Early onset prosthetic valve endocarditis: the Cleveland Clinic experience 1992-1997

Optimal Timing of Surgery for Patients with Active Infective Endocarditis

Infective endocarditis (IE) is a rare but serious condition with a dismal prognosis. One of the keys to improving outcomes is the prompt identification of high-risk patients who have intracardiac and extracardiac (systemic and neurologic) complications. However, as cardiac and extracardiac complications indicating surgery add to the surgical risk for active IE, controversies surround the optimal indication and timing for surgery, especially in patients presenting neurologic complications. This article reviews the necessary evaluation for patients with suspected IE and proposes a state-of-the-art patient flow chart for evaluation of suspected IE.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Higher incidence of perivalvular abscess determines perioperative clinical outcome in patients undergoing surgery for prosthetic valve endocarditis

Background

Cardiac surgery for prosthetic valve endocarditis (PVE) is associated with substantial mortality. We aimed to analyze 30-day and 1-year outcome in patients undergoing surgery for PVE and sought to identify preoperative risk factors for mortality with special regard to perivalvular infection.

Methods

We retrospectively analyzed data of 418 patients undergoing valve surgery for infective endocarditis between January 2009 and July 2018. After 1:1 propensity matching 158 patients (79 PVE/79 NVE) were analyzed with regard to postoperative 30-day and 1-year outcomes. Univariate and multivariable analyses were performed to identify potential risk factors for mortality.

Results

315 patients (75.4%) underwent surgery for NVE and 103 (24.6%) for PVE. After propensity matching groups were comparable with regard to preoperative characteristics, clinical presentation and microbiological findings, except a higher incidence of perivalvular infection in patients with PVE (51.9%) compared to NVE (26.6%) (p = 0.001), longer cardiopulmonary bypass (166 [76–130] vs. 97 [71–125] min; p < 0.001) and crossclamp time (95 [71–125] vs. 68 [55–85] min; p < 0.001). Matched patients with PVE showed a 4-fold increased 30-day mortality (20.3%) in comparison with NVE patients (5.1%) (p = 0.004) and 2-fold increased 1-year mortality (PVE 29.1% vs. NVE 13.9%; p = 0.020). Multivariable analysis revealed perivalvular abscess, sepsis, preoperative AKI and PVE as independent risk factors for mortality. Patients with perivalvular abscess had a significantly higher 30-day mortality (17.7%) compared to patients without perivalvular abscess (8.0%) (p = 0.003) and a higher rate of perioperative complications (need for postoperative pacemaker implantation, postoperative cerebrovascular events, postoperative AKI). However, perivalvular abscess did not influence 1-year mortality (20.9% vs. 22.3%; p = 0.806), or long-term complications such as readmission rate or relapse of IE.

Conclusions

Patients undergoing surgery for PVE had a significantly higher 30-day and 1-year mortality compared to NVE. After propensity-matching 30-day mortality was still 4-fold increased in PVE compared to NVE.

Patients with perivalvular abscess showed a significantly higher 30-day mortality and perioperative complications, whereas perivalvular abscess seems to have no relevant impact on 1-year mortality, the rate of readmission or relapse of IE.

Successful Resolution of Early-Onset Prosthetic Valve Endocarditis Associated With Extended Spectrum β-Lactamases Producing Escherichia coli With Medical Management

A 74-year-old male with a recent bioprosthetic mitral valve placement presented with dyspnea, chills, and palpitations. Blood cultures on admission grew extended spectrum β-lactamase Escherichia coli. Transthoracic echocardiogram and transesophageal echocardiography were negative for valvular vegetations, but given the recent history of mitral valve replacement and difficulty visualizing valvular vegetations in prosthetic valve, we initiated treatment of our patient with antibiotics for 6 weeks. Repeat blood cultures showed clearance of the organism and on follow-up, and the patient had no signs of recurrence of infection.

Current and emerging pharmacotherapy for the treatment of infections following open-heart surgery

INTRODUCTION

Patients undergoing open-heart surgery may suffer from postoperative complications, including severe infections. Antimicrobials to treat infectious complications in this population should be selected thoughtfully, taking into account three different and fundamental issues: (i) the site of infection; (ii) the suspected or proven causative agent and its susceptibility pattern; and (iii) the risk of suboptimal pharmacokinetic characteristics and potential toxicity of the chosen drug/s.

AREAS COVERED

The present narrative review summarizes the current and future antimicrobial options for the treatment of infections developing after open-heart surgery.

EXPERT OPINION

The pharmacological treatment of infections developing in cardiac surgery patients poses peculiar challenges, including the need for an active empirical therapy for severe events such as bloodstream infections, deep sternal wound infections, or early-onset postoperative prosthetic endocarditis. In addition, the risk for multidrug-resistant pathogens should also be taken into account in endemic areas. A multidisciplinary evaluation on a patient-by-patient basis, deeply involving infectious diseases specialists and cardiothoracic surgeons, remains essential for appropriately balancing both short-term and long-term risks and benefits of any possible surgical reintervention in combination with adequate pharmacotherapy.

Methicillin-Resistant Staphylococcus aureus Prosthetic Valve Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Staphylococcus aureus prosthetic valve endocarditis (PVE) remains among the most morbid bacterial infections, with mortality estimates ranging from 40% to 80%. The proportion of PVE cases due to methicillin-resistant Staphylococcus aureus (MRSA) has grown in recent decades, to account for more than 15% of cases of S. aureus PVE and 6% of all cases of PVE. Because no large studies or clinical trials for PVE have been published, most guidelines on the diagnosis and management of MRSA PVE rely upon expert opinion and data from animal models or related conditions (e.g., coagulase-negative Staphylococcus infection). We performed a review of the literature on MRSA PVE to summarize data on pathogenic mechanisms and updates in epidemiology and therapeutic management and to inform diagnostic strategies and priority areas where additional clinical and laboratory data will be particularly useful to guide therapy. Major updates discussed in this review include novel diagnostics, indications for surgical management, the utility of aminoglycosides in medical therapy, and a review of newer antistaphylococcal agents used for the management of MRSA PVE.

Early Onset Prosthetic Valve Endocarditis: Experience at a Cardiothoracic Surgical Hospital, 2006-2016

BACKGROUND

Early onset prosthetic valve endocarditis (EO-PVE) is an serious complication associated with heart valve replacement surgery.

OBJECTIVES

To describe the epidemiologic, clinical, and laboratory profile of patients with EO-PVE in a cardiac surgical hospital.

PATIENTS AND METHODS

A retrospective analysis of an endocarditis database, implemented prospectively, with a post hoc study driven by analysis of cases of adults with definite endocarditis occurring up to 12 months after heart valve surgery.

RESULTS

We identified 26 cases in 2,496 surgeries in the period 2006-2016. The average annual incidence was 1.04%. The median time between valve replacement and the diagnosis of EO-PVE was 33 days (interquartile range [IQR] 19.25-118.75). Biologic and mechanical prostheses were affected in 53.8% and 46.2%, respectively. Rheumatic disease was present in 57.7% of patients. The most common causative pathogens were Staphylococcus epidermidis (23.1%). No Staphylococcus aureus infection was reported. Complications were present in 73.1% of cases, including embolism (65.4%), acute renal failure (38.5%), and heart failure (23.1%). The mortality rate at 30 days and 12 months was 3.8% and 34.6%, respectively.

CONCLUSIONS

In our cohort EO-PVE was an serious complication of heart valve replacement with a high morbidity and mortality, despite its low frequency.

Early-onset prosthetic valve endocarditis definition revisited: Prospective study and literature review

OBJECTIVE

To determine the annual incidence of prosthetic valve endocarditis (PVE) and to evaluate its current classification based on the epidemiological distribution of agents identified and their sensitivity profiles.

METHODS

Consecutive cases of PVE occurring within the first year of valve surgery during the period 1997-2014 were included in this prospective cohort study. Incidence, demographic, clinical, microbiological, and in-hospital mortality data of these PVE patients were recorded.

RESULTS

One hundred and seventy-two cases of PVE were included, and the global annual incidence of PVE was 1.7%. Most PVE cases occurred within 120days after surgery (76.7%). After this period, there was a reduction in resistant microorganisms (64.4% vs. 32.3%, respectively; p=0.007) and an increase in the incidence of Streptococcus spp (1.9% vs. 23.5%; p=0.007). A literature review revealed 646 cases of PVE with an identified etiology, of which 264 (41%) were caused by coagulase-negative staphylococci and 43 (7%) by Streptococcus spp. This is in agreement with the current study findings.

CONCLUSIONS

Most PVE cases occurred within 120days after valve surgery, and the same etiological agents were identified in this period. The current cut-off level of 365days for the classification of early-onset PVE should be revisited.

Atrial Septal Abscess in Early-Onset Prosthetic Mitral Band Endocarditis: A Case for Multimodality Imaging

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This case highlights a rare site for abscess formation from infective endocarditis.

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Pathogens have direct access to the prosthesis-annulus interface and perivalvular tissue because the valve sewing ring, mitral annulus, and anchoring sutures are not endothelialized early after valve implantation.

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The interatrial septum is a potential site for prosthetic material endocarditis.

Surgical Versus Medical Therapy for Prosthetic Valve Endocarditis: A Meta-Analysis of 32 Studies

Prosthetic valve endocarditis (PVE) is associated with significant morbidity, and the optimal treatment strategy has not been clearly defined. A systematic review and meta-analysis of 32 studies comparing valve reoperation and medical therapy was performed; it included 2,636 patients, with a mean follow-up of 22 months. A valve reoperation was associated with a lower risk of 30-day mortality, greater survival at follow-up, and a similar rate of PVE recurrence. Prospective studies are warranted to confirm these findings and to clarify clinical decision-making regarding the timing and necessity of a valve reoperation, as opposed to treatment with medical therapy alone.

Surgical treatment of late aortic prosthetic valve endocarditis: 19 years' experience

AIM OF THE STUDY

We retrospectively analyzed the results of operations conducted for aortic prosthetic valve endocarditis in a single center over 19 years.

MATERIAL AND METHODS

From February 1992 to January 2011, we performed operations on 27 patients with aortic prosthetic valve endocarditis. Seventeen patients (63.0%) were male, and the mean age was 39.1 ± 14.2 (16-67) years. Blood cultures were positive in 11 patients (40.7%), and the most commonly identified microorganism was Streptococcus (7 patients, 25.9%). The mean duration of follow-up was 8.6 ± 4.7 years (0.5-18.2), adding up to a total of 136.9 patient/years.

RESULTS

Forty procedures were performed on these 27 patients. The most commonly performed procedure was aortic valve replacement with a prosthetic valve - 16 patients (59.3%). Fifteen patients were operated on during the active phase of infection. In-hospital mortality was observed in 11 patients (40.7%). Postoperatively, 12 patients (44.4%) had low cardiac output, 3 (11.1%) suffered from a heart block; none of them required permanent pacemaker implantation. The actuarial survival for 1 and 5 years was 55.6 ± 9.6% and 47.6 ± 9.7%, respectively.

CONCLUSIONS

Prosthetic valve endocarditis of the aortic valve is a challenging situation for the surgeon. The surgical treatment carries a high mortality rate and long-term survival is low. Among the survivors, however, recurrence and the need for reoperation are unlikely.

Surgical aortic valve replacement in very elderly patients aged 80 years and over: evaluation of early clinical outcomes

BACKGROUND

An increasing number of very elderly patients aged ≥80 years will require aortic valve replacement (AVR) for severe aortic stenosis (AS). Many are classified as high-risk surgical candidates. Transcatheter aortic valve implantation (TAVI) has been proposed as an alternative to surgical AVR (SAVR) for high-risk patients. We evaluated early clinical outcomes of very elderly patients undergoing SAVR to optimise TAVI candidate selection.

METHODS

We conducted a retrospective case review of 132 consecutive patients aged ≥80 years undergoing isolated SAVR (49 patients) or combined SAVR/CABG (83 patients) during February 2002-January 2010 at a single tertiary referral hospital. Risk for cardiac surgery was calculated using the logistic EuroSCORE (ES(log)). Mortality and morbidity data were collected for the 30-day postoperative period.

RESULTS

Thirty-day mortality rate was 8.3% for patients undergoing SAVR (6.1% for isolated SAVR and 9.6% for SAVR/CABG). Permanent stroke occurred in 3.8% and renal insufficiency in 7.6% of the cohort. Thirty-five percent of patients had left ventricular ejection fraction <50%, 67% had advanced symptoms (NYHA class III or IV), and 42% of patients were stratified as high-risk (ES(log)≥20%).

CONCLUSIONS

SAVR can be performed in very elderly patients with acceptable operative morbidity and mortality. The outcomes at our institution are comparable to contemporary SAVR and TAVI outcomes.

Can implantable cardiac electronic device infections be defined as ‘early’ or ‘late’ based on the cause of infection?

Implantable cardiac electronic device (ICED) infections are a major cause of morbidity and mortality. Understanding the pathogenesis of these infections is important in their prevention and management. We hypothesized that ICED infections could be classified as ‘early’ or ‘late’, based on differences in microbiological cause within or beyond 1 year of implantation, respectively. A comprehensive review of the literature was undertaken to test this hypothesis. Prosthetic valve endocarditis cases were included for comparison. Articles were included if the time from device implantation to infection, definite evidence of infection (pocket/bacteraemia/endocarditis) and a positive microbiological diagnosis were included. There were no statistically significant differences in microbiology to support a 1 year cut-off between early and late ICED infection. Staphylococcus aureus and coagulase-negative staphylococci were the predominant causes of ICED infection both within and beyond 1 year of ICED implantation. To further assess the microbiological causes of ICEDs and their implications for pathogenesis a large-scale multi-centre study is required.

Late Outcomes of Mitral Valve Repair for Mitral Regurgitation Due to Degenerative Disease

Background—

The pathological spectrum of degenerative diseases of the mitral valve (MV) that causes mitral regurgitation (MR) is broad, and there is limited information on late outcomes of MV repair in various subgroups of patients and pathologies. This study examines this issue.

Methods and Results—

All 840 patients who had MV repair for MR due to degenerative diseases from 1985 to 2004 were prospectively followed with clinical and echocardiographic evaluations at biennial intervals up to 26 years, median of 10.4 years. Clinical, hemodynamic, and pathological variables were evaluated for their association with outcomes. Age, left ventricular ejection fraction, and functional class were predictors of late cardiac- and valve-related deaths by multivariable analysis. MV repair failed to restore life span to normal in patients with functional class IV. Thirty-eight patients had repeat MV surgery, and the probability of reoperation at 20 years was 5.9%. During the follow-up, recurrent severe MR developed in 37 patients, and moderate MR developed in 61. Age, isolated prolapse of the anterior leaflet, the degree of myxomatous changes in the MV, lack of mitral annuloplasty, and duration of cardiopulmonary bypass were associated with increased risk of recurrent MR. At 20 years, the freedom from recurrent severe MR was 90.7%, and the freedom from moderate or severe MR was 69.2%.

Conclusions—

MV repair for degenerative MR restored life span to normal except in patients with symptoms at rest and impaired left ventricular function. Advanced age and complex mitral valve pathologies increased the risk of late recurrent MR.

Evaluating treatment options for patients with infective endocarditis: when is it the right time for surgery?

Infective endocarditis remains a life-threatening condition with an unchanging incidence and mortality of nearly 30% at 1 year. Surgery is required in 25–50% of acute infections and 20–40% of patients during convalescence. Operative procedures are often technically challenging and high-risk, often due to coexistent multisystem disease. However, international guidelines provide clear indications for surgical intervention, which are applicable for the majority of patients. These are not, however, supported by particularly robust clinical evidence and decision-making often needs to be tailored to the advancing age of the overall patient cohort, the presence of multisystem disease, comorbidities, prior antibiotic therapy of varying duration and the availability of surgical expertise. Native valve endocarditis will be the initial focus of this article, along with subgroups including prosthetic valve endocarditis. We present the treatment options for patients with infective endocarditis, evaluate the evidence-base that supports current clinical practice and attempt to provide an insight and subsequent recommendations for the timing of surgery.

Do all patients with prosthetic valve endocarditis need surgery?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was 'do all patients with prosthetic valve endocarditis need surgery?' Seventeen papers were found using the reported search that represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. These studies compared the outcome and survival between surgically and non-surgically treated patients with prosthetic valve endocarditis. Of these studies, two were prospective observational studies and the rest were retrospective studies. The results of most of these papers were in accordance with the guidelines of the American College of Cardiology and American Heart association. These studies showed that unless a patient is not a surgical candidate, an operation is the treatment of choice in prosthetic valve endocarditis. Surgery should be performed as soon as possible, particularly in haemodynamically unstable patients and those who develop complications such as heart failure, valvular dysfunction, regurgitation/obstruction, dehiscence and annular abscess. In addition to the above indications and cardiac/valvularrelated complications of prosthetic valve endocarditis, infection with Staphylococcus aureus plays an important role in the outcome, and the presence of this micro-organism should be considered an urgent surgical indication in the treatment of prosthetic valve endocarditis. Surgery should be performed before the development of any cerebral or other complications. In contrast, in stable patients with other micro-organisms, particularly those with organisms sensitive to antibiotic treatment who have no structural valvular damage or cardiac complications, surgery can be postponed. The option of surgical intervention can also be revisited if there is a change in response to the treatment. This option is reserved for selected patients only and we conclude that as soon as the diagnosis of prosthetic valve endocarditis is made, cardiac surgeons should be involved.

Infective endocarditis at autopsy: a review of pathologic manifestations and clinical correlates

The frequency of autopsies appears to be declining, and the usefulness has been challenged. We reviewed cases of autopsied active infective endocarditis (IE) during 2 periods based on the availability of high-tech 2-dimensional echocardiograms: Period 1 (P1) included 40 cases studied from 1970 to 1985, and Period 2 (P2) included 28 cases seen from 1986 to 2008--that is, before and after the introduction of echocardiograms in our institution. We conducted the study to reassess the pathology of IE and to determine how frequently diagnosis is not made during life.The age of patients increased 10 years on average between the 2 periods, and comorbidities were significantly more frequent in P2. While the frequency of rheumatic valve disease and prosthetic valve endocarditis (PVE) decreased, degenerative valve disease increased. Isolated mitral or aortic valve IE was most common. Right-sided IE was observed in patients with Staphylococcus aureus bacteremia from infected venous lines. In most cases IE involved only the cusps of cardiac valves. "Virulent" microorganisms caused ulcerations, rupture, and perforation of the cusps and necrosis of chordae tendiniae and perivalvular apparatus. In PVE the lesions were located behind the site of attachment, and vegetations were seen on the sewing ring in both metallic and biologic prostheses. Infection spread to adjacent structures and myocardium with ring abscess observed in 88% of cases. Prosthetic detachment causing valve regurgitation was associated with abscesses in 76% of cases; these patients developed persistent sepsis and severe cardiac failure. Obstruction occurred in patients with PVE of the mitral valve. Acute purulent pericarditis was observed in 22% of cases, mainly in patients with aortic valve IE and myocardial abscesses.Gross infarcts were seen in 63% of cases but were asymptomatic in most instances. The spleen, kidneys, and mesentery were the sites most frequently involved. Myocardial infarctions were found in less than 10% of cases. Abscesses were also frequently found and were a common source of persistent fever and bacteremia. Glomerulonephritis was more common in the first period. Brain pathology consisted of ischemic and hemorrhagic infarcts and abscesses. Cerebral bleeding was more frequent in patients with PVE on anticoagulant therapy. Neutrophilic meningitis was observed in S. aureus IE.Diagnosis of IE was not made during life in 14 (35%) cases during P1 and 12 (42.8%) cases in P2. Overall, diagnosis was missed until autopsy in 38.2% of cases. IE was hospital acquired in 28 instances. While a clinical diagnosis was made in all but 4 cases of early-onset PVE (23.5%), the diagnosis was not made during life in 22 of 51 patients with native-valve IE (43.1%). Of these 22 patients, IE was hospital acquired in 11 (50%). The absence of fever, cardiac murmurs, and many of the typical stigmata of endocarditis may have led to the diagnosis being overlooked clinically.Brain bleeding, cardiac failure and less frequently acute myocardial infarct were the most common causes of death.IE continues to be missed frequently until autopsy. Postmortem examination is an important tool for evaluating the quality of care, and for guiding teaching and research related to cardiovascular infections.

Surgery in current therapy for infective endocarditis

The introduction of the Duke criteria and transesophageal echocardiography has improved early recognition of infective endocarditis but patients are still at high risk for severe morbidity or death. Whether an exclusively antibiotic regimen is superior to surgical intervention is subject to ongoing debate. Current guidelines indicate when surgery is the preferred treatment, but decisions are often based on physician preferences. Surgery has shown to decrease the risk of short-term mortality in patients who present with specific symptoms or microorganisms; nevertheless even then it often remains unclear when surgery should be performed. In this review we i) systematically reviewed the current literature comparing medical to surgical therapy to evaluate if surgery is the preferred option, ii) performed a meta-analysis of studies reporting propensity matched analyses, and iii), briefly summarized the current indications for surgery.

Prosthetic valve endocarditis

Prosthetic valve endocarditis (PVE) is associated with a high mortality during the early and midterm follow-up despite diagnostic and therapeutic improvements; its incidence is increasing and reaches 20-30% of all infective endocarditis episodes. In this review, changes in epidemiology, microbiology, diagnosis and therapy that have evolved in the past few years are analyzed. Staphylococci (both Staphylococcus aureus and coagulase-negative Staphylococcus) have emerged as the most common cause of PVE and are associated with a severe prognosis. Moreover, diagnosis may often be difficult because of its complications and extracardiac manifestations; thus, a comprehensive assessment of the clinical, echocardiographic and laboratory data must be performed. Early PVE, comorbidity, severe heart failure and new prosthetic dehiscence are predictors of mortality. Therapy is not indicated by evidence-based recommendations but mostly on identification of the high-risk conditions. A PVE is a common indication for surgery, whereas medical treatment alone may be achieved in a few instances. Systematic prophylaxis should be used to prevent this severe complication of cardiac valve replacement.

The changing face of prosthetic valve endocarditis at a tertiary-care hospital: 1986-2005

INTRODUCTION AND OBJECTIVES

To investigate changes in the clinical characteristics, etiology and prognosis of prosthetic valve endocarditis at a tertiary-care hospital.

METHODS

Retrospective cohort study of all patients diagnosed with prosthetic valve endocarditis using modified Duke criteria between 1986 and 2005. The analysis covered two time periods: January 1986 to December 1995 (P1) and January 1996 to December 2005 (P2).

RESULTS

In total, 133 episodes of endocarditis occurred in 122 patients. Of these, 73 (54.9%) were diagnosed in P1 and 60 (45.1%) in P2, with incidences of 2.19% and 2.18%, respectively. The patients' mean age (SD) was 52.6+/-16.6 years in P1 and 66.2+/-11.5 years in P2 (P=.0001). Clinical characteristics were similar in the two study periods. The increase in Enterococcus infection was remarkable (12.5% in P2 vs. 4.9% in P1; relative risk [RR]=2.5; 95% confidence interval [CI], 0.7-9.6), as was the decrease in viridans group Streptococcus infection (12.5% in P2 vs. 31.1% in P1; RR=0.4; 95% CI, 0.2-0.9). Some 90.4% of patients (63/73) underwent surgery in P1, while 68.3% (41/60) underwent surgery in P2. The difference was significant (RR=0.8; 95% CI, 0.6-0.9). The in-hospital mortality rate was 28.8% in P1 and 30% in P2 (RR=1; 95% CI, 0.6-1.7).

CONCLUSIONS

Changes in the epidemiology and microbiological etiology of prosthetic valve endocarditis were observed over the 20-year study period. Diagnostic and therapeutic approaches also changed, but mortality remained high.

Acute infective endocarditis

Acute infective endocarditis is a complex disease with changing epidemiology and a rapidly evolving knowledge base. To consistently achieve optimal outcomes in the management of infective endocarditis, the clinical team must have an understanding of the epidemiology, microbiology, and natural history of infective endocarditis, as well as a grasp of guiding principles of diagnosis and medical and surgical management. The focus of this review is acute infective endocarditis, though many studies of diagnosis and treatment do not differentiate between acute and subacute disease, and indeed many principles of diagnosis and management of infective endocarditis for acute and subacute disease are identical.

[Infective endocarditis: considerations regarding optimal timing for surgical treatment]

BACKGROUND

Treatment of infective endocarditis is primarily conservative. Persistent infection, tissue destruction und hemodynamic instabilities argue - in dependence on the microorganisms involved - for an urgent surgical treatment, even when there is still no control of the local and systemic infection. For timing of the surgical intervention, the following suggestions seem to be valid: TIMING OF THE SURGICAL INTERVENTION: Delayed surgical indication is considered a prognostic factor of extraordinary relevance for surgical treatment of infective endocarditis. Presence of intramyocardial, paravalvular and root abscess or development of a septic cardiomyopathy (in addition to the valve-related disturbed pump and muscular function), systemic sepsis and irreversible extracardiac organ destruction (liver, spleen, kidney, brain, lung, bone, etc.) reduce the surgical prognosis even after successful and complete surgical treatment. Extracardiac foci may determine the postoperative course. After cerebral embolization the cardiac operation should be performed as early as possible (within 24-48 h after embolization). Extreme extent of cardiac and extracardiac tissue destruction due to delayed surgical indication can result in a situation, where adequate surgical treatment of the local focus is not likely to be successful anymore and prognosis becomes infaust. In their own patients, the authors observed: NYHA (New York Heart Association) III-IV > 50%; renal failure (dialysis) > 15%, systemic embolization > 30%, cerebral embolization > 8%, cardiogenic shock > 10%.

SURGICAL TREATMENT

The most important aspect is complete debridement of all infected tissue with a safety margin of about 3 mm. This holds true, even if it results in resection of the entire aortic root, mitral ring, aortic wall, and atrial tissue. There is no contraindication to the implantation of prosthetic materials (valves, bovine pericardium, mitral rings) as long as surgical debridement has been prompt and aggressive. Not the type of prosthesis, but the quality of surgical debridement is of prognostic relevance. Reconstructive techniques are suggested whenever possible and are primarily effective for the treatment of mitral and tricuspid valves. Prompt and aggressive eradication of extracardiac foci is important to the patient's postoperative course.

POSTOPERATIVE COURSE AND TIMING OF THE OPERATION

After successful surgical treatment of the intracardiac focus, the postoperative course is mainly determined by extracardiac foci, systemic sepsis, and persistent secondary organ destruction.

PERSPECTIVE

As the results of conservative treatment of infective endocarditis are still not satisfactory, in some subgroups improved surgical results due to aggressive and radical debridement of infective tissue (with a safety margin of at least 3 mm) will suggest the surgical treatment option even in those patients, that have primarily been considered for conservative treatment.

[Timing and indications for surgical intervention in infective endocarditis]

This paper reviews current knowledge on the indications for and timing of cardiac surgery in patients with infective endocarditis. The main indications for surgery are haemodynamic compromise, persisting infection, peripheral embolisation, large size of vegetations, large valvular and paravalvular damage and infections caused by certain microorganisms.

Prosthetic valve endocarditis: current approach and therapeutic options

Despite improvements in medical and surgical therapy, prosthetic valve endocarditis is still associated with a severe prognosis, and remains a diagnostic and therapeutic challenge. Diagnosis of prosthetic valve endocarditis is more difficult than that of the native valve endocarditis and the application of Duke criteria is less useful in this setting. Therapeutic strategies are not guided by evidence-based recommendations and are mainly based on a careful prognostic evaluation, which allows the identification of high-risk subgroups. Continuous effort have to be made to detect early this severe complication of valve replacement and to prevent it using systematic prophylaxis.

Acute dehiscence of a valve prosthesis 5 years after implantation

Propionibacterium acnes, a common human skin organism [Perry A.L., Lambert P.A., Under the microscope Propionibacterium acnes, Lett App Microbiol 2006; 42:185-186], mostly considered a contaminant, has rarely been associated with cases of infectious endocarditis [Vanagt W.Y., Daenen W.J., Delhaas T., Propionibacterium acnes endocarditis on an annuloplasty ring in an adolescent boy, Heart 2004; 90:56]. We report on a 48-year old man with a history of mitral valve replacement who acutely developed dyspnoea, tachypnoea and forward failure. Transesophageal echocardiography showed a dehiscence of the St. Jude mechanical mitral prosthesis necessitating urgent surgery. The prosthesis was replaced by another St. Jude mechanical valve. Blood cultures were initially negative but after a prolonged incubation period the tissue cultures became positive for Propionibacterium acnes. In cases of valvular dehiscence without macroscopic signs of endocarditis, communication between clinicians and the laboratory is important in order to incubate blood and tissue samples for a longer period of time to be able to detect exceptional causes of endocarditis.

Subcoronary Ross Procedure in Patients With Active Endocarditis

BACKGROUND

The Ross procedure has gained increasing interest as an attractive alternative to a prosthetic aortic valve substitute within the last decade. Because of a probably better resistance to infection as one of its advantages, the pulmonary autograft is theoretically preferable for active endocarditis.

METHODS

Between June 1994 and July 2003, the Ross procedure was performed using the subcoronary and inclusion technique in 296 patients (231 male, 65 female). Twenty patients had an active endocarditis of the aortic valve at the time of operation. A bicuspid valve was present in 10 patients. One patient had previous aortic valve surgery. Clinical and echocardiographic follow-up was complete.

RESULTS

Early mortality was 1, late mortality was 0. There were no recurrence of endocarditis and no neurologic events during the mean follow-up of 47.3 +/- 28.6 months. All patients were in New York Heart Association class I. Mean and maximum pressure gradient across the autograft was 3.5 +/- 2.0 and 6.5 +/- 3.4, respectively, with no autograft insufficiency in 15, 1+ in 4. Comparing postoperative with the last investigations, there were no significant changes of pressure gradients or grade of regurgitation. Mean and maximum homograft pressure gradients were 7.9 +/- 3.7 and 16.2 +/- 8.1 mm Hg, respectively, at last investigation; most patients had no or mild homograft regurgitation (0+, n = 13; 1+, n = 5; 2+, n = 1).

CONCLUSIONS

Native valve endocarditis can be treated with excellent results using the Ross procedure with the subcoronary and inclusion technique, with low mortality and morbidity rates and a very low recurrence rate of endocarditis.

Prosthetic valve endocarditis: who needs surgery? A multicentre study of 104 cases

OBJECTIVES

To identify the prognostic markers of a bad outcome in a large population of 104 patients with prosthetic valve endocarditis (PVE), and to study the influence of medical versus surgical strategy on outcome in PVE and thus to identify patients for whom surgery may be beneficial.

DESIGN

Multicentre study.

METHODS AND RESULTS

Among 104 patients, 22 (21%) died in hospital. Factors associated with in-hospital death were severe co-morbidity (6% of survivors v 41% of those who died, p = 0.05), renal failure (28% v 45%, p = 0.05), moderate to severe regurgitation (22% v 54%, p = 0.006), staphylococcal infection (16% v 54%, p = 0.001), severe heart failure (22% v 64%, p = 0.001), and occurrence of any complication (60% v 90%, p = 0.05). By multivariate analysis, severe heart failure (odds ratio 5.5) and Staphylococcus aureus infection (odds ratio 6.1) were the only independent predictors of in-hospital death. Among 82 in-hospital survivors, 21 (26%) died during a 32 month follow up. A Cox proportional hazards model identified early PVE, co-morbidity, severe heart failure, staphylococcus infection, and new prosthetic dehiscence as independent predictors of long term mortality. Mortality was not significantly different between surgical and non-surgical patients (17% v 25%, respectively, not significant). However, both in-hospital and long term mortality were reduced by a surgical approach in high risk subgroups of patients with staphylococcal PVE and complicated PVE.

CONCLUSIONS

Firstly, PVE not only carries a high in-hospital mortality risk but also is associated with high long term mortality and needs close follow up after the initial episode. Secondly, congestive heart failure, early PVE, staphylococcal infection, and complicated PVE are associated with a bad outcome. Thirdly, subgroups of patients could be identified for whom surgery is associated with a better outcome: patients with staphylococcal and complicated PVE. Early surgery is strongly recommended for these patients.