Case definitions for infective endocarditis

Emerging new therapeutic antibody derivatives for cancer treatment

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Asymptomatic and symptomatic embolic events in infective endocarditis: associated factors and clinical impact

Background

Embolic complications of infective endocarditis are common. The impact of asymptomatic embolism is uncertain.

Objectives

To determine the frequency of emboli due to IE and to identify events associated with embolism.

Methods

Retrospective analysis of an endocarditis database, prospectively implemented, with a post hoc study driven by analysis of data on embolic events. Data was obtained from the International Collaboration Endocarditis case report forms and additional information on embolic events and imaging reports were obtained from the medical records. Variables associated with embolism were analyzed by the statistical software R version 3.1.0.

Results

In the study period, 2006–2011, 136 episodes of definite infective endocarditis were included. The most common complication was heart failure (55.1%), followed by embolism (50%). Among the 100 medical records analyzed for emboli in left-sided infective endocarditis, 36 (36%) were found to have had asymptomatic events, 11 (11%) to the central nervous system and 28 (28%) to the spleen. Cardiac surgery was performed in 98/136 (72%). In the multivariate analysis, splenomegaly was the only associated factor for embolism to any site (p < 0.01, OR 4.7, 95% CI 2.04–11). Factors associated with embolism to the spleen were positive blood cultures (p = 0.05, OR 8.9, 95% CI 1.45–177) and splenomegaly (p < 0.01, OR 9.28, 95% CI 3.32–29); those associated to the central nervous system were infective endocarditis of the mitral valve (p < 0.05, OR 3.5, 95% CI 1.23–10) and male gender (p < 0.05, OR 3.2, 95% CI 1.04–10). Splenectomy and cardiac surgery did not impact on in-hospital mortality.

Conclusions

Asymptomatic embolism to the central nervous system and to the spleen were frequent. Splenomegaly was consistently associated with embolic events.

Etiology and Risk Factors of 339 Cases of Infective Endocarditis: Report from a 10-year National Prospective Survey in the Slovak Republic

The authors studied the etiology, outcome and risk factors of 339 cases of infective endocarditis (IE) in Slovakia over the last 10 years. Aortic valve was infected in 59.9%, mitral in 38.1% and tricuspidal/pulmonary in 5.0% of cases. The majority of IE were caused by staphylococci (29.2%), 15.0% were due to viridans streptococci, 7.4% due to Enterococcus faecalis, 3.9% due to the HACEK group (Haemophilus spp., Actinobacillus spp., Corynebacterium spp., Eikenella spp., Kingella spp.) and 39.2% were culture negative. The following risk factors were the most frequently identified: rheumatic fever in 24.2%, dental surgery in 13.3%, previous cardiosurgery in 7.1% and neoplasia in 7.1%. All patients were treated with antimicrobials and 42.5% of patients also with surgery (valvular prosthesis replacement): 61 (18.0%) died, and 278 (82.0%) survived at day 60 after the diagnosis of endocarditis was made. Univariate analysis did not show significant differences in most of the recorded risk factors between patients who died and those who survived: apart from staphylococcal etiology (44.3% vs. 26.6%, P < 0.01), persistent bacteremia (with three or more positive blood cultures 24.6% vs. 9.7% P < 0.002) which were significantly associated with higher attributable mortality, as was absence of surgery (55.7% vs. 6.1% P < 0.001), whereas antibiotic therapy in combination with surgery significantly predicted better outcome (P < 0.001). We compared risk factors, etiology, therapeutic strategies and outcome of IE in two periods: from 1991-1997 (180 cases) and from 1998-2001 (159 cases). Rheumatic fever was less commonly observed in second period (1998-2001) P < 0.01 since its prevalence in Slovakia is rapidly decreasing. Dental surgery was less frequent as well (20.5% vs. 5.0% P < 0.001). There was a significant shift in etiology within the second study period: negative-culture endocarditis (despite better bacteriological techniques) (P < 0.001) was more frequently observed in the 1st period and represented 53.3% of all cases in 1998-2001 in comparison to 26.7% in 1991-1997. Enterococci (P < 0.0002) were also more frequent in the 2nd period. Persistent bacteremia (3 or more positive blood cultures 20.5% vs. 3.1%, P < 0.001 was less commonly observed within the 2nd period (1998-2001) in comparison to 1991-1997. More patients in the second period (1998-2001) had complications of IE (P < 0.001) than in the 1st period. However mortality was lower (22.2% vs. 13.2%, P < 0.044) because of more surgical intervention in the 2nd period (52.8% vs. 33.3%, P < 0.001).

Incidence of pneumococcal endocarditis: A regional health register-based study in Denmark 1981–1996

The aim of this study was to determine the incidence of pneumococcal endocarditis in 3 Danish counties. By linking the National Hospital Discharge Registry to regional blood culture registries maintained by the Department of Clinical Microbiology and autopsy registries from the Department of Pathology, a total of 31 cases of pneumococcal endocarditis was identified in the 3 counties during a period of 16 y (1981-1996). One patient experienced 2 independent episodes as determined by serotyping. The annual incidence increased approximately 4-fold during the study period, giving an overall incidence rate of 0.15 per 100,000 inhabitants. Pneumococcal endocarditis was diagnosed in 1.2% of cases of pneumococcal bacteraemia. Some cases may have remained undetected, and this underlines the need for clinical attention to this diagnosis. The study confirms that linkage of health registries is a valid method of conducting surveys of uncommon diseases.

The invasive and saprophytic syndromes due to Aspergillus spp

Aspergillus spp. produce a wide range of invasive and sapropytic syndromes which may involve any tissue. Within a given tissue or organ the pathology and pathogenesis varies enormously, ranging from angioinvasive disease to noninvasive saprophytic disease. The individual invasive and saprophytic syndromes in which a causative role can be attributed to Aspergillus spp. are detailed specifically with reference to the underlying pathology and pathogenesis, the clinical setting and features, and the manner in which a diagnosis can be established.

Incidence and short-term prognosis of infective endocarditis in Denmark, 1980-1997

Infective endocarditis is a serious bacterial infection, but there are relatively few data about its occurrence and prognosis. The incidence rate, 30-d case fatality and mortality rate of infective endocarditis were estimated in this registry-based cohort study. The Danish National Registry of Patients was used to estimate national incidence rates, and information on the date of death was obtained through linkage to the Civil Registration System. The study included 3351 patients with infective endocarditis from 1980 to 1997. The incidence rate for men increased from 4 to 6 per 100,000 person-years, and for women from 3 to 4 per 100,000 person-years. The mean incidence rate varied from 1.5 per 100,000 person-years in women younger than 50 y to 15.5 in men older than 70 y. The incidence increased in most age groups but was most pronounced in younger men. The overall 30-d case fatality rate of 23% increased with age and decreased with calendar time. The mean mortality rate was 0.94 per 100,000 y and decreased in the study period in most age groups. There was an increasing incidence of infective endocarditis and an improvement in the prognosis.

Staphylococcus aureus bacteremia and endocarditis

Staphylococcus aureus is a leading cause of bacteremia and endocarditis. Over the past several years, the frequency of S aureus bacteremia (SAB) has increased dramatically. This increasing frequency, coupled with increasing rates of antibiotic resistance, has renewed interest in this serious, common infection. S aureus is a unique pathogen because of its virulent properties, its protean manifestations, and its ability to cause endocarditis on architecturally normal cardiac valves. Although the possibility of underlying endocarditis arises in virtually every patient with SAB, only a minority of bacteremic patients will actually have cardiac involvement. Distinguishing patients with S aureus infective endocarditis (IE) from those with uncomplicated SAB is essential, but often difficult. In this review, the authors summarize recent changes in the epidemiology of SAB and IE, discuss the challenges in distinguishing SAB from IE, and discuss current trends in the management of patients with SAB and IE.

The prospective role of transesophageal echocardiography in the diagnosis and management of patients with suspected infective endocarditis

STUDY OBJECTIVES

Transesophageal echocardiography (TEE) has a high sensitivity for the diagnosis of infective endocarditis (IE), but the prospective role of TEE when added to a careful clinical examination has not been well-studied.

DESIGN

We compared the results of TEE to a clinical evaluation by an infectious disease specialist in 43 consecutive patients in whom TEE was ordered to rule out IE. Prior to TEE, the patients were classified on clinical grounds as to their likelihood of IE using a modification of the von Reyn criteria. Changes in management occurring as a result of TEE also were evaluated.

MEASUREMENTS AND RESULTS

TEE was positive in 11 patients, negative in 29, and indeterminate in 3. TEE was positive in 6 (46%) of 13 high probability patients, 2 (67%) of medium probability patients, and 3 (11%) of 27 low probability patients. A change in management based on TEE occurred in 4 (31%) patients with high probability, in no patients with medium probability, and in 1 (4%) patient with low probability.

CONCLUSIONS

TEE confirms IE in patients with high probability of IE and often leads to a management change. However, TEE is unlikely to establish the diagnosis or change management in patients with low probability.

Staphylococcus aureus bacteremia and endocarditis

Staphylococcus aureus is a leading cause of bacteremia and endocarditis. Over the past several years, the frequency of S. aureus bacteremia (SAB) has increased dramatically. This increasing frequency, coupled with increasing rates of antibiotic resistance, has renewed interest in this serious, common infection. S. aureus is a unique pathogen because of its virulent properties, its protean manifestations, and its ability to cause endocarditis on architecturally normal cardiac valves. Although the possibility of underlying endocarditis arises in virtually every patient with SAB, only a minority of bacteremic patients will actually have cardiac involvement. Distinguishing patients with S. aureus infective endocarditis (IE) from those with uncomplicated SAB is essential, but often difficult. In this review, the authors summarize recent changes in the epidemiology of SAB and IE, discuss the challenges in distinguishing SAB from IE, and discuss current trends in the management of patients with SAB and IE.

A retrospective review of 228 episodes of infective endocarditis where rheumatic valvular disease is still common

Two hundred and twenty-eight episodes of infective endocarditis in adult patients (mean age 36 years) were reviewed retrospectively. There were 183 episodes (80%) of native valve, 15 (7%) early prosthetic valve and 30 (13%) late prosthetic valve endocarditis. The most common predisposing factor was rheumatic valvular disease (65%). None of the patients were intravenous drug users. According to the Duke criteria, the number of definite, probable and rejected episodes were 121 (53%), 94 (41%) and 13 (6%), respectively. Additional minor criteria increased the number of definite endocarditis to 82%. The Duke criteria are not primarily intended to influence treatment decisions but are helpful in standardising research activities. The choice of the level of sensitivity or specificity of the criteria may be adjusted according to the aim of the study and prevalence of disease in a particular area. More sensitive criteria may be valuable in those countries where the prevalence of rheumatic valvular disease is still high.

Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis

Although the sensitivity and specificity of the Duke criteria for the diagnosis of infective endocarditis (IE) have been validated by investigators from Europe and the United States, several shortcomings of this schema remain. The Duke IE database contains records collected prospectively on >800 cases of definite and possible IE since 1984. Databases on echocardiograms and on patients with Staphylococcus aureus bacteremia at Duke University Medical Center are also maintained. Analyses of these databases, our experience with the Duke criteria in clinical practice, and analysis of the work of others have led us to propose the following modifications of the Duke schema. The category "possible IE" should be defined as having at least 1 major criterion and 1 minor criterion or 3 minor criteria. The minor criterion "echocardiogram consistent with IE but not meeting major criterion" should be eliminated, given the widespread use of transesophageal echocardiography (TEE). Bacteremia due to S. aureus should be considered a major criterion, regardless of whether the infection is nosocomially acquired or whether a removable source of infection is present. Positive Q-fever serology should be changed to a major criterion.

Echocardiography in patients with suspected endocarditis: a cost-effectiveness analysis

PURPOSE

We sought to determine the appropriate use of echocardiography for patients with suspected endocarditis.

PATIENTS AND METHODS

We constructed a decision tree and Markov model using published data to simulate the outcomes and costs of care for patients with suspected endocarditis.

RESULTS

Transesophageal imaging was optimal for patients who had a prior probability of endocarditis that is observed commonly in clinical practice (4% to 60%). In our base-case analysis (a 45-year-old man with a prior probability of endocarditis of 20%), use of transesophageal imaging improved quality-adjusted life expectancy (QALYs) by 9 days and reduced costs by $18 per person compared with the use of transthoracic echocardiography. Sequential test strategies that reserved the use of transesophageal echocardiography for patients who had an inadequate transthoracic study provided similar QALYs compared with the use of transesophageal echocardiography alone, but cost $230 to $250 more. For patients with prior probabilities of endocarditis greater than 60%, the optimal strategy is to treat for endocarditis without reliance on echocardiography for diagnosis. Patients with a prior probability of less than 2% should receive treatment for bacteremia without imaging. Transthoracic imaging was optimal for only a narrow range of prior probabilities (2% or 3%) of endocarditis.

CONCLUSION

The appropriate use of echocardiography depends on the prior probability of endocarditis. For patients whose prior probability of endocarditis is 4% to 60%, initial use of transesophageal echocardiography provides the greatest quality-adjusted survival at a cost that is within the range for commonly accepted health interventions.

Individual value of each of the Duke criteria for the diagnosis of infective endocarditis

OBJECTIVES: To assess the value of each of the Duke criteria for the diagnosis of infective endocarditis (IE). METHODS: Detailed review was done of charts of all cases discharged with the diagnosis of IE, and classification as 'definite', 'possible' and 'rejected' cases was made according to the Duke criteria. The diagnostic impact of each criterion was assessed by reclassifying each 'definite' case after subtraction of each individual criterion and by reclassifying each 'possible' and 'rejected' case after addition of each individual criterion. RESULTS: From 1983 to 1993, 179 cases were identified in the databases of two hospitals. When the Duke criteria were applied, 124 (6967%) were classed as 'definite', 43 (2466%) as 'possible' and 12 (763%) as 'rejected' cases. Of the 67 pathologically proven cases, 52 (78610%) were 'definite' cases when the criteria were applied before pathology. If the major microbiological criterion is subtracted, 53% (69%) of the 'definite' cases become 'possible' or 'rejected'. When the echocardiographic criterion is subtracted, 34% (68%) of the 'definite' cases become possible or rejected. Among minor criteria, fever and predisposition, contributing to the classification of respectively 31% (68%) and 27% (68%) of the 'definite' cases, were the most powerful. On the other hand, the minor microbiological criterion and immunologic phenomena were responsible for the classification of only 2% (62%) and 6% (64%) respectively, of the 'definite' cases. CONCLUSIONS: Depending on the criterion examined, 47-98% of the 'definite' cases of IE would remain 'definite' if this particular criterion were absent. The major microbiological criterion had the highest relative importance. In this retrospective study, in which only 32 (18%) patients had a transesophageal echocardiogram, the echocardiogram contributed to 15% (66%) of the 'definite' cases according to the major criterion and to 19% (66%) according to the minor criterion. This study illustrates that the degree of certainty of the diagnosis of IE often depends on the presence/absence of only one criterion.

Etiology and risk factors of 180 cases of native valve endocarditis. Report from a 5-year national prospective survey in Slovak Republic

Risk factors, etiology, and outcome of 180 cases of infective endocarditis (IE) in the Slovak Republic for 5 years were prospectively studied in a national survey. According to the Duke Endocarditis Service Criteria (1994), 169 cases were considered definitive and 21 possible/probable. The aortic valve was infected in 46.7%, mitral in 47.2%, and tricuspidal/pulmonary in 6.1% of cases. The majority of endocarditis cases was caused by Staphylococcus aureus and coagulase-negative staphylococci (CNS) (33.3%); only 12.2% were due to viridans streptococci; 11.7% were due to Enterococcus faecalis; 6.1% due to Haemophilus spp.; 10.1% due to other organisms; and 26.7% were culture negative. Single positive cultures of CNS were not considered clinically significant. More than 25% of 180 patients were older than 60 years. Rheumatic fever was a risk factor in 35.5%, dental surgery in 20.5%, prior cardiosurgery in 7.8%, and neoplasia in 6.7%. All patients were treated with antimicrobials (average length of therapy was 29.5 days) and 33.3% of patients also had surgery (valvular prosthesis replacement). Forty (22.2%) died, and 140 (77.8%) survived at day 60 after the diagnosis of endocarditis was made. All 40 deaths were attributable to infection. Univariate analysis comparing deaths and survivors did not show significant differences in most of the recorded risk factors between both groups, except age > 60 (40.0% versus 21.4%, p < 0.05), staphylococcal etiology (55.0% versus 27.1%, p < 0.04), and antibiotic therapy < 21 days (without surgery) (65.0% versus 3.6%, p < 0.01). These risk factors were significantly more frequently associated with deaths. Viridans streptococcal IE and surgical therapy in addition to antibiotics were associated with lower mortality in comparison to staphylococcal endocarditis (p < 0.045) or to cases treated with antibiotics only (p < 0.05). In comparison to other nationally based surveys in Europe (Greece, Croatia, France), the percentage of culture-negative endocarditis and spectrum of pathogens differed significantly.

Infective endocarditis associated with upper endoscopy: case report and review

We describe a 73-year-old male who developed native valve infective endocarditis due to Staphylococcus capitis as a consequence of repeated oesophageal dilatation. The patient was treated with appropriate antibiotic therapy but his condition deteriorated and he died. We review 10 previously reported cases of infective endocarditis associated with upper endoscopy and discuss the issue of prophylaxis of high risk patients prior to upper endoscopy involving various invasive procedures, e.g. biopsy, dilatation and sclerotherapy.

[Tricuspid valve endocarditis. Demonstration of a rare disease exemplified with 3 case reports]

BACKGROUND

Endocarditis of the tricuspid valve is a rare form of valvular endocarditis and occurs mainly in patients with special risk factors.

CASE REPORTS

The three case reports demonstrate 3 young patients (age 30 to 37 years, 2 female and 1 male) with a typical history of those risk factors. The two women were intravenous drug addicts and one of them had suffered already an episode of tricuspid valve endocarditis several years ago. The man developed his infection after implantation of a pacemaker. In all of the three patients the endocarditis was due to infection with staphylococci twice staphylococcus epidermidis and once staphylococcus aureus. In two of the three patients the endocarditis could not be cured by intravenous antibiotics alone and these patients had to undergo cardiac valvular surgery. All patients left the hospital after several weeks without signs of infection.

CONCLUSION

In clinical praxis the introduction of a special endocarditis service, a small team which has to be consulted in every suspected case of endocarditis, seems to be beneficial as well as the use of the Duke criteria for diagnosis in those cases.

Revised diagnostic criteria for infective endocarditis

New clinical criteria have been developed for the diagnosis of infective endocarditis that have incorporated precise echocardiographic parameters into the schema. Direct comparisons with the older criteria have now confirmed that the newer criteria are substantially more sensitive than the older criteria in suspected cases of infective endocarditis, while retaining a high specificity and negative predictive value.

Comparison of the von Reyn and Duke criteria for the diagnosis of infective endocarditis: a critical analysis of 161 episodes

The newly proposed diagnostic criteria for infective endocarditis (Duke criteria) were evaluated in 161 consecutive episodes treated for suspected infective endocarditis (IE) at one institution over a 5-year period. A significantly higher proportion of episodes were diagnosed as definite endocarditis by the new Duke criteria compared with a diagnosis as definite or probable endocarditis by the older von Reyn criteria (68% vs 56%; p < 0.05). If all 161 episodes were to be reclassified, excluding pathological data, which are seldom available at the start of treatment, the Duke criteria classified significantly more episodes as 'definite' compared with the analogous category 'probable' endocarditis by the von Reyn criteria (60% vs 44%; p < 0.01). Forty-four pathologically proven episodes were reclassified in the same way, and 73% of these episodes were classified as 'definite' IE by the Duke criteria compared to 55% classified as 'probable' IE using the von Reyn criteria In 33 (20%) episodes no heart murmur could be detected on admission and the Duke criteria provided an initial diagnosis of 'definite' IE in 58% of these episodes compared with only 6% classified as 'definite' or 'probable' IE by the von Reyn criteria (p < 0.0001). The newly proposed Duke criteria are an improvement on the older von Reyn criteria in the clinical diagnosis of IE, especially in initial phase of treatment. However, the sensitivity when establishing a correct clinical diagnosis of 'definite' IE for the pathologically proven cases was only 73%. The category of 'possible' IE by the Duke criteria is confusing, since it does not say anything of the likelihood on an actual IE; the only objective fact is that no alternative diagnosis has been proven.