Determinants of the occurrence of and survival from prosthetic valve endocarditis

Healthcare exposures and associated risk of endocarditis after open-heart cardiac valve surgery

BACKGROUND

Infective endocarditis (IE) following cardiac valve surgery is associated with high morbidity and mortality. Data on the impact of iatrogenic healthcare exposures on this risk are sparse. This study aimed to investigate risk factors including healthcare exposures for post open-heart cardiac valve surgery endocarditis (PVE).

METHODS

In this population-linkage cohort study, 23,720 patients who had their first cardiac valve surgery between 2001 and 2017 were identified from an Australian state-wide hospital-admission database and followed-up to 31 December 2018. Risk factors for PVE were identified from multivariable Cox regression analysis and verified using a case-crossover design sensitivity analysis.

RESULTS

In 23,720 study participants (median age 73, 63% male), the cumulative incidence of PVE 15 years after cardiac valve surgery was 7.8% (95% CI 7.3-8.3%). Thirty-seven percent of PVE was healthcare-associated, which included red cell transfusions (16% of healthcare exposures) and coronary angiograms (7%). The risk of PVE was elevated for 90 days after red cell transfusion (HR = 3.4, 95% CI 2.1-5.4), coronary angiogram (HR = 4.0, 95% CI 2.3-7.0), and healthcare exposures in general (HR = 4.0, 95% CI 3.3-4.8) (all p < 0.001). Sensitivity analysis confirmed red cell transfusion (odds ratio [OR] = 3.9, 95% CI 1.8-8.1) and coronary angiogram (OR = 2.6, 95% CI 1.5-4.6) (both p < 0.001) were associated with PVE. Six-month mortality after PVE was 24% and was higher for healthcare-associated PVE than for non-healthcare-associated PVE (HR = 1.3, 95% CI 1.1-1.5, p = 0.002).

CONCLUSIONS

The risk of PVE is significantly higher for 90 days after healthcare exposures and associated with high mortality.

Surgical Challenges in Infective Endocarditis: State of the Art

Infective endocarditis (IE) is still a life-threatening disease with frequent lethal outcomes despite the profound changes in its clinical, microbiological, imaging, and therapeutic profiles. Nowadays, the scenario for IE has changed since rheumatic fever has declined, but on the other hand, multiple aspects, such as elderly populations, cardiovascular device implantation procedures, and better use of multiple imaging modalities and multidisciplinary care, have increased, leading to escalations in diagnosis. Since the ESC and AHA Guidelines have been released, specific aspects of diagnostic and therapeutic management have been clarified to provide better and faster diagnosis and prognosis. Surgical treatment is required in approximately half of patients with IE in order to avoid progressive heart failure, irreversible structural damage in the case of uncontrolled infection, and the prevention of embolism. The timing of surgery has been one of the main aspects discussed, identifying cases in which surgery needs to be performed on an emergency (within 24 h) or urgent (within 7 days) basis, irrespective of the duration of antibiotic treatment, or cases where surgery can be postponed to allow a brief period of antibiotic treatment under careful clinical and echocardiographic observation. Mainly, guidelines put emphasis on the importance of an endocarditis team in the handling of systemic complications and how they affect the timing of surgery and perioperative management. Neurological complications, acute renal failure, splenic or musculoskeletal manifestations, or infections determined by multiresistant microorganisms or fungi can affect long-term prognosis and survival. Not to be outdone, anatomical and surgical factors, such as the presence of native or prosthetic valve endocarditis, a repair strategy when feasible, anatomical extension and disruption in the case of an annular abscess (mitral valve annulus, aortic mitral curtain, aortic root, and annulus), and the choice of prosthesis and conduits, can be equally crucial. It can be hard for surgeons to maneuver between correct pre-operative planning and facing unexpected obstacles during intraoperative management. The aim of this review is to provide an overview and analysis of a broad spectrum of specific surgical scenarios and how their challenging management can be essential to ensure better outcomes and prognoses.

Ultra-multiplex PCR technique to guide treatment of Aspergillus-infected aortic valve prostheses

Prosthetic valve endocarditis is a serious complication after heart valve replacement, accounting for about 20-30% of infective endocarditis (IE). Aspergillosis infection accounts for 25-30% of fungal endocarditis, and the mortality rate is 42-68%. Aspergillus IE often has negative blood cultures and lacks fever, which makes diagnosis difficult and delays antifungal therapy. Our study reported a case of IE in a patient with Aspergillus infection after aortic valve replacement. Ultra-multiplex polymerase chain reaction was used to identify Aspergillus infection and guide treatment. The purpose of this study was to enhance the understanding of the management of patients with endocarditis infected by fungi after valve replacement regarding the early detection, timely intervention, and treatment of the fungal infection to reduce the risk of death and improve the long-term survival of patients.

Multivalvular Endocarditis: A Rare Condition with Poor Prognosis

Background. Infective endocarditis (IE) is a severe condition. Our aim was to describe the profile and prognosis of patients with multivalvular infective endocarditis (MIE) and compare them to single-valve IE (SIE). Methods. We used a retrospective analysis of the Spanish IE Registry (2008−2020). Results. From 4064 definite cases of valvular IE, 577 (14.2%) had MIE. In patients with MIE, the most common locations were mitral (552, 95.7%) and aortic (550, 95.3%), with mitral-aortic involvement present in 507 patients (87.9%). The most common etiologies were S. viridans (192, 33.3%) and S. aureus (113, 19.6%). MIE involved only native valves in 450 patients (78.0%). Compared with patients with SIE, patients with MIE had a similar age (69 vs. 67 years, respectively, p = 0.27) and similar baseline characteristics, but were more frequently men (67.1% vs. 72.9%, p = 0.005) and had a higher incidence of intracardiac complications (36.2% vs. 50.4%, p < 0.001), heart failure (42.7% vs. 52.9%, p < 0.001), surgical indication (67.7 vs. 85.1%, p < 0.001), surgery (46.3% vs. 56.3%), and in-hospital mortality (26.9% vs. 34.3%, p < 0.001). MIE was an independent predictor of in-hospital mortality (odds ratio (OR) 1.3, 95% confidence interval (CI) 1.1−1.7, p = 0.004) but did not have an independent association with 1-year mortality (OR 1.1, 95% CI 0.9−1.4, p = 0.43). Conclusions. About one-seventh of the valvular IE patients had MIE, mainly due to mitral-aortic involvement. MIE is associated with a poor in-hospital prognosis. An early diagnosis and treatment of IE might avoid its spread to a second valve.

A fatal case of early prosthetic valve endocarditis caused by multidrug-resistant (MDR) - Sphingomonas paucimobilis

Sphyngomonas paucimobilis (S. paucimobilis) is a low-pathogenicity, gram-negative bacilli (GNB) that are previously known as an opportunist microorganism. Recent studies have shown that S. paucimobilis is an emerging pathogen causing various infections. Multidrug-resistant GNB has emerged as a major clinical and therapeutic dilemma in various hospital-associated infections. Although rare, S. paucimobilis could be associated with infective endocarditis (IE). Prosthetic valve endocarditis (PVE) is the most severe type of IE, which has high mortality rates despite diagnostic and treatment advances. We report a fatal case of early PVE associated with multidrug-resistant (MDR) - S. paucimobilis complicated with perivalvular abscess, complete heart block, valve detachment, and septic arthritis.

Long-term outcomes of aortic root replacement for endocarditis

BACKGROUND

Infective endocarditis (IE) involving the aortic valve and root is associated with high risk requiring thoughtful surgical decision-making. The impact of valve and conduit choices and patient factors on long-term outcomes in this patient population is poorly documented.

METHODS

From January 1976 to December 2013, 485 patients underwent aortic root and valve replacement at a single institution. Cox's proportional hazard model identified predictors of long-term survival and cumulative incidence functions were compared to assess need for reoperation with death as a competing risk.

RESULTS

Median age at time of operation was 56.6 years (interquartile range: 23.1) with the indication for operation being endocarditis in 14.6% (n = 71). Stentless root replacement was used in 70% IE versus 34% non-IE (p < .001). Endocarditis at time of root replacement did not have a significant impact on survival through 15 years (IE: 37.3% vs. non-IE: 42.5%; log-rank; p = .13). After multivariable adjustment, survival was similar between patients with and without endocarditis (hazard ratio: 1.1; 95% confidence interval: [0.77, 1.62]; p = .57). Freedom from reoperation at 15 years did not vary significantly by endocarditis status (IE: 95.9% vs. non-IE: 73.6%; p = .07). Among endocarditis patients, freedom from reoperation at 10 years was similar between homograft and stentless bioprosthetic conduits (95.3% vs. 88.5%; log-rank; K-sample; p = .46).

CONCLUSIONS

In a sample with frequent use of stentless prostheses, aortic root replacement for infective endocarditis had acceptable risk and long-term survival similar to root replacement for other indications. In the setting of endocarditis, root replacement with homograft or stentless bioprosthetic root has excellent durability through 15 years.

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.

Prosthetic valve endocarditis - A trouble or a challenge?

Prosthetic valve endocarditis (PVE) represents a rare and serious complication of valve replacement associated with high morbidity and mortality, which significantly differs from native valve endocarditis (NVE). There are two major problems: establishing diagnosis and treatment of PVE. Diagnosis in PVE is challenging and often requires several imaging methods besides standard microbiological analyzes. Transesophageal echocardiographic examination remains the widely used imaging technique in PVE diagnosis, but additional techniques such as computed tomography (CT) and ¹⁸F-fluodeoxyglucose positron emission tomography/CT are often necessary. Persistent fever, embolic complications, valve dehiscence, intracardial abscess, heart failure, as well as staphylococcal and fungal PVE require surgical treatment to avoid lethal outcome. The introduction of transcatheter valve implantations and devices significantly complicated the approach - diagnostic and therapeutic to PVE patients. Despite constantly increasing knowledge regarding pathogenesis and treatment of PVE, the optimal therapy remains a matter of debate. Additional studies are necessary to define therapeutic strategies for this potentially fatal complication.

Catastrophic Prosthetic Valve Endocarditis Caused by Rare Black Fungi

Fungal infection of prosthetic heart valves is rare and can lead to severe complications including death. Dematiaceous mold, also known as "black fungi," are an extremely rare cause of endocarditis that usually affect immunocompromised hosts. The infection is usually chronic and can lead to heart failure and embolic complications. These fungi have limited antifungal treatment modalities. We present a rare case of prosthetic aortic valve, root, and graft infection in an immunocompetent host that revealed itself through renal, mesenteric, and cerebral embolic phenomenon. The patient underwent removal and replacement of the aortic graft followed by small bowel resection for mesenteric infarction. Patient had a successful postoperative course and underwent a long-term antifungal treatment with amphotericin B and voriconazole.

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.

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.

Excision of Aortic Vegetation in Brucella Endocarditis

A 19-year-old man with brucella endocarditis was treated by antimicrobial therapy and surgical excision of vegetation with preservation of the native aortic valve.

Choice of prosthetic heart valve in a developing country

Mechanical prostheses and stented xenografts (bioprosthesis) are most commonly used substitutes for aortic and mitral valve replacement. The mechanical valves have the advantage of durability but are accompanied with the risk of thromboembolism, problems of long-term anticoagulation, and associated risk of bleeding. In contrast, bioprosthetic valves do not require long-term anticoagulation, but carry the risk of structural valve degeneration and re-operation. A mechanical valve is favoured in young patients (<40 years) if reliable anticoagulation is ensured. In elderly patients (>60 years), a bioprosthesis is a suitable substitute. In middle-aged patients (40-60 years), risk of re-operation in a bioprosthesis is equal to that of bleeding in a mechanical valve. Traditionally, a bioprosthesis is opted in patients with limited life expectancy. Calculation of life expectancy, based solely upon chronological age, is erroneous. In developing countries, the calculated life expectancy is much lower than that of Western population, hence age related Western cut-offs are not valid in developing countries. Besides age, cardiac condition of the patient, systemic illnesses, socio-economic status, gender and geographical location also decide the life expectancy of the patients. Selection of the prosthetic valve substitute should be based on: aspiration of the patient, life expectancy, socio-economic and educational background, occupation of the patient, availability, cost, monitoring of anti-coagulation, monitoring of valve function and other valve related complications, and possibility of re-operation.

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.

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.

Valve disease in pregnancy

Maternal cardiac disease is a major cause of non-obstetric morbidity and accounts for 10-25% of maternal mortality. Valvular heart disease may result from congenital abnormalities or acquired lesions, some of which may involve more than one valve. Maternal and fetal risks in pregnant patients with valve disease vary according to the type and severity of the valve lesion along with resulting abnormalities of functional capacity, left ventricular function, and pulmonary artery pressure. Certain high-risk conditions are considered contraindications to pregnancy, while others may be successfully managed with observation, medications, and, in refractory cases, surgical intervention. Communication between the patient׳s obstetrician, maternal-fetal medicine specialist, obstetrical anesthesiologist, and cardiologist is critical in managing a pregnancy with underlying maternal cardiac disease. The management of the various types of valve diseases in pregnancy will be reviewed here, along with a discussion of related complications including mechanical prosthetic valves and infective endocarditis.

Evaluation of fever and infections in cardiac surgery patients

Fever following cardiac surgery is common and may be infectious or noninfectious in etiology. In this article, we review the major causes of postoperative fever while highlighting special considerations in cardiac surgery patients. We also outline a structured approach to evaluation and present an overview of diagnostic and management considerations for mediastinitis, postpericardiotomy syndrome, prosthetic valve endocarditis, aortic vascular graft infections, and ventricular assist device infections.

Early and late outcomes after reoperation for prosthetic valve endocarditis

OBJECTIVE

Prosthetic valve endocarditis remains a challenging complication after heart valve replacement. To identify predictive risk factors, we have reviewed 30 patients who underwent surgery for prosthetic valve endocarditis between March 1986 and May 1999.

METHODS

There were 15 men and 15 women (mean age 51 years). Prosthetic valve endocarditis was classified as early (< or = 1 year after operation) in 10 cases, and as late in the other 20 cases. The most common indication for surgery was moderate to severe congestive heart failure due to prosthetic valve dysfunction in 21 (70%) patients. The average follow-up period was 6.5 years, with a range of 0.3 to 14.1 years.

RESULTS

The most common microorganism was Staphylococcus epidermidis in both patients with early (50%) and late prosthetic valve endocarditis (25%). The in-hospital mortality was 13.3% (4/30). There were six late deaths. The actuarial survival at 5 years was 78% and 66% at 10 years. An early onset of prosthetic valve endocarditis was the only significant determinant of both in-hospital mortality (p = 0.005) and overall mortality (p = 0.021). Emergency surgery had a statistically significant relationship with in-hospital mortality (p = 0.045). No significant influence on mortality after reoperation for prosthetic valve endocarditis was found in age, sex, valve position, antecedent native valve endocarditis, or in the type of pathological findings (ring abscess, valve dehiscence, and vegetation).

CONCLUSION

Early onset of prosthetic valve endocarditis and emergency surgery were important risk factors for mortality due to prosthetic valve endocarditis.

Surgical treatment of infective endocarditis in active intravenous drug users: a justified procedure?

BACKGROUND

Infective endocarditis is a life threatening complication of intravenous drug abuse, which continues to be a major burden with inadequately characterised long-term outcomes. We reviewed our institutional experience of surgical treatment of infective endocarditis in active intravenous drug abusers with the aim of identifying the determinants long-term outcome of this distinct subgroup of infective endocarditis patients.

METHODS

A total of 451 patients underwent surgery for infective endocarditis between January 1993 and July 2013 at the University Hospital of Heidelberg. Of these patients, 20 (7 female, mean age 35 ± 7.7 years) underwent surgery for infective endocarditis with a history of active intravenous drug abuse. Mean follow-up was 2504 ± 1842 days.

RESULTS

Staphylococcus aureus was the most common pathogen detected in preoperative blood cultures. Two patients (10%) died before postoperative day 30. Survival at 1, 5 and 10 years was 90%, 85% and 85%, respectively. Freedom from reoperation was 100%. Higher NYHA functional class, higher EuroSCORE II, HIV infection, longer operating time, postoperative fever and higher requirement for red blood cell transfusion were associated with 90-day mortality.

CONCLUSIONS

In active intravenous drug abusers, surgical treatment for infective endocarditis should be performed as extensively as possible and be followed by an aggressive postoperative antibiotic therapy to avoid high mortality. Early surgical intervention is advisable in patients with precipitous cardiac deterioration and under conditions of staphylococcal endocarditis. However, larger studies are necessary to confirm our preliminary results.

Fungal Prosthetic Valve Endocarditis by Candida parapsilosis: A Case Report

Introduction:

Fungal prosthetic valve endocarditis (PVE) is rare but serious complication of valve replacement surgery. Candida species, particularly Candida albicans is the most common isolated pathogen in fungal PVE (1–6%of cases).

Case Presentation:

We describe a 35-year-old woman who underwent mechanical mitral valve replacement about 3 years ago. She was admitted with neurological symptoms and later with dyspnea and hypotension. Transesophageal echocardiography showed large and mobile prosthetic valve vegetation. She underwent mitral valve surgery. The explanted valve and vegetation revealed lots of budding yeasts and the isolated yeast was identified as C. parapsilosis. Amphotericin B and broad spectrum antibiotic were started immediately. Unfortunately, the patient died two days after surgery, due to sepsis probably related to the candidemia.

Conclusions:

Fungal endocarditis is uncommon infection, but it is a serious problem in patients with prosthetic valve. Fungal PVE can occur years after the surgery, thus long-term follow-up is essential.

FDG-PET in cardiac infections

Cardiac infections include a group of conditions involving the heart muscle, the pericardium, or the endocardial surface of the heart. Infections can extend to prosthetic material or the leads in case of the implantation of devices. Despite their relative low incidence, these conditions that are associated with high morbidity and mortality involve a relevant burden of diagnostic workup. Early diagnosis is crucial for adequate management of patient, as early treatment improves the prognosis; unfortunately, the clinical manifestations are often nonspecific. Accurate and timely diagnosis typically requires the correlation of imaging findings with laboratory data. (18)F-FDG-PET is a well-established imaging modality for the diagnosis and management of malignancies, and evidence is also increasing regarding its value for assessing infectious and inflammatory diseases. This article summarizes published evidence on the usefulness of (18)F-FDG-PET for the diagnosis of cardiac infections, mainly focused on endocarditis and cardiovascular device infections. Nevertheless, the diagnostic potential of (18)F-FDG-PET in patients with pericarditis and myocarditis is also briefly reviewed, considering the most likely future advances and new perspectives that the use of PET/magnetic resonance would open in the diagnosis of such conditions.

Current diagnosis and treatment of infective endocarditis

The incidence of infective endocarditis continues to rise with a yearly incidence of around 15,000 to 20,000 new cases in the USA. As a result, rapid diagnosis, effective treatment and prompt recognition of complications are essential to desirable clinical outcomes. Recent guidelines such as the Duke criteria have incorporated echocardiography for diagnosis of infective endocarditis, making this diagnostic test mandatory for patients with suspected infective endocarditis. The diversity of pathogens that can cause infective endocarditis, some of which cannot be cultured easily, makes diagnosis even more difficult. Coagulase-negative staphylococci and viridans streptococci groups continue to be the major causative microorganisms of infective endocarditis. In the case of culture-negative endocarditis or infective endocarditis caused by fastidious microorganisms, the polymerase chain reaction and probe-based diagnostic methods are available to clinical reference laboratories.

Management of prosthetic heart valve complications

OPINION STATEMENT

With greater awareness and treatment of valvular heart disease, there are now an increasing number of patients with prosthetic heart valves. However, replacement of a diseased valve with a prosthetic valve creates the opportunity for new and unique complications that once diagnosed require specific treatments. Complications which may occur depend not only on the type of prosthesis but also are influenced by clinical factors that are important to understand and may affect treatment strategies. Tissue prostheses tend to deteriorate over time while mechanical prostheses require anticoagulation with its attendant risks. The rate of serious prosthetic heart valve complications is approximately 3 % per year. They include bleeding, systemic embolization, obstruction due to thrombus or pannus formation, patient-prosthesis mismatch, infective endocarditis, structural deterioration, prosthetic and peri-prosthetic regurgitation, and hemolysis. Importantly, the risk of prosthetic heart valve complications can be reduced by appropriate choices made at the time of surgery such as utilization of the correct prosthesis size and type. In addition, adherence to current guidelines for anticoagulation, endocarditis prophylaxis, and the timing of clinical and echocardiographic surveillance is also important to prevent complications. Should complications occur, rapid diagnosis, usually with echocardiography, is pivotal and can provide important hemodynamic as well as anatomic information critical to determining appropriate treatment and timing of surgical re-intervention if necessary. Optimal treatment of prosthetic heart valve complications remains a challenge and new treatment strategies continue to evolve.

Surgical intervention for infective endocarditis in a veteran population

BACKGROUND

Surgical management of infective endocarditis can be challenging. Veteran patients are unique because they often have significant comorbidities, and surgical management of endocarditis in this population has not been well described.

METHODS

Using a prospective database, 46 consecutive patients who underwent valve surgery for acute infective endocarditis between 1987 and 2009 were identified. Survival was assessed using the Kaplan-Meier method.

RESULTS

All patients were men (mean age, 56 ± 9 years). The most common indication for surgical intervention was congestive heart failure (60%). The aortic valve was the only valve infected in most patients (65%). Operative morbidity and mortality were 33% and 9%, respectively. The 1-year, 3-year, 5-year, and 10-year unadjusted survival rates were 72%, 57%, 51%, and 30%, respectively.

CONCLUSIONS

Although acceptable short-term outcomes can be achieved in veterans undergoing surgical treatment for endocarditis, unadjusted long-term survival may be poor.

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.

Extensive Salmonella enteritidis endocarditis involving mitral, tricuspid valves, aortic root and right ventricular wall

After conducting a PubMed search, 11 articles describing a total of 12 cases of native valve Salmonella enteritidis (S. enteritidis) endocarditis were identified in the English literature. Only 13 cases of prosthetic valve endocarditis attributed to S. enteritidis have been published in the English literature. Only 1 case involving the myocardium and other valves concomitantly could be located. Transthoracic echocardiography proved inadequate to demonstrate valvular vegetations. Transesophageal echocardiography was instrumental in establishing the diagnosis of endocarditis by documenting vegetations. S. enteritidis endocarditis can cause devastating endovascular infections in immunocompromised patients. Patients who present with multiple vague symptoms with medical histories that include diabetes mellitus, immunocompromise, and prosthetic heart valves should alert clinicians to strongly consider S. enteritidis endocarditis in their differential diagnoses. Despite considerable effort, S. enteritidis endocarditis poses very high risk for morbidity and mortality.

Complexity and subtlety of infective endocarditis

Infective endocarditis (IE) is an uncommon clinical entity that, if unrecognized, leads to serious morbidity and mortality. Approximately 15,000 new cases of IE occur in the United States each year. Despite advances in early diagnosis, antimicrobial treatment, and surgical techniques, reported mortality from referral centers has changed little throughout several decades. Early recognition of IE requires understanding of its epidemiology, risk factors, clinical presentations, physical examination signs, microbiological associations, and electrocardiographic and chest radiographic findings. Once IE is suspected, further testing with blood cultures and echocardiography can confirm the diagnosis and lead to early treatment with bactericidal antibiotics and surgery when appropriate, thus reducing the morbidity and mortality of IE. Unrecognized and untreated, IE is invariably fatal. Early recognition of IE and an in-depth understanding of the clinical vagaries of IE are mandatory for all patient care providers.

Long-term outcomes in valve replacement surgery for infective endocarditis

BACKGROUND

Infective endocarditis is associated with a high rate of long-term mortality. Patients with a history of intravenous drug use (IVDU) are at increased risk for infective endocarditis. However, few studies have reported results of surgical treatment on this population. We present 19.5 years of experience with surgically treated patients with infective endocarditis.

METHODS

A retrospective study of all cardiac surgeries with a diagnosis of infective endocarditis at a single institution from 1986 to 2005 was performed. Logistic stepwise regression with an end point of operative mortality was done. Variables were age, gender, race, history of drug use, previous valve surgery, and previous valve replacement. Perioperative and outcome variables were compared between IVDU and non-IVDU populations.

RESULTS

The IVDU population required surgery at a younger age (39 +/- 9 years versus 54 +/- 15 years; p < 0.001). Overall operative mortality was 12% (41/346). The perioperative complication rate was similar for both groups. When adjusted for age, the two groups had similar long-term survival (p = 0.78). Kaplan-Meier estimator showed that survival at 10 and 15 years was 66% and 54% for IVDU and 56% and 42% for non-IVDU (number at risk, 19, 11, and 61, 28, respectively; p = 0.137). Reoperation for recurrent infective endocarditis was necessary in 9 (17%) of 52 of the IVDU group versus 14 (5%) of 270 of the non-IVDU group (p = 0.03).

CONCLUSIONS

Patients with a history of IVDU required reoperation for recurrent infective endocarditis at a significantly higher rate than the non-IVDU patients. Long-term survival was similar between the younger IVDU population and the older non-IVDU population. Anticipated life span is one of many factors when considering prosthetic valve choice in this population.

Successful treatment of polymicrobial multivalve infective endocarditis

A 57-year-old man presented with triple valve infective endocarditis. There were vegetations on the tricuspid, mitral, and aortic valve. He had multiple complications such as pulmonary abscess, severe anaemia, and congestive heart failure. His general condition was extremely poor. Intensive medical therapy, such as blood transfusion, mechanical ventilation, and inotropic support, allowed him to tolerate surgery. Triple valve replacement was successfully performed without major complication. Vegetation cultures grew Streptococcus bovis and Enterecoccus faecalis. At 1 year follow-up, the patient is alive in NYHA functional class I.

Risk Factors of Prosthetic Valve Endocarditis: A Case-Control Study

BACKGROUND

Prosthetic valve endocarditis is an important cause of the morbidity and mortality associated with heart valve replacement surgery. The objective of this study was to assess risk factors of prosthetic valve endocarditis related to patients, perioperative events, and postoperative complications.

METHODS

This was a retrospective case-control study conducted in a tertiary care hospital in Santander, Spain, from January 1986 to January 1998. Cases were patients with "definite" and "possible" infective endocarditis defined according to the Durack criteria. Controls were patients undergoing prosthetic valve replacement who at the time of the study had not developed infective endocarditis. Information was abstracted from medical records. Cases and controls (1:2) were matched by sex, age at operation (+/- 5 years), surgery of one or more valves in the same anatomic position, and date of operation (+/- 6 months).

RESULTS

There were 81 cases and 162 controls. In the multivariate analysis, risk factors significantly associated with prosthetic valve endocarditis were functional class III or IV (New York Heart Association), alcohol consumption, prior history of endocarditis, fever in the intensive care unit, and gastrointestinal bleeding. Functional class III or IV and complications of the surgical wound were independent predictors of early infective endocarditis, whereas fever in the intensive care unit and gastrointestinal bleeding were predictors of prosthetic valve endocarditis late after operation.

CONCLUSIONS

Patients with prosthetic valve endocarditis differ from people without infective endocarditis with regard to intrinsic and postoperative risk factors but not regarding perioperative-related variables.

Prosthetic Valve Endocarditis Caused by Acinetobacter lwoffi

We are reporting a case of recurrent prosthetic-valve endocarditis (PVE) caused by an unusual pathogen. The patient suffered 2 consecutive relapses of Acinetobacter lwoffi bacteremia, although he had completed a full course of treatment with antibiotics to which the microorganism was susceptible. He was finally successfully operated with replacement of the infected aortic valve. Acinetobacter spp are relatively low-grade but potentially virulent pathogens, and endocarditis caused by these species can be fulminant, accompanied by septic complications, and fatal. Although some patients with relapsed PVE may respond to a second course of antibiotics and medical treatment rather than early valve replacement is suggested in A lwoffi PVE, combined antibiotic treatment and early surgical intervention may be considered as the first option in these patients. There are only a few cases of Acinetobacter endocarditis in the literature, and it is the first case reported in Greece to our knowledge.