Comparison of features of active infective endocarditis involving native cardiac valves in nonintravenous drug users with and without predisposing cardiac disease

Contribution of Severe Dental Caries Induced by Streptococcus mutans to the Pathogenicity of Infective Endocarditis

Streptococcus mutans, a major pathogen of dental caries, is regarded as a causative agent of infective endocarditis (IE), which mainly occurs in patients with underlying heart disease. However, it remains unknown whether severe dental caries that extend to pulp space represent a possible route of infection. In the present study, we evaluated the virulence of S. mutans for IE development using rats with concurrent severe dental caries and heart valve injury. Dental caries was induced in rats through the combination of a caries-inducing diet and the administration of S. mutans into the oral cavity. Then, the heart valves of a subset of rats were injured using a sterile catheter and wire under general anesthesia. The rats were euthanized at various times with various stages of dental caries. The number of teeth affected by dental caries with pulp exposure was increased in the rats in a time-dependent manner. S. mutans was recovered from injured heart tissue, which was mainly observed in rats with higher number of S. mutans bacteria in mandibular bone and a larger number of teeth in which caries extended to pulp. Dental caries was more severe in rats with heart injury than in rats without heart injury. Sequencing analysis targeting 16S rRNA revealed that specific oral bacteria appeared only in rats with heart injury, which may be related to the development of dental caries. Our findings suggest that dental caries caused by the combination of S. mutans infection and sucrose intake may contribute to S. mutans colonization in injured heart tissue.

Incidence of infective endocarditis caused by viridans group streptococci in Sweden - effect of cessation of antibiotic prophylaxis in dentistry for risk individuals

Introduction

In October 2012, the Swedish Medical Products Agency published new recommendations for the cessation of prophylactic antibiotics in dentistry for the prevention of infective endocarditis (IE). Previously, 2 g of amoxicillin per os would be administered 1 h before invasive dental procedures to patients with valve prosthesis, complicated heart valve disease, and to those with previous endocarditis.

Objectives

The aim of this study was to evaluate whether the total incidence of IE caused by oral viridans group streptococci (VGS) or IE caused by staphylococci, increased in Sweden after the introduction of the new recommendations.

Methods

The incidence of IE in Sweden before and after October 2012 was calculated and compared using an interrupted time series analysis. Separate analyses were conducted for the total incidence of IE, and IE caused by VGS or Staphylococcus aureus. Cases of IE were identified using the Swedish national registry of IE, which has existed since 1995 and contains data from all Swedish hospital clinics specialising in infectious disease. All cases with hospital admission date from the 1^st of Jan 2008, to the 31^st of Dec 2017 were included. The incidence calculations were corrected for annual changes in population size using data from the Swedish government agency Statistics Sweden.

Results

The results show no statistically significant increase in the slope of the trend line of the total incidence of IE, IE caused by VGS or S. aureus in the Swedish general population after October 2012, compared to before.

Conclusion

The results suggest that the recommended cessation of prophylactic antibiotics for the prevention of IE in dentistry has not led to an increased incidence of IE caused by oral streptococci among the Swedish population.

[Left-sided native valve infective endocarditis: Influence of age and the presence of underlying heart disease]

INTRODUCTION AND OBJECTIVES

Left-sided native valve infective endocarditis (LNVIE) epidemiology has been modified as a result of the increase in average age. The aim of our study is to analyze the influence of age and the presence of predisposing heart disease in the prognosis of these patients.

METHODS

We analyzed a series of 257 cases of LNVIE depending on their age (greater than or equal to 70 years old), both in the overall series and in the subgroup of patients without predisposing heart disease.

RESULTS

Mean age was 54.6 (18.6) years. There was an increase in the percentage of cases of older patients between 1987-2000 and 2001-2014 (9.8 vs. 34.8%, P<.001). These patients present higher prevalence of degenerative valves (50 vs. 22.8%) or not predisposing heart disease (50 vs. 39.9%), P<.001, health-care associated episodes (41.8 vs. 23.6%, P=.016), lower rate of surgery (43.7 vs. 63.8%, P=.005) and higher in-hospital mortality (39.1 vs. 20.7%, P=.003), with no differences in comorbidities. Older patients who did not have predisposing heart disease also suffered higher in-hospital mortality (47 vs. 22%, P=.01). Age greater than or equal to 70 years old is an independent predictor of mortality in patients with LNVIE (OR 2.53, 95% CI 1.24-5.15, P=.011), as in those without previous heart disease (OR 3.98, 95% CI 1.49-10.62, P=.006).

CONCLUSIONS

Patients of age greater than or equal to 70 years old and who suffer an LNVIE are becoming more frequent and have a worse prognosis with a lower rate of surgery and higher rates of in-hospital mortality.

Twenty-Year Experience in the Diagnosis and Treatment of Infective Endocarditis

Aims

The aim of this study was to compare the etiology, clinical course, selected diagnostic methods and efficacy of the treatment used in patients with infective endocarditis (IE) in the nineteen eighties and nineties.

Material and Methods

The study group comprised 300 patients with infective endocarditis hospitalized in the Institute of Cardiology in Warsaw in the following years: from 1982 to 1987 (150 patients: 75 successive patients with IE on the prosthetic valve and 75 successive patients with IE on the native valve), as well as from 1990 to 2003 (150 patients: 75 successive patients with IE on the prosthetic valve and 75 successive patients with IE on the native valve).

Results

In the nineties, immunological symptoms, embolism formation and progressive heart failure were diagnosed decidedly more frequently. Early prosthetic valve endocarditis (PVE) (up to 60 days after operation) occurred significantly more frequently in the eighties. The quantity of negative blood cultures in PVE has not decreased, it is still observed in over 20% of cases. For 20 years the etiology of PVE has remained the same, the dominant pathogen remains Staphylococcus. The frequency of PVE caused by Streptococci has markedly reduced. In both the decades analyzed the etiology of native valve endocarditis (NVE) was similar. In the eighties Streptococcus was predominant. In successive years the number of infections caused by Staphylococci was the same as that caused by Streptococci.

Conclusions

The incidence of early PVE decreased in the nineties. More patients were treated surgically with lesser peri-operative mortality. A lower incidence of infective endocarditis on prosthetic valves caused by streptococci may signify better prophylaxis against infective endocarditis. Infective endocarditis with sterile blood cultures continues to occur frequently.

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

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

Lost without Occam's razor: Escherichia coli tricuspid valve endocarditis in a non-intravenous drug user

The unusual case of a 31-year-old woman who developed tricuspid valve endocarditis with positive blood cultures for Escherichia coli is presented. The patient had no underlying cardiac disease or predisposing conditions that could have made her susceptible to the native valve infection. Despite a lengthy course of intravenous antibiotics only a partial response was achieved. The patient underwent cardiac surgery and had a good postoperative recovery.

Gender differences in infective endocarditis: pre- and co-morbid conditions lead to different management and outcomes in female patients

The impact of gender on the presenting characteristics, management, and outcomes in infective endocarditis (IE) has not been adequately studied. The goal of our study was to better understand differences in management and outcome of IE between genders. Data were obtained prospectively from 439 patients in the Duke Endocarditis Database from 1996 to 2004. Baseline characteristics of patients were examined using univariable analysis. Variables associated with gender, in-hospital surgery and long-term mortality in patients with IE were considered for multivariable analysis. Hemodialysis, diabetes mellitus, and immunosuppression were more frequent in female patients with IE. Intracardiac abscesses and new conduction abnormalities were more common in male patients. The following factors were predictive of short-term mortality through univariable analysis: female gender, age, diabetes mellitus, septic pulmonary infarcts, intracranial hemorrhage, infection with Staphylococcus aureus, and persistently positive blood cultures. Female gender was not associated with mortality in an adjusted analysis of short-term outcome. Age, diabetes mellitus, renal failure requiring hemodialysis, cancer, pulmonary edema, systemic embolization, persistently positive blood cultures, and chronic indwelling central catheters but not female gender were associated with long-term mortality using univariable and an adjusted analysis. In both analyses, surgery was associated with improved mortality. Female gender, a history of diabetes mellitus, hemodialysis, and immunosuppression therapy were predictive of a medical management without the use of surgery, although in the adjusted analysis there was no association between surgery and gender. In conclusion, differences between genders in treatment and outcomes frequently reported in patients with IE most likely result from pre- and co-existing conditions such as diabetes mellitus, renal failure requiring hemodialysis, and chronic immunosuppression.

Current characteristics of infective endocarditis in Japan: an analysis of 848 cases in 2000 and 2001

The Japanese Circulation Society appointed a committee to develop guidelines for the prevention, diagnosis and management of infective endocarditis in Japan. In making such guidelines, the committee required information on the current clinical characteristics of infective endocarditis and therefore performed a nationwide questionnaire survey of cases from 2000 and 2001. In total, data were received for 848 cases from 277 of the 817 hospitals surveyed. Mean age was 55+/-18 years and most patients were aged in their 50 s or 60 s; 53.9% of the patients had infective endocarditis of unknown origin (without any prior predisposing conditions or procedures) and the second most common etiology was post dental procedures. The most common microorganism was Gram-positive cocci (345 streptococci and 221 staphylococci) and methicillin resistant Staphylococcus aureus (MRSA) was found in 7.3%. Although more than 90% of cases with Streptococcus viridans were sensitive to penicillin G, 6.6% were resistant. All MRSAs were sensitive to vancomycin. The information obtained from the survey assisted in the making of the guidelines, which should become an indispensable tool for all clinicians.