A systematic review of population-based studies of infective endocarditis

Determinants of Cerebral Lesions in Endocarditis on Systematic Cerebral Magnetic Resonance Imaging

Background and Purpose—

Cerebral lesions are frequent complications of infective endocarditis (IE) and have a prognostic impact. Cerebral MRI identifies lesions in a high number of patients. However, their determinants have not been identified. The aim of the study was to define the determinants of cerebral lesions in patients with IE undergoing systematic cerebral MRI.

Methods—

Determinants of ischemic lesions and of microbleeds were prospectively analyzed in 120 patients with left-sided IE, using systematic cerebral MRI.

Results—

Median age was 60 years (interquartile range 51–72); IE occurred on a prosthetic valve in 37 patients (30.8%) and was due to Streptococci in 47 patients and Staphylococci in 36; 15 (12.5%) had neurological symptoms. MRI detected ischemic lesions in 64 patients (53.3%; territorial lesions in 32 and small lesions in 57) and microbleeds in 72 (60.0%). In multivariate analysis, ischemic lesions were associated with vegetation length (odds ratio 1.10/mm; 95% confidence interval 1.03–1.16; P =0.003) and Staphylococcus aureus IE (odds ratio 2.65; 95% confidence interval 1.01–6.96; P =0.05). A vegetation length >4 mm identified ischemic lesions with a sensitivity of 74.6% and a specificity of 51.5%. Microbleeds were associated with prosthetic IE (odds ratio 8.01; 95% confidence interval 2.58–24.90; P =0.0003) and not with prior anticoagulant therapy ( P =0.67).

Conclusions—

Systematic cerebral MRI frequently detects ischemic lesions and microbleeds during acute IE. The high sensitivity of MRI shows that each millimeter increase in vegetation length is associated with a 10% increase in the rate of ischemic lesions. Conversely, microbleeds are associated only with prosthetic IE in this study.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00144885.

Multiple sites on Streptococcus gordonii surface protein PadA bind to platelet GPIIbIIIa

Infective endocarditis is a life threatening disease caused by a bacterial infection of the endocardial surfaces of the heart. The oral pathogen, Streptococcus gordonii is amongst the most common pathogens isolated from infective endocarditis patients. Previously we identified a novel cell wall protein expressed on S. gordonii called platelet adherence protein A (PadA) that specifically interacts with platelet GPIIb/IIIa. The interaction between PadA and GPIIb/IIIa resulted in firm platelet adhesion, dense granule secretion and platelet spreading on immobilised S. gordonii. This study set out to identify specific motifs on the PadA protein that interacts with platelet GPIIb/IIIa. Proteomic analysis of the PadA protein identified two short amino acid motifs which have been previously shown to be important for fibrinogen binding to GPIIb/IIIa and contributing to the generation of outside-in signalling. Site directed mutagenesis on the PadA protein in which ₄₅₄AGD was substituted to AAA, and the ₃₈₃RGT was substituted to AAA suggests the RGT motif has no role in supporting platelet adhesion however plays a role in dense granule secretion and platelet spreading. In contrast to this the AGD motif has no role to play in supporting firm platelet adhesion or dense granule secretion however plays a role in platelet spreading. These results suggest that multiple sites on S. gordonii PadA interact with GPIIb/IIIa to mediate a number of platelet responses that likely contribute to the thrombotic complications of infective endocarditis.

High-dose daptomycin therapy for left-sided infective endocarditis: a prospective study from the international collaboration on endocarditis

The use of daptomycin in Gram-positive left-sided infective endocarditis (IE) has significantly increased. The purpose of this study was to assess the influence of high-dose daptomycin on the outcome of left-sided IE due to Gram-positive pathogens. This was a prospective cohort study based on 1,112 cases from the International Collaboration on Endocarditis (ICE)-Plus database and the ICE-Daptomycin Substudy database from 2008 to 2010. Among patients with left-sided IE due to Staphylococcus aureus, coagulase-negative staphylococci, and Enterococcus faecalis, we compared those treated with daptomycin (cohort A) to those treated with standard-of-care (SOC) antibiotics (cohort B). The primary outcome was in-hospital mortality. Time to clearance of bacteremia, 6-month mortality, and adverse events (AEs) ascribable to daptomycin were also assessed. There were 29 and 149 patients included in cohort A and cohort B, respectively. Baseline comorbidities did not differ between the two cohorts, except for a significantly higher prevalence of diabetes and previous episodes of IE among patients treated with daptomycin. The median daptomycin dose was 9.2 mg/kg of body weight/day. Two-thirds of the patients treated with daptomycin had failed a previous antibiotic regimen. In-hospital and 6-month mortalities were similar in the two cohorts. In cohort A, median time to clearance of methicillin-resistant S. aureus (MRSA) bacteremia was 1.0 day, irrespective of daptomycin dose, representing a significantly faster bacteremia clearance compared to SOC (1.0 versus 5.0 days; P < 0.01). Regimens with higher daptomycin doses were not associated with increased incidence of AEs. In conclusion, higher-dose daptomycin may be an effective and safe alternative to SOC in the treatment of left-sided IE due to common Gram-positive pathogens.

New guidelines and the development of an international consensus on recommendations for the antibiotic prophylaxis of infective endocarditis

During the last five years there has been a considerable change in attitude towards antibiotic prophylaxis of endocarditis in many countries so that far fewer cardiac patients are advised to receive prophylaxis in comparison with previous years. Much greater emphasis is now given to the maintenance of good oral hygiene as the main method of preventing endocarditis and prophylaxis is only recommended for patients with the highest risk cardiac conditions undergoing dental procedures. Most countries have now abandoned prophylaxis for urological and gastrointestinal procedures. The UK National Institute for Health and Clinical Excellence guidance, which does not recommend prophylaxis for any group of patients undergoing dental procedures, is regarded as too extreme by many experts in other countries. The assertion that more patients would die from fatal anaphylaxis after oral amoxicillin, the main prophylactic agent, than would die from endocarditis because prophylaxis is withheld, may not be correct since the risks of dying after oral amoxicillin have probably been overestimated. There is a lack of clinical evidence either for or against the efficacy of antibiotic prophylaxis. Unless convincing data is obtained from future research any new international consensus guidelines will continue to be based mainly on expert opinion rather than on good evidence.

Trends in hospitalization rates and outcomes of endocarditis among Medicare beneficiaries

OBJECTIVES

The aim of this study was to determine the hospitalization rates and outcomes of endocarditis among older adults.

BACKGROUND

Endocarditis is the most serious cardiovascular infection and is especially common among older adults. Little is known about recent trends for endocarditis hospitalizations and outcomes.

METHODS

Using Medicare inpatient Standard Analytic Files, we identified all fee-for-service beneficiaries age ≥65 years with a principal or secondary diagnosis of endocarditis from 1999 to 2010. We used Medicare Denominator Files to report hospitalizations per 100,000 person-years. Rates of 30-day and 1-year mortality were calculated using Vital Status Files. We used mixed-effects models to calculate adjusted rates of hospitalization and mortality and to compare the results before and after 2007, when the American Heart Association revised their recommendations for endocarditis prophylaxis.

RESULTS

Overall, 262,658 beneficiaries were hospitalized with endocarditis. The adjusted hospitalization rate increased from 1999 to 2005, reaching 83.5 per 100,000 person-years in 2005, and declined during 2006 to 2007. After 2007, the decline continued, reaching 70.6 per 100,000 person-years in 2010. Adjusted 30-day and 1-year mortality rates ranged from 14.2% to 16.5% and from 32.6% to 36.2%, respectively. There were no consistent changes in adjusted rates of 30-day and 1-year mortality after 2007. Trends in rates of hospitalization and outcomes were consistent across demographic subgroups. Adjusted rates of hospitalization and mortality declined consistently in the subgroup with a principal diagnosis of endocarditis.

CONCLUSIONS

Our study highlights the high burden of endocarditis among older adults. We did not observe an increase in adjusted rates of hospitalization or mortality associated with endocarditis after publication of the 2007 guidelines.

HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort

The HACEK organisms (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) are rare causes of infective endocarditis (IE). The objective of this study is to describe the clinical characteristics and outcomes of patients with HACEK endocarditis (HE) in a large multi-national cohort. Patients hospitalized with definite or possible infective endocarditis by the International Collaboration on Endocarditis Prospective Cohort Study in 64 hospitals from 28 countries were included and characteristics of HE patients compared with IE due to other pathogens. Of 5591 patients enrolled, 77 (1.4%) had HE. HE was associated with a younger age (47 vs. 61 years; p<0.001), a higher prevalence of immunologic/vascular manifestations (32% vs. 20%; p<0.008) and stroke (25% vs. 17% p = 0.05) but a lower prevalence of congestive heart failure (15% vs. 30%; p = 0.004), death in-hospital (4% vs. 18%; p = 0.001) or after 1 year follow-up (6% vs. 20%; p = 0.01) than IE due to other pathogens (n = 5514). On multivariable analysis, stroke was associated with mitral valve vegetations (OR 3.60; CI 1.34–9.65; p<0.01) and younger age (OR 0.62; CI 0.49–0.90; p<0.01). The overall outcome of HE was excellent with the in-hospital mortality (4%) significantly better than for non-HE (18%; p<0.001). Prosthetic valve endocarditis was more common in HE (35%) than non-HE (24%). The outcome of prosthetic valve and native valve HE was excellent whether treated medically or with surgery. Current treatment is very successful for the management of both native valve prosthetic valve HE but further studies are needed to determine why HE has a predilection for younger people and to cause stroke. The small number of patients and observational design limit inferences on treatment strategies. Self selection of study sites limits epidemiological inferences.

Role of procalcitonin in the diagnosis of infective endocarditis: a meta-analysis

BACKGROUND

Infective endocarditis (IE) is a diagnostic challenge. We aimed to systemically summarize the current evidence on the diagnostic value of procalcitonin (PCT) in identifying IE.

METHODS

We searched EMBASE, MEDLINE, Cochrane database, and reference lists of relevant articles with no language restrictions through September 2012 and selected studies that reported the diagnostic performance of PCT alone or compare with other biomarkers to diagnose IE. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random effects models.

RESULTS

We found 6 qualifying studies that included 1006 episodes of suspected infection with 216 (21.5%) confirmed IE episodes from 5 countries. Bivariate pooled sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios were 64% (95% confidence interval [CI], 52%-74%), 73% (95% CI 58%-84%), 2.35 (95% CI 1.40-3.95), and 0.50 (95% CI 0.35-0.70), respectively. Of the 5 studies examining C-reactive protein (CRP), the pooled sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios were 75% (95% CI 62%-85%), 73% (95% CI 61%-82%), 2.81 (95% CI 1.70-4.65), and 0.34 (95% CI 0.19-0.60), respectively. The global measures of accuracy, area under the receiver operating characteristic curve (AUC) and diagnostic odds ratio (dOR), showed CRP (AUC 0.80, dOR 8.55) may have higher accuracy than PCT (AUC 0.71, dOR 4.67) in diagnosing IE.

CONCLUSIONS

Current evidence does not support the routine use of serum PCT or CRP to rule in or rule out IE in patients suspected to have IE.

Central retinal artery occlusion due to infective endocarditis

We present a case of central retinal artery occlusion (CRAO) in a 59-year-old male suffering from infective endocarditis. The patient was receiving antibiotic treatment for the endocarditis for 5 days prior to the event and received conservative treatment for the CRAO without any improvement. A few days after the event, the patient underwent heart surgery with aortic and mitral valve replacement and eventually recovered without any other side-effects. CRAO is a rare but devastating embolic complication of infective endocarditis and can happen regardless of whether a patient is receiving systemic antibiotic treatment or not. These patients need close observation, because an immediate diagnosis and an urgent therapeutic procedure are mandatory, as the prognosis for vision is poor.

Infective endocarditis in the U.S., 1998-2009: a nationwide study

Background

Previous studies based on local case series estimated the annual incidence of endocarditis in the U.S. at about 4 per 100,000 population. Small-scale studies elsewhere have reported similar incidence rates. However, no nationally-representative population-based studies have verified these estimates.

Methods and Findings

Using the 1998–2009 Nationwide Inpatient Sample, which provides diagnoses from about 8 million U.S. hospitalizations annually, we examined endocarditis hospitalizations, bacteriology, co-morbidities, outcomes and costs. Hospital admissions for endocarditis rose from 25,511 in 1998 to 38, 976 in 2009 (12.7 per 100,000 population in 2009). The age-adjusted endocarditis admission rate increased 2.4% annually. The proportion of patients with intra-cardiac devices rose from 13.3% to 18.9%, while the share with drug use and/or HIV fell. Mortality remained stable at about 14.5%, as did cardiac valve replacement (9.6%). Other serious complications increased; 13.3% of patients in 2009 suffered a stroke or CNS infection, and 5.5% suffered myocardial infarction. Amongst cases with identified pathogens, Staphylococcus aureus was the most common, increasing from 37.6% in 1998 to 49.3% in 2009, 53.3% of which were MRSA. Streptococci were mentioned in 24.7% of cases, gram-negatives in 5.6% and Candida species in 1.0%. We detected no inflection in hospitalization rates after changes in prophylaxis recommendations in 2007. Mean age rose from 58.6 to 60.8 years; elderly patients suffered higher rates of myocardial infarction and death, but slightly lower rates of Staphylococcus aureus infections and neurologic complications. Our study relied on clinically diagnosed cases of endocarditis that may not meet strict criteria. Moreover, since some patients are discharged and readmitted during a single episode of endocarditis, our hospitalization figures probably slightly overstate the true incidence of this illness.

Conclusions

Endocarditis is more common in the U.S. than previously believed, and is steadily increasing. Preventive efforts should focus on device-associated and health-care-associated infections.

Partial oral treatment of endocarditis

BACKGROUND

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

STUDY DESIGN

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

CONCLUSION

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

The risk for bacterial endocarditis in cirrhotic patients: a population-based 3-year follow-up study

BACKGROUND

We noted only rare reports of cirrhotic patients with bacterial endocarditis (BE). There is insufficient data on the risk of BE in liver cirrhosis. This is the first national population-based study evaluating the risk of BE in cirrhotic patients.

METHODS

We used the National Health Insurance Database, which is derived from the Taiwan National Health Insurance Program. The study cohort comprised 40803 patients with cirrhosis and the comparison cohort consisted of 40841 randomly selected subjects with a similar age and sex distribution.

RESULTS

Of the total 81644 patients, 192 (0.24%) experienced BE during the 3-year follow-up period, 121 patients from the study cohort (0.30% of the cirrhotic patients) and 71 patients from the comparison group (0.17% of non-cirrhotic patients) (p<0.001). After adjusting for patient age, sex, and comorbid disorders, the Cox regression analysis showed that cirrhotic patients had a high risk of BE compared to non-cirrhotic patients during the 3-year follow-up period (hazard ratio 2.04, 95% confidence interval 1.61-2.44, p<0.001).

CONCLUSION

We conclude that liver cirrhosis is a risk factor for the occurrence of BE.

Endocarditis and risk of cancer: a Danish nationwide cohort study

BACKGROUND

Endocarditis may be a marker for bacteremia-associated occult cancer. Intensive antibiotic treatment in endocarditis is suggested to reduce long-term cancer risk. We examined these hypotheses in a nationwide cohort study.

METHODS

Endocarditis patients and cancer cases were identified from the Danish National Registry of Patients and the Danish Cancer Registry during 1978-2008. We compared the incidences of various cancers among study subjects to expected incidences based on national age-, sex-, and site-specific rates.

RESULTS

We observed 997 cancers among 8445 endocarditis patients (median follow-up of 3.5 years), reflecting an increased standardized incidence rate (SIR) of 1.61 (95% confidence interval [CI], 1.51-1.71). Cancer risk was highly elevated during the first 3 months of follow-up (SIR=8.03; 95% CI, 6.92-9.26), partly due to a 15- to 30-fold increased risk of hematological or liver cancers. Between 3-month and 5-year follow-ups, cancer incidence remained 1.5-fold higher than expected, including 2- and 4-fold increased SIRs for colorectal and liver cancers, respectively. Beyond 5 years of observation, the overall cancer SIR was 1.21 (95% CI, 1.10-1.34). Long-term associations were weak for several cancers hypothesized to be associated with antibiotic use, including prostate, gastric, and breast cancer.

CONCLUSION

Endocarditis is a substantial clinical marker for presence of occult cancer. We found no evidence of decreased long-term cancer risk after antibiotic treatment for endocarditis.

Temporal trends in infective endocarditis in the context of prophylaxis guideline modifications: three successive population-based surveys

OBJECTIVES

The goal of this study was to evaluate temporal trends in infective endocarditis (IE) incidence and clinical characteristics after 2002 French IE prophylaxis guideline modifications.

BACKGROUND

There are limited data on changes in the epidemiology of IE since recent guidelines recommended restricting the indications of antibiotic prophylaxis of IE.

METHODS

Three 1-year population-based surveys were conducted in 1991, 1999, and 2008 in 3 French regions totaling 11 million inhabitants age ≥20 years. We prospectively collected IE cases from all medical centers and analyzed age- and sex-standardized IE annual incidence trends.

RESULTS

Overall, 993 expert-validated IE cases were analyzed (323 in 1991; 331 in 1999; and 339 in 2008). IE incidence remained stable over time (95% confidence intervals given in parentheses/brackets): 35 (31 to 39), 33 (30 to 37), and 32 (28 to 35) cases per million in 1991, 1999, and 2008, respectively. Oral streptococci IE incidence did not increase either in the whole patient population (8.1 [6.4 to 10.1], 6.3 [4.8 to 8.1], and 6.3 [4.9 to 8.0] in 1991, 1999, and 2008, respectively) or in patients with pre-existing native valve disease. The increased incidence of Staphylococcus aureus IE (5.2 [3.9 to 6.8], 6.8 [5.3 to 8.6], and 8.2 [6.6 to 10.2]) was not significant in the whole patient population (p = 0.228) but was significant in the subgroup of patients without previously known native valve disease (1.6 [0.9 to 2.7], 3.7 [2.6 to 5.1], and 4.1 [3.0 to 5.6]; p = 0.012).

CONCLUSIONS

Scaling down antibiotic prophylaxis indications was not associated with an increased incidence of oral streptococcal IE. A focus on avoidance of S. aureus bacteremia in all patients, including those with no previously known valve disease, will be required to improve IE prevention.

Epidemiology, characteristics, and outcome of infective endocarditis in Italy: the Italian Study on Endocarditis

BACKGROUND

The characteristics of patients with infective endocarditis (IE) vary significantly by region of the world. The aim of this study was to evaluate the contemporary epidemiology, characteristics, and outcome of IE in a large, nationwide cohort of Italian patients.

METHODS

We conducted a prospective, observational study at 24 medical centers in Italy, including all the consecutive patients with a definite or possible diagnosis of IE (modified Duke criteria) admitted from January 2004 through December 2009. A number of clinical variables were collected through an electronic case report form and analyzed to comprehensively delineate the features of IE. We report the data on patients with definite IE.

RESULTS

A total of 1,082 patients with definite IE were included. Of these, 753 (69.6%) patients had infection on a native valve, 277 (25.6%) on a prosthetic valve, and 52 (4.8%) on an implantable electronic device. Overall, community-acquired (69.2%) was more common than nosocomial (6.2%) or non-nosocomial (24.6%) health care-associated IE. Staphylococcus aureus was the most common pathogen (22.0%). In-hospital mortality was 15.1%. From the multivariate analysis, congestive heart failure (CHF), stroke, prosthetic valve infection, S. aureus, and health care-associated acquisition were independently associated with increased in-hospital mortality, while surgery was associated with decreased mortality.

CONCLUSIONS

The current mortality of IE remains high, and is mainly due to its complications, such as CHF and stroke.

Management of infective endocarditis: challenges and perspectives

Despite improvements in medical and surgical therapies, infective endocarditis is associated with poor prognosis and remains a therapeutic challenge. Many factors affect the outcome of this serious disease, including virulence of the microorganism, characteristics of the patients, presence of underlying disease, delays in diagnosis and treatment, surgical indications, and timing of surgery. We review the strengths and limitations of present therapeutic strategies and propose future directions for better management of endocarditis according to the most recent research. Novel perspectives on the management of endocarditis are emerging and offer hope for decreasing the rate of residual deaths by accelerating the process of diagnosis and risk stratification, reducing delays in starting antimicrobial therapy, rapid transfer of high-risk patients to specialised medico-surgical centres, development of new surgical methods, and close long-term follow-up.

Oral streptococcal bacteremia in hospitalized patients: taxonomic identification and clinical characterization

Oral streptococci have been associated with systemic diseases, including infective endocarditis and neutropenic bacteremia. We analyzed 58 recent oral streptococcal bloodstream isolates, and we obtained clinical and demographic data for source patients. The sodA gene was found to be a better target than the 16S-23S rRNA internal transcribed spacer for DNA sequence-based species identification. Together, Streptococcus mitis and Streptococcus oralis were significantly more likely than the 12 combined remaining species to be isolated from neutropenic patients.

A randomised clinical trial of comprehensive cardiac rehabilitation versus usual care for patients treated for infective endocarditis--the CopenHeartIE trial protocol

INTRODUCTION

Infective endocarditis (IE) is among the most serious infectious diseases in the western world. Treatment requires lengthy hospitalisation, high-dosage antibiotic therapy and possible valve replacement surgery. Despite advances in treatment, the 1-year mortality remains at 20-40%. Studies indicate that patients experience persisting physical symptoms, diminished quality of life and difficulties returning to work up to a year postdischarge. No studies investigating the effects of rehabilitation have been published. We present the rationale and design of the CopenHeart(IE) trial, which investigates the effect of comprehensive cardiac rehabilitation versus usual care for patients treated for IE.

METHODS AND ANALYSIS

We will conduct a randomised clinical trial to investigate the effects of comprehensive cardiac rehabilitation versus usual care on the physical and psychosocial functioning of patients treated for IE. The trial is a multicentre, parallel design trial with 1 : 1 individual randomisation to either the intervention or control group. The intervention consists of five psychoeducational consultations provided by specialised nurses and a 12-week exercise training programme. The primary outcome is mental health (MH) measured by the standardised Short Form 36 (SF-36). The secondary outcome is peak oxygen uptake measured by the bicycle ergospirometry test. Furthermore, a number of exploratory analyses will be performed. Based on sample size calculation, 150 patients treated for left-sided (native or prosthetic valve) or cardiac device endocarditis will be included in the trial. A qualitative and a survey-based complementary study will be undertaken, to investigate postdischarge experiences of the patients. A qualitative postintervention study will explore rehabilitation participation experiences.

ETHICS AND DISSEMINATION

The study complies with the Declaration of Helsinki and was approved by the regional research ethics committee (no H-1-2011-129) and the Danish Data Protection Agency (no 2007-58-0015). Study findings will be disseminated widely through peer-reviewed publications and conference presentations.

REGISTRATION

Clinicaltrials.gov identifier: NCT01512615.

Incidence, predisposing factors, and aetiology of infective endocarditis in the Czech Republic

OBJECTIVES

The aim of this study was to evaluate the incidence and epidemiological characteristics of infective endocarditis (IE) in the Czech Republic. These results represent the first data on the epidemiology of IE from the post-communist countries.

METHODS

This was a prospective multi-centre observational study monitoring the occurrence of IE in the catchment areas of 29 hospitals during a 12-month period. The total monitored territory involved a population of 3.9 million people (37.7% of the total Czech population). Patients were included in the study if they had a diagnosis of possible or definite endocarditis according to the modified Duke criteria.

RESULTS

One hundred and thirty-four episodes of IE in 132 patients were reported. Thus the crude incidence of IE was 3.4 cases/100,000 inhabitants/y. Vegetations were most frequently found on the aortic and mitral valves. The most frequent agent was Staphylococcus aureus (29.9%). The aetiology remained unexplained in 33.6% of cases, mainly because of previous antibiotic therapy. Surgical intervention during antibiotic therapy was performed in 36 patients (27.5%). Thirty-six patients died during hospitalization (in-hospital mortality rate 27.5%). The most common predisposing cardiac factors were remote cardiac surgery (19.4%) and degenerative valvular changes (11.9%). The most common extracardiac factors were pyogenic infections of skin and soft tissues (13.0%) and chronic haemodialysis (8.2%).

CONCLUSIONS

Our results document the changing epidemiological characteristics of IE, namely an increasing incidence of the disease and an increasing role of Staphylococcus aureus as a major pathogen. A shift was evident in predisposing factors for IE: almost 39% of IE episodes were associated with both cardiac and extracardiac modern medical procedures.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Molecular methods for diagnosis of infective endocarditis

Infective endocarditis (IE) is a life-threatening disease associated with high mortality. Conventional microbiologic diagnosis is based mainly on culture-dependent methods that often fail because of previous antibiotic therapy or the involvement of fastidious or slowly growing microorganisms. In recent years, molecular techniques entered the field of routine diagnostics. Amplification-based methods proved useful for detection of microorganisms in heart valve tissue. More recently, they were applied to blood samples from patients with IE. Direct detection of microorganisms in valve specimens by fluorescence in situ hybridization allowed identification of the causative agent and simultaneous visualization of complex microbial communities. These techniques will gain more importance in the near future, provided that procedures are standardized and results are interpreted with caution. With this review, we intend to give an overview of the impact and limitations of molecular techniques for the diagnosis of IE, including a focus on recent developments.

Infective endocarditis

Infective endocarditis (IE) is lethal if not aggressively treated with antibiotics alone or in combination with surgery. The epidemiology of this condition has substantially changed over the past four decades, especially in industrialized countries. Once a disease that predominantly affected young adults with previously well-identified valve disease--mostly chronic rheumatic heart disease--IE now tends to affect older patients and new at-risk groups, including intravenous-drug users, patients with intracardiac devices, and patients exposed to healthcare-associated bacteremia. As a result, skin organisms (for example, Staphylococcus spp.) are now reported as the pathogen in these populations more often than oral streptococci, which still prevail in the community and in native-valve IE. Moreover, progress in molecular diagnostics has helped to improve the diagnosis of poorly cultivable pathogens, such as Bartonella spp. and Tropheryma whipplei, which are responsible for blood-culture-negative IE more often than expected. Epidemiological data indicate that IE mostly occurs independently of medico-surgical procedures, and that circumstantial antibiotic prophylaxis is likely to protect only a minute proportion of individuals at risk. Therefore, new strategies to prevent IE--including improvement of dental hygiene, decontamination of carriers of Staphylococcus aureus, vaccination, and, possibly, antiplatelet therapy--must be explored.

Increasing incidence and mortality of infective endocarditis: a population-based study through a record-linkage system

Background

Few population-based studies provide epidemiological data on infective endocarditis (IE). Aim of the study is to analyze incidence and outcomes of IE in the Veneto Region (North-Eastern Italy).

Methods

Residents with a first hospitalization for IE in 2000-2008 were extracted from discharge data and linked to mortality records to estimate 365-days survival. Etiology was retrieved in subsets of this cohort by discharge codes and by linkage to a microbiological database. Risk factors for mortality were assessed through logistic regression.

Results

1,863 subjects were hospitalized for IE, with a corresponding crude rate of 4.4 per 100,000 person-years, increasing from 4.1 in 2000-2002 to 4.9 in 2006-2008 (p = 0.003). Median age was 68 years; 39% of subjects were hospitalized in the three preceding months. 23% of patients underwent a cardiac valve procedure in the index admission or in the following year. Inhospital mortality was 14% (19% including hospital transfers); 90-days and 365-days mortality rose through the study years. Mortality increased with age and the Charlson comorbidity index, in subjects with previous hospitalizations for heart failure, and (in the subcohort with microbiological data) in IE due to Staphylococci (40% of IE).

Conclusions

The study demonstrates an increasing incidence and mortality for IE over the last decade. Analyses of electronic archives provide a region-wide picture of IE, overcoming referral biases affecting single clinic or multicentric studies, and therefore represent a first fundamental step to detect critical issues related to IE.

[Infectious endocarditis in a Norwegian hospital 1997-2006]

BACKGROUND

Infective endocarditis is a serious disease with high morbidity and mortality. The causative microorganism and predisposing factors have changed over time. Four retrospective studies of this condition have been published in Norway; the most recent in 1998. Aetiology, treatment and mortality have been reviewed for such patients admitted to a Norwegian hospital in a 10-year period.

MATERIAL AND METHODS

Medical records were reviewed for all patients ≥ 18 years admitted to Aalesund hospital, and diagnosed with infective endocarditis (as primary or secondary diagnosis) according to relevant ICD 9 and ICD 10 codes, in the period 01.01.1997-31.12.2006. Demographical, clinical, and laboratory data were recorded.

RESULTS

57 patients were diagnosed with infective endocarditis; the average age was 66 years and 37 were men. The average annual incidence was 6.3/100000 pr year. The average length of treatment was six weeks, and the first choice of antibiotics was usually a combination of penicillin and aminoglycosides (46%). The most common causative microorganism was S.aureus (21%). 42 (74%) patients had one or more complications. Nine (16%) patients died during their hospital stay.

INTERPRETATION

The incidence of infective endocarditis in Aalesund hospital was in the upper range of previous reports. In accordance with previous studies, we found that staphylococcus is currently the most common causative micro-organism. The age of onset has increased compared to earlier Norwegian studies.

Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis

Background

Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species.

Methods and Findings

We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity.

Conclusions

The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

[What has changed in the profile of infective endocarditis?]

In industrialized countries, after the eradication of rheumatic fever, rheumatic valve diseases progressively disappeared and the proportion of post-rheumatic infective endocarditis (IE) significantly decreased. Intravenous drug use, prosthetic valves, degenerative valve sclerosis, and invasive procedures have become the most important risk factors for IE. These changes also resulted in a decreasing incidence of streptococcal IE, which was compensated by an increased incidence of staphylococcal IE.

Epidemiological trends of infective endocarditis: a population-based study in Olmsted County, Minnesota

OBJECTIVE

To provide a contemporary profile of epidemiological trends of infective endocarditis (IE) in Olmsted County, Minnesota.

PATIENTS AND METHODS

This study consists of all definite or possible IE cases among adults in Olmsted County from January 1, 1970, through December 31, 2006. Cases were identified using resources of the Rochester Epidemiology Project.

RESULTS

We identified 150 cases of IE. The age- and sex-adjusted incidences of IE ranged from 5.0 to 7.9 cases per 100,000 person-years with an increasing trend over time differential with respect to sex (for interaction, P=.02); the age-adjusted incidence of IE increased significantly in women (P=.006) but not in men (P=.79). We observed an increasing temporal trend in the mean age at diagnosis (P=.04) and a decreasing trend in the proportion of cases with rheumatic heart disease as a predisposing condition (P=.02). There were no statistically significant temporal trends in the incidence of either Staphylococcus aureus or viridans group streptococcal IE. Data on infection site of acquisition were available for cases seen in 2001 and thereafter, with 50.0% designated as health care-associated, 42.5% community-acquired, and 7.5% nosocomial.

CONCLUSION

The incidence of IE among women increased from 1970 to 2006. Ongoing surveillance is warranted to determine whether the incidence change in women will be sustained. Subsequent analysis of infection site of acquisition and its impact on the epidemiology of IE are planned.

Treatment strategies for infective endocarditis

IMPORTANCE OF THE FIELD

Despite significant advances in medical, surgical, and critical care interventions, infective endocarditis (IE) remains a disease associated with considerable morbidity and mortality. Estimates from the American Heart Association place the incidence of IE in the US at 10,000 - 15,000 new cases each year. This may be due to the changing epidemiology of IE, including increasing antimicrobial resistance, increasing heart surgeries, prosthetic valve implantation, and widespread use of intravenous drugs. Furthermore, a new form of the disease, healthcare-associated IE, which is associated with new therapeutic modalities such as intravenous catheters, hyperalimentation lines, pacemakers, and dialysis shunts, has emerged.

AREAS COVERED IN THIS REVIEW

We present the latest therapeutic and preventive strategies for IE caused by a variety of bacterial and fungal pathogens. The general methods employed included an extensive literature search, confined to the last 10 years, using key words such as 'infective endocarditis', 'culture-negative endocarditis', 'treatment guidelines for IE', and 'prophylaxis for IE'.

WHAT THE READER WILL GAIN

Comprehensive information regarding the changing epidemiology of IE is provided. The latest guidelines with respect to therapy and prophylaxis of IE are reviewed.

TAKE HOME MESSAGE

Successful management of IE depends on maintaining a high index of suspicion for the disease and, when IE is diagnosed, close cooperation of medical and surgical disciplines is required. Further research is needed to better understand and provide optimal therapy for complex situations such as multidrug-resistant and polymicrobial IE.

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.