Clinical manifestations of infective endocarditis in relation to infectious agents: An 8-year retrospective study

AIM

To compare clinical complications and outcomes of infective endocarditis (IE) episodes caused by Staphylococcus aureus (S. aureus) and other most frequent aetiological agents (streptococci, enterococci, coagulase-negative staphylococci, and culture-negative IE).

METHODS

A total of 117 IE episodes assessed by all internal medicine services of a major teaching institution in the Czech Republic over an eight-year period were identified.

RESULTS

We found that S. aureus IE episodes (n = 36) were significantly more associated with systemic embolism (41.7% vs 18.5%, P = 0.01), severe sepsis/septic shock (33.3% vs 3.7%, P < 0.0001), and in-hospital mortality (33% vs 12.3%, P = 0.01). No differences in local, structural, and/or functional complications (cardiac abscess formation, impaired integrity of the valvular apparatus, conduction disturbances, or incidence of heart failure) were observed between studied groups. Long-term survival estimates were significantly improved in patients with IE caused by agents other than S. aureus (13.78 median years vs 5.48 median years, P=0.03).

CONCLUSIONS

IE episodes caused by S. aureus are associated with both increased short-term and long-term mortality. Of all the studied parameters, only systemic embolism and severe sepsis/septic shock predicted in-hospital mortality.

Managing infective endocarditis in the elderly: new issues for an old disease

The incidence of infective endocarditis (IE) rises in industrialized countries. Older people are more affected by this severe disease, notably because of the increasing number of invasive procedures and intracardiac devices implanted in these patients. Peculiar clinical and echocardiographic features, microorganisms involved, and prognosis of IE in elderly have been underlined in several studies. Additionally, elderly population appears quite heterogeneous, from healthy people without past medical history to patients with multiple diseases or who are even bedridden. However, the management of IE in this population has been poorly explored, and international guidelines do not recommend adapting the therapeutic strategy to the patient's functional status and comorbidities. Yet, if IE should be treated according to current recommendations in the healthiest patients, concerns may rise for older patients who suffer from several chronic diseases, especially renal failure, and are on polypharmacy. Treating frailest patients with high-dose intravenous antibiotics during a prolonged hospital stay as recommended for younger patients could also expose them to functional decline and toxic effect. Likewise, the place of surgery according to the aging characteristics of each patient is unclear. The aim of this article is to review the recent data on epidemiology of IE and its peculiarities in the elderly. Then, its management and various therapeutic approaches that can be considered according to and beyond guidelines depending on patient comorbidities and frailty are discussed.

Infective endocarditis in patients with hepatic diseases

Few data have been published regarding the epidemiology and outcome of infective endocarditis (IE) in patients with chronic hepatic disease (CHD). A retrospective analysis of the Studio Endocarditi Italiano (SEI) database was performed to evaluate the epidemiology and outcome of CHD+ patients compared with CHD- patients. The diagnosis of IE was defined in accordance with the modified Duke criteria. Echocardiography, diagnosis, and treatment procedures were in accordance with current clinical practice. Among the 1722 observed episodes of IE, 300 (17.4 %) occurred in CHD+ patients. The cause of CHD mainly consisted of chronic viral infection. Staphylococcus aureus was the most common bacterial species in CHD+ patients; the frequency of other bacterial species (S. epidermidis, streptococci, and enterococci) were comparable among the two groups. The percentage of patients undergoing surgery for IE was 38.9 in CHD+ patients versus 43.7 in CHD- patients (p = 0.06). Complications were more common among CHD+ patients (77 % versus 65.3 %, p < 0.001); embolization (43.3 % versus 26.1 %, p < 0.001) and congestive heart failure (42 % versus 34.1 %, p = 0.01) were more frequent among CHD+ patients. Mortality was comparable (12.5 % in CHD- and 15 % in CHD+ patients). At multivariable analysis, factors associated with hospital-associated mortality were having an infection sustained by S. aureus, a prosthetic valve, diabetes and a neoplasia, and CHD. Being an intravenous drug user (IVDU) was a protective factor and was associated with a reduced death risk. CHD is a factor worsening the prognosis in patients with IE, in particular in patients for whom cardiac surgery was required.

Cardiac surgery during the acute phase of infective endocarditis: discrepancies between European Society of Cardiology guidelines and practices

AIMS

Indications for surgery in acute infective endocarditis (IE) are detailed in guidelines, but their application is not well known. We analysed the agreement between the patient's attending physicians and European Society of Cardiology guidelines regarding indications for surgery. We also assessed whether surgery was performed in patients who had an indication.

METHODS AND RESULTS

From the 2008 prospective population-based French survey on IE, 303 patients with definite left-sided native IE were identified. For each case, we prospectively recorded (i) indication for surgery according to the attending physicians and (ii) indication for surgery according to guidelines. Surgery was indicated in 194 (65%) patients according to attending physicians and in 221 (73%) according to guidelines, while 139 (46%) underwent surgery. Agreement was moderate between attending physicians and guidelines (kappa 0.41-0.59) and between indication according to guidelines and the performance of surgery (kappa 0.38). Of the 90 (30%) patients not operated despite indication, contraindication to surgery was reported by the attending physicians in 42 (47%), and indication was not identified in 48 (53%). One-year survival was 76% in patients with indication and surgery performed (n = 131), 69% in patients without indication and no surgery (n = 74), 56% in patients with identified indication and contraindication to surgery (n = 42), and 60% in patients with no identified indication (n = 48; P = 0.059).

CONCLUSION

Cardiac surgery during acute IE was recommended in almost three out of four patients, although fewer than half were actually operated. Indication was not acknowledged by the attending physicians in one out of six patients.

Diagnosis of blood culture-negative endocarditis and clinical comparison between blood culture-negative and blood culture-positive cases

PURPOSE

To analyze the clinical characteristics of blood culture-negative endocarditis (BCNE) and how it compares to those of blood culture-positive endocarditis (BCPE) cases and show how molecular tools helped establish the etiology in BCNE.

METHODS

Adult patients with definite infective endocarditis (IE) and having valve surgery were included. Valves were studied by polymerase chain reaction (PCR). Statistical analysis compared BCNE and BCPE.

RESULTS

One hundred and thirty-one patients were included; 53 (40 %) had BCNE. The mean age was 45 ± 16 years; 33 (62 %) were male. BCNE was community-acquired in 41 (79 %). Most patients were referred from other hospitals (38, 73 %). Presentation was subacute in 34 (65 %), with fever in 47/53 (90 %) and a new regurgitant murmur in 34/42 (81 %). Native valves were affected in 74 %, mostly left-sided. All echocardiograms showed major criteria for IE. Antibiotics were used prior to BC collection in 31/42 (74 %). Definite histological diagnosis was established for 35/50 (70 %) valves. PCR showed oralis group streptococci in 21 (54 %), S. aureus in 3 (7.7 %), gallolyticus group streptococci in 2 (5.1 %), Coxiella burnetii in 1 (2.5 %) and Rhizobium sp. in 1 (2.5 %). In-hospital mortality was 9/53 (17 %). Fever (p = 0.06, OR 4.7, CI 0.91-24.38) and embolic complications (p = 0.003, OR 3.3, CI 1.55-6.82) were more frequent in BCPE cases, while new acute regurgitation (p = 0.05, OR 0.3, CI 0.098-0.996) and heart failure (p = 0.02, OR 0.3, CI 0.13-0.79) were less so.

CONCLUSIONS

BCNE resulted mostly from prior antibiotics and was associated with severe hemodynamic compromise. Valve histopathology and PCR were useful in confirming the diagnosis and pointing to the etiology of BCNE.

Coordinated Molecular Cross-Talk between Staphylococcus aureus, Endothelial Cells and Platelets in Bloodstream Infection

Staphylococcus aureus is an opportunistic pathogen often carried asymptomatically on the human body. Upon entry to the otherwise sterile environment of the cardiovascular system, S. aureus can lead to serious complications resulting in organ failure and death. The success of S. aureus as a pathogen in the bloodstream is due to its ability to express a wide array of cell wall proteins on its surface that recognise host receptors, extracellular matrix proteins and plasma proteins. Endothelial cells and platelets are important cells in the cardiovascular system and are a major target of bloodstream infection. Endothelial cells form the inner lining of a blood vessel and provide an antithrombotic barrier between the vessel wall and blood. Platelets on the other hand travel throughout the cardiovascular system and respond by aggregating around the site of injury and initiating clot formation. Activation of either of these cells leads to functional dysregulation in the cardiovascular system. In this review, we will illustrate how S. aureus establish intimate interactions with both endothelial cells and platelets leading to cardiovascular dysregulation.

Infective endocarditis requiring ICU admission: epidemiology and prognosis

Background

Very few studies focused on patients with severe infective endocarditis (IE) and multiple complications leading to Intensive Care Unit (ICU) admission. Studied primary outcomes depended on the series and multiple prognostic factors have been identified. Our goal was to determinate characteristics of patients, in-hospital mortality and independent prognostic factors in an overall population of patients admitted to ICU for a left-sided, definite, active and severe IE.

Methods

Retrospective study performed in 9 ICUs during an 11-year period.

Results

Data of 248 patients (mean age = 62.4 ± 13.3 years; 63.7 % male) were studied. Native and prosthetic valves were involved in 195 and 53 patients, respectively. Causative pathogens, identified in 225 patients, were mainly streptococci (45.6 %) and staphylococci (43.4 %). On ICU admission, 127 patients exhibited extra-cardiac involvement. Ninety-five patients had one or more neurological complications, as followed: ischemic stroke (n = 66), cerebral hemorrhage (n = 31), meningitis (n = 16), brain abscess (n = 16), and intracranial mycotic aneurysm (n = 10). Criteria prompting to cardiac surgery appeared during ICU stay for 186 patients and between ICU and hospital discharges in 5 patients. Due to contra-indications, surgery required by IE was only performed during hospitalization in 125 patients. Moreover, surgery was considered adequate according to usual guidelines in 76 of 191 patients with indication(s) of valvular surgery: for patients with surgical procedure considered as emergency (n = 69), 17 surgical procedures underwent within the first 24 h following indication; for patients with urgent surgical indication (n = 102), surgery was performed during the first week following indication in 40 patients; finally, elective surgery (n = 20) was performed for 19 patients. During hospitalization, 103 (41.5 %) patients died. Four independent prognostic factors were identified: SAPS II > 35 (AOR = 2.604; 95 % CI: 1.320–5.136; p = 0.0058), SOFA > 8 (AOR = 3.327; 95 % CI: 1.697–6.521; p = 0.0005), IE due to methicillin resistant Staphylococcus aureus (AOR = 4.981; 95 %CI = 1.433–17.306; p = 0.0115) and native IE (AOR = 0.345; 95 % CI: 0.169–0.703; p = 0.0034).

Conclusions

Mortality in patients admitted to ICU for left-sided IE remains high, especially in cases of endocarditis due to methicillin resistant Staphylococcus aureus, when organ failures occur and ICU scores are high.

Current controversies in infective endocarditis

Infective endocarditis is a life-threatening disease caused by a focus of infection within the heart. For clinicians and scientists, it has been a moving target that has an evolving microbiology and a changing patient demographic. In the absence of an extensive evidence base to guide clinical practice, controversies abound. Here, we review three main areas of uncertainty: first, in prevention of infective endocarditis, including the role of antibiotic prophylaxis and strategies to reduce health care-associated bacteraemia; second, in diagnosis, specifically the use of multimodality imaging; third, we discuss the optimal timing of surgical intervention and the challenges posed by increasing rates of cardiac device infection.

Nonredundant Roles of Interleukin-17A (IL-17A) and IL-22 in Murine Host Defense against Cutaneous and Hematogenous Infection Due to Methicillin-Resistant Staphylococcus aureus

Staphylococcus aureus is the leading cause of skin and skin structure infections (SSSI) in humans. Moreover, the high frequency of recurring SSSI due to S. aureus, particularly methicillin-resistant S. aureus (MRSA) strains, suggests that infection induces suboptimal anamnestic defenses. The present study addresses the hypothesis that interleukin-17A (IL-17A) and IL-22 play distinct roles in immunity to cutaneous and invasive MRSA infection in a mouse model of SSSI. Mice were treated with specific neutralizing antibodies against IL-17A and/or IL-22 and infected with MRSA, after which the severity of infection and host immune response were determined. Neutralization of either IL-17A or IL-22 reduced T cell and neutrophil infiltration and host defense peptide elaboration in lesions. These events corresponded with increased abscess severity, MRSA viability, and CFU density in skin. Interestingly, combined inhibition of IL-17A and IL-22 did not worsen abscesses but did increase gamma interferon (IFN-γ) expression at these sites. The inhibition of IL-22 led to a reduction in IL-17A expression, but not vice versa. These results suggest that the expression of IL-17A is at least partially dependent on IL-22 in this model. Inhibition of IL-17A but not IL-22 led to hematogenous dissemination to kidneys, which correlated with decreased T cell infiltration in renal tissue. Collectively, these findings indicate that IL-17A and IL-22 have complementary but nonredundant roles in host defense against cutaneous versus hematogenous infection. These insights may support targeted immune enhancement or other novel approaches to address the challenge of MRSA infection.

Temporal trends in infective endocarditis epidemiology from 2007 to 2013 in Olmsted County, MN

BACKGROUND

The aim of this study is to determine if there have been contemporary shifts in infective endocarditis (IE) epidemiology in our local population; an analysis of cases from 2007 to 2013 was conducted.

METHODS

This is a population-based review of all adults (≥18 years) residing in Olmsted County, MN, with definite or possible IE using the Rochester Epidemiology Project from January 1, 2007, to December 31, 2013.

RESULTS

We identified 51 cases of IE in Olmsted County, MN, between 2007 and 2013. Median age of IE cases was 68.8 years (interquartile range 55.6-76.5), and 41% were females. Age- and sex-adjusted incidence of IE was 7.4 (95% CI 5.3-9.4) cases per 100,000 person-years. From a multivariable Poisson regression model, incidence of IE did not change significantly during the study period (P = .222) but was significantly higher in males and those of older age (P < .001). The annual incidences (per 100,000 person-years) were 2.5 for Staphylococcus aureus, 1.1 for viridans group streptococci, 1.6 for Enterococcus species, and 0.8 for coagulase-negative staphylococci. Only 19.6% (10/51) of Olmsted County patients underwent valve surgery between 2007 and 2013 as compared with 44.4% (197/444) of non-Olmsted County patients treated at Mayo Clinic Rochester.

CONCLUSION

In this population-based study, no significant change in the overall incidence of IE in Olmsted County, MN, between 2007 and 2013 was seen, and it was similar to that seen between 1970 and 2006. Male gender and older age were associated with increased IE risk. With a lesser extent of cases attributable to viridans group streptococcal IE compared with previous years, S aureus was the predominant pathogen in IE cases during 2007 to 2013. The relatively low valve surgery rate was disparate from that reported from large, tertiary care centers (including our own) with non-population-based cohorts, which are subject to referral bias and can influence the expected characterization of IE.

Syncope secondary to left ventricular outflow tract obstruction, an interesting presentation of infective endocarditis

We describe a case of a 74-year-old woman who presented with symptoms of fever and lethargy, associated with an episode of cardiac syncope and exertional shortness of breath (SOB). She was diagnosed with Staphylococcus aureus infective mural endocarditis (IE) and subsequent transoesophageal echocardiogram (TOE) confirmed this diagnosis. As the vegetative mass arose from the septal wall, an unusual location, it caused left ventricular outflow tract (LVOT) obstruction and therefore behaved similarly to a subaortic valvular stenosis. There were no conduction abnormalities on the ECG and no clinical or echocardiographic features of congestive heart failure. The finding of LVOT obstruction explained the unusual presentation with syncope and exertional SOB making this case unique. Owing to the large vegetative mass and thereby its high risk of septic emboli, the patient underwent successful surgical resection of the mass with resolution of the obstruction. She successfully completed intravenous antibiotics and was discharged from hospital.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association

BACKGROUND

Infective endocarditis is a potentially lethal disease that has undergone major changes in both host and pathogen. The epidemiology of infective endocarditis has become more complex with today's myriad healthcare-associated factors that predispose to infection. Moreover, changes in pathogen prevalence, in particular a more common staphylococcal origin, have affected outcomes, which have not improved despite medical and surgical advances.

METHODS AND RESULTS

This statement updates the 2005 iteration, both of which were developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It includes an evidence-based system for diagnostic and treatment recommendations used by the American College of Cardiology and the American Heart Association for treatment recommendations.

CONCLUSIONS

Infective endocarditis is a complex disease, and patients with this disease generally require management by a team of physicians and allied health providers with a variety of areas of expertise. The recommendations provided in this document are intended to assist in the management of this uncommon but potentially deadly infection. The clinical variability and complexity in infective endocarditis, however, dictate that these recommendations be used to support and not supplant decisions in individual patient management.

Invasive streptococcal disease: a review for clinicians

INTRODUCTION

Streptococci are a genus of Gram-positive bacteria which cause diverse human diseases. Many of these species have the potential to cause invasive infection resulting from the presence of bacteria in a normally sterile site.

SOURCES OF DATA

Original articles, reviews and guidelines.

AREAS OF AGREEMENT

Invasive infection by a streptococcus species usually causes life-threatening illness. When measured in terms of deaths, disability and cost, these infections remain an important threat to health in the UK. Overall they are becoming more frequent among the elderly and those with underlying chronic illness. New observational evidence has become available to support the use of clindamycin and intravenous immunoglobulin in invasive Group A streptococcal disease.

AREAS OF CONTROVERSY

Few interventions for the treatment and prevention of these infections have undergone rigorous evaluation in clinical trials. For example, the role of preventative strategies such as screening of pregnant women to prevent neonatal invasive Group B streptococcal disease needs to be clarified.

FUTURE PROSPECTS

Studies of invasive streptococcal disease are challenging to undertake, not least because individual hospitals treat relatively few confirmed cases. Instead clinicians and scientists must work together to build national and international networks with the aim of developing a more complete evidence base for the treatment and prevention of these devastating infections.

Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake

Infective endocarditis (IE)((1)) is a severe condition complicating 10-25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features. S. aureus isolates causing community-acquired, definite native-valve IE (n=72) and bacteremia (n=54) were collected prospectively as part of a French multicenter cohort. Phenotypic traits previously reported or hypothesized to be involved in staphylococcal IE pathogenesis were tested. In parallel, the genotypic profiles of all isolates, obtained by microarray, were analyzed by discriminant analysis of principal components (DAPC)((2)). No significant difference was observed between IE and bacteremia strains, regarding either phenotypic or genotypic univariate analyses. However, the multivariate statistical tool DAPC, applied on microarray data, segregated IE and bacteremia isolates: IE isolates were correctly reassigned as such in 80.6% of the cases (C-statistic 0.83, P<0.001). The performance of this model was confirmed with an independent French collection IE and bacteremia isolates (78.8% reassignment, C-statistic 0.65, P<0.01). Finally, a simple linear discriminant function based on a subset of 8 genetic markers retained valuable performance both in study collection (86.1%, P<0.001) and in the independent validation collection (81.8%, P<0.01). We here show that community-acquired IE and bacteremia S. aureus isolates are genetically distinct based on subtle combinations of genetic markers. This finding provides the proof of concept that bacterial characteristics may contribute to the occurrence of IE in patients with S. aureus bacteremia.

Endocarditis due to gram-negative bacilli at a French teaching hospital over a 6-year period: clinical characteristics and outcome

BACKGROUND

Infective endocarditis (IE) due to gram-negative bacilli (GNB) is rare. However, several studies described a change in the epidemiological profile of patients within the past few years.

METHODS

We reviewed all cases diagnosed and followed in the infectious diseases ward of a French teaching hospital in Paris between 2009 and 2014, inclusive.

RESULTS

Among the 17 patients with definite GNB-IE (11 male, mean age 54 years), 12 (70%) were due to non-HACEK GNB and 5 (30%) to HACEK group GNB. A prosthetic valve was involved in 10 cases (8 in non-HACEK and 2 in HACEK group). Escherichia coli (4/12 patients) and Pseudomonas aeruginosa (3/12 patients) were the most common pathogens in the first group; all the pathogens in the second group were Haemophilus spp. One-third of the patients with non-HACEK GNB had nosocomial IE, whereas injection drug use-related infections were rare (2/12). All patients with HACEK infection had at least one complication (intracardiac abscess, stroke or other systemic embolization). All patients were treated by antibiotic combination therapy during a median time of 42 days (interquartile range (IQR) = 42-42) and 10 (59%) underwent cardiac surgery. One death at 9 months was observed in the non-HACEK group.

CONCLUSIONS

Regarding HACEK IE, this report supports the frequent association with vascular complications. Regarding non-HACEK GNB IE, this report supports the increasing proportion of nosocomial infections. We reported a high proportion of surgery in the therapeutic management of both HACEK and non-HACEK groups associated with no in-hospital mortality.

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.

Global and regional burden of infective endocarditis, 1990-2010: a systematic review of the literature

Infective endocarditis (IE) is a life-threatening disease associated with serious complications. The GBD 2010 (Global Burden of Disease, Injuries, and Risk Factors) study IE expert group conducted a systematic review of IE epidemiology literature to inform estimates of the burden on IE in 21 world regions in 1990 and 2010. The disease model of IE for the GBD 2010 study included IE death and 2 sequelae: stroke and valve surgery. Several medical and science databases were searched for IE epidemiology studies in GBD high-, low-, and middle-income regions published between 1980 and 2008. The epidemiologic parameters of interest were IE incidence, proportions of IE patients who developed stroke or underwent valve surgery, and case fatality. Literature searches yielded 1,975 unique papers, of which 115 published in 10 languages were included in the systematic review. Eligible studies were population-based (17%), multicenter hospital-based (11%), and single-center hospital-based studies (71%). Population-based studies were reported from only 6 world regions. Data were missing or sparse in many low- and middle-income regions. The crude incidence of IE ranged between 1.5 and 11.6 cases per 100,000 people and was reported from 10 countries. The overall mean proportion of IE patients that developed stroke was 0.158 ± 0.091, and the mean proportion of patients that underwent valve surgery was 0.324 ± 0.188. The mean case fatality risk was 0.211 ± 0.104. A systematic review for the GBD 2010 study provided IE epidemiology estimates for many world regions, but highlighted the lack of information about IE in low- and middle-income regions. More complete knowledge of the global burden of IE will require improved IE surveillance in all world regions.

Daptomycin for the Treatment of Infective Endocarditis: Results from European Cubicin(®) Outcomes Registry and Experience (EU-CORE)

INTRODUCTION

The European Cubicin(®) Outcomes Registry and Experience (EU-CORE(SM)) was a retrospective, non-interventional, multicenter study which evaluated the safety and effectiveness of daptomycin therapy in patients with Gram-positive infections including infective endocarditis (IE).

METHODS

Data from the EU-CORE registry were collected for patients with IE who had received at least one dose of daptomycin between January 2006 and April 2012, across 18 countries in Europe (12), Latin America (5) and Asia (1). Clinical outcomes were assessed as success (cured or improved), failure or non-evaluable. Adverse events (AEs) were recorded during treatment and for up to 30 days post-treatment; follow-up data were collected for 2 years.

RESULTS

Of 6075 patients included in the EU-CORE registry, 610 were diagnosed with IE as primary infection; 149 (24.4%) right-sided IE (RIE), 414 (67.9%) left-sided IE (LIE), and 47 (7.7%) with both right- and left-sided IE (BRLIE). Overall clinical success was achieved in 80.0% of patients (RIE 88.6%, LIE 76.6% and BRLIE 82.9%). Success rates for methicillin-resistant Staphylococcus aureus (MRSA) infections were 90.9%, 71.7% and 66.6% in patients with RIE, LIE and BRLIE, respectively. The overall sustained clinical success rate in patients followed for up to 2 years was 86.7% (RIE 93.5%, LIE 88.3% and BRLIE 77.8%). AEs deemed possibly related to daptomycin in the investigator's opinion were reported in 2 (1.3%) RIE, 18 (4.3%) LIE and 1 (2.1%) BRLIE patients. There were 11 (1.8%) patients (2 with RIE, 8 with LIE and 1 with BRLIE) with AEs of creatine phosphokinase elevation reported as possibly related to daptomycin.

CONCLUSION

Data from this real-world clinical setting showed that daptomycin was well tolerated and effective for the treatment of LIE and BRLIE in addition to RIE caused by Gram-positive bacteria, including MRSA. Two-year follow-up data showed that a high proportion of patients had a sustained response.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Significant publications on infectious diseases pharmacotherapy in 2013

PURPOSE

The most important articles on infectious diseases (ID) pharmacotherapy published in the peer-reviewed literature in 2013, as nominated and selected by panels of pharmacists and others with ID expertise, are summarized.

SUMMARY

Members of the Houston Infectious Diseases Network were asked to nominate articles published last year in prominent biomedical journals that had a major impact in the field of ID pharmacotherapy. A list of 27 nominated articles on ID-related topics in general and 26 articles specifically focused on human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) was compiled. In a national online survey conducted in January 2014, members of the Society of Infectious Diseases Pharmacists (SIDP) were asked to select from the list those articles that they felt had made the greatest contributions to the field of ID pharmacotherapy. Of 168 SIDP members surveyed, 108 (64%) and 53 (32%) participated in the selection of ID- and HIV/AIDS-related articles, respectively. Summaries of the top-ranked articles in both categories are presented.

CONCLUSION

Major topics explored in the top-ranked ID articles of 2013 include the use of cefepime for gram-negative infections due to AmpC or extended-spectrum β-lactamase-producing Enterobacteriaceae, optimizing antibiotic therapy through the use of extended- or continuous-infusion regimens, the use of the oral integrase inhibitor dolutegravir to combat HIV disease, and new approaches to treatment of Clostridium difficile infection and enterococcal endocarditis.

Staphylococcus aureus Bloodstream Infection and Endocarditis--A Prospective Cohort Study

OBJECTIVES

To update the epidemiology of S. aureus bloodstream infection (SAB) in a high-income country and its link with infective endocarditis (IE).

METHODS

All consecutive adult patients with incident SAB (n = 2008) were prospectively enrolled between 2009 and 2011 in 8 university hospitals in France.

RESULTS

SAB was nosocomial in 54%, non-nosocomial healthcare related in 18% and community-acquired in 26%. Methicillin resistance was present in 19% of isolates. SAB Incidence of nosocomial SAB was 0.159/1000 patients-days of hospitalization (95% confidence interval [CI] 0.111-0.219). A deep focus of infection was detected in 37%, the two most frequent were IE (11%) and pneumonia (8%). The higher rates of IE were observed in injecting drug users (IE: 38%) and patients with prosthetic (IE: 33%) or native valve disease (IE: 20%) but 40% of IE occurred in patients without heart disease nor injecting drug use. IE was more frequent in case of community-acquired (IE: 21%, adjusted odds-ratio (aOR) = 2.9, CI = 2.0-4.3) or non-nosocomial healthcare-related SAB (IE: 12%, aOR = 2.3, CI = 1.4-3.5). S. aureus meningitis (IE: 59%), persistent bacteremia at 48 hours (IE: 25%) and C-reactive protein > 190 mg/L (IE: 15%) were also independently associated with IE. Criteria for severe sepsis or septic shock were met in 30% of SAB without IE (overall in hospital mortality rate 24%) and in 51% of IE (overall in hospital mortality rate 35%).

CONCLUSION

SAB is still a severe disease, mostly related to healthcare in a high-income country. IE is the most frequent complication and occurs frequently in patients without known predisposing conditions.

Infective endocarditis in the Pacific: clinical characteristics, treatment and long-term outcomes

Introduction

Data on clinical characteristics and outcomes of infective endocarditis (IE) in the Pacific are scarce.

Methods

Retrospective hospital-based study in New Caledonia, a high-income country, on patients aged over 18 years with definite IE according to the modified Duke criteria (2005–2010).

Results

51 patients were included: 31 (60.8%) men; median age of 52.4 years (IQR 33.0–70.0). Left-sided IE accounted for 47 (92.2%) patients: native valve IE in 34 (66.7%) and prosthetic valve IE in 13 (25.5%). The main underlying heart disease included: rheumatic valve disease in 19 (37.3%), degenerative heart valve disease in 12 (23.5%) and congenital heart disease in 6 (11.8%). Significant comorbidities (Charlson's score >3) were observed in 20 (38.7%) patients. Infection was community acquired in 43 (84.3%) patients. Leading pathogens included Staphylococcus aureus in 16 (31.4%) and Streptococcus spp in 15 (29.4%) patients. Complications were noted in 33 patients (64.7%) and 24 (47.1%) were admitted to the intensive care unit. Cardiac surgery was eventually performed in 22 of 40 (55.0%) patients with a theoretical indication. None underwent emergent cardiac surgery (ie, first 24 h); 2 (3.9%) were operated within 7 days; and 20 (39.2%) beyond 7 days. 11 (21.6%) patients died in hospital and 21 (42.9%) were dead after a median follow-up of 28.8 months (IQR 4.6–51.2). Two (3.9%) were lost to follow-up.

Conclusions

In New Caledonia, IE afflicts relatively young patients with rheumatic heart disease, and carries high complication and mortality rates. Access to heart surgery remains relatively limited in this remote archipelago.

Incidence and outcome of Staphylococcus aureus endocarditis--a 10-year single-centre northern European experience

Staphylococcus aureus is a leading cause of infective endocarditis. Little has been published on the outcome and epidemiology of S. aureus endocarditis (SAE) in the twenty-first century. Our aim was to evaluate the short-term and long-term outcome of SAE in Stockholm, Sweden, and assess its incidence over time. Patients treated for SAE from January 2004 through December 2013 were retrospectively identified at the Karolinska University Hospital. Clinical data were obtained from medical records and the diagnosis was verified according to the modified Duke criteria. Of 245 SAE cases, 152 (62%) were left-sided and 120 (49%) occurred in intravenous drug users. The calculated incidence in Stockholm County was 1.56/100 000 person-years, increasing from 1.28 in 2004-08 to 1.82/100 000 person-years in 2009-13 (p 0.002). In-hospital and 1-year mortality rates were 9.0% (22/245) and 19.5% (46/236), respectively. Age (OR 1.06 per year) and female sex (OR 3.0) were independently associated with in-hospital mortality in multivariate analysis. Involvement of the central nervous system (CNS) was observed in 30 (12%) patients, and valvular surgery was performed during hospitalization in 37 (15%). In left-sided endocarditis the strongest predictors for surgery were severe valvular insufficiency (OR 8.9), lower age (OR 1.07 per year) and no intravenous drug use (OR 10.7), and for CNS involvement lower age (OR 1.04 per year). In conclusion we noted low mortality, low CNS complication rate, and low valvular surgery frequency associated with SAE in our setting. The incidence was high and increased over time. The study provides an update on the outcome and epidemiology of SAE in the twenty-first century.

Clinical epidemiology in Italian Registry of Infective Endocarditis (RIEI): Focus on age, intravascular devices and enterococci

INTRODUCTION

The epidemiology of infective endocarditis (IE) is changing due to a number of factors, including aging and health related comorbidities and medical procedures. The aim of this study is to describe the main clinical, epidemiologic and etiologic changes of IE from a large database in Italy.

METHODS

We prospectively collected episodes of IE in 17 Italian centers from July 2007 to December 2010.

RESULTS

We enrolled 677 patients with definite IE, of which 24% health-care associated. Patients were male (73%) with a median age of 62 years (IQR: 49-74) and 61% had several comorbidities. One hundred and twenty-eight (19%) patients had prosthetic left side IE, 391 (58%) native left side IE, 94 (14%) device-related IE and 54 (8%) right side IE. A predisposing cardiopathy was present in 50%, while odontoiatric and non odontoiatric procedures were reported in 5% and 21% of patients respectively. Symptoms were usually atypical and precocious. The prevalent etiology was represented by Staphylococcus aureus (27%) followed by coagulase-negative staphylococci (CNS, 21%), Streptococcus viridans (15%) and enterococci (14%). CNS and enterococci were relatively more frequent in patients with intravascular devices and prosthesis and S. viridans in left native valve. Diagnosis was made by transthoracic and transesophageal echocardiography in 62% and 94% of cases, respectively. The in-hospital mortality was 14% and 1-year mortality was 21%.

CONCLUSION

The epidemiology is changing in Italy, where IE more often affects older patients with comorbidities and intravascular devices, with an acute onset and including a high frequency of enterococci. There were few preceding odontoiatric procedures.

Nontuberculous Mycobacteria: An Underestimated Cause of Bioprosthetic Valve Infective Endocarditis

From 2010 to 2013, 5 cases of nontuberculous mycobacteria infective endocarditis (IE), exclusively from bioprosthesis, were diagnosed in three hospitals out of 370 blood culture-negative-suspected IE. The porcine origin of this underestimated etiology is questioned.

Background. Atypical mycobacteria, or nontuberculous mycobacteria (NTM), have been barely reported as infective endocarditis (IE) agents.

Methods. From January 2010 to December 2013, cardiac valve samples sent to our laboratory as cases of blood culture-negative suspected IE were analyzed by 16S rDNA polymerase chain reaction (PCR). When positive for NTM, hsp PCR allowed species identification. Demographic, clinical, echocardiographic, histopathological, and Ziehl-Neelsen staining data were then collected.

Results. Over the study period, 6 of 370 cardiac valves (belonging to 5 patients in 3 hospitals) were positive for Mycobacterium chelonae (n = 5) and Mycobacterium lentiflavum (n = 1) exclusively on bioprosthetic material. The 5 patients presented to the hospital for heart failure without fever 7.1–18.9 months (median 13.1 months) after biological prosthetic valve implantation. Echocardiography revealed paravalvular regurgitation due to prosthesis dehiscence in all patients. Histopathological examination of the explanted material revealed inflammatory infiltrates in all specimens, 3 of which were associated with giant cells. Gram staining and conventional cultures remained negative, whereas Ziehl-Neelsen staining showed acid-fast bacilli in all patients. Allergic etiology was ruled out by antiporcine immunoglobulin E dosages. These 5 cases occurred exclusively on porcine bioprosthetic material, revealing a statistically significant association between bioprosthetic valves and NTM IE (P < .001).

Conclusions. The body of evidence confirmed the diagnosis of prosthetic IE. The statistically significant association between bioprosthetic valves and NTM IE encourages systematic Ziehl-Neelsen staining of explanted bioprosthetic valves in case of early bioprosthesis dysfunction, even without an obvious sign of IE. In addition, we strongly question the cardiac bioprosthesis conditioning process after animal sacrifice.

Healthcare-associated infective endocarditis of the pulmonary valve

We report a case of a 66-year-old man with known ischaemic heart disease, diabetes mellitus and stage 4 kidney disease who was admitted to our tertiary centre with shortness of breath and atrial flutter. Transoesophageal echocardiography (TOE) was without suspicion of endocarditis. During hospitalisation, the patient suffered a nosocomial infection in a peripheral vascular catheter caused by Staphylococcus aureus. TOE after positive blood cultures revealed a new vegetation on the pulmonary valve that resolved after antibiotic treatment.

Clinical features, microbiology and surgical outcomes of infective endocarditis: a 13-year study from a UK tertiary cardiothoracic referral centre

BACKGROUND

Infective endocarditis (IE) causes substantial morbidity and mortality. Patient and pathogen profiles, as well as microbiological and operative strategies, continue to evolve. The impact of these changes requires evaluation to inform optimum management and identify individuals at high risk of early mortality.

AIM

Identification of clinical and microbiological features, and surgical outcomes, among patients presenting to a UK tertiary cardiothoracic centre for surgical management of IE between 1998 and 2010.

DESIGN

Retrospective observational cohort study.

METHODS

Clinical, biochemical, microbiological and echocardiographic data were identified from clinical records. Principal outcomes were all-cause 28-day mortality and duration of post-operative admission.

RESULTS

Patients (n = 336) were predominantly male (75.0%); median age 52 years (IQR = 41-67). Most cases involved the aortic (56.0%) or mitral (53.9%) valves. Microbiological diagnoses, obtained in 288 (85.7%) patients, included streptococci (45.2%); staphylococci (34.5%); Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella (HACEK) organisms (3.0%); and fungi (1.8%); 11.3% had polymicrobial infection. Valve replacement in 308 (91.7%) patients included mechanical prostheses (69.8%), xenografts (24.0%) and homografts (6.2%). Early mortality was 12.2%, but fell progressively during the study (P = 0.02), as did median duration of post-operative admission (33.5 to 10.5 days; P = 0.0003). Multivariable analysis showed previous cardiothoracic surgery (OR = 3.85, P = 0.03), neutrophil count (OR = 2.27, P = 0.05), albumin (OR = 0.94, P = 0.04) and urea (OR = 2.63, P < 0.001) predicted early mortality.

CONCLUSIONS

This study demonstrates reduced post-operative early mortality and duration of hospital admission for IE patients over the past 13 years. Biomarkers (previous cardiothoracic surgery, neutrophil count, albumin and urea), predictive of early post-operative mortality, require prospective evaluation to refine algorithms, further improve outcomes and reduce healthcare costs associated with IE.

Prospective comparison of infective endocarditis in Khon Kaen, Thailand and Rennes, France

Prospectively collected, contemporary data are lacking on how the features of infective endocarditis (IE) vary according to region. We, therefore, compared IE in Rennes, France and Khon Kaen, Thailand. Fifty-eight patients with confirmed IE were enrolled at each site during 2011 and 2012 using a common protocol. Compared with French patients, Thais had a lower median age (47 versus 70 years old; P < 0.001) and reported more animal contact (86% versus 21%; P < 0.001). There were more zoonotic infections among Thai than France patients (6 and 1 cases; P = 0.017) and fewer staphylococcal infections (4 versus 15 cases; P = 0.011). Underlying rheumatic heart disease was more prevalent in Thai than in French patients (31% and 4%; P = 0.001), whereas prosthetic heart valves were less prevalent (9% and 35%; P = 0.001). Our data strengthen previous observations that IE in the tropics has distinctive demographic characteristics, risk factors, and etiologies and underscore the need for improved prevention and control strategies.

Association Between Surgical Indications, Operative Risk, and Clinical Outcome in Infective Endocarditis

Background—

Use of surgery for the treatment of infective endocarditis (IE) as related to surgical indications and operative risk for mortality has not been well defined.

Methods and Results—

The International Collaboration on Endocarditis–PLUS (ICE-PLUS) is a prospective cohort of consecutively enrolled patients with definite IE from 29 centers in 16 countries. We included patients from ICE-PLUS with definite left-sided, non–cardiac device–related IE who were enrolled between September 1, 2008, and December 31, 2012. A total of 1296 patients with left-sided IE were included. Surgical treatment was performed in 57% of the overall cohort and in 76% of patients with a surgical indication. Reasons for nonsurgical treatment included poor prognosis (33.7%), hemodynamic instability (19.8%), death before surgery (23.3%), stroke (22.7%), and sepsis (21%). Among patients with a surgical indication, surgical treatment was independently associated with the presence of severe aortic regurgitation, abscess, embolization before surgical treatment, and transfer from an outside hospital. Variables associated with nonsurgical treatment were a history of moderate/severe liver disease, stroke before surgical decision, and Staphyloccus aureus etiology. The integration of surgical indication, Society of Thoracic Surgeons IE score, and use of surgery was associated with 6-month survival in IE.

Conclusions—

Surgical decision making in IE is largely consistent with established guidelines, although nearly one quarter of patients with surgical indications do not undergo surgery. Operative risk assessment by Society of Thoracic Surgeons IE score provides prognostic information for survival beyond the operative period. S aureus IE was significantly associated with nonsurgical management.

Bacteremia, Sepsis, and Infective Endocarditis Associated with Staphylococcus aureus

Bacteremia and infective endocarditis (IE) are important causes of morbidity and mortality associated with Staphylococcus aureus infections. Increasing exposure to healthcare, invasive procedures, and prosthetic implants has been associated with a rising incidence of S. aureus bacteremia (SAB) and IE since the late twentieth century. S. aureus is now the most common cause of bacteremia and IE in industrialized nations worldwide and is associated with excess mortality when compared to other pathogens. Central tenets of management include identification of complicated bacteremia, eradicating foci of infection, and, for many, prolonged antimicrobial therapy. Evolving multidrug resistance and limited therapeutic options highlight the many unanswered clinical questions and urgent need for further high-quality clinical research.

Mechanisms of NDV-3 vaccine efficacy in MRSA skin versus invasive infection

Increasing rates of life-threatening infections and decreasing susceptibility to antibiotics urge development of an effective vaccine targeting Staphylococcus aureus. This study evaluated the efficacy and immunologic mechanisms of a vaccine containing a recombinant glycoprotein antigen (NDV-3) in mouse skin and skin structure infection (SSSI) due to methicillin-resistant S. aureus (MRSA). Compared with adjuvant alone, NDV-3 reduced abscess progression, severity, and MRSA density in skin, as well as hematogenous dissemination to kidney. NDV-3 induced increases in CD3+ T-cell and neutrophil infiltration and IL-17A, IL-22, and host defense peptide expression in local settings of SSSI abscesses. Vaccine induction of IL-22 was necessary for protective mitigation of cutaneous infection. By comparison, protection against hematogenous dissemination required the induction of IL-17A and IL-22 by NDV-3. These findings demonstrate that NDV-3 protective efficacy against MRSA in SSSI involves a robust and complementary response integrating innate and adaptive immune mechanisms. These results support further evaluation of the NDV-3 vaccine to address disease due to S. aureus in humans.

Failure of early diagnosis of infective endocarditis in Japan--a retrospective descriptive analysis

Infective endocarditis (IE) is a severe disease with high morbidity and mortality, and these can be exacerbated by delay in diagnosis. We investigated IE diagnosis in Japan with the emphasis on the delay in diagnosis and its cause and implications. We conducted a retrospective study on 82 definite IE patients at Kobe University Hospital from April 1, 2008, through March 31, 2013. We reviewed charts of the patients for data such as causative pathogens, prescription of inappropriate antibiotic use prior to the diagnosis, existence of risk factors of IE, previous doctor's subspecialty, or duration until the diagnosis, with the primary outcome of 180-day mortality. We also qualitatively, as well as quantitatively, analyzed those cases with delay in diagnosis, and hypothesized its causes and implications. Eighty-two patients were reviewed for this analysis. The average age was 61 ± 14.5-year-old. Fifty percent of patients had known underlying risk factors for IEs, such as prosthetic heart valve (10), valvular heart disease (21), congenital heart disease (3), or cardiomyopathy (2). The median days until the diagnosis was 14 days (range 2 days to 1 year). Sixty-five percent of patients received inappropriate antibiotic before the diagnosis (53). Forty percent of causative organisms were Staphylococcus aureus (MSSA 20, MRSA 13), 32% were viridans streptococci and Streptococcus bovis, 28% were others or unknown (CNS 5, Corynebacterium 3, Cardiobacterium 1, Candida 1). Subspecialties such as General Internal Medicine (15), and Orthopedics (13) were associated with delay in diagnosis. Ten patients (12%) died during follow up, and 8 of them had been received prior inappropriate antibiotics. Significant delay in the diagnosis of IE was observed in Japan. Inappropriate antibiotics were prescribed frequently and may be associated with poor prognosis. Further improvement for earlier diagnosis of IE is needed.

Infective endocarditis in the Lao PDR: clinical characteristics and outcomes in a developing country

INTRODUCTION

Data on infective endocarditis (IE) in Southeast Asia are scarce.

OBJECTIVES

To describe the clinical epidemiology of IE in Lao PDR, a lower middle-income country.

METHODS

A single centre retrospective study at Mahosot Hospital, Vientiane. Patients aged over 1year of age admitted 2006-2012 to Mahosot Hospital with definite or possible IE by modified Duke criteria were included.

RESULTS

Thirty-six patients fulfilled the inclusion criteria; 33 (91.7%) had left-sided IE. Eleven (30.6%) had definite IE and 25 (69.4%) possible left-sided IE. Median age was 25years old [IQR 18-42]. Fifteen patients (41.7%) were males. Underlying heart diseases included: rheumatic valve disease in 12 (33.3%), congenital heart disease in 7 (19.4%), degenerative valve disease in 3 (8.3%), and of unknown origin in 14 (38.9%) patients. Native valve IE was present in 30 patients (83.3%), and prosthetic valve IE in 6 patients (16.7%). The most frequent pathogens were Streptococcus spp. in 7 (19.4%). Blood cultures were negative in 22 patients (61.1%). Complications included: heart failure in 11 (30.6%), severe valve regurgitation in 7 (19.4%); neurological event in 7 (19.4%); septic shock or severe sepsis in 5 (13.9%); and cardiogenic shock in 3 patients (8.3%). No patient underwent heart surgery. Fourteen (38.9%) had died by follow-up after a median of 2.1years [IQR 1-3.2]; and 3 (8.3%) were lost to follow-up.

CONCLUSIONS

Infective endocarditis, a disease especially of young adults and mainly caused by Streptococcus spp., was associated with rheumatic heart disease and had high mortality in Laos.

Infective endocarditis in Turkey: aetiology, clinical features, and analysis of risk factors for mortality in 325 cases

OBJECTIVE

In order to define the current characteristics of infective endocarditis (IE) in Turkey, we evaluated IE cases over a 14-year period in a tertiary referral hospital.

METHODS

All adult patients who were hospitalized in our hospital with a diagnosis of IE between 2000 and 2013 were included in the study. Modified Duke criteria were used for diagnosis. The Chi-square test, Student's t-test, Mann-Whitney U-test, Cox and logistic regression analysis were used for the statistical analysis.

RESULTS

There were 325 IE cases during the study period. The mean age of the patients was 47 years. Causative microorganisms were identified in 253 patients (77.8%) and included staphylococci (36%), streptococci (19%), enterococci (7%), and Brucella spp (5%). A streptococcal aetiology was associated with younger age (<40 years) (p=0.001), underlying chronic rheumatic heart disease (CRHD) (odds ratio (OR) 3.89) or a congenital heart defect (OR 4.04), community acquisition (OR 17.93), and native valve (OR 3.68). A staphylococcal aetiology was associated with healthcare acquisition (OR 2.26) or pacemaker lead-associated endocarditis (OR 6.63) and an admission creatinine level of >1.2mg/dl (OR 2.15). Older age (>50 year) (OR 3.93), patients with perivalvular abscess (OR 9.18), being on dialysis (OR 6.22), and late prosthetic valve endocarditis (OR 3.15) were independent risk factors for enterococcal IE. Independent risk factors for mortality in IE cases were the following: being on dialysis (hazard ratio (HR) 4.13), presence of coronary artery heart disease (HR 2.09), central nervous system emboli (HR 2.33), and congestive heart failure (HR 2.15). Higher haemoglobin (HR 0.87) and platelet (HR 0.996) levels and surgical interventions for IE (HR 0. 33) were found to be protective factors against mortality.

CONCLUSIONS

In Turkey, IE occurs in relatively young patients and Brucella spp should always be taken into consideration as a cause of this infection. We should first consider streptococci as the causative agents of IE in young patients, those with CRHD or congenital heart valve disease, and cases of community-acquired IE. Staphylococci should be considered first in the case of pacemaker lead IE, when there are high levels of creatinine, and in cases of healthcare-associated IE. Enterococci could be the most probable causative agent of IE particularly in patients aged >50 years, those on dialysis, those with late prosthetic valve IE, and those with a perivalvular abscess. The early diagnosis and treatment of IE before complications develop is crucial because the mortality rate is high among cases with serious complications. The prevention of bacteraemia with the measures available among chronic haemodialysis patients should be a priority because of the higher mortality rate of subsequent IE among this group of patients.

Impact of early valve surgery on outcome of Staphylococcus aureus prosthetic valve infective endocarditis: analysis in the International Collaboration of Endocarditis-Prospective Cohort Study

BACKGROUND

The impact of early valve surgery (EVS) on the outcome of Staphylococcus aureus (SA) prosthetic valve infective endocarditis (PVIE) is unresolved. The objective of this study was to evaluate the association between EVS, performed within the first 60 days of hospitalization, and outcome of SA PVIE within the International Collaboration on Endocarditis-Prospective Cohort Study.

METHODS

Participants were enrolled between June 2000 and December 2006. Cox proportional hazards modeling that included surgery as a time-dependent covariate and propensity adjustment for likelihood to receive cardiac surgery was used to evaluate the impact of EVS and 1-year all-cause mortality on patients with definite left-sided S. aureus PVIE and no history of injection drug use.

RESULTS

EVS was performed in 74 of the 168 (44.3%) patients. One-year mortality was significantly higher among patients with S. aureus PVIE than in patients with non-S. aureus PVIE (48.2% vs 32.9%; P = .003). Staphylococcus aureus PVIE patients who underwent EVS had a significantly lower 1-year mortality rate (33.8% vs 59.1%; P = .001). In multivariate, propensity-adjusted models, EVS was not associated with 1-year mortality (risk ratio, 0.67 [95% confidence interval, .39-1.15]; P = .15).

CONCLUSIONS

In this prospective, multinational cohort of patients with S. aureus PVIE, EVS was not associated with reduced 1-year mortality. The decision to pursue EVS should be individualized for each patient, based upon infection-specific characteristics rather than solely upon the microbiology of the infection causing PVIE.

Health Care-Associated Infective Endocarditis: a Growing Entity that Can Be Prevented

Infective endocarditis (IE) continues to be a serious disease with a poor prognosis and high mortality. Neither incidence rates nor mortality have decreased in recent decades. Because of this, it is important to prevent IE in patients at risk. In the past, prevention of IE has focused on antimicrobial prophylaxis, mainly for dental procedures. However, recent major changes in epidemiology, the most significant being the growing frequency and high mortality rate of health care-associated valve endocarditis (HAIE), mean that preventive strategies against IE must also change. Since intravascular catheters are the most common source of bacteremia among patients with HAIE, significant efforts must be made to minimize the risk of catheter-related bloodstream infections. Measures for preventing the infection of prosthetic valves and cardiac implantable devices at the time of implantation also need to be implemented.

Coagulase-negative staphylococci

The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides.

Infective endocarditis epidemiology and consequences of prophylaxis guidelines modifications: the dialectical evolution

Historically, infective endocarditis (IE) affected patients with predisposing cardiac conditions and community-acquired bacteremia. Over the past 30 years, significant changes have occurred, regarding microorganisms, underlying valvular heart diseases, portals of entry, and patients' comorbidities. Given these epidemiological changes and unproven prophylaxis efficacy, experts in most countries currently limit antibiotic indications to patients with high-risk cardiac conditions having oral procedures and, in the UK, recommend discontinuing their use altogether. To date, no epidemiological impact on streptococcal IE incidence has been observed. Policy must now address these epidemiological modifications, focus on community-acquired and health care-associated staphylococcal bacteremia prevention, and prompt the adoption of broader and nonexclusively antibiotic-based strategies.

Aortic vascular graft infection caused by Cardiobacterium valvarum: a case report

A 53-year-old man with a past medical history of total arch replacement surgery and severe aortic regurgitation presented with a 1-month history of persistent general malaise, anorexia, body weight loss and night sweats. His recent history included gingival hyperplasia for 6 years, gingivitis after tooth extraction 3 years before, prolonged inflammatory status for 4 months, fundal hemorrhage and leg tenderness for 2 months. A pathogen was detected from blood culture, but conventional microbiological examination failed to identify the pathogen. The organism was eventually identified as Cardiobacterium valvarum by 16S rRNA analysis, and the patient was diagnosed with infective endocarditis and prosthetic vascular graft infection. The patient received intravenous antibiotic therapy using a combination of ceftriaxone and levofloxacin for 5 weeks and was discharged with a good clinical course. C. valvarum is a rare human pathogen in clinical settings. Only 10 cases have been reported to date worldwide, and therefore, the clinical characteristics of C. valvarum infection are not fully known. This is a first well-described case of C. valvarum infection in Japan, and further, a first report of aortic prosthetic vascular graft infection worldwide. Identification of C. valvarum is usually difficult due to its phenotypic characteristics, and molecular approaches would be required for both clinicians and microbiologists to facilitate more reliable diagnosis and uncover its clinical picture more clearly.