Diagnosis and treatment of infective endocarditis. Current ESC guidelines

To account for the current evidence in the field of infective endocarditis and to harmonize deviant national guidelines, in 2009 the European Society of Cardiology published novel recommendations on the prevention, diagnosis and treatment of infective endocarditis.The most important changes can be found concerning antimicrobial prophylaxis for endocarditis, the antimicrobial treatment of endocarditis caused by S. aureus and the indications for surgical treatment.Due to the weak evidence about prophylactic administration of antibiotics before procedures at risk for bacteraemia to prevent infective endocarditis, the novel guidelines recommend prophylaxis only in patients with the highest risk for infection and lethal course of endocarditis. These are patients with prosthetic valves or prosthetic material used for cardiac repair, patients with previous endocarditis and patients with congenital heart disease. A narrow definition of procedures at risk was proposed only including dental procedures requiring manipulation of the gingival or periapical region of teeth.For endocarditis caused by S. aureus an additional gentamicin administration was previously recommended but this is now seen only as optional due to its nephrotoxicity. In methicillin-resistant strains daptomycin is a possible alternative to vancomycin. In strains susceptible to methicillin, beta-lactamic antibiotics were definitively preferred than the usage of vancomycin due to better outcome. The current guidelines recommend definitive timing and risk constellations for surgical treatment of infective endocarditis. For example, cardiac shock due to valvular lesions refractory to medical treatment should give rise to an emergency intervention within 24 h. Other indication groups contain uncontrolled infection and prevention of embolism and indications were defined as urgent or elective depending on the clinical situation.     

Diagnostik und Therapie der Endokarditis

To account for the current evidence in the field of infective endocarditis and to harmonize deviant national guidelines, in 2009 the European Society of Cardiology published novel recommendations on the prevention, diagnosis and treatment of infective endocarditis. The most important changes can be found concerning antimicrobial prophylaxis for endocarditis, the antimicrobial treatment of endocarditis caused by S. aureus and the indications for surgical treatment. Due to the weak evidence about prophylactic administration of antibiotics before procedures at risk for bacteraemia to prevent infective endocarditis, the novel guidelines recommend prophylaxis only in patients with the highest risk for infection and lethal course of endocarditis. These are patients with prosthetic valves or prosthetic material used for cardiac repair, patients with previous endocarditis and patients with congenital heart disease. A narrow definition of procedures at risk was proposed only including dental procedures requiring manipulation of the gingival or periapical region of teeth. For endocarditis caused by S. aureus an additional gentamicin administration was previously recommended but this is now seen only as optional due to its nephrotoxicity. In methicillin-resistant strains daptomycin is a possible alternative to vancomycin. In strains susceptible to methicillin, beta-lactamic antibiotics were definitively preferred than the usage of vancomycin due to better outcome. The current guidelines recommend definitive timing and risk constellations for surgical treatment of infective endocarditis. For example, cardiac shock due to valvular lesions refractory to medical treatment should give rise to an emergency intervention within 24 h. Other indication groups contain uncontrolled infection and prevention of embolism and indications were defined as urgent or elective depending on the clinical situation.     

Prophylaxis for infective endocarditis: an update

The American Heart Association has updated its recommendations for prevention of bacterial endocarditis. The major changes are less emphasis on administration of parenteral agents and a reduction of the period of prophylaxis. The simplified new recommendations should make compliance easier and should be assiduously implemented by dental and medical practitioners. However, several changes are suggested for possible consideration: Because of the relatively low risk, prophylaxis may not be needed for persons with mitral valve prolapse (unless there is a holosystolic murmur) or for most gastrointestinal endoscopic procedures. Consideration should be given to using a single oral 3-g dose of amoxicillin for dental procedures in all patients at risk and for genitourinary and gastrointestinal tract procedures in patients at risk who have natural cardiac valves. Vancomycin should probably be the agent of choice for prophylaxis in cardiac valve surgery.     

Propionibacterium endocarditis: a case series from the International Collaboration on Endocarditis Merged Database and Prospective Cohort Study

Propionibacterium species are occasionally associated with serious systemic infections such as infective endocarditis. In this study, we examined the clinical features, complications and outcome of 15 patients with Propionibacterium endocarditis using the International Collaboration on Endocarditis Merged Database (ICE-MD) and Prospective Cohort Study (ICE-PCS), and compared the results to 28 cases previously reported in the literature. In the ICE database, 11 of 15 patients were male with a mean age of 52 y. Prosthetic valve endocarditis occurred in 13 of 15 cases and 3 patients had a history of congenital heart disease. Clinical findings included valvular vegetations (9 patients), cardiac abscesses (3 patients), congestive heart failure (2 patients), and central nervous system emboli (2 patients). Most patients were treated with beta-lactam antibiotics alone or in combination for 4 to 6 weeks. 10 of the 15 patients underwent valve replacement surgery and 2 patients died. Similar findings were noted on review of the literature. The results of this paper suggest that risk factors for Propionibacterium endocarditis include male gender, presence of prosthetic valves and congenital heart disease. The clinical course is characterized by complications such as valvular dehiscence, cardiac abscesses and congestive heart failure. Treatment may require a combination of medical and surgical therapy.     

What's new in the prevention of infective endocarditis?

The concept of prophylaxis of infective endocarditis has changed substantially in recent years; currently, prophylaxis is recommended only in patients at highest risk of developing infective endocarditis who are scheduled for dental procedures involving the gingiva. The risk is also increased in individuals with pacemakers and implantable cardioverter/defibrillators. Other high-risk populations include polymorbid patients (diabetes mellitus or chronic hemodialysis), the elderly (particularly those aged 75–79 years), and males. In indicated cases, the drugs used in prevention include amoxycillin or ampicillin.     

New British and American guidelines for the antibiotic prophylaxis of infective endocarditis: do the changes make sense? A critical review

PURPOSE OF REVIEW: The British Society for Antimicrobial Chemotherapy and the American Heart Association have radically revised their guidelines for the antibiotic prophylaxis of endocarditis. This review discusses the evidence behind the most controversial changes and considers possible future developments. RECENT FINDINGS: The new guidelines emphasize good oral hygiene for preventing viridans streptococcal endocarditis. Antibiotic prophylaxis for dental procedures is only recommended for patients with the highest-risk cardiac conditions. American Heart Association guidelines no longer recommend prophylaxis for urological and gastrointestinal procedures. SUMMARY: While only up to 6% of endocarditis cases may be prevented by antibiotic prophylaxis there is controversy as to what to recommend for the individual cardiac patient undergoing a given procedure. The new guidelines about dental prophylaxis are based on epidemiological studies that failed to include sufficient subjects undergoing specific interventions. When considering viridans streptococcal rather than total bacteraemia rates, asserting that the prevalence of bacteraemia after invasive dental procedures is similar to that after toothbrushing may be incorrect. The British Society for Antimicrobial Chemotherapy report probably overestimates the risk of fatal anaphylaxis after an oral dose of amoxicillin. In contrast, the American Heart Association guidelines comment on the absence of any reports of fatal anaphylaxis associated with the antibiotic prophylaxis of endocarditis.     

Epidemiology of bacterial endocarditis in The Netherlands. II. Antecedent procedures and use of prophylaxis.

BACKGROUND--The reported frequency with which endocarditis is ascribed to an antecedent dental or medical procedure varies from 3% to 62%. METHODS--We performed a nationwide prospective study of the epidemiology of bacterial endocarditis in the Netherlands. During a 2-year period, all consecutively hospitalized patients suspected of having endocarditis were visited while still hospitalized for a review of the medical record and an in-person interview that focused on antecedent procedures and administered prophylaxis. All information was checked with pharmacists and dental and medical practitioners. RESULTS--Of 427 patients with late prosthetic or native valve endocarditis, 275 were eligible for antibiotic prophylaxis because of a previously known cardiac lesion (n = 197) or a prosthetic valve (n = 78). Of these 275 patients, 64 (23.3%) had undergone a procedure with an indication for prophylaxis within 180 days of onset; in 31 (11.3%) the procedures had been within 30 days of onset. Antibiotic prophylaxis had been administered to 17 (26.6%) of the 64 patients and to eight (25.8%) of the 31 patients. CONCLUSION--The results indicate that medical and dental procedures cause only a small fraction of endocarditis. The majority of patients develop the disease along other routes. For an incubation period of 180 days, full compliance with prophylaxis might have prevented endocarditis in 47 (17.1%) of 275 patients with late prosthetic or native valve endocarditis involving a previously known cardiac lesion who underwent a procedure with an indication for prophylaxis. For an incubation period of 30 days, prophylaxis might have prevented endocarditis in 23 (8.4%) of these 275 patients, or 5.3% of all patients with endocarditis (n = 427).     

Prophylaxis of endocarditis

For a long time it has been known that bacteraemias caused by medical or dental procedures may cause endocarditis in patients with specific types of congenital or acquired heart disease. In the 1940s it was thought that the administration of antibiotics before such procedures would prevent endocarditis. However, the beneficial effect of this preventive measure on the incidence of endocarditis did not live up to its expectations. Quite soon it became obvious that prophylaxis was not 100% efficacious in man, although it did prevent endocarditis in animals. A controlled study into the protective effect of prophylaxis in humans has never been carried out. In the last decade it has become dear from case-control studies that endocarditis prophylaxis is not a very effective preventive measure but that it reduces an already small risk even further. In this article the theoretical background of endocarditis prophylaxis and possible explanations for its lack of effect are discussed.     

Age-related prevalence of cardiac valvular abnormalities warranting infectious endocarditis prophylaxis

The goal of our study was to determine the prevalence of older patients with cardiac valvular abnormalities warranting endocarditis prophylaxis. We performed a retrospective analysis of 1,000 randomly selected echocardiograms (inpatients and outpatients) from our tertiary care institution. We found that the prevalence of valvular abnormalities increased significantly with age, and that 50% of patients > or =60 years of age warranted endocarditis prophylaxis using current guidelines. With the aging population of the United States and the negative consequences of widespread antibiotic prophylaxis, further investigation is needed to identify patients who are truly at risk for infectious endocarditis.     

Bacterial endocarditis complicating body art

Increasing numbers of patients are living with congenital heart disease at a time when body art is growing in popularity. We present a case of subacute bacterial endocarditis following repeated tattooing in a patient with known valvular heart disease. This case highlights the importance of education of patients with structural heart disease to the potential risks of such procedures, particularly at a time when endocarditis prophylaxis protocols are being revised.     

Echocardiographic and clinical correlations in infectious endocarditis of the left heart

The echocardiographic features were correlated with the clinical findings and outcome in 35 patients with aortic and/or mitral valve endocarditis. There were 26 males and 9 females with a mean age of 38 years. The infection involved native valves in 27 patients and prosthetic valves in 8 patients. Echocardiographically, fourteen patients had involvement of native aortic valve. All patients in this group required surgical intervention, nine patients during antimicrobial therapy. Congestive heart failure was the clinical indication for valvular replacement. A patient died immediately after surgery from low cardiac output syndrome. Six patients had echocardiographic evidence of aortic and mitral valves involvement. A patient in this group expired before surgery, five underwent surgery because of progressive heart failure (aortic or aortic and mitral valves replacement). Seven patients showed lesions on native mitral valve (6 in this group had prolapse syndrome). A patient died from cerebrovascular embolus, two underwent surgery because of persistent infection and embolic events, four were successfully treated with medical therapy. Among patients with prosthetic valve endocarditis, four showed signs of valvular dehiscence and required surgical intervention, during antimicrobial therapy, from congestive heart failure; one patient expired from recurrent infection. The pathological findings correlated well with echocardiographic findings. Conclusions: in IE the localization of lesions by echo has prognostic significance: most patients with aortic valve or aortic and mitral valves endocarditis require early surgical intervention because of congestive heart failure. On the contrary, mitral valve involvement carries a better prognosis, requiring less frequently valvular replacement; the patients with echocardiographic signs of prosthetic valve dehiscence require urgent intervention.(ABSTRACT TRUNCATED AT 250 WORDS)     

Risk of reoperations and acute interventions in valvular surgery

Reoperations in valvular surgery can be subdivided into procedures following reconstructive measures (group A) and interventions following implantation of a valve prosthesis (group B). In group A (valve replacement after conservative mitral surgery, 41 cases from 1976 to 1984 in our institution), operative mortality does not significantly differ from patients undergoing primary isolated mitral valve replacement (7.3% v. 4.4%). In group B, however, the risk of prosthetic valve reoperation mainly depends on the morphological alterations implying the surgical intervention. Among these conditions, prosthetic valve endocarditis has the poorest prognosis (operative mortality 25% in our own experience), especially if an emergency intervention is mandatory as a result of severe heart failure. In contrast to this high risk group, patients being reoperated on an elective basis due to paraprosthetic leakage or recurrent arterial embolism, do not show a higher risk when compared to first procedures. The risk of emergency surgery on native heart valves is discussed under the consideration of patients suffering from acute infective endocarditis (AIE). As in reoperations, the preoperative cardiac functional status and the urgency of the surgical intervention are the principal determinants for the operative risk. Both for reoperations and emergency procedures surgical timing is of great importance in the management of valvular patients; when ever possible, surgery should be carried out before the development of advanced ventricular failure necessitates an intervention under emergency conditions.     

Quadricuspid aortic valve as a cause of severe aortic regurgitation.

Quadricuspid aortic valves (QAVs) constitute a rare congenital malformation, with an incidence ranging from 0.008 to 0.048%. We report a case of severe aortic regurgitation associated with a QAV, which was diagnosed intraoperatively using transesophageal echocardiography. Since the first case described in 1862, 186 QAVs have been reported. In most cases, QAVs are associated with valve regurgitation, with a concurrent stenosis in some patients, while only a small number of QAVs are functionally normal. Once the diagnosis has been made, echocardiographic follow-up is recommended, as progression to severe valve regurgitation is common. Antibiotic prophylaxis is advisable for dental, and "dirty" surgical procedures, to minimize the risk of infective endocarditis.     

Recent Progress in the Understanding of Infective Endocarditis

Infective endocarditis is an uncommon cardiac condition but is associated with significant morbidity and mortality despite advancements in diagnosis and treatment. Recent epidemiologic changes in this disease have resulted in additional challenges for treatment and improving outcome. Health care-associated infection is a growing cause of endocarditis, and the predominance of Staphylococcus aureus infection is associated with increased co-morbid medical conditions, lower rate of surgical intervention, and worse outcome. In order to reduce the high rate of complications and mortality related to endocarditis, attention to the role of antibiotic prophylaxis has been given by major cardiology societies including the American College of Cardiology, American Heart Association, and European Society of Cardiology. These recent guidelines have reduced the role of prophylaxis due to the unclear benefit, but uncertainty remains for certain pre-disposing cardiac lesions. Earlier diagnosis of endocarditis or improved prognostic tests may also reduce the complications of endocarditis by allowing earlier treatment with antibiotics or surgery, and a number of recent, preliminary studies have investigated biomarkers for improving its diagnosis or better prediction of adverse outcome. In patients with complications of endocarditis (heart failure, severe valvular regurgitation, intracardiac abscess or fistula, recurrent emboli, large vegetation or refractory infection), surgery is recommended because outcome is recognized to be poor with medical treatment alone. Recent studies of surgery for infective endocarditis have shown low operative mortality rates, particularly for patients with hemodynamic stability and non-emergent status, and a survival benefit over medical therapy alone for many of these complications. In patients with S. aureus endocarditis, surgery is less commonly performed due to co-morbid conditions, but has been shown to improve outcome and should be considered more aggressively. A growing number of studies have suggested that early surgery during the active phase of infection can be performed at low risk of operative mortality and recurrence of endocarditis, even in patients with cerebral infarction. Additional studies are needed to define the influence of surgical timing on outcome, and its potential benefit in lower-risk patients with endocarditis.     

New French recommendations for the prophylaxis of infectious endocarditis

New French recommendations on infective endocarditis (IE) prevention were recently published and mark a turning point in the history of antibiotic prophylaxis. Endocarditis is an evolving disease, and its clinical and microbiological profile dramatically changes over time. The French surveys that were conducted in 1991 and 1999 showed variations in underlying heart disease with a decrease in native valvular disease and an increase of IE in patients without previously known heart disease. Moreover, the distribution of responsible microorganisms dramatically changed over time, with a marked decrease of oral streptococci. In addition, some dogmas are now challenged. First of all, the part of responsibility of dental procedures is debated, as dental bacteraemia possibly responsible of endocarditis are more likely due to daily manoeuvres such as tooth brushing or chewing gum than to occasional dental procedures. Moreover, as suggested by case-control studies, efficacy--or lack of efficacy--of antibiotic prophylaxis is far from being clinically proved. For all these reasons, the proportion of theoretically avoidable endocarditis seems very low, and the benefit of largely and systematically applied antibiotic prophylaxis may be discussed, not only in terms of financial cost but also in terms of microbiological threat of emergence of antibiotic resistant bacteria. So, the general idea of those new recommendations was to maintain the principle and the modalities of antibiotic prophylaxis, but to limit its indications to situations at high benefit to risk ratio, i.e. procedures at high risk in patients at high risk. Depending on the situation, antibiotic prophylaxis may be either recommended or become optional and decision-making factors are defined. Furthermore, the importance of general prophylaxis was emphasised, concerning more specifically oral and cutaneous hygiene, and patients and practitioners' education, such as, for example, recommendations on blood cultures to be performed before any antibiotic treatment in case on fever occurring in a patient at risk during the 3 months following a procedure at risk.     

Stenotrophomonas maltophilia endocarditis: a systematic review

The disease characteristics, management, and outcome of Stenotrophomonas maltophilia endocarditis were evaluated by examining the reports on the subject identified through a comprehensive literature search. Twenty-three (17 male) cases of S.. maltophilia endocarditis were identified. Mean age was 41 +/- 15 years. All patients presented with fever. Prosthetic valves were involved in 12 (52%) cases. Among native valves, the aortic valve was most frequently involved (50%), followed by the tricuspid valve (36%). Twenty (87%) patients had underlying risk factors for the development of endocarditis, including prior valvular or congenital heart disease surgery (60%), intravenous drug abuse (32%), and infected intravascular lines (18%). The endocarditis was postoperative in 14 patients. Seventeen (74%) patients experienced complications including septic embolism (23%), cardiac abscesses (23%), and congestive heart failure (18%). A combination of two or more antibiotics was used in all cases except one. The frequently used antibiotics were aminoglycosides (59%), trimethoprim-sulfamethoxazole (48%), and penicillins (48%). One half of the patients required cardiac surgery, but the proportion of surgically treated cases was higher among prosthetic valve endocarditis (62%). Mortality was 39% and was equally distributed between patients with prosthetic and native valve endocarditis. The S. maltophilia endocarditis carries high complication and mortality rates. The antibiotic regimen should consist of a combination of multiple antibiotics guided by the sensitivity panel. Early surgery may be considered in patients not responding to antibiotic treatment and in those with prosthetic valve endocarditis.     

Infective endocarditis in intravenous drug users

Since its first documented case in 1646, the epidemiology of endocarditis has significantly evolved. In the modern era, endocarditis has been increasingly associated with invasive procedures, medical devices, and intravenous drug use (IVDU). Patients at greatest risk include those with immunosuppression due to diabetes mellitus, human immunodeficiency virus (HIV), transplant medications, and increased survival of those with congenital heart or prosthetic heart valves. Prevalence of this disease has also significantly evolved due to technology in detection and prophylaxis. We aim to provide a comprehensive review of injection IVDU epidemiology, mechanism, medical and surgical treatment, ethical dilemmas involved in the treatment of this high-risk population, and future directions in the management of this lethal disease.     

Clinical course and complications of infective endocarditis in patients growing up with congenital heart disease

BACKGROUND: Although a high number of patients with congenital heart disease (CHD) undergo surgical palliation or definite correction up to adolescence, adult congenital heart disease (ACHD) may remain a potential lifelong risk factor for infective endocarditis (IE) in patients growing up with congenital heart disease (GUCH). METHODS: In a retrospective case study of a tertiary care center long-term clinical course and complications of patients with IE and GUCH were analysed. RESULTS: Data of 52 patients with CHD, who fulfilled the Saiman criteria for infective endocarditis and were treated between April 1986 and March 2001, were identified: Risk factors for infective endocarditis were previous cardiovascular operation (51.9%), use of foreign material (38.5%), dental or other surgical procedures without recommended antibiotic prophylaxis (25.0%), or cardiac catheterization (5.8%). Staphylococcal (38.9%) or streptococcal species (35.2%) were cultivated in most cases as causative microorganisms. Complications were: recurrence of IE (7.7%), septic embolisms (30.8%) leading to central nervous complications (7.7%), embolism of pulmonary arteries (7.7%), renal arteries (1.9%), arteries of the extremities (9.6%), or infarction of spleen (1.9%). Other cardiac (23.1%) or extracardiac (13.5%) complications were frequent. The need of re-operations during or after IE was high (67.3%). The hospital mortality was 1.9%, late mortality was 7.7%. CONCLUSIONS: Patients with IE and CHD show a broad clinical spectrum of cardiac and extracardiac complications. They may lead to a complicative short- and long-term course with the potential risk of death and a high number of re-operation. Efforts have to be made to improve long-term outcome of patients with ACHD by an interdisciplinary cooperation.     

Infectious endocarditis. A study of 50 patients in a non-university hospital

The authors report the results of a single centre study of 50 consecutive patients (average age 66 +/- 14 years; 36 men), admitted between 1992 and 2001 to a peripheral hospital for infectious endocarditis (IE). The median interval to diagnosis was 57 days. There was an underlying cardiac disease in 52% of cases, usually valvular (42%). The site of the IE was the mitral valve in 21 cases, the aortic valve in 19 cases, mitro-aortic valves in 5 cases, native tricuspid valves in 2 cases and pacing catheters in 4 cases (associated with valvular endocarditis in one patient). The causal organism was usually a streptococcus (60%, including 28% of streptococcus bovis), or a staphylococcus (22%): no organism could be found in 7 patients. The average follow-up was 33 +/- 30 months: surgery was indicated in half the patients and 3 patients were turned down because of their poor general condition. In all, 34% of patients died (24% of their IE) in a median interval of 6 months, mainly from infectious or haemodynamic complications. Poor prognostic factors were: age > 70 years, "blind" antibiotic therapy, large-sized vegetations, embolism and renal failure. These data, comparable to the results observed in large series in the literature, underline the importance of multi-disciplinary management of IE and strict prophylaxis.     

Perioperative preventive antibiotic treatment with fosfomycin in heart surgery: serum kinetics in extracorporeal circulation and determination of concentration in heart valve tissue

A prospective clinical study was carried out to assess the adequacy of perioperative antibiotic prophylaxis using fosfomycin in patients undergoing open-heart surgery for valve diseases for the prevention of early postoperative endocarditis, as well as for serious mediastinal infections that are caused mostly by multiresistant staphylococci and Gram-negative bacteria. Perioperative pharmacokinetics and tissue penetration were determined within the harvested heart valves and subcutaneous tissue. Reliable bactericidal serum levels were established at the first measurement 10 min after the end of intravenous infusion (203.7 +/- 44.7 micrograms/ml) and were maintained during surgery for at least 120 min (124.6 +/- 58.4 micrograms/ml), even in cases of prolonged extracorporeal circulation. Cardiopulmonary bypass did not alter the serum elimination of fosfomycin in comparison with patients not undergoing extracorporeal circulation. Peak tissue concentrations were achieved in both aortic and mitral valves after 30 min, ranging between 27.1 and 76.9 micrograms/g for aortic valves and 39.6-69.4 micrograms/g for mitral valves, depending on the degree of valvular degeneration. MIC values of 16 micrograms/g were maintained in both valves for at least up to 60 min. There was no evidence of renal impairment, adverse reactions or infections during the postoperative course or thereafter for a period of 3 months. It is concluded that perioperative intravenous antibiotic prophylaxis using fosfomycin (5 g t.i.d. in adults), beginning with induction of anesthesia and continued for 48 h postoperatively, provides rapid, reliable bactericidal serum levels and valvular tissue concentrations that will inhibit most Gram-positive and Gram-negative organisms that cause bacterial endocarditis and other serious infections following cardiac surgery.