Global Trends in Infective Endocarditis Epidemiology

Imaging in Infective Endocarditis-Current Opinions and Trends in Cardiac Computed Tomography

Infective endocarditis is a rare disease with an increasing incidence and an unaltered high mortality rate, despite medical development. Imaging plays an integrative part in the diagnosis of infective endocarditis, with echocardiography as the initial diagnostic test. Research data in the utility of cardiac computed tomography (CCT) in the diagnostic algorithm of IE are rising, which indicates its importance in detection of IE-related lesion along with the exclusion of coronary artery disease. The latest 2023 European Society of Cardiology Guidelines in the management of IE classified CCT as class of recommendation I and level of evidence B in detection of both valvular and paravalvular lesions in native and prosthetic valve endocarditis. This review article provides a comprehensive and contemporary review of the role of CCT in the diagnosis of IE, the optimization of acquisition protocols, the morphology characteristics of IE-related lesions, the published data of the diagnostic performance of CCT in comparison to echocardiography as the state-of-art method, as well as the limitations and future possibilities.

The Interplay of Malignancy and Endocarditis: A Report of a Rare Case of Marantic Endocarditis in Metastatic Lung Adenocarcinoma

Endocarditis involves inflammation of the inner layer of the heart, known as the endocardium. This condition typically presents with vegetation, with bacteria and fungi usually being the primary culprits. It is divided into two main categories based on its cause: infectious endocarditis and noninfectious endocarditis (NIE). Most cases of NIE are associated with malignancies, most of which are adenocarcinomas of the pancreas and lungs. We present the case of a 63-year-old man with recently diagnosed stage 3 non-small cell lung cancer and a previous history of thrombosis to the renal and popliteal arteries alongside an extensive cardiovascular history who presented with blurry vision secondary to multiple acute ischemic strokes, initially thought to be a consequence of septic emboli due to bacterial endocarditis; however, further workup revealed otherwise, illustrating the complex relationship between malignancy and endocarditis and its ramification.

Insights into microorganisms, associated factors, and the oral microbiome in infective endocarditis patients

Introduction

Infective Endocarditis (IE) is a rare, life-threatening infection of the endocardium with multisystem effects. Culprit microorganisms derived from different niches circulate through the bloodstream and attach to the endocardium, particularly the heart valves. This study aimed to investigate culprit microorganisms among a cross-sectional cohort of IE patients, their associated factors, and to explore the potential relationship to the oral microbiome.

Methods

In this observational study, we undertook a cross-sectional analysis of 392 medical records from patients diagnosed with IE. The primary outcome of this study was to analyse the association between the IE culprit microorganisms and the underlying anatomical types of IE (native valve (NVE), prosthetic valve (PVE), or cardiac device-related (CDE)). Secondary outcomes encompassed a comparative analysis of additional factors, including: the treatment approaches for IE, and the categorisation of blood cultures, extending to both genus and species levels. Additionally, we cross-referenced and compared the species-level identification of IE bacteraemia outcome measures with data from the expanded Human Oral Microbiome Database (eHOMD).

Results

A culprit microorganism was identified in 299 (76.28%) case participants. Staphylococcal infections were the most common (p < 0.001), responsible for 130 (33.16%) hospitalisations. There were 277 (70.66%) cases of NVE, 104 (26.53%) cases of PVE, and 11 (2.81%) cases of CDE. The majority of PVE occurred on prosthetic aortic valves (78/104, 75%), of which 72 (93.5%) were surgical aortic valve replacements (SAVR), 6 (7.8%) were transcatheter aortic valve implants, and one transcatheter pulmonary valve implant. Overall, underlying anatomy (p = 0.042) as well as the treatment approaches for IE (p < 0.001) were significantly associated with IE culprit microorganisms. Cross-reference between IE bacteraemia outcomes with the eHOMD was observed in 267/392 (68.11%) cases.

Conclusions

This study demonstrated that IE patients with a history of stroke, smoking, intravenous drug use, or dialysis were more likely to be infected with Staphylococcus aureus. CDE case participants and patients who had previous SAVR were most associated with Staphylococcus epidermidis. IE patients aged 78+ were more likely to develop enterococci IE than other age groups. Oral microorganisms indicated by the eHOMD are significantly observed in the IE population. Further research, through enhanced dental and medical collaboration, is required to correlate the presence of oral microbiota as causative factor for IE.

Impact of Intermediate Susceptibility to Penicillin on Antimicrobial Treatment and Outcomes of Endocarditis Caused by Viridans and Gallolyticus Group Streptococci

BACKGROUND

Evidence supporting combination treatment with a beta-lactam plus an aminoglycoside (C-BA) for endocarditis caused by viridans and gallolyticus group streptococci (VGS-GGS) with intermediate susceptibility to penicillin (PENI-I) is lacking. We assessed the clinical characteristics and outcomes of PEN-I VGS-GGS endocarditis and compared the effectiveness and safety of C-BA with third-generation cephalosporin monotherapy.

METHODS

Retrospective analysis of prospectively collected data of a cohort of definite endocarditis caused by penicillin-susceptible and PENI-I VGS-GGS (penicillin minimum inhibitory concentration ranging from 0.25 to 2 mg/L) between 2008 and 2018 in 40 Spanish hospitals. We compared cases treated with monotherapy or with C-BA and performed multivariable analyses of risk factors for in-hospital and 1-year mortality.

RESULTS

A total of 914 consecutive cases of definite endocarditis caused by VGS-GGS with complete or intermediate susceptibility to penicillin were included. A total of 688 (75.3%) were susceptible to penicillin and 226 (24.7%) were PENI-I. Monotherapy was used in 415 (45.4%) cases (cephalosporin in 331 cases) and 499 (54.6%) cases received C-BA. In-hospital mortality was 11.9%, and 190 (20.9%) patients developed acute kidney injury. Heart failure (odds ratio [OR]: 6.06; 95% confidence interval [CI]: 1.37-26.87; P = .018), central nervous system emboli (OR: 9.83; 95% CI: 2.17-44.49; P = .003) and intracardiac abscess (OR: 13.47; 95% CI: 2.24-81.08; P = .004) were independently associated with in-hospital mortality among PEN-I VGS-GGS cases, while monotherapy was not (OR: 1.01; 95% CI: .26-3.96; P = .982).

CONCLUSIONS

Our findings support the use of cephalosporin monotherapy in PEN-I VGS-GGS endocarditis in order to avoid nephrotoxicity without adversely affecting patient outcomes.

Infective Endocarditis-Update for the Perioperative Clinician

Infective endocarditis is a common pathology routinely encountered by perioperative physicians. There has been a need for a comprehensive review of this important topic. In this expert review, the authors discuss in detail the incidence, etiology, definition, microbiology, and trends of infective endocarditis. The authors discuss the clinical and imaging criteria for diagnosing infective endocarditis and the perioperative considerations for the same. Other imaging modalities to evaluate infective endocarditis also are discussed. Furthermore, the authors describe in detail the clinical risk scores that are used for determining clinical prognostic criteria and how they are tied to the current societal guidelines. Knowledge about native and prosthetic valve endocarditis, with emphasis on the timing of surgical intervention-focused surgical approaches and analysis of current outcomes, are critical to managing such patients, especially high-risk patients like those with heart failure, patients with intravenous drug abuse, and with internal pacemakers and defibrillators in situ. And lastly, with the advancement of percutaneous transcatheter valves becoming a norm for the management of various valvular pathologies, the authors discuss an in-depth review of transcatheter valve endocarditis with a focus on its incidence, the timing of surgical interventions, outcome data, and management of high-risk patients.

A Three-Year Retrospective Study Assessing the Quality of the Course of Management of Infective Endocarditis in a Tertiary Hospital in Riyadh, Saudi Arabia

BACKGROUND

Infective endocarditis (IE) is one of the most misdiagnosed diseases in Saudi Arabia because of the variable treatment regimen. This study aims to assess the quality of the management of infective endocarditis in a tertiary care teaching hospital.

METHODS

A single-center retrospective cohort study was conducted, based on electronic medical records extracted from the BestCare electronic medical record system, of all patients who presented with infective endocarditis as a final diagnosis from 2016 to 2019.

RESULTS

Out of a total of 99 patients diagnosed with infective endocarditis, 75% of our patients had blood cultures ordered before initiating empirical antibiotic therapy. Positive blood cultures were reported in 60% of patients. Staphylococcus aureus was the most common organism, identified in 18% of our patients, followed by Streptococcus viridans at 5%. Empirical antibiotics were initiated in 81% of patients. Proper antibiotic coverage was initiated within a week for 53% of the patients, and 14% had proper antibiotic coverage within two weeks. On echocardiography, 62% of the patients had vegetation that was present in a single valve. The mitral valve had the highest incidence of vegetation (24%), followed by the aortic valve (21%). Follow-up echocardiography was done in 52% of patients. It showed regressed vegetation in 43% of patients, while only 9% of patients had no vegetation regression. Valve repair was done in 25% of patients. Out of 99 patients, 47 required ICU admission. The mortality rate was 18%.

CONCLUSION

Overall management of infective endocarditis in the study hospital was appropriate and highly compliant with guidelines, with a few areas that could be improved further.

Clinical Presentation and Risk Factors of Infective Endocarditis in the Elderly: A Systematic Review

Infective endocarditis (IE) is a bacterial infection with high morbidity and mortality rates, particularly among the elderly. This systematic review was conducted to determine the clinical characteristics of IE in older adults and the risk factors that could lead to adverse outcomes. The research employed three databases (PubMed, Wiley, and Web of Science), with a primary search for studies that have described cases of IE in patients older than 65 years. From a total of 555 articles, 10 were selected for inclusion in the current study, comprising a total of 2222 patients with a confirmed diagnosis of IE. The primary findings were an increased incidence of staphylococcal and streptococcal infections (33.4% and32.0%, respectively), an increased prevalence of comorbidities, namely, cardiovascular disease, diabetes, and cancer, and a significantly greater mortality risk than the younger group. Regarding mortality risks, the pooled odds ratio for cardiac disorders was OR = 3.81, septic shock OR = 8.22, renal complications OR = 3.75, and advancing age OR = 3.54 were most frequently mentioned. Taking into consideration the fact that the majority of the elderly population suffers from significant complications and is unable to undergo surgery due to an increased risk of complications after the procedure, it is imperative that effective treatment methods should be investigated.

Peculiar clinical and diagnostic features of infective endocarditis in Yemen: Comparative analysis with a Western University Hospital

The aim of this study was to describe the pattern, characteristics, and outcomes of infective endocarditis (IE) in Yemen and compare the results with the findings of a Western university hospital. Patients (pts) with a final diagnosis of IE observed in Al-Thawra Sanaa Cardiac Center were prospectively enrolled in 1-year time period. Clinical and diagnostic findings were compared to clinical and diagnostic data of 50 pts with IE observed at Sapienza University Hospital in Rome, Italy. The mean age was 38 ± 6. Predisposing factors for IE were rheumatic heart disease (RHD) in 34 pts (68%), congenital heart disease in 9 pts (18%), prosthetic valve IE in 4 pts (8%), and previous IE in 3 pts (6%). Transthoracic echocardiography (TTE) was done in 50 pts and transesophageal echocardiography (TEE) in 25. Blood cultures were taken in all pts and were positive in 3 pts (6%) and negative in 47 (94%). TTE was positive in 34/50 pts (68%) and TEE in 20/25 (80%). Compared to Sapienza University pts, Al-Thawra Cardiac Center pts had a younger age (p = 0.003), more predisposing RHD (p = 0.0004), less prosthetic heart valves IE (p = 0.002), and more negative blood cultures (p = 0.0001). IE is still a common disease in Yemen among RHD pts and affects the younger age group. It has severe complications which need early diagnosis and proper management. Echocardiography is of prime diagnostic value in the absence of positive blood cultures. An effort should be made to prevent rheumatic fever and RHD.

Socioeconomic variations determine the clinical presentation, aetiology, and outcome of infective endocarditis: a prospective cohort study from the ESC-EORP EURO-ENDO (European Infective Endocarditis) registry

AIMS

Infective endocarditis (IE) is a life-threatening disease associated with high mortality and morbidity worldwide. We sought to determine how socioeconomic factors might influence its epidemiology, clinical presentation, investigation and management, and outcome, in a large international multicentre registry.

METHODS AND RESULTS

The EurObservational Programme (EORP) of the European Society of Cardiology EURO-ENDO (European Infective Endocarditis) registry comprises a prospective cohort of 3113 adult patients admitted for IE in 156 hospitals in 40 countries between January 2016 and March 2018. Patients were separated in three groups, according to World Bank economic stratification [group 1: high income (75.6%); group 2: upper-middle income (15.4%); group 3: lower-middle income (9.1%)]. Group 3 patients were younger [median age (interquartile range, IQR): group 1, 66 (53-75) years; group 2, 57 (41-68) years; group 3, 33 (26-43) years; P < 0.001] with a higher frequency of smokers, intravenous drug use, and human immunodeficiency virus infection (all P < 0.001) and presented later [median (IQR) days since symptom onset: group 1, 12 (3-35); group 2, 19 (6-54); group 3, 31 (12-62); P < 0.001] with a higher likelihood of developing congestive heart failure (13.6%, 11.1%, and 22.6%, respectively; P < 0.001) and persistent fever (9.8%, 14.2%, and 27.9%, respectively; P < 0.001). Among 2157 (69.3%) patients with theoretical indication for cardiac surgery, surgery was performed less frequently in group 3 patients (75.5%, 76.8%, and 51.3%, respectively; P < 0.001), who also demonstrated the highest mortality (15.0%, 23.0%, and 23.7%, respectively; P < 0.001).

CONCLUSION

Socioeconomic factors influence the clinical profile of patients presenting with IE across the world. Despite younger age, patients from the poorest countries presented with more frequent complications and higher mortality associated with delayed diagnosis and lower use of surgery.

Infective endocarditis in developing countries: An update

Introduction

Despite advances in diagnostic and treatment, morbidity and mortality due to infective endocarditis (IE) has not decreased. There is a discrepancy in epidemiology of IE between developed and developing countries. Over the last years, increased early detection and consequently prevalence of rheumatic heart disease (RHD) and congenital heart disease (CHD) which are considered predisposing conditions for IE, is noted. Here, we present a review of literature on IE in developing countries.

Methods

We conducted a systematic literature search of IE studies in developing countries through PubMed and Embase. We have divided the studies into two groups: studies published before 2015 (group 1) and studies ≥ 2015 (group 2). The outcome was defined as a difference in epidemiology, microbiology, treatment, and mortality over time. The Scale for Assessment of Narrative Review Articles guidelines was applied.

Findings

In total, 16 studies were included. The total number of IE cases was 1,098 and 1,505 in groups 1 and 2, respectively. We compared 4/7 cohorts from group 1 (n = 789) with 5/9 cohorts from group 2 (n = 636). Six studies were not included in the comparison because they were interacting between the two cohorts. Males predominated in all studies. Rheumatic heart disease was higher in group 1 than in group 2 (42.3% vs. 30.3%, p < 0.001) while for CHD there was no change (17.6% vs. 16.7%, p = 0.672). Streptococci infections was lower in group 1 than group 2 (26.2% vs. 37.7%, p < 0.001). The proportion of Staphylococcus aureus was 15.3% in group 1 and 23.6% in group 2, p < 0.001. Negative blood culture (NBC) was higher in group 1 than in group 2 (42.2% vs. 34.1%, p = 0.002). Patients in group 1 received more surgery than in group 2 (38.8% vs. 28.8%, p < 0.001). Mortality was similar in the two groups (20.9% vs. 22.3%, p = 0.518).

Conclusion

This review shows a scarcity of studies on IE in developing countries. Rheumatic heart disease and congenital heart disease are common predisposing conditions. Other risk factors are prosthetic valves, degenerative valve disease (DVD), intravenous drug use, and human immunodeficiency virus infection. While the proportion of IE cases caused by Streptococcus and Staphylococcus has increased, the number of NBC and patients getting surgery has decreased. Mortality has not changed over time. Timely diagnosis and management of patients with RHD and CHD and comprehensive management of IE are warranted.

Infective Endocarditis in High-Income Countries

Infective endocarditis remains an illness that carries a significant burden to healthcare resources. In recent times, there has been a shift from Streptococcus sp. to Staphylococcus sp. as the primary organism of interest. This has significant consequences, given the virulence of Staphylococcus and its propensity to form a biofilm, rendering non-surgical therapy ineffective. In addition, antibiotic resistance has affected treatment of this organism. The cohorts at most risk for Staphylococcal endocarditis are elderly patients with multiple comorbidities. The innovation of transcatheter technologies alongside other cardiac interventions such as implantable devices has contributed to the increased risk attributable to this cohort. We examined the pathophysiology of infective endocarditis carefully. Inter alia, the determinants of Staphylococcus aureus virulence, interaction with host immunity, as well as the discovery and emergence of a potential vaccine, were investigated. Furthermore, the potential role of prophylactic antibiotics during dental procedures was also evaluated. As rates of transcatheter device implantation increase, endocarditis is expected to increase, especially in this high-risk group. A high level of suspicion is needed alongside early initiation of therapy and referral to the heart team to improve outcomes.

Clinical Characteristics and Risk Factors for in-Hospital Mortality in 240 Cases of Infective Endocarditis in a Tertiary Hospital in China: A Retrospective Study

Purpose

This study aimed (i) to investigate the clinical characteristics and risk factors related to in-hospital mortality in patients with infective endocarditis (IE) and (ii) to compare the differences in three age groups.

Methods

A total of 240 IE cases diagnosed using the modified Duke criteria between January 2016 and December 2019 were included and retrospectively studied. Patients were stratified into three age groups: < 50 y, 50–65 y, and > 65 y.

Results

The mean age of the patients was 51 ± 14 y, and 154 patients (64.2%) were male. In addition, 136 (56.7%) patients with IE had no previous cardiac disease. Congenital heart disease (CHD, 21.3%) was the most common underlying heart disease, followed by rheumatic heart disease (RHD, 8.8%). Streptococcus was found in 55 (22.9%) patients and was the most common causative pathogen, comprising 52.9% of all positive blood cultures. Echocardiography showed the presence of vegetations in 88.3% of cases and the predominant involvement of the left heart valves. Fever and cardiac murmur were the most frequent presentations, with no significant differences among age groups. Compared with younger patients, elderly patients had a lower operation rate and higher in-hospital mortality. The independent risk factors of in-hospital mortality were age > 65 y, intracranial infection, splenic embolization, cerebral hemorrhage, NYHA class III–IV, and prosthetic valve infection.

Conclusion

CHD replaces RHD as the most common underlying heart disease in IE patients. Patients without previous cardiac disease are at increased risk of IE. Streptococcus is still the primary causative pathogen of IE. Elderly patients present with more comorbidities and complications, in addition to a more severe prognosis than younger patients. Age older than 65 y, intracranial infection, splenic embolization, cerebral hemorrhage, NYHA class III–IV, and prosthetic valve infection showed poorer in-hospital outcomes.

Vertebral Osteomyelitis and Infective Endocarditis Co-Infection

Many cases of vertebral osteomyelitis (VO) and infective endocarditis (IE) co-infection have been reported, and it has been recognized that attention should be paid to the possibility of both diseases co-existing during diagnosis and treatment. However, the incidence, clinical status, and outcomes of IE in patients with VO remain unclear. For this study, the eligibility criteria for patient recruitment included all cases of VO at the five medical university hospitals. Patients with a history of spinal surgery were excluded from this study. Echocardiography was routinely performed for all patients with VO. IE was diagnosed according to the modified Duke criteria for definite endocarditis. We analyzed demographic data, underlying conditions, clinical features, laboratory data, echocardiography, radiologic images, treatments, and outcomes. VO was diagnosed in 59 patients and IE was diagnosed in seven patients (12%). There were no significant differences in the clinical features, microorganisms, or radiographic status between the VO-IE co-infection and VO-only groups. In this study, using routine echocardiography for VO, the IE prevalence was 12%. The lack of specific clinical features and laboratory findings may hamper the diagnosis of IE. Therefore, clinicians are always required to suspect IE in patients with VO.

Cytokine Hemoadsorption During Cardiac Surgery Versus Standard Surgical Care for Infective Endocarditis (REMOVE): Results From a Multicenter Randomized Controlled Trial

BACKGROUND

Cardiac surgery often represents the only treatment option in patients with infective endocarditis (IE). However, IE surgery may lead to a sudden release of inflammatory mediators, which is associated with postoperative organ dysfunction. We investigated the effect of hemoadsorption during IE surgery on postoperative organ dysfunction.

METHODS

This multicenter, randomized, nonblinded, controlled trial assigned patients undergoing cardiac surgery for IE to hemoadsorption (integration of CytoSorb to cardiopulmonary bypass) or control. The primary outcome (change in sequential organ failure assessment score [ΔSOFA]) was defined as the difference between the mean total postoperative SOFA score, calculated maximally to the 9th postoperative day, and the basal SOFA score. The analysis was by modified intention to treat. A predefined intergroup comparison was performed using a linear mixed model for ΔSOFA including surgeon and baseline SOFA score as fixed effect covariates and with the surgical center as random effect. The SOFA score assesses dysfunction in 6 organ systems, each scored from 0 to 4. Higher scores indicate worsening dysfunction. Secondary outcomes were 30-day mortality, duration of mechanical ventilation, and vasopressor and renal replacement therapy. Cytokines were measured in the first 50 patients.

RESULTS

Between January 17, 2018, and January 31, 2020, a total of 288 patients were randomly assigned to hemoadsorption (n=142) or control (n=146). Four patients in the hemoadsorption and 2 in the control group were excluded because they did not undergo surgery. The primary outcome, ΔSOFA, did not differ between the hemoadsorption and the control group (1.79±3.75 and 1.93±3.53, respectively; 95% CI, -1.30 to 0.83; P=0.6766). Mortality at 30 days (21% hemoadsorption versus 22% control; P=0.782), duration of mechanical ventilation, and vasopressor and renal replacement therapy did not differ between groups. Levels of interleukin-1β and interleukin-18 at the end of integration of hemoadsorption to cardiopulmonary bypass were significantly lower in the hemoadsorption than in the control group.

CONCLUSIONS

This randomized trial failed to demonstrate a reduction in postoperative organ dysfunction through intraoperative hemoadsorption in patients undergoing cardiac surgery for IE. Although hemoadsorption reduced plasma cytokines at the end of cardiopulmonary bypass, there was no difference in any of the clinically relevant outcome measures.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03266302.

Sequelae of Infective Endocarditis: Ruptured Aortic Root Abscess in a 38-Year-Old Female With Complicated Infective Endocarditis

A 38-year-old female with no known comorbidities or previous history of heart disease presented to the hospital with a three-day history of drowsiness and shortness of breath. Transthoracic echocardiography was performed, which showed large vegetations on aortic and tricuspid valves. In addition, there was severe aortic regurgitation with a possible abscess on the non-coronary cusp of the aortic valve.

The patient was admitted, and a provisional diagnosis of disseminated tuberculosis, Infective endocarditis (IE), and sepsis was made. Surgical intervention was planned. Intraoperative findings revealed that a fistula had formed connecting the aorta and right atrium, which was closed with an autologous graft derived from the patient’s pericardial tissue. Vegetations were removed, and the aortic valve was replaced with a metallic valve.

This case report presents a patient with complicated IE with a ruptured aortic root abscess. Mechanical complications associated with IE, such as in our case, are rare among patients with IE. However, surgical intervention should be considered as an option in complicated cases of IE when standard therapy fails.

Infective Endocarditis: New Challenges in a Classic Disease

Infective endocarditis is a relatively rare, but deadly infection, with an overall mortality of around 20% in most series. Clinical manifestations have evolved in response to significant epidemiological shifts in industrialized nations, with a move toward a nosocomial or health-care-related pattern, in older patients, with more episodes associated with prostheses and/or intravascular electronic devices and a predominance of staphylococcal and enterococcal etiology.Diagnosis is often challenging and is based on the conjunction of clinical, microbiological, and imaging information, with notable progress in recent years in the accuracy of echocardiographic data, coupled with the recent emergence of other useful imaging techniques such as cardiac computed tomography (CT) and nuclear medicine tools, particularly ¹⁸F-fluorodeoxyglucose positron emission/CT.The choice of an appropriate treatment for each specific case is complex, both in terms of the selection of the appropriate agent and doses and durations of therapy as well as the possibility of using combined bactericidal antibiotic regimens in the initial phase and finalizing treatment at home in patients with good evolution with outpatient oral or parenteral antimicrobial therapies programs. A relevant proportion of patients will also require valve surgery during the active phase of treatment, the timing of which is extremely difficult to define. For all the above, the management of infective endocarditis requires a close collaboration of multidisciplinary endocarditis teams.

Clinical, Microbiological, and Imaging Characteristics of Infective Endocarditis in Latin America: A Systematic Review

OBJECTIVES

We aimed to describe the clinical, microbiological, and imaging characteristics of patients with infective endocarditis (IE) in studies from Latin America (LATAM).

METHODS

A systematic search through PubMed, EMBASE, LILACS, and SciELO from inception until February 2021 was conducted. We included observational studies that assessed adults with IE from LATAM and reported data on clinical, microbiological, or imaging characteristics. Data were independently extracted by 2 authors and the risk of bias was evaluated by study design with its respective tool. Findings were summarized using descriptive statistics.

RESULTS

Forty-four studies were included. Most cases were male (68.5%), had a predisposing condition including valve disease (24.3%), or had a prosthetic valve (23.4%). Clinical manifestations included fever (83.9%), malaise (63.2%), or heart murmur (57.7%). A total of 36.4% and 27.1% developed heart failure or embolism, respectively. Blood cultures were negative in 23.9% and S. aureus (18.6%) and the viridans group streptococci (17.8%) were the most common isolates. Most cases were native valve IE (67.3%) affecting mainly left-sided valves. Echocardiographic findings included vegetations (84.3%) and regurgitation (75.9%). In-hospital mortality was 25.1%.

CONCLUSIONS

This is the first systematic review that evaluated the characteristics of IE in LATAM patients. A lack of multicenter studies reflects the need for these studies in LATAM.

Global epidemiology of valvular heart disease

Valvular heart disease (VHD) is a major contributor to loss of physical function, quality of life and longevity. The epidemiology of VHD varies substantially around the world, with a predominance of functional and degenerative disease in high-income countries, and a predominance of rheumatic heart disease in low-income and middle-income countries. Reflecting this distribution, rheumatic heart disease remains by far the most common manifestation of VHD worldwide and affects approximately 41 million people. By contrast, the prevalence of calcific aortic stenosis and degenerative mitral valve disease is 9 and 24 million people, respectively. Despite a reduction in global mortality related to rheumatic heart disease since 1900, the death rate has remained fairly static since 2000. Meanwhile, deaths from calcific aortic stenosis have continued to rise in the past 20 years. Epidemiological data on other important acquired and congenital forms of VHD are limited. An ageing population and advances in therapies make an examination of the changing global epidemiology of VHD crucial for advances in clinical practice and formulation of health policy. In this Review, we discuss the global burden of VHD, geographical variation in the presentation and clinical management, and temporal trends in disease burden.

Type IV Pili of Streptococcus sanguinis Contribute to Pathogenesis in Experimental Infective Endocarditis

Streptococcus sanguinis is a common cause of infective endocarditis (IE). Efforts by research groups are aimed at identifying and characterizing virulence factors that contribute to the ability of this organism to cause IE. This Gram-positive pathogen causes heart infection by gaining access to the bloodstream, adhering to host extracellular matrix protein and/or platelets, colonizing the aortic endothelium, and incorporating itself into the aortic vegetation. While many virulence factors have been reported to contribute to the ability of S. sanguinis to cause IE, it is noteworthy that type IV pili (T4P) have not been described to be a virulence factor in this organism, although S. sanguinis strains typically encode these pili. Type IV pili are molecular machines that are capable of mediating diverse virulence functions and surface motility. T4P have been shown to mediate twitching motility in some strains of S. sanguinis, although in most strains it has been difficult to detect twitching motility. While we found that T4P are dispensable for direct in vitro platelet binding and aggregation phenotypes, we show that they are critical to the development of platelet-dependent biofilms representative of the cardiac vegetation. We also observed that T4P are required for in vitro invasion of S. sanguinis into human aortic endothelial cells, which indicates that S. sanguinis may use T4P to take advantage of an intracellular niche during infection. Importantly, we show that T4P of S. sanguinis are critical to disease progression (vegetation development) in a native valve IE rabbit model. The results presented here expand our understanding of IE caused by S. sanguinis and identify T4P as an important virulence factor for this pathogen.

IMPORTANCE This work provides evidence that type IV pili produced by Streptococcus sanguinis SK36 are critical to the ability of these bacteria to attach to and colonize the aortic heart valve (endocarditis). We found that an S. sanguinis type IV pili mutant strain was defective in causing platelet-dependent aggregation in a 24-h infection assay but not in a 1-h platelet aggregation assay, suggesting that the type IV pili act at later stages of vegetation development. In a rabbit model of disease, a T4P mutant strain does not develop mature vegetations that form on the heart, indicating that this virulence factor is critical to disease and could be a target for IE therapy.

Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach

Investigating causation is a primary goal in forensic/legal medicine, aiming to establish the connection between an unlawful/negligent act and an adverse outcome. In malpractice litigation involving a healthcare-associated infection due to a failure of infection prevention and control practices, the medicolegal causal analysis needs to quantify the individual causal probabilities to meet the evidentiary requirements of the court. In this paper, we present the investigation of the most probable cause of bacterial endocarditis in a patient who underwent an invasive procedure at a dental/oral surgical practice where an outbreak of bacterial endocarditis had already been identified by the state Department of Health. We assessed the probability that the patient’s endocarditis was part of the outbreak versus that it was an unrelated sporadic infection using the INFERENCE (Integration of Forensic Epidemiology and the Rigorous Evaluation of Causation Elements) approach to medicolegal causation analysis. This paper describes the step-by-step application of the INFERENCE approach to demonstrate its utility in quantifying the probability of causation. The use of INFERENCE provides the court with an evidence-based, transparent, and reliable guide to determine liability, causation, and damages.

The New Challenge for Heart Endocarditis: From Conventional Prosthesis to New Devices and Platforms for the Treatment of Structural Heart Disease

Infective endocarditis is a sinister condition with considerable morbidity and mortality. Its relevance in the current era is compounded by the increased use of implanted devices such as replacement valves or cardiac implantable electronic devices. These infections are caused by multiple different bacteria with different virulence, pathogenicity, and antimicrobial resistance. Unlike in native endocarditis, the presence of foreign tissue permits sustenance by inflammatory and thrombotic processes as the artificial surfaces promote inflammatory responses and hypercoagulability. Prevention of these infections has been suggested with the use of homografts in combination with antibiotics. Others have attempted to use "low fouling coats" with little clinical success thus far. The use of antibiotic prophylaxis plays a pivotal part in reducing the incidence of prosthesis-related endocarditis. This remains especially crucial with the increasing use of transcatheter heart valve therapies. The widespread use of cardiac implantable electronic devices such as permanent pacemakers, implantable cardioverter defibrillators, and cardiac resynchronization therapy devices has also heralded a noticeable increase in cases of infectious endocarditis affecting complex equipment which can be difficult to treat. Multimodality strategies are needed with input from surgeons and cardiologists to ensure treatment is both prompt and successful, tailored to the individual needs of the patients.

Long-term Outcomes Are Poor in Intravenous Drug Users Following Infective Endocarditis, Even After Surgery

BACKGROUND

Previous studies of outcomes in people who inject drugs (PWID) with infective endocarditis (IE) have often been retrospective, have had small sample sizes, and the duration of follow-up has been short and limited to patients who were operated on.

METHODS

PWID treated for IE between 1 January 2006 and 31 December 2016 were identified from a prospectively collected database. PWID hospitalized with other infections acted as a novel comparison group. Outcomes were all-cause mortality, cause of death, relapse, recurrence, and reoperation.

RESULTS

There were 105 episodes of IE in 92 PWID and 112 episodes of other infections in 107 PWID in whom IE was suspected but rejected. Survival at 30 days for the IE group was 85%, and 30-day survival following surgery was 96%. The most common pathogens were Staphylococcus species (60%) and Streptococcus species (30%). The surgical intervention rate was 47%. Survival for the IE group at 1, 3, 5, and 10 years was 74%, 63%, 58%, and 44%, respectively. This was significantly lower compared with the comparator group of other infections in PWID (P = .0002). Mortality was higher in patients who required surgery compared with those who did not (hazard ratio, 1.8 [95% confidence interval, .95-3.3]). The commonest cause of death was infection (66%), usually a further episode of IE (55%).

CONCLUSIONS

Although early survival was good, long-term life expectancy was low. This was attributable to ongoing infection risk, rather than other factors known to affect prognosis in PWID. Surgery conferred no long-term survival advantage. More efforts are needed to reduce reinfection risk following an episode of IE in PWID.While early survival for people who inject drugs (PWID) with infective endocarditis is good, long-term survival is poor due to ongoing infection risk. Surgery conferred no long-term survival advantage, so more efforts are needed to reduce reinfection risks for PWID.

Clinical Features and Outcomes of Streptococcus anginosus Group Infective Endocarditis: A Multicenter Matched Cohort Study

Background

Although Streptococcus anginosus group (SAG) endocarditis is considered a severe disease associated with abscess formation and embolic events, there is limited evidence to support this assumption.

Methods

We performed a retrospective analysis of prospectively collected data from consecutive patients with definite SAG endocarditis in 28 centers in Spain and Italy. A comparison between cases due to SAG endocarditis and viridans group streptococci (VGS) or Streptococcus gallolyticus group (SGG) was performed in a 1:2 matched analysis.

Results

Of 5336 consecutive cases of definite endocarditis, 72 (1.4%) were due to SAG and matched with 144 cases due to VGS/SGG. SAG endocarditis was community acquired in 64 (88.9%) cases and affected aortic native valve in 29 (40.3%). When comparing SAG and VGS/SGG endocarditis, no significant differences were found in septic shock (8.3% vs 3.5%, P = .116); valve disorder, including perforation (22.2% vs 18.1%, P = .584), pseudoaneurysm (16.7% vs 8.3%, P = .108), or prosthesis dehiscence (1.4% vs 6.3%, P = .170); paravalvular complications, including abscess (25% vs 18.8%, P = .264) and intracardiac fistula (5.6% vs 3.5%, P = .485); heart failure (34.7% vs 38.9%, P = .655); or embolic events (41.7% vs 32.6%, P = .248). Indications for surgery (70.8% vs 70.8%; P = 1) and mortality (13.9% vs 16.7%; P = .741) were similar between groups.

Conclusions

SAG endocarditis is an infrequent but serious condition that presents a prognosis similar to that of VGS/SGG.

Cardiovascular disease burden: Italian and global perspectives

BACKGROUND

Cardiovascular disease (CVD) is still the leading cause of death worldwide, responsible for an estimated 17.8 million deaths globally in 2017, accounting for 31.8% of all deaths. In this review, we aim to provide an updated overview of CVD burden from an Italian and a global perspective.

METHODS

Crude and age-standardized incidence and prevalence, as well as age-standardized mortality rate and morbidity rate (expressed as disability-adjusted life years - DALYs), of different cardiovascular conditions, derived from the Global Burden of Disease Injuries, and Risk Factors Study (GBD) 2017, were reported and compared between Italy and the world.

RESULTS

Crude prevalence of CVD in Italy is nearly twofold higher than global prevalence (12.9% vs. 6.6%), while age-standardized estimates are similar (6.2% vs. 6.3%). Mortality and morbidity from CVD are reduced in Italy, as compared to worldwide estimates (age-standardized mortality rate 113/100,000 vs. 233/100,000; age-standardized rate of DALYs lost 1764/100,000 vs. 4598/100,000). Of the evaluated cardiovascular conditions, the most important CVD burden is due to ischemic heart disease, which show a crude prevalence of 3.6% in Italy (age-standardized: 1.7%), doubling the corresponding crude global estimate (1.7%; age-standardized: 1.6%).

CONCLUSIONS

This latest update on the epidemiology of CVD within Italy and the world summarizes the burden of major cardiovascular conditions. CVD, especially ischemic heart disease, is still an important cause of mortality and morbidity. The impact of increasing life-expectancy is a key determinant of CVD epidemiology in Italy, if compared to worldwide data, since older age is one of the major risk factors for CVD.

Current Challenges in the Management of Infective Endocarditis

Infective endocarditis is a relatively rare, but deadly cause of sepsis, with an overall mortality ranging from 20 to 25% in most series. Although the classic clinical classification into syndromes of acute or subacute endocarditis have not completely lost their usefulness, current clinical forms have changed according to the profound epidemiological changes observed in developed countries. In this review, we aim to address the changing epidemiology of endocarditis, several recent advances in the understanding of the pathophysiology of endocarditis and endocarditis-triggered sepsis, new useful diagnostic tools as well as current concepts in the medical and surgical management of this disease. Given its complexity, the management of infective endocarditis requires the close collaboration of multidisciplinary endocarditis teams that must decide on the diagnostic approach; the appropriate initial treatment in the critical phase; the detection of patients needing surgery and the timing of this intervention; and finally the accurate selection of patients for out-of-hospital treatment, either at home hospitalization or with oral antibiotic treatment.

A narrative review of early surgery versus conventional treatment for infective endocarditis: do we have an answer?

The most appropriate strategy and timing for surgery in infective endocarditis (IE) remains an argument of debate. Despite some authors promote the adoption of an early surgical approach (within 48 hours) to limit mortality and complications, no robust randomized trials are available on this argument and the evidence on this subject remain at the "expert opinion" level. Additionally, the different messages promulgated by the American and European guidelines contributed to fuel confusion regarding the relative priority of the surgical over medical therapy in IE. The European Society of Cardiology (ESC) guidelines individuates three level of urgency: emergency surgery, to be performed within 24 hours; urgent surgery, recommended within a few days; elective surgery to be performed after 1-2 weeks of antibiotic therapy. Urgent surgery is recommended for most cases of IE. In the American Heart Association (AHA)'s guidelines define early surgery as "during the initial hospitalization and before completion of a full course of antibiotics." Some of the available evidences showed that are no proven benefits in delaying surgery if a definite diagnosis of IE has been established. However, this argument is controversial across the literature and several factors including the center specific experience can play a role in decision-making. In this review the latest evidences on IE clinical and surgical characteristics along with the current studies on the adoption of an early surgical approach are analyzed to clarify whether enough evidence is available to inform an update of the guidelines.

The quest for the optimal surgical management of tricuspid valve endocarditis in the current era: a narrative review

Tricuspid valve endocarditis (TVE) is a growing concern with increasing rates and mortality burden. The currently changing etiology, the antibiotic resistance and the raise in iatrogenic causes as with implantable cardiac devices [cardiac implantable electronic device (CIED)], represent a challenge for the management of these patients. The progressively widespread use of CIEDs is adding to the more commonly known intravenous (IV) drug abuse in the list of causes. Treatment strategies include medical therapy alone or surgery. From the surgical standpoint tricuspid valve repair, replacement or the staged procedure of valvectomy as bridge to replacement are available options. Treatment of endocarditis related to implantable device is another expanding field which requires a coordinated action with microbiologists in consideration of the microorganism antibiotic resistance. This review summarizes the currently available evidences on TVE including surgical indications, timing of interventions and technical considerations. The conflicting results of the available observational evidences and the non-unanimous consensus on many aspects of TVE impede to reach a definitive conclusion regarding the best management strategy and demands for randomized studies in this field.

Outpatient Antimicrobial Therapy for Infective Endocarditis is Safe

Infective endocarditis (IE) is common and is associated with significant mortality, morbidity and health care burden. Outpatient antimicrobial therapy in carefully selected patients, supported by a multidisciplinary team is safe and beneficial for both the patient and the health care system. In this article, we review current literature of outpatient antimicrobial therapy in infective endocarditis and propose that most patients with IE should be considered and appropriate pathways developed to facilitate this.

Infective Endocarditis: A Case Series

Infective endocarditis (IE) is an infection of the endocardial surface of the heart. The incidence of IE worldwide is approximately 3 to 10 per 100,000 people annually. Twenty percent of patients die during the hospital stay, and the mortality may reach 25 to 30% six months postinfection. We hereby present our experience of six patients, of whom five survived. The cause of one death was late presentation and lack of coverage for Burkholderia in the prescribed empirical antibiotic therapy. One of our patients, with culture-negative endocarditis, responded to doxycycline and did not require any surgery. Five out of six patients who underwent surgery had vegetations more than 10 mm in size, and one patient had an aortic valve abscess (caused by Staphylococcus haemolyticus). Both prosthetic endocarditis and native valve endocarditis can be treated successfully with antimicrobial agents and surgery (when indicated). A high index of suspicion is required to diagnose IE caused by fungus and atypical bacteria.

Infective endocarditis profile, prognostic factors and in-hospital mortality: 6-year trends from a tertiary university center in South America

BACKGROUND

Infective endocarditis (IE) remains an expressive health problem with high morbimortality rates. Despite its importance, epidemiological and microbiological data remain scarce, especially in developing countries.

AIM

This study aims to describe IE epidemiological, clinical, and microbiological profile in a tertiary university center in South America, and to identify in-hospital mortality rate and predictors.

METHODS

An observational, retrospective study of 167 patients, who fulfilled modified Duke's criteria during a six-year enrollment period, from January 2010 to December 2015. The primary outcome was defined as in-hospital mortality analyzed according to treatment received (clinical vs surgical). Multivariate analysis identified mortality predictors.

RESULTS

The median age was 60 years (Q₁ -Q₃ 50-71), and 66% were male. Echocardiogram demonstrated vegetations in 90.4%. An infective agent was identified in 76.6%, being Staphylococcus aureus (19%), Enterococcus (12%), coagulase-negative staphylococci (10%), and Streptococcus viridans (9.6%) the most prevalent. Overall in-hospital mortality was 41.9%, varying from 49.4% to 34.1%, in clinical and surgical patients, respectively (P = .047). On multivariate analysis, diabetes mellitus (odds ratio [OR], 2.5), previous structural heart disease (OR, 3.1), and mitral valve infection (OR, 2.1) were all-cause death predictors. Surgical treatment was the only variable related to a better outcomes (OR, 0.45; 95% Confidence Interval, 0.2-0.9).

CONCLUSION

This study presents IE profile and all-cause mortality in a large patient's cohort, comprising a 6-years' time window, a rare initiative in developing countries. Elderly and male patients predominated, while S. aureus was the main microbiological agent. Patients conservatively treated presented higher mortality than surgically managed ones. Epidemiological studies from developing countries are essential to increase IE understanding.

Infective Endocarditis: A Contemporary Review

Infective endocarditis (IE), initially described more than 350 years ago, involves infection of the endocardial surface of the heart. The clinical manifestations of IE can involve every organ system, and the cardiac manifestations can include valvular vegetation, abscess, periannular extension of infection, and myopericarditis. Echocardiography is crucial in the diagnosis of IE, but alternative imaging modalities are playing an increasing role in the diagnosis and management of IE. Multidisciplinary care is imperative to the management of IE, often requiring the expertise of cardiologists, cardiothoracic surgeons, infectious diseases specialists, radiologists, and neurologists. We performed a literature search of the PubMed database from January 1st, 2000, to September 30th, 2019, using the terms infective endocarditis, diagnosis, and management to find the most pertinent and highest-quality evidence. This review summarizes key aspects of IE, with a focus on emerging advances in diagnosis. We also highlight growing patient populations at risk for IE, including patients with intracardiac devices and congenital heart disease.

Assessing efficacy of CytoSorb haemoadsorber for prevention of organ dysfunction in cardiac surgery patients with infective endocarditis: REMOVE-protocol for randomised controlled trial

INTRODUCTION

Infective endocarditis (IE) is associated with high mortality and morbidity. Multiple organ failure is the main cause of death after surgery for IE. Cardiopulmonary bypass (CPB) can cause a systemic inflammatory response. In a pilot study (REMOVE-pilot (Revealing mechanisms and investigating efficacy of hemoad-sorption for prevention of vasodilatory shock in cardiac surgery patients with infective endocarditis - a multicentric randomized controlled group sequential trial)), we found that plasma profiles of cytokines during and after CPB were higher in patients with IE compared with patients with non-infectious valvular heart disease. Sequential Organ Failure Assessment (SOFA) scores on the first and second postoperative days and in-hospital mortality were also higher in IE patients. This protocol describes the design of the REMOVE trial on cytokine-adsorbing columns, for example, CytoSorb, for non-selective removal of cytokines. The aim of the REMOVE study is to demonstrate efficacy of CytoSorb on the prevention of multiorgan dysfunction in patients with IE undergoing cardiac surgery.

METHODS AND ANALYSIS

The REMOVE study is an interventional randomised controlled multicenter trial with a group sequential (Pocock) design for assessing efficacy of CytoSorb in patients undergoing cardiac surgery for IE. The change in mean total SOFA (∆ SOFA) score between preoperative and postoperative care will be used as primary endpoint. Data on 30-day mortality, changes in cytokines levels, duration of mechanical ventilation, length of intensive care unit and hospital stay, and postoperative stroke will be collected as secondary endpoints. An interim analysis will be conducted after including 25 participating patients per study arm (with a focus on feasibility of the recruitment as well as differences in cytokines and cell-free DNA levels).

ETHICS AND DISSEMINATION

The protocol was approved by the institutional review board and ethics committee of the University of Jena as well as by the corresponding ethics committee of each participating study centre. The results will be published in a renowned international medical journal, irrespective of the outcomes of the study.

TRIAL REGISTRATION NUMBER

The ClinicalTrials.gov registry (NCT03266302).

Patients with infective endocarditis referred to Division of Cardiovascular and Pulmonary Diseases at Oslo University Hospital between 2014 and 2017

Objectives. Infective endocarditis has potential for severe complications and high mortality. The number of patients with prosthetic valves has risen, and an increase in incidence of infective endocarditis has been suggested. We aimed to examine the epidemiology, etiology, treatment and outcome of patients admitted to Division of Cardiovascular and Pulmonary Diseases at Oslo University Hospital, and explore changes in incidence over the last four years. Design. We conducted a retrospective study including all patients admitted to a tertiary hospital in Oslo, Norway, and diagnosed with infective endocarditis according to ICD-10 between 2014 and 2017. Results. Two hundred and ninety-one patients ≥18 years were included (61.3 ± 13.8 years, 75.6% men). 36.4% had previous valve surgery and this proportion decreased during the period. The aortic valve was most commonly affected (51.9%). Streptococci were the most frequent microorganisms (35.1%), while staphylococci accounted for 26.8%. 81.8% were treated surgically, at a median of 6.5 (0-120) days after admission. Hemodynamic changes or instability was the primary surgical indication (51.5%). One-year mortality was 20.6%. Surgery within a week after admission resulted in poorer 1-year prognosis than surgery after one week. Also, surgically treated patients who died were significantly older than those who survived. Conclusions. In this cohort, streptococci were the most common causative microorganism. Approximately, one-third of the patients had prosthetic valves. Mortality remains high, underscoring the need for continuous medical awareness. A high number of streptococcus infections in this cohort suggest dental origin.

Changes in inflammatory and vasoactive mediator profiles during valvular surgery with or without infective endocarditis: A case control pilot study

Background

More than 50% of patients with infective endocarditis (IE) develop an indication for surgery. Despite its benefit, surgery is associated with a high incidence of multiple organ dysfunction syndrome (MODS) and mortality, which may be linked to increased release of inflammatory mediators during cardiopulmonary bypass (CPB). We therefore assessed plasma cytokine profiles in patients undergoing valve surgery with or without IE.

Methods

We performed a prospective case-control pilot study comparing patients undergoing cardiac valve surgery with or without IE. Plasma profiles of inflammatory mediators were measured at 7 defined time points and reported as median (interquartile). The degree of MODS was measured using sequential organ failure assessment (SOFA) score.

Results

Between May and December 2016 we included 40 patients (20 in each group). Both groups showed similar distribution of age and gender. Patients with IE had higher preoperative SOFA (6.9± 2.6 vs 3.8 ± 1.1, p<0.001) and operative risk scores (EuroSCORE II 18.6±17.4 vs. 1.8±1.3, p<0.001). In-hospital mortality was higher in IE patients (35% vs. 5%; p<0.001). Multiple organ failure was the cause of death in all non-survivors. At the end of CPB, median levels of following inflammatory mediators were higher in IE compared to control group: IL-6 (119.73 (226.49) vs. 24.48 (40.09) pg/ml, p = 0.001); IL-18 (104.82 (105.99) vs. 57.30 (49.53) pg/ml, p<0.001); Mid-regional pro-adrenomedullin (MR-proADM) (2.06 (1.58) vs. 1.11 (0.53) nmol/L, p = 0.003); MR- pro-atrial natriuretic peptide (MR-proANP) (479.49 (224.74) vs. 266.55 (308.26) pmol/l, p = 0.028). IL-1β and TNF- α were only detectable in IE patients and first after starting CPB. Plasma levels of IL-6, IL-18, MRproADM, and MRproANP during CPB were significantly lower in survivors than in those who died.

Conclusion

The presence of infective endocarditis during cardiac valve surgery is associated with increased inflammatory response as evident by higher plasma cytokine levels and other inflammatory mediators. Actively reducing inflammatory response appears to be a plausible therapeutic concept.

Trial registration

ClinicalTrials.gov, ID: NCT02727413.

Association of Novel Streptococcus sanguinis Virulence Factors With Pathogenesis in a Native Valve Infective Endocarditis Model

Streptococcus sanguinis (S. sanguinis) is an abundant oral commensal which can cause disseminated human infection if it gains access to the bloodstream. The most important among these diseases is infective endocarditis (IE). While virulence phenotypes of S. sanguinis have been correlated to disease severity, genetic factors mediating these phenotypes, and contributing to pathogenesis are largely uncharacterized. In this report, we investigate the roles of 128 genes in virulence-related phenotypes of S. sanguinis and characterize the pathogenic potential of two selected mutants in a left-sided, native valve IE rabbit model. Assays determining the ability of our mutant strains to produce a biofilm, bind to and aggregate platelets, and adhere to or invade endothelial cells identified sixteen genes with novel association to these phenotypes. These results suggest the presence of many uncharacterized genes involved in IE pathogenesis which may be relevant for disease progression. Two mutants identified by the above screening process – SSA_1099, encoding an RTX-like protein, and mur2, encoding a peptidoglycan hydrolase – were subsequently evaluated in vivo. Wild type (WT) S. sanguinis reliably induced cardiac vegetations, while the SSA_1099 and mur2 mutants produced either no vegetation or vegetations of small size. Splenomegaly was reduced in both mutant strains compared to WT, while pathology of other distal organs was indistinguishable. Histopathology analyses suggest the cardiac lesions and vegetations in this model resemble those observed in humans. These data indicate that SSA_1099 and mur2 encode virulence factors in S. sanguinis which are integral to pathogenesis of IE.

Iranian Registry of Infective Endocarditis (IRIE): Time to relook at the guideline, regarding to regional differences

Aims

Infective endocarditis (IE) remained a potentially fatal disease with high rate of mortality and morbidity. The epidemiology and global burden of IE are largely different between the countries. We aimed to address the epidemiological aspects of IE in a tertiary hospital in Tehran, Iran.

Methods and Results

Between 2006–2018, all adults patients with diagnosis of IE were enrolled in the Iranian Registry of Infective Endocarditis (IRIE). The data were analyzed using the χ², Kolmogorov–Smirnov, and Mann–Whitney U tests. Overall, 602 patients, 407 (67.6%) men, mean age 46 ± 16 years were recruited. Positive blood culture found in 49%.The most common underlying heart diseases were: Congenital heart diseases (CHD) particularly bicuspid aortic valves (BAV) and ventricular septal defects (VSD) in 37%, followed by degenerative heart diseases :flail and mitral valve prolapse (16.3%), intravenous drug user in 12.6%, prosthetic valves in 11.1%, previous IE (8.9%), rheumatic heart diseases (RHD) in 8.4%. The most causative microorganisms were Staphylococcus aureus, Enterococci, coagulase-negative staphylococci and Streptococcus viridans. Cardiac or extra cardiac complications occurred in 56.6% of the patients.

Conclusions

Based on IRIE, IE occurs in the younger population in Iran with high rates of blood culture-negative IE. RHD are not the main cause of IE in Iran, CHD including BAV and VSDs, followed by prolaptic or flail mitral valve were the most common. These 2 groups can be considered a high-risk group for IE. More than half of the patients with IE had cardiac or extra cardiac complications.

A changing profile of infective endocarditis at a tertiary hospital in China: a retrospective study from 2001 to 2018

Background

Infective endocarditis (IE) is a lethal disease which has been changing significantly over the past decades; however, information about IE in China remains scarce. This study surveyed the changes in clinical characteristics of IE at a tertiary hospital in south China over a period of nearly 18 years.

Methods

Medical records with IE patients consecutively hospitalized between June 2001 and June 2018 were selected from the electronic medical records system in Nanfang Hospital of Southern Medical University. Data were divided by admission time into two groups equally: early-period group, June 2001 to December 2009 and later-period group, January 2010 to July 2018.

Results

A Total of 313 IE patients were included in our study. Compared with the early-period group, patients in the later-period group included fewer intravenous drug users (IVDUs), older age at onset, reduced development of pulmonary embolism, less renal dysfunction, decreased proportion of Staphylococcus aureus infection and fewer vegetations observed in the right heart by echocardiography. The later-period group also showed a higher proportion of ischemic strokes and higher proportion of positive microbiological findings compared with the early-period group. The in-hospital mortality remained about the same between the two periods and the multivariate analysis identified intravenous drug addicted, prosthetic valve endocarditis, hemorrhagic stroke, acute congestive heart failure, renal insufficiency, left-sided endocarditis, early surgical as independent predictors of in-hospital mortality.

Conclusions

Our study demonstrated a dramatic change in the profile of IE over a period of 18 years at a tertiary hospital in south China and presented several independent predictors of in-hospital mortality. The geographic variations observed in our study will be of important value to profile the clinical feature of China and offer the reference for clinical decisions in our region.

Trends in Hospitalization for Infective Endocarditis as a Reason for Admission or a Secondary Diagnosis

We postulate that the trends for infective endocarditis (IE) are different for patients admitted for this condition compared with those admitted for a different reason with IE as a secondary diagnosis. Using the Myocardial Infarction Data Acquisition System (MIDAS) database, we analyzed 21,443 records of patients hospitalized with diagnosis of IE from 1994 to 2015. There were 9,191 patients hospitalized with IE as the primary diagnosis, and 12,252 patients with IE as a secondary diagnosis. Piecewise linear models were used to detect changes in trends. A bootstrap method was used to assess the statistical significance of the slopes and break point of each model. Differences in co-morbidities and microbiological patterns were analyzed. Trend analysis showed a significant decrease in IE as the primary diagnosis starting in the year 2004 (p <0.01). Hospitalizations with IE as a secondary diagnosis showed a linear increase in incidence (p <0.001), without any change points. In primary diagnosis IE, the proportion of streptococci as a causative microorganism was higher compared with staphylococci (p <0.001). On the contrary, in secondary diagnosis IE, the proportion of staphylococci was higher than streptococci (p <0.001). The proportion of gram-negative and other organism IE was similar in both groups. In conclusion, this study showed 2 divergent temporal trends in hospitalizations for IE as a primary or secondary diagnosis starting in 2004. The profile of the microorganisms reveals a steady higher proportion of staphylococcal infection in secondary diagnosis IE compared with streptococcal infection. Different strategies are needed for the prevention of IE.

Epidemiological and clinical profile of infective endocarditis at a Brazilian tertiary care center: an eight-year prospective study

INTRODUCTION

Infective endocarditis (IE) is a systemic infectious disease requiring a multidisciplinary team for treatment. This study presents the epidemiological and clinical data of 73 cases of IE in Rio de Janeiro, Brazil.

METHODS

This observational prospective cohort study of endocarditis patients during an eight-year study period described 73 episodes of IE in 70 patients (three had IE twice). Community-associated (CAIE) and healthcare-acquired infective endocarditis (HAIE) were diagnosed according to the modified Duke criteria. The collected data included demographic, epidemiologic, and clinical characteristics, including results of blood cultures, echocardiographic findings, surgical interventions, and outcome.

RESULTS

Analysis of data from the eight-year study period and 73 cases (70 patients) of IE showed a mean age of 46 years (SD=2.5 years; 1-84 years) and that 65.7% were male patients. The prevalence of CAIE and HAIE was 32.9% and 67.1%, respectively. Staphylococcus aureus (30.1%), Enterococcus spp. (19.1%), and Streptococcus spp. (15.0%) were the prevalent microorganisms. The relevant signals and symptoms were fever (97.2%; mean 38.6 + 0.05°C) and heart murmur (87.6%). Vegetations were observed in the mitral (41.1%) and aortic (27.4%) valves. The mortality rate of the cases was 47.9%.

CONCLUSIONS

In multivariate analysis, chronic renal failure (relative risk [RR]= 1.60; 95% confidence interval [CI] 1.01-2.55), septic shock (RR= 2.19; 95% CI 1.499-3.22), and age over 60 years (RR= 2.28; 95% CI 1.44-3.59) were indirectly associated with in-hospital mortality. The best prognosis was related to the performance of cardiovascular surgery (hazard ratio [HR]= 0.51; 95% CI 0.26-0.99).

The Many Faces of Bacterium-Endothelium Interactions during Systemic Infections

A wide variety of pathogens reach the circulatory system during viral, parasitic, fungal, and bacterial infections, causing clinically diverse pathologies. Such systemic infections are usually severe and frequently life-threatening despite intensive care, in particular during the age of antibiotic resistance. Because of its position at the interface between the blood and the rest of the organism, the endothelium plays a central role during these infections. Using several examples of systemic infections, we explore the diversity of interactions between pathogens and the endothelium. These examples reveal that bacterial pathogens target specific vascular beds and affect most aspects of endothelial cell biology, ranging from cellular junction stability to endothelial cell proliferation and inflammation.

Right-sided infective endocarditis in patients with uncorrected ventricular septal defect and patent ductus arteriosus: Two case reports

Uncorrected left-to-right shunt congenital heart defect is a predisposing factor for infective endocarditis (IE), especially right-sided IE which has different clinical manifestations and complications from left-sided IE. Prompt diagnosis by means of transthoracic echocardiography and timely antibiotics management for IE are encouraged to prevent multiorgan failure and fatal pulmonary embolism.

Clinical - microbiological characterization and risk factors of mortality in infective endocarditis from a tertiary care academic hospital in Southern India

Aims

To dissect the clinical-microbiological profile of Infective endocarditis (IE) population and to determine the risk factors for IE related mortality.

Methods

A cohort study was conducted using relevant data from clinical records of patients (≥12 years) with definite/possible IE from December 2007 to December 2013 and was analyzed using appropriate statistical tests.

Results

In the cohort of 139 IE patients, mean age was 47.9 ± 15.8 years, with male preponderance (68.3%). Rheumatic heart disease was the commonest (30.9%) underlying cardiac lesion followed by mitral valve prolapse with mitral regurgitation (23.7%), degenerative valvular disease (23%), congenital heart disease (15.8%) and prosthetic valves (3.6%). Vegetations were detected in 94.2% cases. Blood cultures were positive in 69.8% cases, commonest organism isolated was α – hemolytic streptococci (30.9%) followed by Enterococcus (12.9%) and methicillin sensitive Staphylococcus aureus (10.8%). Complications observed were congestive cardiac failure (31.2%), acute kidney injury (25.9%), stroke (21.6%), septic shock (16.5%), embolic phenomenon non-stroke (8.6%), atrial fibrillation (5%) and ring abscess (2.9%). Mortality rate was 17.3%. Congestive cardiac failure, increase in the peak leucocyte count and stroke were the independent predictors of mortality.

Conclusions

This study reiterates the persistent dominance of rheumatic heart disease in the population studied and α – hemolytic Streptococci as the commonest responsible microorganism.

Infective Endocarditis in Low- and Middle-Income Countries

Infective endocarditis (IE) is a rare, life-threatening disease with a mortality rate of 25% and significant debilitating morbidities. Although much has been reported on contemporary IE in high-income countries, conclusions on the state of IE in low- and middle-income countries (LMICs) are based on studies conducted before the year 2000. Furthermore, unique challenges in the diagnosis and management of IE persist in LMICs. This article reviews IE studies conducted in LMICs documenting clinical experiences from the year 2000 to 2016. Presented are the causes of IE, management of patients with IE, and prevailing challenges in diagnosis and treatment of IE in LMICs.

Heterologous expression of Streptococcus mutans Cnm in Lactococcus lactis promotes intracellular invasion, adhesion to human cardiac tissues and virulence

In S. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in the Galleria mellonella invertebrate model. To further characterize Cnm as a virulence factor, the cnm gene from S. mutans strain OMZ175 was expressed in the non-pathogenic Lactococcus lactis NZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall of L. lactis. Similar to S. mutans, expression of Cnm in L. lactis enabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence in G. mellonella. Using an ex vivo human heart tissue colonization model, we showed that Cnm-positive strains of either S. mutans or L. lactis outcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitated L. lactis adhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute of S. mutans and confirm the usefulness of the L. lactis heterologous system for further characterization of bacterial virulence factors.

Infective endocarditis

Infective endocarditis occurs worldwide, and is defined by infection of a native or prosthetic heart valve, the endocardial surface, or an indwelling cardiac device. The causes and epidemiology of the disease have evolved in recent decades with a doubling of the average patient age and an increased prevalence in patients with indwelling cardiac devices. The microbiology of the disease has also changed, and staphylococci, most often associated with health-care contact and invasive procedures, have overtaken streptococci as the most common cause of the disease. Although novel diagnostic and therapeutic strategies have emerged, 1 year mortality has not improved and remains at 30%, which is worse than for many cancers. Logistical barriers and an absence of randomised trials hinder clinical management, and longstanding controversies such as use of antibiotic prophylaxis remain unresolved. In this Seminar, we discuss clinical practice, controversies, and strategies needed to target this potentially devastating disease.