Bacteriological Outcome after Valve Surgery for Active Infective Endocarditis: Implications for Duration of Treatment after Surgery

Perioperative care in infective endocarditis

Patients undergoing surgery for acute infective endocarditis are among those with the highest risk. Their preoperative condition has significant impact on outcomes. There are specific issues related with the preoperative situation, intraoperative findings, and postoperative management. In this narrative review, focus is placed on the most critical aspects in the perioperative period including the management and weaning from mechanical ventilation, the management of vasoplegia, the management of the chest open, antithrombotic therapy, transfusion, coagulopathy, management of atrial fibrillation, the duration of antibiotic therapy, and pacemaker implantation.

Outcomes after surgery for infective endocarditis

The role of surgery in infective endocarditis is becoming established the world over. In spite of all recent advances, endocarditis remains a lethal disease following surgery. With the emergence of more difficult-to-treat microorganisms, sicker and older patients with multiple co-morbidities, and an increase in healthcare-associated infections, the need for surgery in the management of infective endocarditis is only bound to increase. Data on the use of surgery in endocarditis till date is largely from observational data due to the relative rarity of the disease and variable practice patterns around the world. Hopefully, with increasing awareness and more inter-institutional and international collaborations, more robust data will emerge to further establish the role of surgery. For the time being, individual patient management will require the active multi-disciplinary approach of an endocarditis team to provide the best possible outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01647-9.

Risk factors for and consequences of positive valve cultures in patients who undergo cardiac surgery while receiving antimicrobial treatment for infective endocarditis

INTRODUCTION

Cardiac surgery is required in up to half of the patients with infective endocarditis (IE). Positive valve cultures have been associated with higher in-hospital mortality. The aims were to identify risk factors for positive valve cultures and its relation to outcome.

METHODS

Patients subjected to heart valve cultures due to surgery for IE in Skåne University Hospital, Lund, between 2012 and 2021 were identified through microbiology records. Risk factors for positive valve cultures and information on mortality and relapse were retrieved through medical records. Univariable and multivariable logistic regressions were performed.

RESULTS

A total of 345 episodes with IE in 337 patients subjected to cardiac surgery were included and valve cultures were positive in 78 (23%) episodes. In multivariable logistic regression, preoperative fever (adjusted odds ratio (AOR) 2.6, 95% confidence interval (CI) 1.2-5.6, p = 0.02), prosthetic heart valve (AOR 3.3, CI 1.4-7.9, p = 0.01), a single affected valve (AOR 4.8, CI 1.2-20, p = 0.03), blood culture findings of S. aureus, enterococci, or coagulase negative staphylococci compared to viridans streptococci (AOR 20-48, p < 0.001), and a shorter duration of antibiotic treatment (p < 0.001), were associated to positive valve culture. One-year mortality was 13% and a relapse was identified in 2.5% of episodes. No association between positive valve cultures and one-year mortality or relapse was identified.

CONCLUSIONS

Positive valve cultures were associated to short preoperative antibiotic treatment, IE caused by staphylococci, preoperative fever and prosthetic valve but not to relapse or mortality.

Impact of the Duration of Postoperative Antibiotics on the Prognosis of Patients with Infective Endocarditis

Appropriate postoperative antibiotic treatment in patients with infective endocarditis (IE) reduces the risks of recurrence and mortality. However, concerns about adverse drug reactions arise due to prolonged antibiotic usage. Therefore, we compared the recurrence and mortality rates according to the duration of postoperative antibiotic therapy in patients with IE. From 2005 to 2017, we retrospectively reviewed 416 patients with IE treated at a tertiary hospital in South Korea; among these, 216 patients who underwent heart valve surgery and received appropriate antibiotics were enrolled. The patients were divided into two groups based on the duration of usage of postoperative antibiotic therapy; the duration of postoperative antibiotic therapy was more than two weeks in 156 patients (72.2%) and two weeks or less in 60 patients (27.8%). The primary endpoint was IE relapse. The secondary endpoints were 1-year IE recurrence, 1-year mortality, and postoperative complication rates. The median age was 53 (interquartile range: 38-62) years. The relapse rate of IE was 0.9% (2/216). There was no statistical difference in relapse (0.0% vs. 1.3%, p = 0.379), 1-year recurrence (1.7% vs. 1.3%, p = 0.829), or 1-year mortality (10.0% vs. 5.8%, p = 0.274) between patients with postoperative antibiotic administration of two weeks or less versus more than two weeks. The duration of postoperative antibiotic therapy did not affect the 1-year mortality rate (log-rank test, p = 0.393). In conclusion, there was no statistically significant difference in recurrence, mortality, or postoperative complications according to the duration of postoperative antibiotic therapy.

Infective Endocarditis: Predictive Factors for Diagnosis and Mortality in Surgically Treated Patients

Background: Diagnosis of infective endocarditis (IE) often is challenging, and mortality is high in such patients. Our goal was to characterize common diagnostic tools to enable a rapid and accurate diagnosis and to correlate these tools with mortality outcomes. Methods: Because of the possibility of including perioperative diagnostics, only surgically treated patients with suspected left-sided IE were included in this retrospective, monocentric study. A clinical committee confirmed the diagnosis of IE. Results: 201 consecutive patients (age 64 ± 13 years, 74% male) were finally diagnosed with IE, and 14 patients turned out IE-negative. Preoperative tests with the highest sensitivity for IE were positive blood cultures (89.0%) and transesophageal echocardiography (87.5%). In receiver operating characteristics, vegetation size revealed high predictive power for IE (AUC 0.800, p < 0.001) with an optimal cut-off value of 11.5 mm. Systemic embolism was associated with mortality, and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) had predictive power for mortality. Conclusion: If diagnostic standard tools remain inconclusive, we suggest employing novel cut-off values to increase diagnostic accuracy and accelerate diagnosis. Patients with embolism or elevated NT-proBNP deserve a closer follow-up.

Infective Endocarditis: Still More Challenges Than Convictions

After fourteen decades of medical and technological evolution, infective endocarditis continues to challenge physicians in its daily diagnosis and management. Its increasing incidence, demographic shifts (affecting older patients), microbiology with higher rates of Staphylococcus infection, still frequent serious complications and substantial mortality make endocarditis a very complex disease. Despite this, innovations in the diagnosis, involving microbiology and imaging, and improvements in intensive care and cardiac surgical techniques, materials and timing can impact the prognosis of this disease. Ongoing challenges persist, including rethinking prophylaxis, improving the diagnosis criteria comprising blood culture-negative endocarditis and prosthetic valve endocarditis, timing of surgical intervention, and whether to perform surgery in the presence of ischemic stroke or in intravenous drug users. A combined strategy on infective endocarditis is crucial, involving advanced clinical decisions and protocols, a multidisciplinary approach, national healthcare organization and health policies to achieve better results for our patients.

Infective Endocarditis: New Challenges in a Classic Disease

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

Current recommendations and uncertainties for surgical treatment of infective endocarditis: a comparison of American and European cardiovascular guidelines

Surgery is an effective therapy in the treatment of left-sided infective endocarditis (IE) in patients for whom antibiotic treatment alone is unlikely to be curative or may be associated with ongoing risk of complications. However, the interplay between indication for surgery, its risk, and timing is complex and there continue to be challenges in defining the effects of surgery on disease-related outcome. Guidelines published by the American College of Cardiology/American Heart Association and the European Society of Cardiology provide recommendations for the use of surgery in IE, but these are limited by a low level of evidence related to predominantly observational studies with inherent selection and survival biases. Evidence to guide the timing of surgery in IE is less robust, and predominantly based on expert consensus. Delays between IE diagnosis and recognition of an IE complication as a surgical indication and transfers to surgical centres also impact surgical timing. This comparison of the two guidelines exposes areas of uncertainty and gaps in current evidence for the use of surgery in IE across different indications, particularly related to its timing and consideration of operative risk.

Focused Cardiac Ultrasound Examination as a Tool for Diagnosis of Infective Endocarditis and Myocarditis in Dogs and Cats

Symptoms of infective endocarditis (IE) and myocarditis are usually nonspecific and include fever, apathy, and loss of appetite. This condition can lead to severe heart failure with ascites or/and fluid in the thoracic cavity or/and in the pericardial sac. We describe infective endocarditis and myocarditis in 3 dogs and 4 cats. In all animals, the initial diagnosis was performed on the basis of a focused cardiac ultrasound examination performed by a general practitioner after a training in this technique. The initial findings were confirmed by a board-certified specialist in veterinary cardiology. Post mortem positive microbiological results from valves were obtained in 4 of 7 patients. Methicillin-resistant Staphylococcus aureus was confirmed in 2 cases and Staphylococcus epidermidis was confirmed in 2 cases, one of which included Enterococcus sp. coinfection. Histopathological examination confirmed initial diagnosis in 5 of 7 animals. In the remaining 2 patients, the time elapsed from the onset of clinical symptoms to death was about 1 month and no active inflammation but massive fibrosis was found microscopically. This is, to our best knowledge, the first report of IE and myocarditis diagnosed in small animals using focused cardiac ultrasound examination. Therefore, we conclude that common usage of this technique by trained general veterinarians may increase the rate of diagnosed patients with these conditions.

Current Challenges in the Management of Infective Endocarditis

Infective endocarditis is a relatively rare, but deadly cause of sepsis, with an overall mortality ranging from 20 to 25% in most series. Although the classic clinical classification into syndromes of acute or subacute endocarditis have not completely lost their usefulness, current clinical forms have changed according to the profound epidemiological changes observed in developed countries. In this review, we aim to address the changing epidemiology of endocarditis, several recent advances in the understanding of the pathophysiology of endocarditis and endocarditis-triggered sepsis, new useful diagnostic tools as well as current concepts in the medical and surgical management of this disease. Given its complexity, the management of infective endocarditis requires the close collaboration of multidisciplinary endocarditis teams that must decide on the diagnostic approach; the appropriate initial treatment in the critical phase; the detection of patients needing surgery and the timing of this intervention; and finally the accurate selection of patients for out-of-hospital treatment, either at home hospitalization or with oral antibiotic treatment.

A narrative review of the interpretation of guidelines for the treatment of infective endocarditis

The recommendations of the current guidelines and the position papers of professional societies from the European Society of Cardiology/European Society of Cardiothoracic Surgeons (ESC), the American College of Cardiology/American Heart Association/Society of Thoracic Surgeon (ACC/AHA/STS) and American Association of Thoracic Surgeon (AATS) regarding management of patients with valvular heart endocarditis were updated over the past decade. However, some of the recommendations appear to contradict one another. Given the changing paradigms on how the disease manifests, our aim was to review the respective guidelines and highlight these differences whilst drawing attention to the subsequent studies from which they were derived. In particular, concerns regarding antibiotic prophylaxis and therapy, imaging modality for diagnosis and follow-up, cerebrovascular sequalae and timing of surgery are appraised in detail. We also identified the novel techniques used such as transcatheter therapies and advances in imaging modalities used for diagnosis and treatment of this condition. The lack of randomised control trials (RCTs) does raise several issues regarding applicability of findings in day-to-day practice. Therefore, the focus of upcoming studies should be on clearly defined multicenter RCTs to provide more robust evidence for the management and treatment of infective endocarditis as future guidelines will be based on the outcomes of these trials.

Learning From Controversy: Contemporary Surgical Management of Aortic Valve Endocarditis

Aortic valve replacement is the commonest cardiac surgical operation performed worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are goals of the procedure. However, no detailed guidelines on prosthesis selection and surgical strategies guided by the comprehensive evaluation of the extension of the infection and its microbiological characteristics, clinical profile of the patient, and risk of infection recurrence are currently available. Conventional mechanical or stented xenografts are the preferred choice for localized aortic infection. However, in cases of complex IE with the involvement of the root or the aortomitral continuity, the use of homograft is suggested according to the surgeon and center experience. Homograft use should be counterbalanced against the risk of structural degeneration. Prosthetic bioroot or prosthetic valved conduit (mechanical and bioprosthetic) are also potentially suitable alternatives. Further development of preservation techniques enabling longer durability of allogenic substitutes is required. We evaluate the current evidence for the use of valve substitutes in aortic valve endocarditis and propose an evidence-based algorithm to guide the choice of therapy. We performed a systemic review to clarify the contemporary surgical management of aortic valve endocarditis.

A review of current treatment strategies for infective endocarditis

INTRODUCTION

Infective endocarditis is one of the most difficult-to-treat infectious diseases.

AREAS COVERED

We restricted this review to the anti-infective treatment of the main bacteria responsible for infective endocarditis, i.e. staphylococci, streptococci, enterococci, and Gram-negative bacilli, including HACEK. Specific topics of major interest in treatment strategy are covered as well, including empirical treatment, oral switch, and treatment duration. We searched in the MEDLINE database to identify relevant studies, trials, reviews, or meta-analyses until May 2020.

EXPERT OPINION

The use of aminoglycosides for the treatment of endocarditis has been dramatically reduced over the last 20 years. It should be administered once daily, and no longer than 2 weeks. For staphylococcal endocarditis, recent data reinforced the role of anti-staphylococcal penicillins, for methicillin-susceptible isolates (alternative, cefazolin), and vancomycin for methicillin-resistant isolates (alternative, daptomycin). For staphylococcal prosthetic-valve endocarditis, these treatments will be reinforced by the addition of gentamicin during the first 2 weeks, and rifampin throughout the whole treatment duration, i.e. 6 weeks. The optimal duration of antibacterial treatment is 4 weeks for most native valve endocarditis, and 6 weeks for prosthetic-valve endocarditis. The oral switch is safe in patients stabilized after the initial intravenous course.

Infective Endocarditis Guidelines: The Challenges of Adherence-A Survey of Infectious Diseases Clinicians

Background

Guidelines exist to aid clinicians in managing patients with infective endocarditis (IE), but the degree of adherence with guidelines by Infectious Disease (ID) physicians is largely unknown.

Methods

An electronic survey assessing adherence with selected IE guidelines was emailed to 1409 adult ID physician members of the Infectious Diseases Society of America’s Emerging Infections Network.

Results

Five hundred fifty-seven physicians who managed IE responded. Twenty percent indicated that ID was not consulted on every case of IE at their hospitals, and 13% did not recommend transthoracic echocardiography (TTE) for all IE cases. The duration of antimicrobial therapy was timed from the first day of negative blood cultures by 91% of respondents. Thirty-four percent of clinicians did not utilize an aminoglycoside for staphylococcal prosthetic valve IE (PVE). Double β-lactam therapy was “usually” or “almost always” employed by 83% of respondents for enterococcal IE. For patients with active IE who underwent valve replacement and manifested positive surgical cultures, 6 weeks of postoperative antibiotics was recommended by 86% of clinicians.

Conclusions

The finding that adherence was <90% with core guideline recommendations that all patients with suspected IE be seen by ID and that all patients undergo TTE is noteworthy. Aminoglycoside therapy of IE appears to be declining, with double β-lactam regimens emerging as the preferred treatment for enterococcal IE. The duration of postoperative antimicrobial therapy for patients undergoing valve replacement during acute IE is poorly defined and represents an area for which additional evidence is needed.

Short-course antibiotic regimen compared to conventional antibiotic treatment for gram-positive cocci infective endocarditis: randomized clinical trial (SATIE)

Background

Most serious complications of infective endocarditis (IE) appear in the so-called “critical phase” of the disease, which represents the first days after diagnosis. The majority of patients overcoming the acute phase has a favorable outcome, yet they remain hospitalized for a long period of time mainly to complete antibiotic therapy. The major hypothesis of this trial is that in patients with clinically stable IE and adequate response to antibiotic treatment, without signs of persistent infection, periannular complications or metastatic foci, a shorter antibiotic time period would be as efficient and safe as the classic 4 to 6 weeks antibiotic regimen.

Methods

Multicenter, prospective, randomized, controlled open-label, phase IV clinical trial with a non-inferiority design to evaluate the efficacy of a short course (2 weeks) of parenteral antibiotic therapy compared with conventional antibiotic therapy (4–6 weeks).

Sample: patients with IE caused by gram-positive cocci, having received at least 10 days of conventional antibiotic treatment, and at least 7 days after surgery when indicated, without clinical, analytical, microbiological or echocardiographic signs of persistent infection. Estimated sample size: 298 patients. Intervention: Control group: standard duration antibiotic therapy, (4 to 6 weeks) according to ESC guidelines recommendations. Experimental group: short-course antibiotic therapy for 2 weeks. The incidence of the primary composite endpoint of all-cause mortality, unplanned cardiac surgery, symptomatic embolisms and relapses within 6 months after the inclusion in the study will be prospectively registered and compared.

Conclusions

SATIE will investigate whether a two weeks short-course of intravenous antibiotics in patients with IE caused by gram-positive cocci, without signs of persistent infection, is not inferior in safety and efficacy to conventional antibiotic treatment (4–6 weeks).

Trial registration

ClinicalTrials.gov Identifier: NCT04222257 (January 7, 2020).

EudraCT 2019–003358-10.

Clinical Practice Update on Infectious Endocarditis

Infectious endocarditis is a highly morbid disease with approximately 43,000 cases per year in the United States. The modified Duke Criteria have poor sensitivity; however, advances in diagnostic imaging provide new tools for clinicians to make what can be an elusive diagnosis. There are a number of risk stratification calculators that can help guide providers in medical and surgical management. Patients who inject drugs pose unique challenges for the health care system as their addiction, which is often untreated, can lead to recurrent infections after valve replacement. There is a need to increase access to medication-assisted treatment for opioid use disorders in this population. Recent studies suggest that oral and depo antibiotics may be viable alternatives to conventional intravenous therapy. Additionally, shorter courses of antibiotic therapy are potentially equally efficacious in patients who are surgically managed. Given the complexities involved with their care, patients with endocarditis are best managed by multidisciplinary teams.

Determinants and consequences of positive valve culture when cardiac surgery is performed during the acute phase of infective endocarditis

The optimal timing of cardiac surgery in infective endocarditis (IE) remains debated: Early surgery decreases the risk of embolism, and heart failure, but is associated with an increased rate of positive valve culture. To determine the determinants, and the consequences, of positive valve culture when cardiac surgery is performed during the acute phase of IE, we performed a retrospective study of adult patients who underwent cardiac surgery for definite left-sided IE (Duke Criteria), in two referral centres. During the study period (2002-2016), 148 patients fulfilled inclusion criteria. Median age was 65 years [interquartile range, 53-73], male-to-female ratio was 2.9 (110/38). Cardiac surgery was performed after 14 days [5-26] of appropriate antibiotics. Valve cultures returned positive in 46 cases (31.1%). Factors independently associated with positive valve culture were vegetation size ≥ 10 mm (OR 2.83 [1.16-6.89], P = 0.022) and < 14 days of appropriate antibacterial treatment before surgery (OR 4.68 [2.04-10.7], P < 0.001). Positive valve culture was associated with increased risk of postoperative acute respiratory distress syndrome (37.0% vs. 15.7%, P = 0.008) but was associated neither with an increased risk of postoperative relapse nor with the need for additional cardiac surgery. Duration of appropriate antibacterial treatment and vegetation size are independently predictive of positive valve culture in patients operated during the acute phase of IE. Positive valve culture is associated with increased risk of postoperative acute respiratory distress syndrome.

Combination versus monotherapy for the treatment of infections due to carbapenem-resistant Enterobacteriaceae

PURPOSE OF REVIEW

Combination therapy is a common strategy for treatment of multidrug resistant infections. Despite the strong twin rationales of improving efficacy and reducing resistance development, the evidence supporting this strategy remains controversial. The aims of this review are to assess the most recent studies supporting the use of combination therapy for treating infections because of carbapenem-resistant Enterobacteriaceae (CRE) and to highlight relevant areas for further research.

RECENT FINDINGS

Evidence supporting the use of combination therapy for the treatment of CRE remains limited to in-vitro experiments and observational studies with considerable risk of bias. Very few antibiotic combinations have been tested in well designed randomized controlled trials, making it difficult to draw general conclusions for clinical practice.

SUMMARY

Further studies are urgently needed to test the most promising synergistic combinations. New drugs potentially active against CRE should also to be tested in studies with adequate sample size and truly representative of the general patient population.

[Treatment of infectious endocarditis]

Antibiotic treatment of infective endocarditis is part of a multidisciplinary patient management that should be conducted within an "Endocarditis team". Initial antibiotic treatment of infective endocarditis should be parenteral and comply with current international guidelines. A switch to an oral antibiotic regimen may be considered after 2weeks of successful parenteral antibiotic treatment. Aminoglycosides should no longer be used for the initial treatment of native valve Staphylococcus aureus endocarditis. Valve surgery is required in almost half of the patients.

Challenges in Infective Endocarditis

Infective endocarditis is defined by a focus of infection within the heart and is a feared disease across the field of cardiology. It is frequently acquired in the health care setting, and more than one-half of cases now occur in patients without known heart disease. Despite optimal care, mortality approaches 30% at 1 year. The challenges posed by infective endocarditis are significant. It is heterogeneous in etiology, clinical manifestations, and course. Staphylococcus aureus, which has become the predominant causative organism in the developed world, leads to an aggressive form of the disease, often in vulnerable or elderly patient populations. There is a lack of research infrastructure and funding, with few randomized controlled trials to guide practice. Longstanding controversies such as the timing of surgery or the role of antibiotic prophylaxis have not been resolved. The present article reviews the challenges posed by infective endocarditis and outlines current and future strategies to limit its impact.

Aminoglycosides for Surgically Treated Enterococcal Endocarditis

Aminoglycosides are a mainstay of treatment for enterococcal infective endocarditis. However, the benefit of adding aminoglycosides to cell wall-active agents after surgery is unclear. The aim of this study was to determine if adjunctive aminoglycoside treatment after surgery for enterococcal endocarditis leads to better outcomes. We included patients who underwent surgery for enterococcal endocarditis at our institution between July 2007 and July 2014. Treatment was defined as at least 1 dose of an aminoglycoside after surgery. Propensity to receive aminoglycosides was calculated in a model that included age, native vs prosthetic valve endocarditis, chronic kidney disease, high-level aminoglycoside resistance, metastatic infection, invasive disease, positive valve culture, and creatinine on the day of surgery. A multivariable Cox proportional hazards model was used to compare the primary outcome of death, adjusted for propensity to receive aminoglycosides, among patients who did and did not receive aminoglycosides. A total of 108 patients were identified of whom 37 (34%) received at least 1 dose of an aminoglycoside after surgery, with a median duration of 5 days (interquartile range: 2.5-10). In the multivariable model, patients treated with adjunctive aminoglycoside therapy had better survival than those treated with a cell wall-active agent alone, although the difference did not reach statistical significance (hazard ratio = 0.65, 95% CI: 0.32-1.33). The survival difference was consistently present in subgroups stratified by all-purpose refined diagnosis-related group mortality risk, and with varying definitions of aminoglycoside therapy. In conclusion, antibiotic monotherapy with a cell wall-active agent after surgery for enterococcal endocarditis may be inferior to combination therapy including an aminoglycoside.

Histopathology of valves in infective endocarditis, diagnostic criteria and treatment considerations

BACKGROUND

Infective endocarditis (IE) is a severe disease. Pathogen isolation is fundamental so as to treat effectively and reduce morbidity and mortality. Blood and valve culture and histopathology (HP) are routinely employed for this purpose. Valve HP is the gold standard for diagnosis.

OBJECTIVES

To determine the sensitivity and specificity of clinical criteria for IE (the modified Duke and the St Thomas' minor modifications, STH) of blood and valve culture compared to valve HP, and to evaluate antibiotic treatment duration.

METHODS

Prospective case series of patients, from 2006 to 2014 with surgically treated IE. Statistical analysis was done by the R software.

RESULTS

There were 136 clinically definite episodes of IE in 133 patients. Mean age ± SD was 43 ± 15.6 years and IE was left sided in 81.6 %. HP was definite in 96 valves examined, which were used as gold standard. Sensitivity of blood culture was 61 % (CI 0.51, 0.71) and of valve culture 15 % (CI 0.07, 0.26). The modified Duke criteria were 65 % (CI 0.55, 0.75) sensitive and 33 % specific, while the STH's sensitivity was 72 % (CI 0.61, 0.80) with similar specificity. In multivariate analysis and logistic regression, the only variable with statistical significance was duration of antibiotic therapy postoperatively.

CONCLUSIONS

Valve HP had high sensitivity and valve culture low sensitivity in the diagnosis of IE. The STH's criteria were more sensitive than the modified Duke criteria. Valve HP should guide duration of postoperative antibiotic treatment.

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.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC)

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

Infective endocarditis in New Zealand children 1994-2012

BACKGROUND

New Zealand is a developed country with high incidence of bacterial infections and postinfectious sequelae including rheumatic heart disease. We sought to describe the clinical and microbiology features of children with infective endocarditis (IE) between 1994 and 2012.

METHODS

Retrospective review of patients <16 years identified from hospital records.

RESULTS

In total 85 episodes occurred in 82 children and 68 (80%) were classified as Definite IE and 17 as Possible IE according to modified Duke criteria. From Pacific Island countries, 13 cases were referred. There were 72 children who originated in New Zealand, of whom 52% were either indigenous New Zealand Maori or Pacific migrants. The median age at diagnosis was 7 (0-15) years. Of the 85 cases, 51 (60%) had congenital heart disease 10 children with rheumatic heart disease developed IE. Of the 85 cases, 35 (41%) met our criteria for healthcare-associated IE. 39/85 underwent surgery for IE. As direct result of IE, 4 (4.7%) children died and 9% of survivors had neurologic sequelae. Attributable in-hospital mortality was 4.7%. Staphylococcus aureus was the most common organism, accounting for 26 episodes (30.6%). Other notable pathogens included Corynebacterium diphtheriae (10 cases, 11.8%) and Streptococcus pyogenes (7 cases, 8.2%). In 6 episodes, the microbiologic diagnosis was made by 16S ribosomal RNA testing of excised cardiac tissue.

CONCLUSIONS

Congenital heart disease was the major risk factor for IE; however, rheumatic heart disease is also an important risk factor in New Zealand, with implications for local endocarditis prophylaxis recommendations. In addition to a high burden of healthcare-associated and staphylococcal IE, pathogens such as C. diphtheriae and S. pyogenes occurred. 16S ribosomal RNA testing is a useful tool to determine the etiologic agent in culture-negative IE.

Partial oral treatment of endocarditis

BACKGROUND

Guidelines for the treatment of left-sided infective endocarditis (IE) recommend 4 to 6 weeks of intravenous antibiotics. Conversion from intravenous to oral antibiotics in clinically stabilized patients could reduce the side effects associated with intravenous treatment and shorten the length of hospital stay. Evidence supporting partial oral therapy as an alternative to the routinely recommended continued parenteral therapy is scarce, although observational data suggest that this strategy may be safe and effective.

STUDY DESIGN

This is a noninferiority, multicenter, prospective, randomized, open-label study of partial oral treatment with antibiotics compared with full parenteral treatment in left-sided IE. Stable patients (n = 400) with streptococci, staphylococci, or enterococci infecting the mitral valve or the aortic valve will be included. After a minimum of 10 days of parenteral treatment, stable patients are randomized to oral therapy or unchanged parenteral therapy. Recommendations for oral treatment have been developed based on minimum inhibitory concentrations and pharmacokinetic calculations. Patients will be followed up for 6 months after completion of antibiotic therapy. The primary end point is a composition of all-cause mortality, unplanned cardiac surgery, embolic events, and relapse of positive blood cultures with the primary pathogen.

CONCLUSION

The Partial Oral Treatment of Endocarditis study tests the hypothesis that partial oral antibiotic treatment is as efficient and safe as parenteral therapy in left-sided IE. The trial is justified by a review of the literature, by pharmacokinetic calculations, and by our own experience.

Right-sided infective endocarditis: surgical management

Right-sided infective endocarditis (RSIE) accounts for 5-10% of all cases of infective endocarditis and is predominantly encountered among injecting drug users (IDUs). RSIE diagnosis requires a high index of suspicion as respiratory symptoms predominate. Prognosis of isolated RSIE is favourable, and most cases (70-80%) resolve following antibiotic administration. Surgical intervention is indicated in patients with persistent infection that does not respond to antibiotic therapy, recurrent pulmonary emboli, intractable heart failure and if the size of a vegetation increases or persists at >1 cm. Techniques can be divided into 'prosthetic' (valve replacement or prosthetic annular implantation) or 'non-prosthetic' ones (Kay's or De Vega's annuloplasty, bicuspidalization or valvectomy). In IDUs who run a high risk of complications, vegetectomy and valve repair, avoiding artificial material should be considered as the first line of surgical management as is associated with better late survival.

Evaluation of antibiotic therapy following valve replacement for native valve endocarditis

We retrospectively evaluated 105 patients at the Mayo Clinic between 1970 and 2006 with native valve endocarditis who underwent acute valve surgery. The objective was to determine if outcomes differed based on whether they had received an antibiotic regimen recommended for native valve endocarditis or one for prosthetic valve endocarditis. Fifty-two patients had streptococcal and 53 had staphylococcal infections. Patients with each type of infection were divided into two groups: the first received postoperative monotherapy (with a beta-lactam or vancomycin), and the second received combination therapy (with an aminoglycoside for streptococcal infection, and gentamicin and/or rifampin for staphylococcal infection). The duration and types of antibiotics given pre- and postoperatively, valve cultures results, antibiotic-related adverse events, relapses, and mortality rates within 6 months of surgery were analyzed. Cure rates were similar regardless of the regimen administered. With the small number of patients in each group, a multicenter study with a larger cohort of patients is needed to better define optimal postoperative treatment regimens in this population.

Swedish guidelines for diagnosis and treatment of infective endocarditis

Swedish guidelines for diagnosis and treatment of infective endocarditis (IE) by consensus of experts are based on clinical experience and reports from the literature. Recommendations are evidence based. For diagnosis 3 blood cultures should be drawn; chest X-ray, electrocardiogram, and echocardiography preferably transoesophageal should be carried out. Blood cultures should be kept for 5 d and precede intravenous antibiotic therapy. In patients with native valves and suspicion of staphylococcal aetiology, cloxacillin and gentamicin should be given as empirical treatment. If non-staphylococcal etiology is most probable, penicillin G and gentamicin treatment should be started. In patients with prosthetic valves treatment with vancomycin, gentamicin and rifampicin is recommended. Patients with blood culture negative IE are recommended penicillin G (changed to cefuroxime in treatment failure) and gentamicin for native valve IE and vancomycin, gentamicin and rifampicin for prosthetic valve IE, respectively. Isolates of viridans group streptococci and enterococci should be subtyped and MIC should be determined for penicillin G and aminoglycosides. Antibiotic treatment should be chosen according to sensitivity pattern given 2-6 weeks intravenously. Cardiac valve surgery should be considered early, especially in patients with left-sided IE and/or prosthetic heart valves. Absolute indications for surgery are severe heart failure, paravalvular abscess, lack of response to antibiotic therapy, unstable prosthesis and multiple embolies. Follow-up echocardiography should be performed on clinical indications.

Aortic valve endocarditis: is there an optimal surgical timing?

PURPOSE OF REVIEW

Patients with aortic valve infective endocarditis are likely to undergo surgery during the active phase of the disease. The indication and best timing for surgery, however, are still debated. The present review discusses the benefits and risks of early surgery in aortic endocarditis.

RECENT FINDINGS

Patients with acute aortic regurgitation and clinical or echocardiographic signs of poor tolerance require urgent surgery. Other indications for early surgery include severe perivalvular involvement and high embolic risk. Echocardiography plays an important role in the assessment of embolic risk and helps in choosing the best therapeutic strategy. Several recent studies have identified high-risk subgroups of patients that, without surgery, face poor prognosis. Patients with complicated endocarditis, particularly those with congestive heart failure, will benefit most from surgery. Patients with prosthetic valve endocarditis and cerebral complications represent specific subgroups in which surgical decision is more difficult.

SUMMARY

Patients with severe aortic leaflet destruction and congestive heart failure, patients with perivalvular extension or uncontrolled infection, and patients with high embolic risk have poor outcome under medical therapy. Early surgery is necessary in all such patients with 'complicated' endocarditis, unless severe comorbidity is present.