Risk factors for infective endocarditis: oral hygiene and nondental exposures

Antibiotic prophylaxis for endocarditis: time to reconsider

Some cardiac conditions require antibiotic prophylaxis for some types of dental treatment to reduce the risk of infective endocarditis (IE). All medical and dental practitioners are familiar with this practice but tend to use different regimens in apparently similar circumstances. Generally, the trend has been to prescribe antibiotics if in doubt. This review explores the evidence for antibiotic prophylaxis to prevent IE: does it work and is it safe? The changing nature of IE, the role of bacteraemia of oral origin and the safety of antibiotics are also reviewed. Most developed countries have national guidelines and their points of similarity and difference are discussed. One can only agree with the authority who describes antibiotic guidelines for endocarditis as being 'like the Dead Sea Scrolls, they are fragmentary, imperfect, capable of various interpretations and (mainly) missing!' Clinical case-controlled studies show that the more widely antibiotics are used, the greater the risk of adverse reactions exceeding the risk of IE. However, the consensus is that antibiotic prophylaxis is mandatory for a small number of high-risk cardiac and high-risk dental procedures. There are a large number of low-risk cardiac and dental procedures in which the risk of adverse reactions to the antibiotics exceeds the risk of IE, where prophylaxis should not be provided. There is an intermediate group of cardiac and dental procedures for which careful individual evaluation should be made to determine whether IE or antibiotics pose the greater risk. These categories are presented. All medical and dental practitioners need to reconsider their approach in light of these current findings.

Risk factors for nosocomial infective endocarditis in patients with methicillin-resistant Staphylococcus aureus bacteremia

BACKGROUND AND OBJECTIVE

Nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are increasing. Only a few studies of MRSA infective endocarditis have been conducted, and none have reported its risk factors. We sought to determine the host-related risk factors for infective endocarditis in patients with nosocomial MRSA bacteremia.

SETTING

A 2,000-bed, university-affiliated, tertiary-care hospital.

PATIENTS

Thirty-one patients with nosocomial MRSA infective endocarditis between October 1996 and May 2003.

DESIGN

A retrospective chart review was conducted. Data were compared with those from a control group of patients with nosocomial MRSA bacteremia. Logistic regression was used to identify independent risk factors for nosocomial infective endocarditis.

RESULTS

Compared with patients who had nosocomial MRSA bacteremia and no infective endocarditis, patients who had infective endocarditis had a higher incidence of chronic liver disease and a lower incidence of immunodeficiency. The risk of developing infective endocarditis was approximately 10% for patients with nosocomial MRSA bacteremia.

CONCLUSION

Patients with MRSA bacteremia and underlying chronic liver disease were prone to infective endocarditis.

Stroke-complicated endocarditis with positive lupus anticoagulant--a case report

Twenty to 40% of patients with infective endocarditis (IE) suffer from neurologic complications. Also many and various markers of immunologic activation have been reported in patients with IE and no history of autoimmune or other rheumatologic diseases. The authors present a case of a patient suffering from IE complicated with major cerebrovascular event with concomitant appearance of lupus anticoagulant (LAC). After successful antibiotic treatment there was major clinical improvement with disappearance of LAC. LAC could be added to the list of immunologic markers appearing in the course of infective endocarditis.

A 28-year trend of infective endocarditis associated with congenital heart diseases: a single institute experience

BACKGROUND

Infective endocarditis (IE) is still one of the major complications of congenital heart disease and, therefore, prevention has always been an important issue. But there has been no large scale investigation of IE in Japan.

METHODS

Clinical and microbiological features in 183 patients with congenital heart diseases complicated with infective endocarditis (IE), which were treated in our institute in the last 28 years, were reviewed.

RESULT

During the period, the age distribution of the patients shifted to an older age; 80% were older than 15 years in the latest 7 year period. In the underlying diseases more complex conditions increased, such as the post Rastelli operation. Dental or oral diseases were the major preceding events and Streptococcus was the major pathogen throughout the study periods in the data.

CONCLUSION

The result indicates the importance of continuing education for the prevention of IE and oral hygiene especially in adult patients with a risk for IE.

Dentistry and endocarditis

Bacterial endocarditis (BE), a rare heart infection caused by a bacteremia, has frequently been blamed on but rarely caused by dental procedures. Viridans group streptococci are found abundantly in the mouth and the gingival sulcus but have been surpassed by staphylococci as the leading cause of BE. Antibiotic prophylaxis has been recommended before dental procedures in patients at risk for BE, but it remains controversial because studies have failed to show that antibiotic prophylaxis is an effective preventive for BE or that dental procedures are an important cause of BE. The risks and costs of antibiotic prophylaxis, including antibiotic resistance, cross-reactions with other drugs, allergy, anaphylaxis, and even death, may exceed the benefits in preventing BE. The rationale for the use of antibiotic prophylaxis to prevent BE allegedly caused by dental procedure bacteremias must be seriously reexamined based on recent evidence, particularly the absolute risk rates for endocarditis after a given dental procedure.

Infective endocarditis: a review of the best treatment options

Despite significant advances in antimicrobial therapy and an enhanced ability to diagnose and treat complications, infective endocarditis is still associated with substantial morbidity and mortality today, and its incidence has not decreased over the past decades. This apparent paradox may be explained by a progressive change in risk factors, leading to an evolution in its epidemiological and clinical features. In fact, new risk factors for endocarditis have emerged, such as intravenous drug abuse, diffusion of heart surgery procedures and prosthetic valve implantation, atherosclerotic valve disease in elderly patients, and nosocomial disease. Recently identified microorganisms (including Bartonella spp., Abiotrophia defectiva, and the HACEK group of bacteria [including Haemophilus spp., Actinobacillus spp., Cardiobacterium hominis, Eikenella corrodens and Kingella kingae]) are sometimes the cause of culture-negative endocarditis, and emerging resistant bacteria (such as methicillin- or vancomycin-resistant Staphylococci and vancomycin-resistant Enterococci) are becoming a new challenge for conventional antibiotic therapy. New therapeutic approaches need to be developed for the treatment of infective endocarditis caused by drug-resistant Gram-positive cocci, and some antimicrobial compounds recently introduced in clinical practice (such as streptogramins and oxazolidinones) may be an effective alternative, but further clinical studies are needed in order to confirm their effectiveness and safety. This review should help redefine the best therapeutic and preventive strategies against infective endocarditis.

Investigation of bacteremia following nasotracheal intubation

BACKGROUND

The aim of this study was to detect the risk of bacteremia from nasotracheal intubation in children undergoing dental treatment under general anesthesia.

METHODS

Two 10 ml blood samples were taken, the first as a baseline and the second within 30 s following the nasotracheal intubation. The samples were inoculated into 5 ml aerobic and 5 ml anaerobic blood culture bottles. Following incubation in an automated blood culture system, bacteria were identified by using conventional biochemical methods and commercial identification systems. Mc Nemar's test was used to assess the findings statistically.

RESULTS

Of 74 patients only nine (12.3%) had positive blood cultures after the intubation and seven of these had been intubated without trauma. The incidence of bacteremia was significantly higher after atraumatic intubation (7/9) compared with traumatic intubation (2/9) (P < 0.05). The most common bacteria in positive cultures were Streptococcus viridans, four of 74 (5.4%).

CONCLUSIONS

Since the occurrence of bacteremia after nasotracheal intubation is hazardous for patients at risk for developing infective endocarditis, to prevent further complications prophylactic antibiotic treatment is recommended.

Long-term survival of dialysis patients with bacterial endocarditis in the United States

BACKGROUND

The incidence of bacterial endocarditis is much greater in long-term dialysis patients compared with the general population, and chronic kidney disease has been postulated as an independent host-related risk factor. Limited data are available on the long-term survival of dialysis patients with endocarditis.

METHODS

Dialysis patients hospitalized for bacterial endocarditis between 1977 and 2000 were studied retrospectively using data from the US Renal Data System database. Long-term survival was estimated by means of the life-table method. A Cox proportional hazards model was used to identify the impact of demographic characteristics and comorbidity on outcome.

RESULTS

A total of 13,130 dialysis patients with bacterial endocarditis were identified. The in-hospital mortality rate for the entire cohort was 23.5%. Survival rates at 1, 2, 3, and 5 years were 45.9%, 33.3%, 24.3%, and 14.7% for patients hospitalized between 1977 and 1991 and 41.0%, 29.1%, 20.6%, and 10.9% for those hospitalized between 1992 and 1996, respectively. Survival rates at 1, 2, and 3 years were 38.4%, 25.3%, and 18.3% for patients hospitalized between 1997 and 2000, respectively. The most powerful independent predictors of all-cause death were age, diabetes as cause of end-stage renal disease, and cerebrovascular accident or transient ischemic attack as a comorbid condition.

CONCLUSION

Dialysis patients with bacterial endocarditis have poor long-term survival, even in the current treatment era, with survival rates changing little in the past 2 decades. Additional studies are needed to identify risk-reduction measures and develop additional treatment strategies for dialysis patients with endocarditis.

Correlation between detection rates of periodontopathic bacterial DNA in coronary stenotic artery plaque [corrected] and in dental plaque samples

Utilizing PCR, the 16S rRNA detection rates for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Treponema denticola, and Campylobacter rectus in samples of stenotic coronary artery plaques were determined to be 21.6, 23.3, 5.9, 23.5, and 15.7%, respectively. The detection rates for P. gingivalis and C. rectus correlated with their presence in subgingival plaque.

Penicillins for the prophylaxis of bacterial endocarditis in dentistry

BACKGROUND

Many dental procedures cause bacteraemia and it is believed that this may lead to bacterial endocarditis (BE) in a few people. Guidelines in many countries recommend that prior to invasive dental procedures antibiotics are administered to people at high risk of endocarditis. However, it is unclear whether the potential risks of this prophylaxis outweigh the potential benefits.

OBJECTIVES

To determine whether prophylactic penicillin administration compared to no such administration or placebo before invasive dental procedures in people at increased risk of BE influences mortality, serious illness or endocarditis incidence.

SEARCH STRATEGY

The search strategy was developed on MEDLINE and adapted for use on the Cochrane Oral Health, Heart and Infectious Diseases Groups' Trials Registers (to October 2003), as well as the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2002), OLDMEDLINE (1966 to June 2002); EMBASE (1980 to June 2002); SIGLE (to June 2002); and the Meta-register of current controlled trials.

SELECTION CRITERIA

Due to the low incidence of BE it was anticipated that few if any trials would be located. For this reason, cohort and case controlled studies were included where suitably matched control or comparison groups had been studied. The intervention was the administration of penicillin compared to no such administration before a dental procedure in people with an increased risk of BE. Cohort studies would need to follow those at increased risk and assess outcomes following any invasive dental procedures, grouping by whether prophylaxis was received. Included case control studies would need to match people who had developed endocarditis (and who were known to be at increased risk before undergoing an invasive dental procedure preceding the onset of endocarditis) with those at similar risk but who had not developed endocarditis. Outcomes of interest were: mortality or serious adverse event requiring hospital admission; development of endocarditis following any dental procedure in a defined time period; development of endocarditis due to other non-dental causes; any recorded adverse events to the antibiotics; and cost implications of the antibiotic provision for the care of those patients who develop endocarditis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies for inclusion, then assessed quality and extracted data from the included study.

MAIN RESULTS

No RCTs, CCTs or cohort studies were included. One case-control study met the inclusion criteria. It collected all the cases of endocarditis in the Netherlands over 2 years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxys). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes.

REVIEWERS' CONCLUSIONS

There is no evidence about whether penicillin prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. There is a lack of evidence to support published guidelines in this area. It is not clear whether the potential harms and costs of penicillin administration outweigh any beneficial effect. Ethically practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.

Involvement of periodontopathic biofilm in vascular diseases

Oral bacteria inhabit biofilms, which are firm clusters adhering in layers to surfaces and are not easily eliminated by immune responses and are resistant to antimicrobial agents. Dental plaque is one such biofilm. In the past 10 years, subgingival plaque bacteria forming biofilms have been increasingly reported to be involved in systemic diseases. A close relationship between microbial infections and vascular disease has also been reported in the past two decades. The present review discusses the significance of the ecologic characteristics of biofilms formed by periodontopathic bacteria in order to further clarify the associations between periodontal disease and systemic disease. We focus on the relationships between periodontal disease-associated bacteria forming biofilms and vascular diseases including atherosclerosis and carotid coronary stenotic artery disease, and we discuss the direct and indirect effects on vascular diseases of lipopolysaccharides as well as heat shock proteins produced by periodontopathic bacteria.

Antibiotic prophylaxis: problems in paradise

The age of antibiotic prophylaxis may be receding into its twilight years because the assumption upon which it was based has not proved generally true. Although antibiotics treat infections, limited benefit has been demonstrated in preventing infections. These are two entirely different biologic entities, a distinction which appears to have gone unappreciated by many for more than 50 years. If the principles of antibiotic prophylaxis established more than 40 years ago had been assiduously followed, many of its abuses could have been avoided. This may not have stopped our legal colleagues, but it would have been worth an effort on behalf of our patients. It is likely that the massive overuse of antibiotics as litigation prevention has contributed to the global epidemic of antibiotic-resistant micro-organisms and an unknown number of serious adverse effects to the antibiotics themselves. Even with this abuse, much money has still flowed from defendant to plaintiff. Substantial data exist that antibiotics do not prevent bacteremias. The absolute risk rate for bacterial endocarditis after dental treatment even in at-risk patients is very low. Antibiotic prophylaxis for surgical infections requires specific dosing schedules (perioperative surgical prophylaxis) to be successful. Hopefully the difficulties presented herein regarding antibiotic prophylaxis will lead to their more enlightened use in the future.

Infective endocarditis in dialysis patients: new challenges and old

BACKGROUND

Since the 1960s chronic hemodialysis (HD) has been recognized as a risk factor for the development of infective endocarditis (IE). Historically, it has been particularly associated with vascular access via dual lumen catheters. We wished to examine the risk factors for, and consequences of, IE in the modern dialysis era.

METHODS

Cases of IE (using the Duke criteria) at St. Thomas' Hospital (1980 to 1995), Guy's (1995 to 2002), and King's College Hospitals (1996 to 2002) were reviewed.

RESULTS

Twenty-eight patients were identified as having developed IE (30 episodes of IE). Twenty-seven patients were on long-term HD and one patient was on peritoneal dialysis (PD). Mean age was 54.1 years, and mean duration of HD prior to IE was 46.3 months. Eight patients were diabetic. Primary HD hemoaccess was an arteriovenous fistula (AVF) in 41.3%, a dual-lumen tunneled catheter (DLTC) in 37.9%, a polytetrafluoroethylene (PTFE) graft in 10.3%, and a dual- lumen non-tunneled catheter (DLNTC) in 4%. The presumed source of sepsis was directly related to hemoaccess in 25 HD patients: DLTC in 48%; AVF in 32%; PTFE in 12%; and DLNTC in 4%. Staphylococcus aureus[including methicillin resistant Staphylococcus aureus (MRSA)] was present in 63.3%. The mitral valve was affected in 41.4% of patients, aortic valve in 37.9% of patients, and both valves were affected in 17.2% of patients. Of note, 51.7% of patients had an abnormal valve before the episode of IE. In 15 cases surgery was undertaken. Fourteen patients survived to discharge, and 12 survived for 30 days. In 15 cases antibiotic treatment alone was employed; in this case, eight patients died and seven survived to discharge.

CONCLUSION

This is the largest reported confirmed IE series in dialysis patients. Infective endocarditis in HD patients remains a challenging problem-although hemoaccess via dual-lumen catheters remains a significant risk, many cases developed in patients with AVFs and this group suffered the greatest mortality. An abnormal valve (frequently calcified) was another risk factor; because valve calcification is now common after 5 years on dialysis, more effort in preventing this avoidable form of ectopic calcification may reduce the risk of developing IE.

Progress toward a global understanding of infective endocarditis. Lessons from the International Collaboration on Endocarditis

In the century and a quarter since William Osler delivered his famed Gulstonian lectures on endocarditis, continual advancements have been made in understanding and treating this disease. Here we have reviewed some key aspects of current knowledge in the areas of population epidemiology, host factors, microorganisms, and diagnosis. The advent of the ICE investigation provides the opportunity to further expand our understanding of IE by developing a very large, global database of IE patients whose clinical, echocardiographic, and microbiologic findings have been characterized with standard methodology. Further, ICE may serve as a rich source of material for investigators seeking to perform specific studies. Finally, the ICE infrastructure creates the opportunity for performing randomized trials to test therapeutic strategies. Although many obstacles remain to be overcome, ICE has created the opportunity for a quantum leap in our knowledge of IE over the next 25 years.

[Infectious endocarditis: degree of discordance between clinical guidelines recommendations and clinical practice]

INTRODUCTION AND OBJECTIVES

The present study was made to investigate the degree of discordance between the recommendations of clinical guidelines and actual practice in the care of patients with infectious endocarditis.

MATERIAL AND METHODS

Data was gathered on 34 patients that were admitted to our hospital for native valve infection over a 4-year period. The degree of discordance (%) was obtained by comparing each clinical history with a catalog of 15 specific actions recommended in the clinical guidelines for four consecutive phases: pre-diagnosis, hospital diagnosis, antibiotic treatment, and surgical treatment. A system was constructed, scoring each phase with the greatest detected error (on a severity scale of 0 to 8 points) and adding together the scores for the four phases.

RESULTS

The mean degree of discordance was 30.5% (range, 0-66%). Scores of more than six points were clearly associated with an unfavourable evolution.

CONCLUSIONS

The recommendations of clinical guidelines for infectious endocarditis are inadequately followed in practice, which can affect the course of the disease. It is necessary to increase adherence to clinical guidelines in practice, in order to improve the care of patients with this serious disease.

Valve replacement in patients on chronic renal dialysis: implications for valve prosthesis selection

BACKGROUND

Reports are sparse describing heart valve replacement in patients with end-stage renal disease. This review assesses a 15-year experience and outcomes after valve replacement in patients on chronic preoperative renal dialysis.

METHODS

A computerized database, hospital records, and telephone contact provided outcome data for patients on chronic dialysis undergoing valve replacement between March 22, 1985, and October 13, 2000, in two hospitals.

RESULTS

Seventy-two patients underwent 95 valve procedures (74 operations). Ages ranged from 23 years to 84 years (mean, 57 years). Fifty-five aortic, 30 mitral, and 3 tricuspid valve replacements and 7 valvuloplasties were performed. Six of the 74 procedures were reoperative valve replacements. In the 46 patients with reliable long-term (greater than 30 days) follow-up data, significant bleeding or stroke was documented in 17 of 34 patients with a mechanical valve and 1 of 12 patients with a bioprosthetic valve. Overall survival (including two operative deaths) was 72.8% at 3 months, 65.4% at 6 months, 60.5% at 1 year, 39.8% at 2 years, 28.5% at 3 years, and 15.9% at 6 years (Kaplan-Meier). Type of valve implanted did not influence early and late survival.

CONCLUSIONS

In this series of patients on chronic dialysis, survival appears to justify valve replacement. However, the sixfold higher incidence of late bleeding or stroke in patients on dialysis with a mechanical valve requiring warfarin suggests that bioprosthetic valves are the valve substitute of choice in patients on chronic dialysis.

Progress toward a global understanding of infective endocarditis. Early lessons from the International Collaboration on Endocarditis investigation

In the century and a quarter since William Osler delivered his framed lectures on endocarditis substantial advancements have occurred in the understanding and treatment of this disease. This article summarizes current understanding of endocarditis in the areas of population epidemiology, host factors, microorganisms, diagnosis, and therapy. In addition, the authors discuss possible directions for investigation in the future, including a new multinational consortium, the International Collaboration on Endocarditis (ICE). This collaboration aims to provide a mechanism to advance the understanding of endocarditis in areas difficult to study without an established network. The multinational nature of the collaboration may also permit a more global view of IE and provide opportunities for studies such as randomized trials of therapeutic treatment strategies.

An update on the controversies in bacterial endocarditis of oral origin

OBJECTIVES

The aim of this review was to evaluate the evidence implicating dental procedures in bacterial endocarditis (BE) development and the basis for antimicrobial prophylaxis (AP).

STUDY DESIGN

In this article, the literature is reviewed and meaningful findings about epidemiology, pathogenesis, and AP guidelines for BE of oral origin are highlighted. Available results are used to formulate clinical recommendations for the dental practitioner.

RESULTS

The nature of dental procedures that cause bacteremia, patients at risk for BE, and the effectiveness of AP guidelines, continue to be points of controversy. There appears to be further evidence to support the important role of oral health status in the prevention of BE of dental origin.

CONCLUSIONS

One objective of the dental practitioner in caring for patients at risk for BE should be to promote oral health care. There are no hard data on which to scientifically base the need for AP in patients at risk for BE. However, it would appear prudent, at least from the medicolegal perspective, to provide AP, at least to persons with previous BE or prosthetic heart valves and to those undergoing oral surgery, periodontal treatment, or implant placement.

[Risk factors associated with endocarditis without underlying heart disease]

Infective endocarditis (IE) pathogenesis has changed in the last decades and there is an increasing number of patients without predisposing heart condition. The aim of this study is to asses the clinical features of these non-drug addict patients affected with IE without underlying heart disease and to identify the potential risk factors. From 196 cases of IE, 49 (25% of the series) occurred in patients without underlying heart disease. A presumed portal of entry was identified in the majority (26 cases). The most frequent were digestive (6 cases), haemodialysis (6 cases) and central venous catheters (4 cases). Right heart valves were more often affected (29 vs 6%; p < 0.01). The distribution of the causative microorganism showed a higher proportion of Staphylococcus (57 vs 30%). Despite a similar in-hospital complication rate and a similar need of surgery during the active phase, their prognosis is better than in those with underlying heart disease.