Community-acquired Infective Endocarditis Research Articles

Epidemiological differences, clinical aspects, and short-term prognosis of patients with healthcare-associated and community-acquired infective endocarditis

Epidemiological differences, clinical aspects, and short-term prognosis of patients with healthcare-associated and community-acquired infective endocarditis

Non-nosocomial Healthcare-Associated Infective Endocarditis: A Distinct Entity? Data From the GAMES Series (2008-2021).

Patients who acquire infective endocarditis (IE) following contact with the healthcare system, but outside the hospital, are classified as having non-nosocomial healthcare-associated IE (HCIE). Our aim was to characterize HCIE and establish whether its etiology, diagnosis, and therapeutic approach suggest it should be considered a distinct entity. This study retrospectively analyzes data from a nationwide, multicenter, prospective cohort including consecutive cases of IE at 45 hospitals across Spain from 2008 to 2021. HCIE was defined as IE detected in patients in close contact with the healthcare system (eg, patients receiving intravenous treatment, hemodialysis, or institutionalized). The prevalence and main characteristics of HCIE were examined and compared with those of community-acquired IE (CIE) and nosocomial IE (NIE) and with literature data. IE was diagnosed in 4520 cases, of which 2854 (63%) were classified as CIE, 1209 (27%) as NIE, and 457 (10%) as HCIE. Patients with HCIE showed a high burden of comorbidities, a high presence of intravascular catheters, and a predominant staphylococcal etiology, Staphylococcus aureus being identified as the most frequent causative agent (35%). They also experienced more persistent bacteremia, underwent fewer surgeries, and showed a higher mortality rate than those with CIE (32.4% vs 22.6%). However, mortality in this group was similar to that recorded for NIE (32.4% vs 34.9%, respectively, P = .40). Our data do not support considering HCIE as a distinct entity. HCIE affects a substantial number of patients, is associated with a high mortality, and shares many characteristics with NIE.

In-hospital Outcomes of Infective Endocarditis from 1978 to 2015: Analysis Through Machine-Learning Techniques

BackgroundEarly identification of patients with infective endocarditis (IE) at higher risk for in-hospital mortality is essential to guide management and improve prognosis. MethodsA retrospective analysis was conducted of a cohort of patients followed up from 1978 to 2015, classified according to the modified Duke criteria. Clinical parameters, echocardiographic data, and blood cultures were assessed. Techniques of machine learning, such as the classification tree, were used to explain the association between clinical characteristics and in-hospital mortality. Additionally, the log-linear model and graphical random forests (GRaFo) representation were used to assess the degree of dependence among in-hospital outcomes of IE. ResultsThis study analyzed 653 patients: 449 (69.0%) with definite IE; 204 (31.0%) with possible IE; mean age, 41.3 ± 19.2 years; 420 (64%) men. Mode of IE acquisition: community-acquired (67.6%), nosocomial (17.0%), undetermined (15.4%). Complications occurred in 547 patients (83.7%), the most frequent being heart failure (47.0%), neurologic complications (30.7%), and dialysis-dependent renal failure (6.5%). In-hospital mortality was 36.0%. The classification tree analysis identified subgroups with higher in-hospital mortality: patients with community-acquired IE and peripheral stigmata on admission; and patients with nosocomial IE. The log-linear model showed that surgical treatment was related to higher in-hospital mortality in patients with neurologic complications. ConclusionsThe use of a machine-learning model allowed identification of subgroups of patients at higher risk for in-hospital mortality. Peripheral stigmata, nosocomial IE, absence of vegetation, and surgery in the presence of neurologic complications are predictors of fatal outcomes in machine learning–based analysis.

Surgical treatment for infective endocarditis in the ageing society: a nationwide retrospective study in Japan

ObjectiveThe current status of surgical treatment for infective endocarditis (IE) among very elderly people is unclear.MethodsWe extracted data on patients in Japan with community-acquired IE who were admitted and discharged...

Association between surgical treatment and in-hospital mortality in patients with infective endocarditis stratified by NYHA classification: a nationwide retrospective study in Japan

Abstract Background Heart failure (HF) is one of the major complications of infective endocarditis (IE). The ESC guideline described that surgical treatment should be performed for the patients with IE complicated with HF. However, decision making of surgical indication in real-world clinical setting is not easy for patients with IE concomitant with HF due to complicated conditions, and the clinical benefit of surgical intervention for IE and HF is unclear. Purpose We sought to uncover the association between surgical treatment and in-hospital mortality among the patients admitted for community-acquired IE respectively according to the severity of HF symptoms (NYHA class I to IV). Methods We studied 3,403 patients diagnosed as IE (mean age 65.9 years, 61.6% males) with records of baseline NYHA classification (I to IV) who survived for more than 2 days, using the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan. Patients were classified into four groups: 919 patients (27.0%) in NYHA I, 1,007 patients (29.6%) in NYHA II, 767 patients (22.5%) in NYHA III, and 710 patients (20.9%) in NYHA IV. A multivariable logistic regression model adjusted for age, gender, Barthel Index, Charlson Comorbidity Index, and usage of inotropic therapy at admission was performed to evaluate the association between the surgical treatment and in-hospital mortality. Results Patients with higher NYHA classification were significantly older and were more likely to be female than those with lower NYHA classification. At admission, patients with higher NYHA classification had lower baseline activities and higher comorbidities, and also had more complications including stroke, shock and disseminated intravascular coagulation than those with lower NYHA classification. In-hospital mortality was seen in 406 patients (11.9%) in the entire cohort. The mortality rate significantly increased with the NYHA class (NYHA I, 3.6%; NYHA II, 8.4%; NYHA III, 11.9%; NYHA IV, 27.9%: p<0.001). According to the multivariable logistic regression analysis, surgical treatment was independently associated with lower in-hospital mortality (Odds ratio 0.395, 95% Confidence Interval 0.297–0.526; p<0.001). A fragmentated analysis in each NYHA classification showed that the survival benefit of surgical intervention was pronounced in patients with higher NYHA class (Figure). The limitation of our study was including the potential unmeasured confounders, which lead to overestimate the relationship between the surgical treatment and in-hospital mortality even after excluding the critically ill patients who died within 2 days and adjusting for the measured confounders. Conclusion Surgical treatment was associated with lower in-hospital mortality among the patients with IE complicated with HF, particularly among those with more advanced HF status. Our study implies that surgical treatment might be beneficial for the patients with advanced HF. Funding Acknowledgement Type of funding source: None

Nosocomial Vs. Community-Acquired Infective Endocarditis in Spain: Location, Trends, Clinical Presentation, Etiology, and Survival in the 21st Century.

Major changes have occurred in the epidemiology and etiology of infective endocarditis (IE). Nevertheless, the differences between nosocomial infective endocarditis (NIE) and community-acquired infective endocarditis (CIE) have not been addressed in a population-based study. We conducted a retrospective, nationwide, temporal trend study from 1997 to 2014 analyzing the epidemiology, clinical, geographical, meteorological characteristics of patients diagnosed with IE in Spain, to distinguish NIE from CIE. Among 25,952 patients with IE (62.2 ± 18·6 years; 65.9% men), 45.9% had NIE. The incidence of IE increased from 2.83 to 3.73 due to the NIE incidence increment with a decline in CIE. Patients with NIE were older (63.8 years vs. 60.8 years, p < 0·001), presented a higher Charlson index (1.22 vs. 1.03, p < 0.001), a greater history of implanted cardiac devices (8.7% vs. 4.6%, p < 0.001), and higher mortality (31.5% vs. 21.7%, p < 0.001). The most frequent microorganism for both NIE and CIE was Staphylococcus (p < 0.001), and the North reported a higher incidence (p < 0.001). Risk factors of mortality for NIE were age, Charlson index, hemodialysis, shock, heart failure, and stroke. Risk factors for CIE included female sex, renal disease, and cardiac-device carriers. The etiology of IE shifted from community origins to mostly nosocomial-associated infections. Higher morbidity, mortality, and poorer outcomes are associated with NIE.

National Temporal Trend Analysis of Infective Endocarditis among Patients Infected with HIV in Spain (1997-2014): A Retrospective Study.

Background: People living with human immunodeficiency virus (HIV) (PLWH) form a vulnerable population for the onset of infective endocarditis (IE). We aimed to analyze the epidemiological trend of IE, as well as its microbiological characteristics, in PLWH during the combined antiretroviral therapy era in Spain. Methods: We performed a retrospective study (1997–2014) in PLWH with data obtained from the Spanish Minimum Basic Data Set. We selected 1800 hospital admissions with an IE diagnosis, which corresponded to 1439 patients. Results: We found significant downward trends in the periods 1997–1999 and 2008–2014 in the rate of hospital admissions with an IE diagnosis (from 21.8 to 3.8 events per 10,000 patients/year; p < 0.001), IE incidence (from 18.2 to 2.9 events per 10,000 patients/year; p < 0.001), and IE mortality (from 23.9 to 5.5 deaths per 100,000 patient-years; p < 0.001). The most frequent microorganisms involved were staphylococci (50%; 42.7% Staphylococcus aureus and 7.3% coagulase-negative staphylococci (CoNS)), followed by streptococci (9.3%), Gram-negative bacilli (8.3%), enterococci (3%), and fungus (1.4%). During the study period, we found a downward trend in the rates of CoNS (p < 0.001) and an upward trends in streptococci (p = 0.001), Gram-negative bacilli (p < 0.001), enterococci (p = 0.003), and fungus (p < 0.001) related to IE, mainly in 2008–2014. The rate of community-acquired IE showed a significant upward trend (p = 0.001), while the rate of health care-associated IE showed a significant downward trend (p < 0.001). Conclusions: The rates of hospital admissions, incidence, and mortality related to IE diagnosis in PLWH in Spain decreased from 1997 to 2014, while other changes in clinical characteristics, mode of acquisition, and pathogens occurred over this time.

Infective Endocarditis: A Contemporary Study of Microbiology, Echocardiography and Associated Clinical Outcomes at a Major Tertiary Referral Centre

The epidemiology of infective endocarditis (IE) continues to evolve, with antimicrobial resistance and clinical outcomes largely dependent on the environment of acquisition. This study aimed to provide a contemporary review of the microbiology and antimicrobial management of IE and report echocardiographic findings and predictors of adverse outcomes in community-acquired and health care-associated IE. Consecutive presentations of IE to a major Australian tertiary referral centre between January 2011 and April 2016 were examined. Culprit organisms and resistance patterns were recorded, as was transthoracic and transoesophageal echocardiography. Real-world antimicrobial prescription and use of an outpatient parenteral antimicrobial therapy (OPAT) service were also assessed, and clinical outcomes analysed. Of 204 consecutive cases, 30% were associated with health care, a group with a higher burden of comorbidities and more prone to complications. Health care-associated cases had lower rates of surgical intervention but higher mortality. A history of intravenous drug use (IVDU) conferred risk for recurrent IE whereas multivalvular involvement predicted heart failure hospitalisation. Staphylococcus aureus was isolated in 45%. Whilst methicillin resistance remains low, the prevalence of S. aureus IE is increasing. Single antimicrobial agents were commonly used (83%) and therapy via OPAT was safe and significantly reduced length of hospital stay. Not undergoing transoesophageal echocardiography (TOE) or definitive surgical management conferred poorer prognosis. The epidemiology of IE is evolving and there is need for updated epidemiological data and associated clinical outcomes. Environment of acquisition remains important in the face of increasing health care provision and the changing predominance of culprit microorganisms.

Clinical Characteristics of Infective Endocarditis in Children.

Infective endocarditis (IE) remains a diagnostic and therapeutic challenge associated with high morbidity and mortality. We evaluated the microbial profile and clinical manifestation of IE in children. A retrospective study examining pediatric IE cases treated between 2000 and 2017 at the Department of Pediatric Cardiology, KU Leuven, was conducted. Clinical presentation, treatment, complications, outcome of IE, underlying microorganisms and congenital heart defects were reviewed. Fifty-three patients were diagnosed with IE. Overall, 19 patients (36%) required cardiac surgery. Seven patients (13%) died. Eighty-seven percent of patients had an underlying congenital cardiac defect. Eighteen (34%) children presented with prosthetic graft IE. A causative organism was found in 49 (92%) cases: viridans group streptococci were identified in 17 (32%), Staphylococcus aureus in 13 (25%) and coagulase-negative staphylococci in 11 (20%) children. Community-acquired (CA) IE increased significantly from 8 (33%) cases in 2000-2007 to 20 (74%) cases in 2008-2017 (P < 0.01). Even with viridans streptococci being significantly more prevalent in the CA group (P < 0.01), we did not observe an increase of streptococcal IE from 2008 to 2017. Seventeen (32%) patients presented with hospital-acquired IE during the first year of life with 14 (82%) children after surgery and a prevalence of coagulase-negative staphylococci (53%). The incidence of pediatric IE was similar over the investigated time period with a shift toward CA IE. Streptococci and staphylococci accounted for the majority of cases in both periods. Awareness of IE and its prevention is crucial in patients after implantation of prosthetic grafts.

Be careful about MICs to amoxicillin for patients with Streptococci-related infective endocarditis

BackgroundA variety of microorganisms can cause infective endocarditis (IE), with Staphylococci and Streptococci accounting for the majority of cases. Streptococci are a common cause of community-acquired IE but few studies have focused on this subgroup of endocarditis. MethodsA retrospective multicentre study was conducted between 2012 and 2017 in 12 hospital centres in France. Data were extracted from the local diagnosis-related group database and matched with microbiological results. After identification, the records were retrospectively analysed. ResultsA total of 414 patients with streptococcal endocarditis were included. The patients were predominantly male (72.8%) and the median age was 73.2 years (interquartile range [IQR] 61.3-80.9). The majority of patients (70.6%) had native valve endocarditis. Embolic complications were seen in 38.8% of patients. Viridans group Streptococci (VGS) and bovis-equinus group Streptococci (BGS) accounted for 52.4% and 34.5% of isolated strains, respectively. Minimum inhibitory concentrations (MICs) of amoxicillin were <0.125, 0.125-2 and >2 mg/L for 59.6%, 27% and 1% of isolates, respectively. In-hospital mortality for patients with Streptococci-related IE was 17.8%. In multivariate analysis, the only factor associated with in-hospital mortality was MIC for amoxicillin between 0.25 and 2 mg/L (P = 0.04; OR = 2.23 [95% confidence interval (CI) 1.03-4.88]) whereas performance of cardiac surgery for IE was a protective factor (P = 0.001, OR = 0.23 [95% CI 0.1-0.56]). ConclusionsIE remains a serious and deadly disease despite recent advances in diagnosis and treatment. Adaptation of antibiotic doses to MICs for amoxicillin and surgery may improve patient outcome.

Trends in Epidemiology: Analysis of Risk Factors and Outcomes of Infective Endocarditis: A Retrospective Study (2009-2015).

BackgroundDespite advanced diagnosis and treatment, infective endocarditis (IE) is a potentially life-threatening condition. Although recent studies have provided evidence of changing trends in IE epidemiology, few studies examine patterns within urban minority populations. Here we present the epidemiology, risk factors, and outcomes of IE among an underserved African American population in Brooklyn, New York, compared to the general population.MethodsThis is a retrospective study which included 67 patients with IE diagnosed at The Brooklyn Hospital Center from 2009 to 2015. Patients were selected according to the modified Duke Criteria for definite IE. Various epidemiological parameters were examined via chi-square and Fisher’s exact test using SPSS 24 software (IBM Corp., Armonk, NY).ResultsThe mean age of the 67 patients was 63 years and 46.3% of the patients were men. The majority of patients (70.1%) were African American while Hispanics and Caucasians were 17.9% and 7.5%, respectively. Healthcare-associated IE (58.2%, n=39) outnumbered community-acquired IE (41.8%, n=28). The sites of vegetation were the mitral valve (62.7%, n=42), tricuspid valve (22.4%, n=15), aortic valve (11.9%, n=8), and intravenous catheter (3%, n=2). In valves, 13.4% of the cases were found in prosthetic valves while the majority occurred in native valves. The most common pathogens of IE were the Staphylococcus (50.8%, n=34) species, followed by Streptococcus species (32.8%, n=22). Overall, the in-hospital mortality was 38.8% (n=26) with higher mortality observed for healthcare-associated IE than community-acquired IE (P = .049). Embolic complications were associated with significant mortality (P < .001).ConclusionOur study demonstrated that the common causative pathogens for IE among African Americans trends towards Staphylococcus species followed by Streptococcus species, similar to the contemporary epidemiology of IE. Healthcare-associated IE outnumbered community-acquired IE and was associated with higher mortality. Embolic complications were significantly associated with high mortality. Therefore, efforts made to control healthcare-associated infections are expected to decrease the trend of IE.

1083. Long-Term Prognosis of 448 Infectious Endocarditis Followed by an Endocarditis Team

BackgroundThe management of infective endocarditis (IE) by an expert medico-surgical team through multidisciplinary consultation meetings is now recommended. While it seems clear that it can improve the short-term prognosis of patients, long-term data are still scarce.MethodsAll patients hospitalized between 2013 and 2017 in the three teaching hospitals of our center with an IE treated by the multidisciplinary team were followed prospectively at 1, 3, 6, and 12 months. The main objective was to determine the 1-year mortality of the entire cohort treated by the team.ResultsDuring the study, 493 patients had a certain or possible IE and the outcome at 1 year was known for 448 of them (4 lost to follow-up and 41 followed for less than 1 year): 254 had native valve IE (57%) and 194 had prosthetic valve IE (43%). The median age of IE patients was 69.3 years (155 patients were over 75 years old) and 329 (73%) were men. Healthcare-associated IE (HAIE) accounted for 47% of cases. A microorganism was isolated in 92% of cases (S. aureus = 24%), 252 patients (56%) had an embolic events and 68 (15%) had heart failure. The Charlson Median Comorbidity Index (ICC) was 5.0. Two hundred sixteen patients (48%) underwent surgery. The mortality rates at 1 month, 3 months, 6 months, and 1 year were, respectively, 14.1%, 19.0%, 23.2%, and 27.7%. The ICC at inclusion of patients who died at 1 year was 6.0 vs. 4.0 for survivors. Mortality at 1 year was significantly higher in case of HAIE (33% vs. 23%), documented S. aureus IE (39% vs. 24%), exclusive medical treatment (40% vs. 15%), and heart failure (43% vs. 25%).ConclusionWhile the management of IE by an endocarditis team seems to improve the short-term prognosis of IE, 1-year mortality remains high as patients are increasingly older and have severe comorbidities. Our study confirms that early prognostic factors remain in the long term and that the prognosis is better in community-acquired IE with surgery.Disclosures All authors: No reported disclosures.

Management of infective endocarditis and multidisciplinary approach

IntroductionThe morbi-mortality related to infective endocarditis (IE) remains high as the epidemiology has changed over the last years: ageing of patients, comorbidity and healthcare-associated infections. To optimize IE management, a weekly endocarditis multidisciplinary meeting (EMM) was set up at our facility. We present the activity report of the EMM. Patients and methodsAll patients hospitalized for IE who were presented at the weekly EMM between January 2013 and June 2017 were prospectively included. The main objective was to assess the impact of the EMM on the management of community-acquired IE and healthcare-associated IE by analyzing in-hospital case fatality. ResultsOf the 1139 cases reported during the EMM for suspicion of IE, 493 (86% were definite cases) were selected for the study: 262 patients had community-acquired IE and 231 had healthcare-associated IE; 43% of IEs involved a valvular prosthesis. Following the EMM, infections were documented in 92% of cases: staphylococci in 45% of healthcare-associated IEs and streptococci in 44% of community-acquired IE cases. A septic embolism was diagnosed in 57% of cases. Finally, 49% of patients underwent surgery. The in-hospital case fatality was 12% with no significant difference between community-acquired IEs and healthcare-associated IEs. Case fatality was also significantly higher in elderly patients, in the absence of surgical treatment, initial heart failure, or Staphylococcus aureus IE. ConclusionThe weekly EMM allows our facility to follow the European Society of Cardiology guidelines and to adapt the management of each patient to improve IE prognosis.

Risk factors for poor prognosis in nosocomial infective endocarditis.

Background/AimsThe aim of our study was to compare the characteristics of nosocomial infective endocarditis (NIE) with community-acquired infective endocarditis (CIE) and to determine independent risk factors for in-hospital death.MethodsWe retrospectively reviewed the medical records of 560 patients diagnosed with infective endocarditis. NIE was defined by a diagnosis made > 72 hours after hospital admission or within 2 months of hospital discharge.ResultsAmong the 560 cases reviewed, 121 were classified as NIE. Compared with patients with CIE, patients with NIE were older (mean ± SD, 51.30±18.01 vs. 59.76±14.87, p < 0.001). The in-hospital death rate of the NIE group was much higher than that of the CIE group (27.3% vs. 5.9%, p < 0.001). More patients with NIE had central intravenous catheters, and were undergoing hemodialysis (p < 0.001). Methicillin-resistant Staphylococcus aureus (MRSA) was the most common causal microorganism of NIE, and MRSA (p < 0.001) and fungus (p = 0.002) were more common in NIE compared with CIE. On multiple analysis, age, liver cirrhosis, cancer chemotherapy, central intravenous catheter, hemodialysis, and genitourinary tract manipulation were independent clinical risk factors for NIE. Among the patients with NIE, 33 died during their hospital admission. The independent risk factors for in-hospital death were older age (adjusted odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01 to 1.07; p = 0.037) and chemotherapy for malignancy (adjusted OR, 3.89; 95% CI, 1.18 to 12.87; p = 0.026).ConclusionsBecause of the considerable incidence of NIE and its poor prognosis, we should pay attention to early diagnosis and active management of NIE, especially for older patients and patients receiving chemotherapy.

0298: Prosthetic valve endocarditis. A 15-years cohort study

Prosthetic valve endocarditis (PVE) is an uncommon complication after valve replacement surgery, but potentially fatal. The scarcity of clinical trials makes harder the diagnostic and therapeutic approach of this entity. To define the clinical characteristics and in-hospital evolution of a population with PVE. Retrospective study based on a sample of 173 patients (P) with the diagnosis of infective endocarditis (IE), according to the modified Duke criteria, admitted from 1998 to 2013. We analyzed demographic and clinical features, complications and in-hospital mortality of P with PVE. We found 34 P (20%) with PVE, mean age 60.2±17.6 years with a female predominance (53%). The most common form was the community-acquired IE, registering 11 P (32%) with health care-associated IE. There was a preferential engagement of the mitral valve (56%) and 26% had early PVE. The cardinal complaints at presentation were constitutional symptoms (97%) and fever (74%); 50% of P showed signs of acute heart failure (HF). The most common analytical abnormalities were elevated inflammatory biomarkers (CRP 94% and leukocytosis 41%), anemia (88%) and increased creatinine (60%). The microbial agent was isolated in 24 P (71%), being Staphylococcus spp (26%) and Streptococcus spp (21%) the most common. The prosthesis dehiscence (60%), severe regurgitation (29%) and perivalvular abscess (21%) were the most frequent complications seen at initial echo-cardiographic evaluation. The most common adverse events were acute kidney injury (74%), persistence of HF (56%), septic shock (15%) and stroke (12%). There was need for urgent referral to surgery in 38% of P. The in-hospital mortality was higher than other P with IE (21% vs 13%). The PVE is associated with a poor prognosis at short term. Its adverse developments should lead to the early identification of riskier P and timely consideration of the possible benefit of surgery.

Abstract 17235: Trends in Endocarditis Hospitalizations at US Children's Hospitals From 2003-2014: Impact of the 2007 American Heart Association Antibiotic Prophylaxis Guidelines

Introduction: Over the past decade, national organizations in several countries have released more restrictive guidelines for infective endocarditis (IE) prophylaxis, including the American Heart Association (AHA) 2007 guidelines. Multiple initial studies demonstrated no change in IE rates over time following release of these guidelines, however a more recent analysis over a longer time period in the UK suggested an increase in IE. This prior study primarily included adults. Current IE trends in the pediatric population are unknown. Methods: Children (&lt;18 years) hospitalized with IE at 29 US centers participating in the Pediatric Health Information Systems Database from 2003-2014 were eligible for inclusion. Our primary analysis focused on IE most directly related to the change in the AHA guidelines, and included community-acquired IE cases (antibiotics covering oral streptococcal species started within 7 days of admission) in those &gt;5 years of age (most likely to be receiving dental care). Interrupted time series analysis was used to evaluate IE rates over time indexed to total hospital admissions. Results: A total of 841 IE cases were identified. Median age was 13 years (interquartile range 9-15 years). In the pre-guideline period, the IE rate increased slightly over time (+0.013 IE cases/1000 hospitalizations per 6-month period, see Figure). In the post-guideline period there was a similar trend in IE rates (+0.012 IE cases/1000 hospitalizations per 6-month period) with no significant difference in slope in the pre vs. post period (p=0.9). Additional analyses in those with congenital heart disease, and in those hospitalized with any type of IE (not limited to oral streptococci) at any age, revealed similar results. Conclusions: In contrast to a recent UK study, we found no evidence of a change in IE hospitalization rates associated with revised IE prophylaxis guidelines over an 11 year period across 29 US children’s hospitals.

Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake

Infective endocarditis (IE)(1) is a severe condition complicating 10–25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features. S. aureus isolates causing community-acquired, definite native-valve IE (n=72) and bacteremia (n=54) were collected prospectively as part of a French multicenter cohort. Phenotypic traits previously reported or hypothesized to be involved in staphylococcal IE pathogenesis were tested. In parallel, the genotypic profiles of all isolates, obtained by microarray, were analyzed by discriminant analysis of principal components (DAPC)(2). No significant difference was observed between IE and bacteremia strains, regarding either phenotypic or genotypic univariate analyses. However, the multivariate statistical tool DAPC, applied on microarray data, segregated IE and bacteremia isolates: IE isolates were correctly reassigned as such in 80.6% of the cases (C-statistic 0.83, P<0.001). The performance of this model was confirmed with an independent French collection IE and bacteremia isolates (78.8% reassignment, C-statistic 0.65, P<0.01). Finally, a simple linear discriminant function based on a subset of 8 genetic markers retained valuable performance both in study collection (86.1%, P<0.001) and in the independent validation collection (81.8%, P<0.01). We here show that community-acquired IE and bacteremia S. aureus isolates are genetically distinct based on subtle combinations of genetic markers. This finding provides the proof of concept that bacterial characteristics may contribute to the occurrence of IE in patients with S. aureus bacteremia.

Epidemiology and prognosis of coagulase-negative staphylococcal endocarditis: impact of vancomycin minimum inhibitory concentration.

This study describes coagulase-negative staphylococcal (CoNS) infective endocarditis (IE) epidemiology at our institution, the antibiotic susceptibility profile, and the influence of vancomycin minimum inhibitory concentration (MIC) on patient outcomes. One hundred and three adults with definite IE admitted to an 850-bed tertiary care hospital in Barcelona from 1995-2008 were prospectively included in the cohort. We observed that CoNS IE was an important cause of community-acquired and healthcare-associated IE; one-third of patients involved native valves. Staphylococcus epidermidis was the most frequent species, methicillin-resistant in 52% of patients. CoNS frozen isolates were available in 88 patients. Vancomycin MICs of 2.0 μg/mL were common; almost all cases were found among S. epidermidis isolates and did not increase over time. Eighty-five patients were treated either with cloxacillin or vancomycin: 38 patients (Group 1) were treated with cloxacillin, and 47 received vancomycin; of these 47, 27 had CoNS isolates with a vancomycin MIC <2.0 μg/mL (Group 2), 20 had isolates with a vancomycin MIC ≥2.0 μg/mL (Group 3). One-year mortality was 21%, 48%, and 65% in Groups 1, 2, and 3, respectively (P=0.003). After adjusting for confounders and taking Group 2 as a reference, methicillin-susceptibility was associated with lower 1-year mortality (OR 0.12, 95% CI 0.02-0.55), and vancomycin MIC ≥2.0 μg/mL showed a trend to higher 1-year mortality (OR 3.7, 95% CI 0.9-15.2; P=0.069). Other independent variables associated with 1-year mortality were heart failure (OR 6.2, 95% CI 1.5-25.2) and pacemaker lead IE (OR 0.1, 95%CI 0.02-0.51). In conclusion, methicillin-resistant S.epidermidis was the leading cause of CoNS IE, and patients receiving vancomycin had higher mortality rates than those receiving cloxacillin; mortality was higher among patients having isolates with vancomycin MICs ≥2.0 μg/mL.

Epidemiology and prognosis of healthcare-associated infective endocarditis

Objective To describe the characteristics of healthcare-associated infective endocarditis (HAIE) and to investigate the risk factors of infective endocarditis (IE) case fatality. Methods All consecutive cases of definite IE diagnosed from 1992 to 2012 were collected and categorized into HAIE and community acquired IE (CAIE). The epidemiological and clinical features of HAIE and CAIE were compared. Risk factors for in-hospital case fatality were analyzed by Logistic regression. Results One hundred and fifty-four patients with IE were enrolled; 126 (81.8%) were CAIE and 28 (18.2%) were HAIE. Compared with CAIE patients, HAIE patients were in poorer condition (Charlson comorbidity scale≥2: 35.7% vs 15.1%; χ2=6.382, P=0.012), more frequently associated with a history of prosthetic valve replacement (35.7% vs 7.1%; χ2=17.291, P<0.01), more rheumatic heart disease (35.7% vs 10.3%; χ2=11.631, P=0.002), more recieved immunosuppressive or glucocorticoid therapy (21.4% vs 4.0%; χ2=10.530, P=0.005) and more acute heart failure (17.9% vs 4.8%; χ2=5.923, P=0.029). Viridans group streptococci infection predominated in CAIE (χ2=5.489, P=0.019), while staphylococci and enterococci infections (50.1%) were frequent in HAIE. Other bacterial pathogen infections were more common in HAIE (χ2=5.870, P=0.026). Ten patients died before discharge and the case fatality rate in-hospital was 6.5% (10/154). Case fatality rate in HAIE (17.9%) was significantly higher than CAIE (4.0%; χ2=7.278, P=0.018). Surgery treatment, albumin level, stroke and HAIE were independent risk factors for IE-related deaths. Odds ratios (OR) were 0.081 (95%CI: 0.008-0.873), 0.754 (95%CI: 0.587-0.967), 33.777 (95%CI: 2.751-414.743) and 11.952 (95%CI: 1.045-136.709), respectively. Conclusion HAIE is common and distinctive from CAIE in epidemiology and prognosis, which increases patient fatality. Key words: Endocarditis, bacterial; Community-acquired infections; Healthcare-associated infective endocarditis; Epidemiology; Risk factors

Infective endocarditis involving an apparently structurally normal valve: new epidemiological trend?

Infective endocarditis (IE) has been increasingly diagnosed in patients without previously detected predisposing heart disease, but its clinical features have yet to be fully determined. A recent single-center study including echocardiographic images and surgical findings investigated the incidence of undiagnosed, clinically silent valvular or congenital heart diseases and healthcare-associated infective endocarditis (HAIE). The study confirmed that a large proportion of patients with IE have no previous history of heart disease. Analysis of underlying disease in these patients showed that undetected mitral valve prolapse was the most common disease, followed by an apparently structurally normal valve. The patients who developed IE of apparently structurally normal valves had different clinical characteristics and worse outcomes. IE involving a structurally normal valve was associated with both nosocomial and non-nosocomial HAIE, whereas community-acquired IE was more frequent than HAIE. The pathophysiologic mechanism involving the development of non-HAIE or community-acquired IE due to predominantly staphylococcal infection in an apparently structurally normal valve is not yet clearly understood. Structurally normal valves are not necessarily free of regurgitation or abnormal turbulence and, given the dynamic nature and fluctuating hemodynamic effects of conditions such as poorly controlled hypertension, end-stage renal disease, and sleep apnea, further investigation is necessary to evaluate the potential role of these diseases in the development of IE. An apparently normal-looking valve is associated with IE development in patients without previously recognized predisposing heart disease, warranting repartition of at-risk groups to achieve better clinical outcomes.