to our knowledge) of E. durans endocarditis in association with a bioprosthetic aortic valve. After the organism and its antibiotic susceptibility were identified, the 74-year-old male patient was treated successfully with teicoplanin and gentamicin, over a course of 6 weeks.

18F-FDG PET/CT in the diagnosis of prosthetic valve endocarditis

Recent studies have shown promising results using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the diagnosis of prosthetic valve endocarditis (PVE). However, previous studies did not include negative controls. The aim of this study was to compare (18)F-FDG-uptake around prosthetic aortic valves in patients with and without PVE and to determine the diagnostic performance of (18)F-FDG PET/CT in the diagnosis of PVE. (18)F-FDG PET/CT examinations in patients with a prosthetic aortic valve performed 2008-2014 were retrieved. Eight patients with a final diagnosis of definite PVE were included in the analysis of the diagnostic performance of (18)F-FDG PET/CT. Examinations performed on suspicion of malignancy in patients without PVE (n = 19) were used as negative controls. Visual and semi-quantitative analysis was performed. Maximal standardized uptake value (SUVmax) in the valve area was measured and SUVratio was calculated by dividing valve SUVmax by SUVmax in the descending aorta. The sensitivity was 75 %, specificity 84 %, positive likelihood ratio [LR(+)] 4.8 and negative likelihood ratio [LR(-)] 0.3 on visual analysis. Both SUVmax and SUVratio were significantly higher in PVE patients [5.8 (IQR 3.5-6.5) and 2.4 (IQR 1.7-3.0)] compared to non-PVE patients [3.2 (IQR 2.8-3.8) and 1.5 (IQR 1.3-1.6)] (p < 0.001). ROC-curve analysis of SUVratio yielded an area under the curve of 0.90 (95 % CI 0.74-1.0). (18)F-FDG-uptake around non-infected aortic prosthetic valves was low. The level of (18)F-FDG-uptake in the prosthetic valve area showed a good diagnostic performance in the diagnosis of PVE.

Aortic Valve Endocarditis Caused by Abiotrophia defectiva: Case Report and Literature Overview

Abiotrophia defectiva or nutritionally variant Streptococcus (NVS) are a rare but important cause of infectious endocarditis, with high rates of bacteriological failure and mortality. We report the case of a 74-year-old man admitted for fever, fatigue and general malaise in the absence of any underlying cardiac, immunosuppressive illness and previous dental manipulations. Transthoracic and transesophageal echocardiogram revealed bacterial vegetation and significant aortic stenosis and regurgitation. Initial blood culture reported gram-positive cocci in chains, subsequently identified as A. defectiva. The patient completed 6 weeks of antibiotic therapy with ampicillin, with a significant decrease of serum inflammatory markers. He refused cardiac surgery and had relapsing endocarditis with positive blood culture for the same pathogen. The patient was then submitted to double-valve cardiac surgery, obtaining a prompt resolution of clinical signs and symptoms, without other relapse or any complications.

CONCLUSION

Infectious diseases caused by A. defectiva are extremely rare illnesses. Due to the difficult isolation of the pathogen and the slow clinical progression, clinicians should be aware of this bacterium when dealing with blood culture-negative infective endocarditis.

The Preoperative Evaluation of Infective Endocarditis via 3-Dimensional Transesophageal Echocardiography

Transesophageal echocardiography continues to have a central role in the diagnosis of infective endocarditis and its sequelae. Recent technological advances offer the option of 3-dimensional imaging in the evaluation of patients with infective endocarditis. We present an illustrative case and review the literature regarding the potential advantages and limitations of 3-dimensional transesophageal echocardiography in the diagnosis of complicated infective endocarditis. A 51-year-old man, an intravenous drug user who had undergone bioprosthetic aortic valve replacement 5 months earlier, presented with prosthetic valve endocarditis. Preoperative transesophageal echocardiography with 3D rendition revealed a large abscess involving the mitral aortic intervalvular fibrosa, together with a mycotic aneurysm that had ruptured into the left atrium, resulting in a left ventricle-to-left atrium fistula. Three-dimensional transesophageal echocardiography enabled superior preoperative anatomic delineation and surgical planning. We conclude that 3-dimensional transesophageal echocardiography can be a useful adjunct to traditional 2-dimensional transesophageal echocardiography as a tool in the diagnosis of infective endocarditis.

C4b-Binding Protein Deposition is Induced in Diseased Aortic Heart Valves, Coinciding with C3d

BACKGROUND AND AIM OF THE STUDY

It has been found recently that activated complement is more widespread in diseased aortic valves compared to the endogenous complement inhibitors C1-inhibitor and clusterin. Previously, another endogenous inhibitor of complement, C4b-binding protein (C4BP) has been described in atherosclerotic diseased coronary arteries. The study aim was to analyze C4BP levels in diseased aortic valves.

METHODS

Aortic valve tissue was derived from surgical procedures and classified as 'degenerative', 'atherosclerotic' or 'atherosclerotic with bacterial infection'. Valves were stained with specific antibodies against C4BP, C3d and caspase-3. Areas of positivity were then quantified using computer- assisted morphometry.

RESULTS

In atherosclerotic valves, the areas of C4BP and C3d positivity (38.8 +/- 0.4% versus 32.7 +/- 1.0%, respectively) were significantly higher compared to the degenerative and control groups. In atherosclerotic valves with bacterial infection, the area of positivity for C4BP was even further increased compared to atherosclerotic valves (65.1 +/- 1.2%; 70.1 +/- 1.9% for C3d). The areas of C4BP and C3d positivity were not significantly different in all groups. Caspase-3 was only present in <10% of endothelial cells in the atherosclerotic valves without bacterial infection and in neutrophilic granulocytes in atherosclerotic valves, with and without bacterial infection.

CONCLUSION

It has been shown for the first time that C4BP is deposited in the diseased aortic valve, coinciding with C3d. The area of C4BP positivity was more extensive compared to the areas of other endogenous complement inhibitors (C1-inhibitor and clusterin).

Gerbode Defect as a Result of Fungal Aortic Valve Endocarditis

A 63-year-old male patient with HIV disease presented with dyspnea and complete heart block, and was found to have aortic valve (AV) endocarditis secondary to Candida parapsilosis infection. Echocardiography demonstrated AV endocarditis and possible aortic root versus subannular abscess with moderate AV regurgitation (AR), a ventricular septal defect (VSD) and possible left ventricular to right atrial shunt (Gerbode defect). Large AV vegetations, subannular abscess with an acquired membranous VSD, Gerbode defect, and tricuspid annular abscess at the insertion of septal leaflet were noted intraoperatively. The patient underwent AV replacement with a stented bioprosthesis, two-sided VSD patch closure, and tricuspid valve (TV) repair with an annuloplasty ring. The left-sided patch closed the VSD and facilitated AV replacement, while the right-sided patch facilitated the TV repair.

Prosthetic valve endocarditis with valvular obstruction after transcatheter aortic valve replacement

Patients with severe aortic stenosis who are at high risk for open-heart surgery might be candidates for transcatheter aortic valve replacement (TAVR). To our knowledge, this is the first report of Streptococcus viridans endocarditis that caused prosthetic valve obstruction after TAVR. A 77-year-old man who had undergone TAVR 17 months earlier was admitted because of evidence of prosthetic valve endocarditis. A transthoracic echocardiogram revealed a substantial increase in the transvalvular peak gradient and mean gradient in comparison with an echocardiogram of 7 months earlier. A transesophageal echocardiogram showed a 1.5-cm vegetation obstructing the valve. Blood cultures yielded penicillin-sensitive S. viridans. The patient was hemodynamically stable and was initially treated with vancomycin because of his previous penicillin allergy. Subsequent therapy with levofloxacin, oral penicillin (after a negative penicillin skin test), and intravenous penicillin eliminated the symptoms of the infection. Transcatheter aortic valve replacement is a relatively new procedure, and sequelae are still being discovered. We recommend that physicians consider obstructive endocarditis as one of these.

[Surgical treatment for aortic valve endocarditis combined with bacterial meningitis and vertebral osteomyelitis;report of a case]

A 59-year-old man was referred to our hospital with disturbance of consciousness. Bacterial meningitis was diagnosed by a spinal tap, and penicillin sensitive Streptococcus pneumonia was detected by blood culture. Magnetic resonance imaging revealed a vertebral osteomyelitis. Treatment with antibiotics was started immediately. Four days after admission, congestive heart failure suddenly occurred. Echocardiography showed mobile vegetation on the aortic valve, and severe regurgitation. As acute heart failure could not be controlled, the aortic valve was replaced by ATS 22AP valve on the 7th day after admission. Antibiotic therapy was continued for 8 weeks. The postoperative course was uneventful.

A Fatal Case of Endocarditis on CoreValve ReValving System Caused by Enterococcus faecium Complicated by Iatrogenic Pancytopenia and Subacute Disseminated Intravascular Coagulation

During the past few years, a new and attractive approach--transcatheter aortic valve implantation (TAVI)--has been developed for patients who are symptomatic of aortic stenosis and, due to the high expected operative risk, would not be otherwise treated. Unfortunately, TAVI can result in endocarditis of the percutaneously implanted valve that may present atypically and cause delays in diagnosis and treatment. Herein, the case is described of a 79-year-old female affected by endocarditis on aortic valve percutaneously implanted caused by Enterococcus faecium, complicated by iatrogenic pancytopenia and subacute disseminated intravascular coagulation, that proved fatal at six months after TAVI.

Early surgical intervention and optimal medical treatment for Candida parapsilosis endocarditis

We herein report the case of a 72-year-old man with endocarditis of the aortic valve who underwent urgent aortic valve replacement 36 hours after admission due to an aggravation of aortic valve regurgitation. Postoperative cultures of the blood and site of valve vegetation identified Candida parapsilosis as a pathogen. Antifungal therapy with amphotericin B and fluconazole was initiated after surgical treatment. Thereafter, the patient displayed a favorable clinical course. Candida parapsilosis endocarditis involving the native valves is extremely rare and associated with a very high mortality rate. Prompt surgical treatment and the aggressive use of antifungal agents are required to save the patient's life.

Two Case Reports of Group B Streptococcal Infective Endocarditis Complicated by Embolism

Streptococcus agalactiae (Group B streptococcus, GBS) is the major pathogen encountered in the perinatal period, although the incidence of GBS infection has recently increased among non-pregnant adults. Nevertheless, GBS infective endocarditis (IE) is uncommon and often accompanies aortic embolism. We experienced two cases of GBS IE. In Case 1, mobile vegetation of the aortic valve caused an infective cerebral aneurysm. In Case 2, the patient experienced an acute aortic embolic episode. Generally, early surgery for large mobile sites of vegetation is recommended as a class IIb therapy in the guidelines. GBS IE often exhibits a severe clinical course and specificity of vegetation. Therefore, early surgery should be considered in such cases.

Outcome of aortic valve replacement for active infective endocarditis in patients on chronic hemodialysis

BACKGROUND

The high risk of morbidity and mortality for patients on hemodialysis who are undergoing cardiac surgery is increased for those with active infective endocarditis (AIE). This retrospective observational single-center study evaluated the impact of chronic hemodialysis on the outcome of aortic valve replacement in patients with aortic AIE.

METHODS

Data were retrospectively collected for consecutive patients undergoing aortic valve surgery for AIE diagnosed according to modified Duke criteria between October 1994 and January 2011. Characteristics and outcomes of patients receiving preoperative chronic hemodialysis were analyzed.

RESULTS

Aortic valve AIE was present in 992 patients. Forty-five (4.5%) of the aortic valve AIE patients were receiving long-term hemodialysis preoperatively, 19 of whom (42.2%) had diabetes mellitus. Mean logistic EuroSCORE was 64.2% ± 32.2%. Twenty-four preoperative septic emboli were found in 15 patients. Results of microbiologic cultures were positive in 36 patients, with the major causative organisms identified as Staphylococcus aureus (n = 17) and Enterococcus faecalis (n = 10). Isolated aortic valve replacement was performed in 19 patients (42.2%), and 26 patients (57.8%) underwent concomitant procedures. The mean follow-up was 5.3 ± 5.2 years (range, 0.1 to 17.1 years). Postoperative complications occurred in 30 patients (66.7%). Nineteen patients (42.2%) died within 30 days of surgery, which in 8 patients was attributable to a cardiac cause.

CONCLUSIONS

In patients receiving chronic hemodialysis who undergo aortic valve replacement for acute AIE, postoperative mortality is high, especially in patients undergoing aortic root replacement or culture-negative AIE.

Aortic valve endocarditis complicated by ST-elevation myocardial infarction

Infective endocarditis complicated by abscess formation and coronary artery compression is a rare clinical event with a high mortality rate, and diagnosis requires a heightened degree of suspicion. We present the clinical, angiographic, and echocardiographic features of a 73-year-old woman who presented with dyspnea and was found to have right coronary artery compression that was secondary to abscess formation resulting from diffuse infectious endocarditis. We discuss the patient's case and briefly review the relevant medical literature. To our knowledge, this is the first reported case of abscess formation involving a native aortic valve and the right coronary artery.

MRI visualization of Staphyloccocus aureus-induced infective endocarditis in mice

Infective endocarditis (IE) is a severe and often fatal disease, lacking a fast and reliable diagnostic procedure. The purpose of this study was to establish a mouse model of Staphylococcus aureus-induced IE and to develop a MRI technology to characterize and diagnose IE. To establish the mouse model of hematogenous IE, aortic valve damage was induced by placing a permanent catheter into right carotid artery. 24 h after surgery, mice were injected intravenously with either iron particle-labeled or unlabeled S. aureus (strain 6850). To distinguish the effect of IE from mere tissue injury or recruited macrophages, subgroups of mice received sham surgery prior to infection (n = 17), received surgery without infection (n = 8), or obtained additionally injection of free iron particles to label macrophages (n = 17). Cardiac MRI was performed 48 h after surgery using a self-gated ultra-short echo time (UTE) sequence (TR/TE, 5/0.31 ms; in-plane/slice, 0.125/1 mm; duration, 12∶08 min) to obtain high-resolution, artifact-free cinematographic images of the valves. After MRI, valves were either homogenized and plated on blood agar plates for determination of bacterial titers, or sectioned and stained for histology. In the animal model, both severity of the disease and mortality increased with bacterial numbers. Infection with 105 S. aureus bacteria reliably caused endocarditis with vegetations on the valves. Cinematographic UTE MRI visualised the aortic valve over the cardiac cycle and allowed for detection of bacterial vegetations, while mere tissue trauma or labeled macrophages were not detected. Iron labeling of S. aureus was not required for detection. MRI results were consistent with histology and microbial assessment. These data showed that S. aureus-induced IE in mice can be detected by MRI. The established mouse model allows for investigation of the pathophysiology of IE, testing of novel drugs and may serve for the development of a clinical diagnostic strategy.

Rothia aeria endocarditis in a patient with a bicuspid aortic valve: case report

Rothia aeria is an uncommon pathogen mainly associated with endocarditis in case reports. In previous reports, endocarditis by R. aeria was complicated by central nervous system embolization. In the case we report herein, endocarditis by R. aeria was diagnosed after acute self-limited diarrhea. In addition to the common translocation of R. aeria from the oral cavity, we hypothesize the possibility of intestinal translocation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry and genetic sequencing are important tools that can contribute to early and more accurate etiologic diagnosis of severe infections caused by Gram-positive rods.

Surgical experience with infective endocarditis and aortic root abscess

PURPOSE

This study was conducted to evaluate the surgical outcomes of active infective endocarditis with aortic root abscess formation.

MATERIALS AND METHODS

Between February 1999 and June 2012, 49 patients underwent surgery for active endocarditis with aortic root abscess. The infected valve was native in 29 patients and prosthetic in 20 patients. The patients' mean age was 50±14 years, and 36 patients were male. Surgery was urgent/emergent in 15 patients (31%). The abscess involved the aortic annulus (11), left ventricular outflow tract (18), fibrous trigone (16), and mitral annulus (4). In all patients, wide debridement of abscess and aortic valve replacement with or without patch reconstruction of aortic root or annulus was performed.

RESULTS

There were 6 (12%) operative deaths. Causes of early mortality were sepsis (2) and multi-organ failure (4). On postoperative echocardiogram, there was significant improvement of left ventricular dimension (LVEDD, from 58.8±11.8 mm to 52.6±8.2 mm, p<0.001); however, LV ejection fraction was significantly decreased (from 61.4±12.0% to 49.8±16.5%, p<0.001). The mean follow-up duration was 68.7±40.4 months. There was no late death or recurrent endocarditis during follow up. New York Heart Association functional class significantly improved from 3.2±0.7 to 1.2±0.4 (p<0.001). Kaplan-Meier estimated survival at 10 years was 87.2%.

CONCLUSION

Surgical treatment for active endocarditis with aortic root abscess is still challenging, and was associated with high operative mortality. Nevertheless, long-term survival was excellent with good functional capacity after recovery from the early postoperative period.

Ruptured anterior mitral leaflet aneurysm in aortic valve infective endocarditis--evaluation by three-dimensional echocardiography

Ruptured aneurysm of the anterior mitral leaflet is a rare but a devastating complication secondary to aortic valve infective endocarditis. We report a case of 30-year-old male with native aortic valve endocarditis who was referred to us for evaluation of worsening of heart failure after an initial period of responsiveness to antibiotics. Detailed evaluation with two-dimensional and three-dimensional transthoracic echocardiography revealed ruptured anterior mitral leaflet aneurysm with severe eccentric mitral regurgitation along with a large vegetation on the aortic valve. The patient underwent successful surgical closure of the defect along with aortic valve replacement.