Endocarditis prophylaxis for patients with mitral valve prolapse: A quantitative analysis

Antimicrobial prophylaxis of bacterial endocarditis is widely recommended for patients with mitral valve prolapse who undergo procedures that may cause bacteremia. The benefits and risks of this practice have been analyzed on the basis of published data and responses to a questionnaire survey of leading authorities on bacterial endocarditis. Among 10 million patients with mitral valve prolapse undergoing a dental procedure, an estimated 47 nonfatal cases and two fatal cases of bacterial endocarditis would occur if no prophylaxis were given, five cases of bacterial endocarditis and 175 deaths due to drug reactions would occur if all patients were given prophylaxis with a penicillin, and 12 nonfatal cases and one fatal case of bacterial endocarditis would be expected if a policy of prophylaxis with erythromycin were adopted. Even using assumptions most favorable to the penicillin regimen, this analysis predicts that no prophylaxis and penicillin prophylaxis would result in a similar number of deaths. No prophylaxis or prophylaxis with erythromycin appears preferable to prophylaxis with a penicillin.     

Vancomycin therapy of bacterial endocarditis.

Fifteen patients with bacterial endocarditis were treated with vancomycin between 1967 and 1976. The indications for vancomycin therapy were penicillin-cephalosporin allergy in six patients, antibiotic resistant bacteria in six, initial therapy in one and culture-negative endocarditis in two. The causative microorganisms were Staph. epidermidis (four patients), Staph. aureus (two patients), diphtheroids (four patients), viridans streptococci (two patients) and enterococci (one patient). Minimum inhibitory concentrations of vancomycin for these organisms ranged from 0.8 to 3.1 micrograms/ml. The patients received vancomycin for two to 10 weeks (mean five weeks). Cure was achieved in 13 patients, including six with prosthetic valve endocarditis (PVE). Two patients had a relapse of PVE and cultures of blood or heart valve were positive within two months of vancomycin therapy. Vancomycin serum levels did not exceed 50 micrograms/ml, and no serious drug toxicity was encountered in any patient. Three patients had minimal audiogram changes beyond the social hearing range. One patient had mild phlebitis and a rash, and one patient had a transient leukopenia. Vancomycin is an effective nontoxic antibiotic in patients with endocarditis when penicillin or cephalosporin therapy is not appropriate.     

Prosthetic valve endocarditis due to Cardiobacterium hominis occurring after upper gastrointestinal endoscopy

Bacterial endocarditis secondary to endoscopic procedures has been convincingly documented in only four cases. We describe a case of prosthetic valve endocarditis due to Cardiobacterium hominis that developed after upper gastrointestinal endoscopy. Because of this, we recommend subacute bacterial endocarditis prophylaxis in patients who have a prior history of endocarditis or valve replacement.     

Staphylococcus capitis endocarditis due to a transvenous endocardial pacemaker infection: case report and review of Staphylococcus capitis endocarditis.

OBJECTIVES: Newer microbiologic methods to determine the species of coagulase-negative staphylococci (CoNS) have evolved which have shown that most endocarditis due to CoNS is caused by Staphylococcus epidermidis, and far fewer by Staphylococcus warneri and Staphylococcus lugdunensis. METHODS: The recent opportunity to successfully treat a patient with methicillin-resistant Staphylococcus capitis endocarditis secondary to an infected transvenous pacemaker led to a review of the literature relating to S. capitis endocarditis. RESULTS: Thirteen previously recorded patients were identified. Twelve (86%) patients were male. Ten had endocarditis associated with a native valve, two with prosthetic valves and one with a transvenous pacemaker. Mortality was low in all 14 cases (including this case report) with only two deaths; one in a patient with a native valve and the other with a prosthetic valve. Four of the isolates were methicillin resistant but sensitive to vancomycin, which was used in the treatment of eight patients. Those patients with prosthetic cardiac devices appear to do better when the devices are surgically removed. CONCLUSIONS: CoNS as a cause of endocarditis appears to be increasing and the current ability to determine the species of these organisms should elicit the epidemiology, clinical characteristics and biomolecular mechanisms involved in the induction of valvular disease.     

Short and long-term prognosis of prosthetic valve endocarditis in non-drug addicts

INTRODUCTION AND OBJECTIVES: Prosthetic valve infective endocarditis is a complication of valvular replacement surgery with a high morbimortality during the in-hospital phase and an important risk of complications during follow-up. The objective of the present study is to assess the clinical features and the short and long-term prognosis of this disease. PATIENTS AND METHODS: A prospective study of 43 consecutive cases of prosthetic valve endocarditis in non-addict patients from January 1987 to March 1997. RESULTS: The mean age was 51 +/-16 years. Eight patients (19%) had early prosthetic valve endocarditis (two months following heart surgery), fourteen patients (32%) had intermediate (between 2 and 12 months post surgery) and twenty-one (49%) had late prosthetic valve endocarditis (more than one year after heart surgery). Transesophageal echocardiography was performed in 32 patients with a sensibility of 81%. Complications occurred in 86% of patients and 53% of patients underwent surgery during the active phase (25% was emergency surgery). Inpatient mortality was 23% (50% in early prosthetic valve endocarditis). After a mean follow-up of 56 months there were 5 cases of recurrence, four patients required late surgery and 5 patients died. Survival (excluding early mortality) was 82% at 5 years with no significant differences among patients who received only medical treatment and those who underwent surgery in the active phase. CONCLUSIONS: Early mortality of prosthetic valve endocarditis is, according to our experience of 20%. The prognosis of survivors to the active phase is favourable in the majority. Early prosthetic valve endocarditis still causes a high mortality rate despite the use of combined medical surgical treatment in most cases.     

Infective endocarditis: an epidemiological review of 128 episodes.

OBJECTIVES: The objective was to determine the current epidemiology of infective endocarditis. PATIENTS AND METHODS: All microbiologically positive episodes of infective endocarditis treated at The University Hospital of Wales over a 9-year period from March 1987 to March 1996 was reviewed. Patients originated from the catchment area of The University Hospital of Wales or were referred from other hospitals in Wales. Data extraction was from records held in the Microbiology Department and, whenever possible, from patients' casenotes. The epidemiological parameters were: (1) age and sex of patients; (2) distribution of affected sites; (3) frequency of predisposing risk factors (cardiac and extracardiac); (4) incidence of early prosthetic valve endocarditis; and (5) mortality rates. RESULTS: There were 128 microbiologically positive episodes of endocarditis in 125 patients. The mean age of the population was 53.1 years and the aortic valve was the most frequently involved site of infection (51.6%). A presumed source of infection was identified in 20% if episodes. The commonest predisposing cardiac risk factor in native valve episodes was bicuspid aortic valve (16.7%) but there was no identifiable cardiac risk factor in a much larger proportion (37.7%) of native valve episodes. There was a low incidence (0.6%) of culture positive early prosthetic valve episodes and low mortality rates for both native and prosthetic valve endocarditis (12.3% and 24.5%) in this study. Viridans streptococci were the predominant organisms. In prosthetic valve episodes with onset after the 60th postoperative day but within one postoperative year the identity of the isolate suggested, in most cases, perioperative valve contamination. CONCLUSIONS: The epidemiology of infective endocarditis has undergone significant change. Inability to detect clinically common predisposing lesions, and the frequent absence of any identifiable predisposing cardiac risk factor mean that initial diagnosis is often difficult and demands a high index of suspicion. There was a low incidence of culture positive early prosthetic valve episodes and there were low mortality rates for both native and prosthetic valve endocarditis; these figures suggest improvements in cardiac care. The microbiological evidence indicates that the duration of the postoperative time period used for classifying prosthetic valve endocarditis into 'early' and 'late' episodes should be extended from 60 days to 1 year.     

Actinobacillus actinomycetemcomitans prosthetic valve endocarditis

Actinobacillus actinomycetemcomitans, a fastidious gram-negative bacillus, has been reported as the cause of prosthetic valve endocarditis in 11 patients. Two additional patients are reported and the literature is reviewed. All cases occurred greater than 1 year after implantation of the prosthesis. Six of the 13 patients had had recent dental work or had poor dentition. Three patients had received endocarditis prophylaxis. Ten of 13 were cured with antibiotics alone. Only one patient suffered from congestive heart failure, and only one had documented evidence of major systemic emboli during antimicrobial therapy. Valve replacement was necessary in only two during antimicrobial therapy. A actinomycetemcomitans should be considered as a possible etiologic agent in late prosthetic valve endocarditis, particularly when blood cultures are initially negative. A regimen of a beta-lactam antibiotic in combination with an aminoglycoside is recommended for 4-6 weeks. The excellent in vitro activity of the third-generation cephalosporins and rifampin promise new therapeutic options.     

Factors affecting survival in prosthetic valve endocarditis. Review of the effectiveness of prophylaxis

We review factors affecting survival of 44 episodes of prosthetic valve endocarditis occurring in 39 patients from 1965 to 1982. The mortality was 31.8 percent (14/44), and 21.6 percent (8/37) if the fungal cases are excluded. The development of a new murmur of valvular regurgitation in 18 patients led to valve replacement or death in every patient. Streptococcal endocarditis in 11 patients resulted in no deaths and only two valve replacements; staphylococcal infections had a mortality of 27.1 percent (6/22). Length of medical therapy before valve replacement did not relate to a successful outcome. Eight cases of early staphylococcal endocarditis occurred in which the organism was susceptible to the prophylactic antibiotic therapy. Changes in prophylaxis have led to no cases of early endocarditis over the past three years in 261 valve replacements.     

Erysipelothrix rhusiopathiae endocarditis: microbiologic, epidemiologic, and clinical features of an occupational disease

Ninety percent of the 49 reported cases of serious Erysipelothrix rhusiopathiae infection have been episodes of presumed or proved endocarditis. E. rhusiopathiae endocarditis correlates highly with occupation (farming, animal exposure), affects more males than females, exhibits a peculiar aortic valve tropism, displays a characteristic erysipeloid cutaneous lesion (in 40% of cases), and is associated with significant mortality (overall rate, 38%). Comparison with other unusual gram-positive rods causing endocarditis shows that E. rhusiopathiae resembles Listeria monocytogenes and Lactobacillus species in its propensity to involve structurally damaged but native left-sided valves. Unlike diphtheroid endocarditis, E. rhusiopathiae endocarditis has not involved prosthetic valves and is not associated with intravenous drug abuse, as is Bacillus species endocarditis. E. rhusiopathiae is exquisitely susceptible to penicillin but resistant to vancomycin. Since vancomycin is often employed in empiric therapy for presumed endocarditis, prompt microbiologic differentiation of E. rhusiopathiae from other gram-positive organisms is necessary to avoid delays in the initiation of appropriate antibiotic therapy.     

Micrococcus luteus: a rare pathogen of valve prosthesis endocarditis]

A rare case of prosthetic valve endocarditis caused by Micrococcus luteus is described and compared with the few cases reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. Micrococcus luteus is a constituent of the normal human buccal bacterial flora which forms yellowish colonies and appears as a gram-positive coccus typically arranged in tetrades. Although of low virulence, the germ may become pathogenic in patients with impaired resistance, colonizing the surface of heart valves. In contrast to staphylococci (for which it may easily be mistaken) it is usually penicillin-sensitive. However, the most promising antibiotic regimen proposed for treatment of Micrococcus luteus seems to be a combination of vancomycin, amikacin, and rifampicin. If the infection leads to severe hemodynamic alterations, however, valve replacement may become necessary similar to the situation in prosthetic valve endocarditis caused by more aggressive and highly resistant bacteria.     

Staphylococcus capitis endocarditis: two cases and review of the literature

Coagulase negative staphylococci are the principal cause of prosthetic valve endocarditis but are a rare cause of native valve infections. However, the incidence of native valve endocarditis is increasing. Staphylococcus capitis is a coagulase negative staphylococcus with the capacity to cause endocarditis on native heart valves. Two cases of native valve endocarditis caused by S capitis are presented; both in patients with aortic valve disease. The patients were cured with prolonged intravenous vancomycin and rifampicin and did not need surgery during the acute phase of the illness. Five of the six previously described cases of endocarditis caused by this organism occurred on native valves and responded to medical treatment alone.


Keywords: Staphylococcus capitis; endocarditis; valvar disease; coagulase negative staphylococci     

Infective endocarditis--analysis of 116 surgically and 26 medically treated patients

We have reviewed 116 cases of bacterial endocarditis treated surgically and 26 cases treated medically since 1973. There were 123 patients with native valve endocarditis and 19 patients with prosthetic valve endocarditis. Overall, the left-sided valves were infected most frequently. There were 10 cases with right-sided valves involved. Multiple valves were infected in 6 patients. There were 6 perioperative deaths in the surgical group. The most common cause of death was multi-organ failure associated with uncontrollable sepsis. The overall operative mortality for active endocarditis was 7.7% (4/55), and for healed endocarditis, 3.3% (2/61). For active native valve endocarditis, the mortality was 4.2% (2/48), for healed native valve endocarditis, 3.6% (2/55), for active prosthetic valve endocarditis, 28.6% (2/7), and for healed prosthetic valve endocarditis, 0%. There was no difference in the operative mortality between active native valve endocarditis and healed native valve endocarditis. The mortality of active prosthetic valve endocarditis was significantly higher than that of active native valve endocarditis (p less than 0.01). Of the 26 patients treated medically, 7 died during the initial hospitalization. The major factor related to mortality in the medically treated patients was persistent sepsis (four patients), and congestive heart failure (three patients). The overall mortality of the medical group for active valve endocarditis was 15% (3/20), and for active prosthetic valve endocarditis, 67% (4/6). We conclude that patients with infective endocarditis with significant valve lesions who are unresponsive to medical therapy should be considered for urgent surgery.     

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.     

Clinical outcome and echocardiographic findings of native and prosthetic valve endocarditis in the 1990s

Prosthetic valve endocarditis is considered to be associatedwith a more severe prognosis than native valve endocarditis.Among other factors, inappropriate visualization of vegetationsin prosthetic valve endocarditis by transthoracic echocardiographyis responsible for this observation. Since the introductionof transoesophageal echocardiography into clinical practicethe diagnostic sensitivity and specificity of the detectionof vegetations located on prosthetic valves have been enhanced.Therefore we aimed to determine and compare the prognosis ofprosthetic valve endocarditis and native valve endocarditisin the era of this improved diagnostic approach. One hundred and six episodes of infective endocarditis in 104patients were seen at our institution between 1989 and 1993.Eighty patients (77%) had native valve endocarditis and 24 (23%)had late prosthetic valve endocarditis. In the latter grouptwo patients had recurrent infective endocarditis. Patientswith prosthetic valve endocarditis were older (mean age 64 vs54 years in native valve endocarditis; P<0.00l) and the majoritywas female (62% vs 38% in native valve endocarditis; P<0.001In prosthetic valve endocarditis, infection of a valve in themitral position predominated (65% vs 30% in native valve endocarditis;P<0.0l), whereas in native valve endocarditis more than halfthe cases had isolated aortic valve endocarditis (51% vs 27%in prosthetic valve endocarditis; P<0.01). In prostheticvalve endocarditis more cases were caused by Staphylococcusaureus (31% vs 14% in native valve endocarditis; P<0.08),whereas in native valve endocarditis the most frequent organismswere streptococci (29% vs l9% in prosthetic valve endocarditis;P<0.12). Differences in the clinical features of native valveendocarditis and prosthetic valve endocarditis could not befound except for a higher rate of embolism in native valve endocarditis(40% vs l9% in prosthetic valve endocarditis; P<0.05). Vegetationscould be detected by transthoracic echocardiography more frequentlyin native valve endocarditis (71% vs 15% in prosthetic valveendocarditis; P<0.0001). Transoesophageal echocardiographyvisualized vegetations in 95% of the episodes of native valveendocarditis and in 80% of the episodes of prosthetic valveendocarditis (P<0.09). Thus, the diagnostic gain by transoesophagealechocardiography was greatest in prosthetic valve endocarditis.Patients with native valve endocarditis had significantly largervegetations than patients with prosthetic valve endocarditis(P<0.05 for length, P<0.00l for width). The median timeto diagnosis was similar in native valve endocarditis and prostheticvalve endocarditis (31 vs 28 days). Surgery was performed in 74% of patients with native valve endocarditisand in 58% of those with prosthetic valve endocarditis; themedian time delay between the diagnosis of infective endocarditisand surgery tended to be shorter in prosthetic valve endocarditisthan in native valve endocarditis (45 vs 60 days). The in-hospitalmortality and the mortality during a follow-up of 22±10 months did not significantly differ between native valveendocarditis and prosthetic valve endocarditis (21% vs 17% 28%vs 25%). In summary in the era of transoesophageal echocardiography,late prosthetic valve endocarditis does not seem to carry aworse prognosis than native valve endocarditis. This can beattributed in part to the improved diagnostic accuracy achievedby transoesophageal echocardiography leading to comparable diagnosticlatency periods in both patient groups. Finally, better characterizationof vegetations on prosthetic valves by transoesophageal echocardiographyallows early lifesaving surgery in patients with prostheticvalve endocarditis.     

Prosthetic valve endocarditis: current approach and therapeutic options

Despite improvements in medical and surgical therapy, prosthetic valve endocarditis is still associated with a severe prognosis, and remains a diagnostic and therapeutic challenge. Diagnosis of prosthetic valve endocarditis is more difficult than that of the native valve endocarditis and the application of Duke criteria is less useful in this setting. Therapeutic strategies are not guided by evidence-based recommendations and are mainly based on a careful prognostic evaluation, which allows the identification of high-risk subgroups. Continuous effort have to be made to detect early this severe complication of valve replacement and to prevent it using systematic prophylaxis.     

Staphylococcus capitis prosthetic valve endocarditis: report of two rare cases and review of literature

Staphylococcus epidermidis is the most common organism associated with prosthetic valve endocarditis. Staphylococcus capitis, a coagulase-negative Staphylococcus, is a rare cause of endocarditis. We report two cases of S.capitis prosthetic valve endocarditis, both involving prosthetic aortic valve and complicated by aortic root abscess. We also review the literature for this rare condition caused by this rare organism.     

Benefits of endocarditis prevention in patients with prosthetic heart valves

The beneficial effect of prophylaxis for IE was studied in 229 patients with prosthetic heart valves in whom 287 diagnostic or therapeutic interventions were performed. The prevention used was similar to that recommended by the American Heart Association. Prosthetic valve endocarditis was not observed in any of these patients. This result was compared with that of 304 patients with prosthetic heart valves, in whom without any prevention 390 similar interventions were performed during the same observation period. The incidence of prosthetic valve endocarditis occurring within 14 days after the intervention was 1.5/100 interventions (n = 6). All patients had to be reoperated. One patient died perioperatively. Two more patients developed prosthetic valve endocarditis 8 and 13 weeks, respectively, after the initial intervention. This retrospective study documents the benefit of the prophylaxis for IE used.     

感染性心内膜炎主动脉瓣置换手术方法探讨

目的探讨感染性心内膜炎主动脉瓣置换的手术方法。方法回顾分析我院手术治疗的3例感染性心内膜炎主动脉瓣病变患者的临床资料及间断全层缝合主动脉壁置换主动脉瓣的手术方法。术中均可见主动脉瓣赘生物,瓣叶裂,穿孔,主动脉瓣环水肿,主动脉内膜断裂,瓣周脓肿形成。切除病变主动脉瓣,清除坏死组织及赘生物,以碘伏涂抹主动脉根部并浸泡机械瓣膜及换瓣线,游离主动脉根部至瓣环水平,避免损伤冠状动脉,带垫片换瓣线自主动脉壁外进针,垫片置于主动脉壁外侧,16-20针间断缝合,机械瓣环上打结,置换机械瓣膜。结果3例患者术后恢复顺利,3个月至1年随诊,预后良好。结论间断全层缝合主动脉壁置换主动脉瓣方法可以预防复发感染性心内膜炎,减少瓣周漏的发生,安全、有效,远期效果良好。     

Current status of endocarditis prevention

There are currently no randomized and carefully controlled human trials to definitively prove that endocarditis prophylaxis is efficient. Furthermore, most cases of endocarditis are not attributable to a medical procedure. Thus, even with a high level of application of endocarditis prophylaxis only a minority of cases could be prevented. Endocarditis is a rare disease. On the other hand, its morbidity is increasing! In addition, infective endocarditis remains still a major medical concern because of its mortality between 5% and 76%. In addition, in up to 40% of all patients suffering from endocarditis one or more heart valves have to be replaced in the following 5 to 8 years. Without treatment endocarditis has a lethality of 100%. Therefore, there is worldwide agreement that endocarditis prophylaxis is necessary. Combining the recommendations of the German and the American Heart Association, as well as the results of the European consensus conferences, with newer insights into the pathophysiology of endocarditis the following aspects are elucidated: depending on their risk of endocarditis patients are allocated into 3 groups. In the first group there are patients with prosthetic cardiac valves, patients who suffered from previous endocarditis and patients with complex cyanotic congenital heart disease and surgically constructed shunts or conduits of the aorta and/or pulmonary circulation. In these high-risk patients the prophylactic regimen for dental, oral, respiratory tract procedures is oral amoxycillin. In genitourinary and gastrointestinal procedures ampicillin and gentamicin i.v. is recommended. In patients with mostly congenital cardiac malformations, acquired valvular dysfunction, hypertrophic obstructive cardiomyopathy and mitral valve prolapse or thickened leaflets and valvular regurgitation oral amoxycillin is recommended for all medical procedures (second group). The third group consists of patients with isolated secundum atrial defect, previous coronary bypass graft surgery, patients with cardiac pacemakers or defibrillators. In this patient cohort the individual risk of endocarditis is not higher than in the general population. Therefore, endocardits prophylaxis is not recommended.     

Infective endocarditis: incidence and mortality in the North East Thames Region.

A survey of infective endocarditis in the North East Thames Regional Health Authority was carried out over a period of 30 months from 1982 to 1984. The incidence, clinical characteristics, and in-hospital mortality were studied. Important causes of endocarditis were dental treatment, the presence of dental disease, drug abuse, and cytoscopy. The omission or incorrect administration of antibiotic prophylaxis in patients with valve disease was noted, but failure of correctly prescribed antibiotic prophylaxis was not recorded. Adverse prognostic features were increased age, prosthetic valve infection, Gram negative or staphylococcal infections, and aortic valve involvement. In contrast, mortality was lower in patients with mitral valve prolapse, ventricular septal defect, and streptococcus viridans infection. Deaths were usually attributable to irreversible complications present at the time of diagnosis. Vegetations were detected on the echocardiogram in half of those studied and mortality was higher in those with vegetations than without. Operation for native valve infection was associated with a low mortality and it is likely that the overall mortality for infective endocarditis has been improved by surgical intervention.