Occurrence Of Infective Endocarditis Research Articles

#1916 Infective endocarditis in young female hemodialysis patient: a case report and literature review

Abstract Background and Aims Infective endocarditis (IE) in hemodialysis patient is one of major infective and cardiovascular complications with high morbidity and mortality. Compared to general population, incidence of IE among hemodialysis (HD) patients is 50-60 times higher. Despite the devastating implications, there is no particular preventive measures of IE for HD patients. Previous studies revealed leading risk factors for IE in HD population including use of central venous catheters (CVCs), first 6 months period of renal replacement therapy (RRT), aortic valve disease, and previous endocarditis. Case Summary We report a case of IE in a 21-year-old female hemodialysis patient using AV fistula for the past 16 months with no prior history of heart valve disease, previous endocarditis, and IV drug abuse. Patient presented with fever of 38.5°C, dyspnea, and cough since three days before admission. Physical examination revealed grade 5 pansystolic murmur with punctum maximum at apex. Vegetation on the anterior mitral leaflet (AML) was first detected through trans-thoracal echocardiography. Patient was treated with ceftriaxone and vancomycin for 14 days, followed by oral antibiotics in outpatient setting after clinical resolution. Conclusion This case provides insight of the occurrence of IE in relatively young patient in the absence of well-known risk factors, making strict prevention, prompt diagnosis and treatment are of the utmost importance. Possible pathophysiological mechanisms for IE in HD patients are bacteremia from repeated vascular manipulation and valvular calcification that compromises valve to colonization. Therefore, besides infection prevention, managing the progression of valvular calcification among HD patients remains an issue to be addressed in future studies.

Abstract 17886: Temporal Trends, Healthcare Resource Utilization and In Hospital Outcomes of Infective Endocarditis Following Transcatheter Edge-to-Edge Repair Using Mitraclip Among Elderly Patients With Severe Mitral Regurgitation: A National Perspectives

Introduction: Procedural proficiency combined with the careful selection of patients with severe mitral regurgitation, who are at high or prohibitive risk for cardiac surgery, may have influenced the incidence and outcomes of infective endocarditis (IE) following mitral Transcatheter edge-to-edge repair (TEER). Objective: To assess the temporal trends, healthcare resource utilization (HRU), and in-hospital outcomes of IE post-TEER. Methods: We used the National inpatient sample registry to identify all patients aged > 65 with definite IE post-TEER between 2016 and 2020. Temporal incidence trends, in-hospital mortality, length of stay, and discharge disposition were analyzed. Results: During the study period, there were an estimated 71 cases of endocarditis among patients 65 years and older following mitral TEER, representing 355 discharges (1.0% of TEER-associated discharges) nationally. The temporal trend of the incidence of IE is shown in Figure 1. Relative to its absence, the occurrence of IE following TEER was associated with a 30.3% increased risk of HRU (Patient Average Treatment effect - PATE estimate = 0.303; 95% confidence interval (CI) =0.214 - 0.391; P<0.001); a 13.2% increased risk of AKI (PATE estimate = 0.132; 95% confidence interval (CI) =0.033 - 0.232; p=0.009) and a 6.2% increased risk of in-hospital mortality (PATE estimate = 0.062; 95% confidence interval (CI) =0.008 - 0.117; p=0.025) Conclusions: Among elderly patients with severe symptomatic mitral regurgitation, who are at high or prohibitive risk for cardiac surgery, the incidence of TEER-associated IE appears to be trending downwards. The occurrence of TEER-associated IE confers small but significant high HRU, complication rates, including AKI and in-hospital mortality, compared to those without IE. High-fidelity studies are needed to elucidate these findings.

Risk of endocarditis among patients with coagulase-negative Staphylococcus bacteremia

Coagulase-negative staphylococci (CoNS) are currently considered typical microorganisms causing infective endocarditis (IE) in patients with prosthetic valves. The objective was to determine variables associated with IE in patients with CoNS bacteremia. We performed an analysis of the clinical characteristics of patients with CoNS bacteremia admitted to a university hospital in Madrid (Spain) from 2021 to December 2022 according to the occurrence of IE. This study is an evaluation of a bacteremia registry. During the study period, 106 patients with CoNS bacteremia were detected. In 85 patients an echocardiogram was performed during hospital admission to rule out IE. Among them, 12 episodes were detected that met IE criteria (14.2%). Of the 6 patients with heart valve prostheses, 5 patients (83.3%) had IE (p < 0.001). Patients with IE more frequently had positive blood cultures more than 12 h after the first draw (58.3% versus 13.4%; p < 0.001). There was a tendency to associate community-acquired bacteremia and to that all blood culture bottles obtained were positive with an increased risk of IE (p = 0.091 and p = 0,057, respectively). Attributable mortality to infection was higher in patients with IE relative to all other patients (16.7% vs. 0%; p = 0.033). The multivariable analysis included having valve prosthesis and persistent bacteremia for more than 12 h. Both were independently associated with IE: valve prosthesis OR 38.6 (95% CI 5.8–258; p < 0.001) and persistent bacteremia OR 2.6 (95% CI 1.1–6.8; p = 0.046). In conclusion, a high percentage of cases of CoNS bacteremia may be due to IE. Some of the variables related to a higher risk of IE, such as having a valvular prosthesis or presenting positive blood cultures for more than 12 h, should lead to rule out or confirm the presence of IE by performing echocardiography.

Neutrophils Protect Against Staphylococcus aureus Endocarditis Progression Independent of Extracellular Trap Release.

Infective endocarditis (IE) is characterized by an infected thrombus at the heart valves. How bacteria bypass the immune system and cause these thrombi remains unclear. Neutrophils releasing NETs (neutrophil extracellular traps) lie at this interface between host defense and coagulation. We aimed to determine the role of NETs in IE immunothrombosis. We used a murine model of Staphylococcus aureus endocarditis in which IE is provoked on inflamed heart valves and characterized IE thrombus content by immunostaining identifying NETs. Antibody-mediated neutrophil depletion and neutrophil-selective PAD4 (peptidylarginine deiminase 4)-knockout mice were used to clarify the role of neutrophils and NETs, respectively. S. aureus mutants deficient in key virulence factors related to immunothrombosis (nucleases or staphylocoagulases) were investigated. Neutrophils releasing NETs were present in infected thrombi and within cellular infiltrates in the surrounding vasculature. Neutrophil depletion increased occurrence of IE, whereas neutrophil-selective impairment of NET formation did not alter IE occurrence. Absence of S. aureus nuclease, which degrades NETs, did not affect endocarditis outcome. In contrast, absence of staphylocoagulases (coagulase and von Willebrand factor binding protein) led to improved survival, decreased bacteremia, smaller infiltrates, and decreased tissue destruction. Significantly more NETs were present in these vegetations, which correlated with decreased bacteria and cell death in the adjacent vascular wall. Neutrophils protect against IE independent of NET release. Absence of S. aureus coagulases, but not nucleases, reduced IE severity and increased NET levels. Staphylocoagulase-induced fibrin likely hampers NETs from constraining infection and the resultant tissue damage, a hallmark of valve destruction in IE.

Abstract 13084: Occurrence of Infective Endocarditis After Transcatheter versus Surgical Pulmonary Valve Implantation: Results of a Nationwide Administrative Database

Background: It is unclear if the risk of infective endocarditis (IE) differs between transcatheter (TPVI) and surgical (SPVR) pulmonary valve implantation. We sought to address this question using administrative data including a large nationwide patient population. Methods: All congenital heart disease (CHD) patients ≥4 years of age who underwent isolated pulmonary valve implantation were identified in the BARMER Health Insurance Company database (≈9 million members, representative of the German population). Data from 01/2005 to 12/2018 were analyzed with regard to overall survival and complications particularly focusing on IE. Results: Overall, 461 pulmonary valve implantations were performed in 413 patients (59.4% male, median age 18.6 years (IQR 12.8-31.3)). Of those, 38.4% (n=177) underwent TPVI, while 61.6% (n=284) were treated with SPVR. Overall, IE was diagnosed in 8.0% (n=37) of cases after a median of 1.3 years (IQR 0.2-3.7). In the TPVI cohort, IE occurred in 10.2% (n=18) of cases, while IE was diagnosed in 6.7% (n=19) of cases with SPVR ( p =0.217). Furthermore, 5.0% (n=23) of all patients died during follow-up (of those n=4 within 90 days after diagnosis of IE). On multivariable Cox-regression analysis, previous diagnosis of IE was associated with a higher risk of re-IE ( p =0.025), but no association between IE and age ( p =0.17), sex ( p =0.34) or type of CHD was found ( p =0.71). While the overall rate of IE was not dependent on the treatment modality, there were significant time-dependent differences: Within the first year of follow-up, freedom from IE or death was significantly higher in the TPVI cohort (HR 5.26 [95% CI 1.59-16.67], p =0.006) compared to SPVR), but within the 3-10 year period the probability reversed in favor of the SPVR cohort (HR 10.07 [95% CI 3.41-29.76], p &lt;0.001) compared to TPVI). Conclusion: In a cohort of 413 patients undergoing pulmonary valve implantation, infective endocarditis occurred in 8.0% of cases. The overall rate of infective endocarditis was not significantly different between surgical and interventional pulmonary valve procedures. However, while early endocarditis was more often related to surgical procedures, the mid-term IE risk was significantly lower in surgically treated patients.

High Mortality and Graft Loss after Infective Endocarditis in Kidney Transplant Recipients: A Case-Controlled Study from Two Centers.

Kidney transplant recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation, and outcome. While infective endocarditis (IE) is among such complications in KTRs, the literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria) in adult KTRs from January 2010 to December 2018 were included, as well as two controls per case, and followed until 31 December 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan–Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus, and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated, age, vascular nephropathy, and elevated calcineurin inhibitor through levels were significantly associated with the occurrence of IE in our study. Patient and death-censored graft survival were greatly diminished five years after IE, compared to controls being 50.3% vs. 80.6% (p < 0.003) and 29.7% vs. 87.5% (p < 0.002), respectively. IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.

Long-term results of right ventricular outflow tract reconstruction with Contegra®

Right ventricular outflow tract reconstruction is a common feature for the treatment of congenital heart disease. However, the best substitute for pulmonary valvulation is still unknown, since the whole valves impair in above ten years. Pulmonary homograft appears to be the best substitute, but the lack of availability of this substitute, especially the low diameter, conducted to the development of other valves, biological or synthetic. The Contegra® valve is a bioprosthesis obtained from bovine jugular vein. Available in diameters from 12 to 22 mm, these conduits should constitute a good alternative to the homograft, especially concerning low weight children. The objective of this study was to describe the long-term evolution of Contegra® in our institution. We conducted a retrospective monocentric observational study at the CHRU of Tours including all patients implanted with a Contegra® valve between January 2001 and December 2018. Over this 17-year period, 58 Contegra® implanted in 52 patients were included (average age 6.7 ± 5.4 years at valvulation). Survival without revision surgery for conduit failure was 87% (95 CI {79–97}) at 2 years, 67% (95 CI {54–84}) at 5 years and 60% (95 CI {43–82}) at 10 years ( Fig. 1 ). A lower age at implantation, a smaller diameter, and the occurrence of infective endocarditis was significantly associated with the revision surgery. Only 5 patients had infectious endocarditis over this period. Endocarditis-free survival was 94% (95 CI {88–100}) at 2 years, 92% (95 CI {84–100}) at 5 years and 92% (95 CI {84–100}) at 10 years. Our study suggests that Contegra® valve could constitute an attractive substitute for right ventricular outflow tract reconstruction. A multicenter study comparing long-term evolution of the whole valves currently available for pulmonary valvulation could confirm our results.

A RARE CASE OF INFECTIVE ENDOCARDITIS FOLLOWING CORONARY ANGIOPLASTY WITH AN UNUSUAL PRESENTATION OF ENDOPHTHALMITIS

Objective: There is a rise in the global incidence of infective endocarditis due to gram-negative bacilli like Pseudomonas aeruginosa and involving structures of the left side of the heart such as valve apparatus and papillary muscles. It is due to the increasing usage of implantable cardiac devices and prosthetic valves. Occurrence of infective endocarditis following minor cardiac procedures like coronary angiography or angioplasty is extremely rare. Infective endocarditis has varied clinical presentations making its diagnosis difficult. Hence a high degree of clinical suspicion by the treating physician is essential for rapid diagnosis and treatment. Design and method: We present a case of a 54 year old man, a non-intravenous drug user with long standing history of diabetes mellitus, who underwent a per-cutaneous coronary angioplasty for a double vessel block of the coronary vasculature. Six months later he presented to the emergency room with a febrile illness. His initial blood report was positive for dengue fever. His clinical symptoms rapidly worsened over one day with development of endogenous endophthalmitis of left eye, erythema nodosum, new-onset Janeway lesions and transient glomerulonephritis. Blood and vitreous fluid cultures showed growth of Pseudomonas aeruginosa. Results: Transthoracic echocardiogram showed presence of an oscillating vegetation attached to the papillary muscle of the left ventricle, associated with moderate mitral regurgitation and new onset mitral valve prolapse. He was aggressively treated with a combination therapy of intravenous and intravitreal antibiotics. His clinical features and blood hemogram showed gradual improvement over the next four weeks, responding to medical treatment. Echocardiogram was repeated which showed no resolution in findings. As his visual acuity showed no improvement, an enucleation surgery of his left eye was planned. One day prior to the surgery, patient became unresponsive with no recordable pulse rate and blood pressure. He had developed a sudden cardiac arrest and died. Conclusions: Complications and systemic embolization are more commonly associated with the left heart infective endocarditis. Despite various advances and administration of adequate treatment, infective endocarditis is associated with a guarded prognosis. It has significantly high degree of morbidity and mortality.

Infective endocarditis in hemodialysis patients: A 10-year observational single center study.

The incidence of infective endocarditis (IE) in chronic hemodialysis (CHD) patients remains high, despite the preventive measures implemented by nephrologists, especially the rigorous respect of hygiene, the use of antibiotic locks for catheters and the use of tunneled catheters instead of non-tunneled. The objective of this study was to determine the clinical, biological, and echocardiographic characteristics, and the prognosis of IE in CHD. It was a retrospective study, conducted from December 2010 to March 2020, at the Nephrology and Cardiology units of University Hospital in Oujda, Morocco. We compiled a series of 31 CHD patients having developed IE. Eleven cases (35.4%) were collected between 2010 and 2015, and 20 cases (64.6%) between 2016 and 2020. The mean age was 47 ± 19 years, 58% were male, and 25.8% of patients had diabetes. Vascular access for hemodialysis was by arteriovenous fistula, non-tunneled catheter, and tunneled catheter in 22.5%, 32.2%, and 45.2%, of the cases, respectively. About 25.8% of patients had benefited from more than two catheters (tunneled or non-tunneled) during the 3 months preceding the occurrence of IE. The mitral, tricuspid, and aortic valves were the site of IE in 41.9%, 41.9%, and 13% of the cases, respectively. Right heart IE and left heart IE were observed in 42% (13 cases) and 58% (18 cases) of cases, respectively. Blood cultures were negative in 58.1% of the cases at the time of diagnosis of IE. Staphylococcus aureus was identified in 69.2% of the cases. Mortality occurred in 54.8% of the cases. IE remains a severe condition in CHD patients with an increasing incidence. Rigorous prevention and screening strategies should be implemented at the hemodialysis centers.

Maternal and perinatal outcomes of pregnant women with tetralogy of Fallot: a tertiary center experience from south-India

Background Women with tetralogy of Fallot especially uncorrected are at increased risk of adverse maternal and perinatal outcomes. Method We reviewed the maternal complications and pregnancy outcomes of women with tetralogy of Fallot (ToF), having corrected or uncorrected lesion during the period from 2011 to 2019 attending a south-Indian tertiary care center. Data regarding demographics, clinical course, and medications received and echocardiographic diagnosis regarding ToF, labor and delivery details, and postpartum follow-up was collected from the records. For each case, four women matched for age (±2 years), without a diagnosis of heart disease, were included as controls. We compared the outcomes in pregnant women with ToF and controls as well between those who have undergone repair with those without repair and also with the controls. Results There were 27 pregnancies in 19 patients with ToF, including eight pregnancies in seven women with uncorrected lesions. There was no maternal death or occurrence of infective endocarditis. Women with uncorrected lesion had significantly higher rates of fetal growth restriction (37.5% vs 6.7%), preterm birth (50% vs. 13.3%) resulting in lower birth weight (1907.5 g vs. 2607.3 g)) compared to those with a corrected lesion. Women with corrected lesion had similar outcomes to the controls (p > .5). Conclusion Women with uncorrected ToF are at increased risk of perinatal complications compared to those with corrected lesion and require care under a multidisciplinary team, with an individualized plan for delivery to optimize the outcomes.

Comparative analysis of the oral microbiota between iron-deficiency anaemia (IDA) patients and healthy individuals by high-throughput sequencing

BackgroundThe relationship between oral microbiota and IE (infective endocarditis) is well established. Opportunistic pathogens in normal oral flora enter the bloodstream through daily oral cleaning or invasive dental procedures, leading to the occurrence of infective endocarditis. An in vitro iron-deficient condition leads to a drastic community shift in oral microbiota with increasing proportions of taxa related to infective endocarditis. To investigate the relationship among insufficient iron supply, oral microbiota and the risk of IE and to conduct a population amplification study, iron-deficiency anaemia is used as an in vivo model.MethodsThis cross-sectional study enrolled 24 primary iron-deficiency anemia (IDA) patients from 2015.6 to 2016.6 from the hematology department of West China Hospital, Sichuan University, and 24 healthy controls. High-throughput sequencing compared the dental plaque microbiota of 24 IDA (iron-deficiency anaemia) patients and 24 healthy controls.ResultsSequences were classified into 12 phyla, 28 classes, 50 orders, 161 genera and 497 OTUs (the IDA and control groups shared the same 384 OTUs). Iron deficiency leads to lower internal diversity in the oral flora. The abundances of genera Corynebacterium, Neisseria, Cardiobacterium, Capnocytophaga, and Aggregatibacter were significantly higher in healthy controls, while genera Lactococcus, Enterococcus, Lactobacillus, Pseudomonas and Moraxella showed higher proportions in the IDA group (P < 0.05). The relative abundances of genera Lactococcus, Enterococcus, Pseudomonas and Moraxella were significantly negatively correlated with the concentration of serum ferritin (P < 0.05).ConclusionsWithout an increase of oral streptococci, the main pathogen of IE, it is difficult to determine whether IDA can increase the risk of IE. However, the iron-deficient condition did lead to changes in the oral microbiota community structure. The genera that showed higher proportions in the IDA group were frequently reported as antibiotic-resistant. As antibiotics are commonly recommended to prevent IE before dental procedures, this study offers new ideas of personalized prevention of IE.

Relationship of oral conditions to the incidence of infective endocarditis in periodontitis patients with valvular heart disease: a cross-sectional study.

Infective endocarditis (IE) is a life-threatening infectious disease, but the pathogenesis of the disease remains uncertain. The objective of this study was to examine whether oral infectious conditions are associated with the occurrence of IE in valvular heart disease (VHD) patients. A total of 119 periodontitis (P) patients with or without VHD were enrolled, and cross-sectional analyses were performed. Patients were classified as follows: (1) mild-to-moderate P without VHD, (2) mild-to-moderate P with VHD, (3) severe P without VHD, or (4) severe P with VHD. A total of 78 VHD patients were classified as (1) VHD without IE or (2) VHD with IE. Conditional logistic regression analysis was performed to compute the odds ratio (OR) and 95% confidence interval (CI). No significant differences were observed between patients with or without VHD in oral conditions. A significant increase in the percentage of alveolar bone loss in VHD patients with IE was observed compared with that of patients without IE. The ratio of both Porphyromonas gingivalis (Pg) IgG titer > 1.68 and Pg fimA type II genotype in patients with IE was significantly higher than in patients without IE. There was a significant correlation between the occurrence of IE and clinical oral findings (number of remaining teeth: OR, 0.17; rate of alveolar bone loss > 40%: OR, 11.8). VHD patients with IE might have severe periodontitis compared with patients without IE, although further investigation will be needed because this is based on only 7 VHD patients with IE. The patients with IE had fewer remaining teeth, more advanced bone resorption compared with those of patients without IE. These findings suggest a possible association between the occurrence of IE and periodontal infection.

Knowledge of Moroccan Dentists Towards the Prophylaxis of Infective Endocarditis

Background: The involvement of oral bacterias in the occurrence of infective endocarditis (IE) has prompted the adoption of antibiotic prophylaxis prior to dental procedures for patients at high-risk. The aim of this paper was to assess the knowledge of Moroccan dentists regarding the management of patients with heart disease at risk of infective endocarditis. Methods: This was a cross-sectional descriptive analytical study which targeted 200 dentists in the city of Rabat- Morocco. A questionnaire with 16 questions was distributed randomly. The level of knowledge of dentists was established based on the number of correct answers for each section and responses were assessed according to the American Heart Association (AHA) 2007 guidelines. Results: Only 133 practitioners have agreed to participate in our study with a response rate of 66,5%. 87% of dentists reported contacting the cardiologist before starting treatment, 33% of practitioners weren’t aware of any guidelines and 20% knew AHA 2007, 52% reported not following guidelines in the management of patients with heart disease. Among the cardiac conditions and dental procedures proposed in the questionnaire which required prophylaxis; 8% and 2% respectively chose the correct answer according to the AHA’s 2007 guidelines. 31% of dentists answered correctly on the prescription of antibiotic prophylaxis protocol according to the latest recommendations. Conclusion: According to our results, the knowledge of Moroccan private general dentists towards endocarditis prophylaxis was in a low level. The study highlights the need for continuous education.

Knowledge of Moroccan Dentists Towards the Prophylaxis of Infective Endocarditis

Background: The involvement of oral bacterias in the occurrence of infective endocarditis (IE) has prompted the adoption of antibiotic prophylaxis prior to dental procedures for patients at high risk. This paper aimed to assess the knowledge of Moroccan dentists regarding the management of patients with heart disease at risk of infective endocarditis.Methods: This was a cross-sectional descriptive-analytical study that targeted 200 dentists in Rabat, Morocco. A questionnaire with 16 questions was distributed randomly. The level of dentists' level of knowledge was established based on the number of correct answers for each section and responses were assessed according to the American Heart Association (AHA) 2007 guidelines.Results: Only 133 practitioners have agreed to participate in our study with a response rate of 66,5%. 87% of dentists reported contacting the cardiologist before starting treatment, 33% of practitioners weren’t aware of any guidelines and 20% knew AHA 2007, 52% reported not following guidelines in the management of patients with heart disease. Among the cardiac conditions and dental procedures proposed in the questionnaire which required prophylaxis; 8% and 2% respectively chose the correct answer according to the AHA’s 2007 guidelines. 31% of dentists answered correctly on the prescription of antibiotic prophylaxis protocol according to the latest recommendations.Conclusion: According to our results, the knowledge of Moroccan private general dentists towards endocarditis prophylaxis was at a low level. The study highlights the need for continuous education.

The occurrence of infective endocarditis with Staphylococcus lugdunensis bacteremia: A retrospective cohort study and systematic review

Staphylococcus lugdunensis is a coagulase-negative staphylococcus with similar virulence characteristics as Staphylococcus aureus. Whether S. lugdunensis causes infective endocarditis (IE) in a similar proportion of cases as S. aureus (reported to be 12.6% in a definitive multicenter prospective study) is unclear. We conducted a retrospective cohort study of adult patients with at least one blood culture positive for S. lugdunensis at our institution from January 2006 to December 2014. We examined microbiology data, ascertained disease severity and determined the proportion of patients with definite or possible IE based on the 2000 Modified Duke Criteria. Because coagulase-negative staphylococci were routinely identified to the species level at our institution from 2012 onwards, we determined the proportion of patients with definite or possible IE before and after implementation of routine speciation. We also compared our results with reported proportions of IE among patients with S. lugdunensis bacteremia (SLB) in other institutions by conducting a systematic review of the scientific literature. Nonparametric bootstrapping methods were performed to determine 95% confidence intervals (CI) for proportions of IE in patients with SLB. Seventy-four patients with SLB were identified, of whom 64% (47/74) had sepsis by SIRS criteria, and 18% (13/74) had severe illness by Pittsburgh bacteremia score (PBS). Kaplan-Meier survival analysis showed that one-year survival among patients with severe illness was worse than patients with non-severe illness (p=0.02). Fifteen percent (11/74) of patients had definite or possible IE (95% CI 6.8-23.0%). The proportion of SLB patients with definite or possible IE was 15.8% (6/38, 95% CI 5.3-28.9%) prior to routine speciation and 13.9% (5/36, 95% CI 2.8-27.8%) after routine speciation (p=0.71). Among patients with at least two positive blood cultures for S. lugdunensis, 25% (10/40, 95% CI 12.5-40.0%) had IE. Systematic review of the literature yielded eight relevant retrospective studies. Of studies that included patients with one or more positive blood cultures for S. lugdunensis, the proportion of IE ranged from 6.3% to 27.0%. The proportion of definite or possible IE among patients with SLB is similar to the proportion of IE among patients with S. aureus bacteremia. The proportions of IE among patients with SLB at other institutions fall within the 95% CI yielded by bootstrapping. Our findings suggest that growth of S. lugdunensis in two separate blood cultures should prompt consideration of workup for IE.

The changing landscape of infective endocarditis in the Netherlands.

Despite advances in the diagnosis and treatment of infective endocarditis (IE), the in-hospital mortality of IE has remained unchanged at about 20 %. Subgroups of patients such as those with prosthetic valve IE, IE associated with congenital heart disease or caused by certain microorganisms such as Staphylococcus aureus are at a much higher risk for complications, and may have one-year mortality rates of up to 60 % [1]. These high mortality rates, in combination with the advent of antibiotics, have led to the recommendation of antibiotic prophylaxis in guidelines since the early 1950s. Lately, increasing debate concerning microbacterial resistance due to possible overuse of antibiotics and lack of evidence supporting the use of antibiotic prophylaxis, has led to a change in policy in favour of restriction of antibiotic prophylaxis. The 2008 National Institute of Health and Clinical Excellence (NICE) guideline for IE has been cause for debate, advocating complete cessation of the use of antibiotic prophylaxis altogether. However, up to 20 % of UK physicians admit to prescribing antibiotic prophylaxis in very high-risk groups [2]. The situation in the UK may therefore be rather similar to the Netherlands, where 2008 European Society of Cardiology (ESC) and national guidelines recommend antibiotic prophylaxis use in high-risk patients, during high-risk procedures. In the current issue of the Journal, Krul et al. [3] have shown a gradual increase in the incidence of IE in a large non-academic hospital in the Netherlands. They have started the registry of cases in parallel with the introduction of the new guidelines for the prevention of endocarditis in the Netherlands. The design of the study may have caused under-registration of the occurrence of IE, as only the diagnosis treatment code (DBC) was screened for IE. Patients suffering from multiple disorders in intensive care environments may thus have been missed. Interestingly, the authors show that the increase of IE is mainly due to increase in prosthetic valve endocarditis, thus a population that received antibiotic prophylaxis to prevent IE according to ESC and Dutch guidelines. One could conclude from these figures that the increase in IE incidence is due to a higher prevalence of predisposing factors for IE rather than more restrictive prescription of antibiotic prophylaxis. This is in line with several recent studies. Finally, improving on larger studies with a similar design [4], the authors were able to retrieve the causal microorganism in all IE cases. They show that microorganisms typically found in mucosal infections caused the majority of IE cases. The notion that IE may be caused by bacteria from the mouth was suggested over 100 years ago [5]. Dental procedures have been pointed out as a source for bacteraemia causing IE. However, several large studies compared dental extraction with daily activities such as tooth brushing, and found that brushing teeth can cause bacteraemia in up to 32 % of cases [6]. Their data suggest that bacteraemia due to simple daily activities (including chewing food) may occur hundreds of times more often than bacteraemia due to dental procedures, or other medical procedures. This again calls the use of antibiotic prophylaxis for IE prevention into question. Rather, prevention of longstanding low-grade infection seems prudent. Krul et al. [3] suggest a large-scale registry to further elucidate mechanisms underlying IE increase in the Netherlands. Such efforts have been undertaken in international consortia such as the International Collaboration for Endocarditis. Other successful approaches have employed population-wide entry of all medical records in research databases such as the Rochester Epidemiology Project in Olmsted County, USA. With the recent introduction of mandatory International Classification of Disease (ICD-10) registration of all patients within the Netherlands, a Dutch national registry is possible. While registry of disease will improve disease understanding, prevention of IE could be most effective by education of our patients at risk for IE. Dental hygiene and prevention of caries and parodontitis are an integral part of the Dutch guidelines, and should be discussed with any patients at risk. In addition, patients suffering from alarm symptoms such as ongoing fever despite antibiotic treatment, or symptoms indicative of heart failure or thrombotic events, should seek medical attention. Patient education, and thereby patient empowerment, could be one of the most important tools to improve patient survival in IE.

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.

Infective Endocarditis in Hypertrophic Cardiomyopathy

Background: Infective endocarditis (IE) is a well-known complication of hypertrophic cardiomyopathy (HCM). Intracardiacdevice (ID) implantation for the treatment of HCM is an additional factor that increases the risk of IE.Objective: The aim of this study was to assess the clinical manifestations and prognosis of IE in patients with HCM.Methods: A retrospective, descriptive and observational study assessed the occurrence of IE and the clinical characteristicsof a population with HCM from June 1992 to January 2014, with median follow-up of 7.5 years.Results: The study evaluated 646 patients with HCM. Left ventricular outflow tract obstruction (LVOTO) was present in38.5% (n=230) of patients and 22% (n=129) had an ID. The incidence of IE was 1.9%. Twelve episodes were confirmed, 7valvular [7/230 (3.04%)] and 5 in ID, 3 in pacemakers and 2 in implantable cardioverter defibrillators [5/129 (6.45%)]. Patientswith valvular IE had resting mean gradient of 48±37 mmHg and during Valsalva maneuver of 126±44 mmHg, respondingto medical treatment in all cases. Infective endocarditis in ID was resolved with percutaneous removal in 5 patients. Onepatient of the valvular group (8%) required valve replacement. No deaths were reported.Conclusions: The incidence of IE in HCM is low. There are two defined populations: left valvular IE confined to patients withLVOTO and IE for ID. Patients with HCM without LVOTO or ID did not present IE.

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

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. 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. 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%). 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.

Turning 18 with congenital heart disease: prediction of infective endocarditis based on a large population

The risk of infective endocarditis (IE) in adults with congenital heart disease is known to be increased, yet empirical risk estimates are lacking. We sought to predict the occurrence of IE in patients with congenital heart disease at the transition from childhood into adulthood. We identified patients from the CONCOR national registry for adults with congenital heart disease. Potential predictors included patient characteristics, and complications and interventions in childhood. The outcome measure was the occurrence of IE up to the age of 40 and 60. A prediction model was derived using the Cox proportional hazards model and bootstrapping techniques. The model was transformed into a clinically applicable risk score. Of 10 210 patients, 233 (2.3%) developed adult-onset IE during 220 688 patient-years. Predictors of IE were gender, main congenital heart defect, multiple heart defects, and three types of complications in childhood. Up to the age of 40, patients with a low predicted risk (<3%) had an observed incidence of less than 1%; those with a high predicted risk (≥3%) had an observed incidence of 6%. The model also yielded accurate predictions up to the age of 60. Among young adult patients with congenital heart disease, the use of six simple clinical parameters can accurately predict patients at relatively low or high risk of IE. After confirmation in other cohorts, application of the prediction model may lead to individually tailored medical surveillance and educational counselling, thus averting IE or enabling timely detection in adult patients with congenital heart disease.