The changing pattern of infective endocarditis in childhood

Lacrimal-duct-probing-induced bacteremia: should children with congenital heart defects receive antibiotic prophylaxis?

PURPOSE

To determine the incidence of bacteremia following lacrimal-duct probing in children, and to evaluate the potential need for antibiotic prophylaxis in children who are at an increased risk of infectious endocarditis (IE).

METHODS

In a prospective study beginning in October 1994, 40 consecutive children requiring lacrimal-duct probing performed by a single pediatric ophthalmologist received preoperative lacrimal and blood cultures followed by postoperative probe-induced transient bacteremia that was defined as a negative preoperative blood culture, followed by a positive postoperative blood culture of the same bacteria identified in the positive lacrimal culture.

RESULTS

The overall infection rate as described above was 7 of 40 children (17.5%) with a 95% confidence interval of 7.3% to 32.8%. Of these, four children had positive postoperative cultures for Haemophilus influenzae (10.0%) and 3 were positive for Streptococcus pneumoniae (7.5%) One child had a negative preoperative blood and lacrimal culture with a postoperative blood culture positive for Streptococcus viridans.

CONCLUSIONS

This study shows a significant incidence of lacrimal-probe-induced bacteremia with organisms that have been documented as etiological agents for IE in children. IE, although less common in children, remains a serious, potentially life threatening infection with high mortality. Although lacrimal-duct probing has never been clearly associated with documented endocarditis, it is the authors' recommendation that it be prudent for patients who are at known high risk for endocarditis to receive SBE prophylaxis considering the low cost/benefit ratio.

Prevention of bacterial endocarditis: recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the infectious Diseases Society of America, the American Academy of Pediatrics and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using root words endocarditis, bacteremia and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the U.S. Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate- and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered.

Prevention of bacterial endocarditis. Recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Infective endocarditis in congenital heart disease

The average life expectancy of patients with congenital heart disease has dramatically improved over the past four decades because of advances in medical and surgical therapy, with patients with complex lesions surviving to adolescence and adulthood. Tetralogy of Fallot, transposition of the great arteries, ventricular septal defects, patent ductus, and bicuspid aortic valves in particular are susceptible to infective endocarditis. Most operated patients are left with some form of residua or sequelae, many of which predispose to infective endocarditis. Surgical palliation, such as systemic-to-pulmonary shunts, and reparative surgery, often requiring prosthetic valve or conduit replacement, are major predisposing conditions. Accordingly, recognition, prevention, and treatment strategies for infective endocarditis assume increasing importance in adolescents and adults with congenital heart disease, operated or not.

Infective endocarditis in infants and children

Due to changing characteristics of infective endocarditis in the past two decades, we, retrospectively analysed 28 cases of infective endocarditis in children of age less than 15 years at Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar from December, 1983 to November, 1993. The incidence of disease was observed as 1.5 cases/1000 children admitted with a M:F ratio of 2:1. Three patients were of age less than 2 years (group I) as 25 were above 2 years of age (group II). The two groups had significant difference in portal of entry of infection, infective microorganisms, echocardiography and prognosis. Congenital heart disease was the commonest underlying cardiac lesion in 24 (85.71%) patients. Portal of entry of infection was apparent in 35.71% only; dental route being more frequent in group II. Streptococcus viridans (in 9 cases) followed by staphylococcus aureus (in 4 cases) were the two common organisms isolated. Patients were treated, for a period of 4-6 weeks with a over all mortality rate of 25%. Factors associated with poor prognosis were age < 2 years, staphylococcal infection ad negative blood cultures. Heart failure resistant to medical therapy was a leading cause of death.

Cardiac complications in children with Staphylococcus aureus bacteremia

Clinically silent endocarditis was detected in 4 (11%) of 36 hospitalized children with staphylococcal bacteremia who underwent echocardiographic examination. Pericarditis was detected in two further children. Only one child had underlying cardiac disease (patent ductus arteriosus). Echocardiography should be considered in children with staphylococcemia even if an obvious extracardiac focus is apparent.

Use of autologous umbilical artery and vein for vascular reconstruction in the newborn

Autologous umbilical artery and vein were evaluated as vascular conduits in newborn lambs. Eight newborn lambs were delivered transabdominally under sterile conditions at term. The umbilical artery and vein were dissected from the cord and stored in culture media. On the same day, each lamb underwent bilateral superficial femoral artery transection and reconstruction. Nine arteries were reconstructed with autologous umbilical vein interposition grafts, five with umbilical artery interposition grafts, and two by primary native artery anastomosis. After the birth weight of the lambs quadrupled (37 to 45 days), they were killed and all grafts and anastomoses were examined grossly and histologically. At the conclusion of the study, both native artery anastomoses (2/2) were patent. Five umbilical vein (5/9) and two umbilical artery (2/5) autografts were also widely patent. Patent autografts retained an intact endothelium supported by a viable media. The nonpatent autografts had become atrophic remnants displaying histologic signs of early closure. Graft failures are attributed to the extreme vasoactive nature of the umbilical vessels. These preliminary results suggest that umbilical vessels may be useful as a vascular autograft if the vasoactive nature of these vessels can be overcome during the immediate perioperative period.

Indications for echocardiography in the diagnosis of infective endocarditis in children

The role of transthoracic echocardiography as a diagnostic tool in children suspected of having infective endocarditis (IE) has not been defined. We hypothesized that echocardiography is only useful in children in whom there is high clinical suspicion of IE based on physical examination findings or persistently positive blood cultures. Echocardiographic reports and medical records of all inpatients (n = 133) from 1990 to 1992 who underwent echocardiography for suspected IE were reviewed. Fifty-nine of the 133 patients (44%) identified had either persistently positive blood cultures (n = 48), physical examination findings of IE (n = 20), or both (n = 9). The echocardiogram was positive in 7 of these patients (12%) and negative in all 74 patients without positive physical findings or positive blood cultures (p = 0.003). A new or changing precordial murmur, embolic phenomena, congestive heart failure, mechanical ventilation, and positive blood cultures were predictive of positive echocardiograms for IE by univariate analysis. The presence of fever, immune deficiency, and central lines, alone or in combination, was not predictive of a positive echocardiogram. In the absence of physical findings or persistently positive blood cultures, echocardiography is a low-yield study and is unlikely to aid in the diagnosis of IE in children.

Adults with congenital heart disease: patient knowledge of endocarditis prophylaxis

OBJECTIVE

To determine whether adults with congenital heart disease have adequate knowledge of infective endocarditis and endocarditis prophylaxis and to ascertain whether an educational program effectively improves patient knowledge and compliance.

MATERIAL AND METHODS

We asked 102 consecutive patients to complete a 12-question survey to assess their knowledge of heart disease, infective endocarditis, and endocarditis prophylaxis.

RESULTS

Of 102 patients, 100 (98%) completed the questionnaire. Sixty-eight patients knew the name of their heart disease. Fifty patients correctly defined endocarditis, but only 43 knew hygiene measures that could prevent endocarditis. Ninety-six patients knew that they needed to take "a medicine" before dental procedures, and 76 of those patients (79%) knew that an antibiotic was necessary. Patient use of cardiac medications and a history of endocarditis correlated significantly with knowledge of endocarditis. Patients who had been to the Adult Congenital Heart Disease Clinic at least once knew endocarditis prevention measures and the importance of regular dental and cardiology follow-up significantly more frequently than did first-time attendees. Despite educational counseling, however, patient recall of endocarditis and its prevention is disappointing.

CONCLUSION

Many adults with congenital heart disease have inadequate knowledge of their cardiac lesion, endocarditis, and endocarditis prophylaxis. Educational efforts for adults with congenital heart disease need to be updated and reinforced regularly.

Cost-effectiveness of infective endocarditis prophylaxis for mitral valve prolapse with or without a mitral regurgitant murmur

To assess the cost-effectiveness of prevention of infective endocarditis (IE) and to calculate cost-effectiveness of currently recommended regimens in patients with mitral valve prolapse (MVP), data on risk of death, complications, and health-care use, and cumulative incremental health-care costs due to the occurrence of IE were combined with data on the prevalence and manifestations of MVP, estimated years of life lost, and efficacy of antibiotic prophylaxis. Effectiveness and costs of standard endocarditis prophylaxis regimens were calculated per IE case prevented and years of life saved. Under the most likely scenario, oral amoxicillin prophylaxis for all MVP patients would prevent 32 cases of IE per million dental procedures at approximate costs of $119,000 per prevented case and $21,000 per year of life saved. Limiting prophylaxis to patients with mitral murmurs would prevent 80 cases of IE per million procedures at costs of about $19,000 per prevented case and $3,000 per year of life saved. Erythromycin prophylaxis was slightly less expensive than amoxicillin per benefit because of lower cost and lack of drug anaphylaxis, whereas intravenous ampicillin was 7 to 30 times more costly. Sensitivity analyses suggested that erythromycin prophylaxis might be cost-saving under some scenarios, whereas intravenous ampicillin use might cause net loss of life. Thus, prevention with oral antibiotics of the cumulative morbidity and incremental health care costs due to IE in MVP patients is reasonably cost-effective for MVP patients with mitral murmurs.

Spectrum of infective endocarditis during infancy and childhood: 20-year review

The medical records of the 29 patients under 18 years of age with infective endocarditis (IE) seen over a 20-year period by our department were reviewed to provide an overview of the spectrum of IE during infancy and childhood. None of the 29 patients had had previous cardiovascular surgery. The mean age at onset of IE was 7 years 2 months; 3 patients (10%) were under 2 years of age at onset. One patient during the early years died following 4 months of treatment with various antibiotics. Three patients underwent urgent surgery, and 17 patients with healed IE had elective surgery. All of the 20 patients who were operated on survived. The remaining 8 were followed with medical treatment alone. Positive blood cultures were obtained from 24 (83%) patients, and streptococci were still commonly found (38%). Ventricular septal defect (VSD) accounted for 66% of underlying heart diseases and rheumatic heart diseases for 14%. Vegetations were detected in 12 (67%) of 18 patients observed by echocardiography. Among these 12 patients, 1 with VSD underwent urgent tricuspid valve replacement and VSD closure because of worsening congestive heart failure due to progressive tricuspid regurgitation. Echocardiography identifies patients at high risk with IE, though the presence of a vegetation on echocardiography does not necessarily of itself dictate surgical intervention.

Development of valve dysfunction in adolescents and young adults with Down syndrome and no known congenital heart disease

We performed examinations and echocardiographic studies in 35 patients with Down syndrome (aged 20 +/- 4.2 years) with no known intracardiac disease. Sixteen patients (46%) had mitral valve prolapse; two of these also had tricuspid valve prolapse. Two had aortic regurgitation. Valve regurgitation was present in 4 (17%) of 23 patients more than 18 years of age but in none of the 12 patients 18 years of age or younger. We recommend screening of adolescent and young adult patients with Down syndrome for the development of valve dysfunction, especially before dental or surgical procedures.

Active infective endocarditis observed in an Indian hospital 1981-1991

Clinical data from 186 patients (133 males and 53 females) with 190 episodes of infective endocarditis (IE) occurring between January 1981 and July 1991 were studied retrospectively at a large referral hospital in Northern India with the intention of highlighting certain essential differences from those reported in the West. The mean age was much lower (25 +/- SD 12 years, range 2 to 75 years). Rheumatic heart disease was the most frequent underlying heart lesion accounting for 79 patients (42%). This was followed by congenital heart disease in 62 (33%) and normal valve endocarditis in 17 (9%). Twenty-four patients had either aortic regurgitation (n = 15) or mitral regurgitation (n = 9) of uncertain etiology. Prosthetic valve infection and mitral valve prolapse were present in only 2 patients each. A definite predisposing factor could be identified in only 28 patients (15%). Postabortal sepsis and sepsis related to childbirth accounted for 6 and 5 cases, respectively. Only 1 patient had history of intravenous drug abuse. Two-dimensional echocardiography showed vegetations in 121 patients (64%). Blood cultures were positive in only 87 (47%), with a total of 90 microbial isolates. Commonest infecting organisms were staphylococci (37 cases) and streptococci (34 cases). Except for a significantly higher number of patients with neurologic complications in the culture-negative group, there were no differences between patients with culture-positive and culture-negative IE. Of the 190 episodes of IE, the patients had received antibiotics before admission in 110 (58%) instances. A significantly greater number of culture-negative patients had received antibiotics than did culture-positive patients (87 vs 23, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Transcatheter occlusion of the persistently patent ductus arteriosus. Forty-month follow-up and prevalence of residual shunting

BACKGROUND

Percutaneous closure of the persistently patent ductus arteriosus with the Rashkind prosthesis is an established effective therapeutic modality, although some patients are left with residual shunting. To evaluate this, a retrospective study of the prevalence of persistent shunting over a 40-month period in the first 190 patients was undertaken.

METHODS AND RESULTS

All patients (male 45, female 145; mean age, 3.9 +/- 3.6 years; range, 5 months to 20 years) had serial clinical and color-flow echocardiographic follow-up at 6-12-month intervals (range, 6-40 months). Four patients required surgical removal of an embolized device, leaving a cohort of 186 patients in whom 196 procedures were performed, resulting in successful placement of 195 devices (43 17-mm [22%] and 152 12-mm [78%]). Complications occurred in seven of 195 procedures (3.6%). Nine of 10 attempted reocclusions (all with 12-mm devices) were successful. The prevalence of residual shunting was 38% at 1 year, 18% at 2 years, and 8% at 40 months. Patients with ductus measuring less than 4 mm had a higher success of initial occlusion. Thirty-four patients were left with residual shunting determined by color-flow Doppler study, but no anatomic or echocardiographic features were found predictive for residual shunting. All remain asymptomatic with 26 (76%) having no detectable murmur, two (6%) a continuous murmur, and six (18%) a systolic murmur.

CONCLUSIONS

Catheter occlusion will obviate the need for surgery in the majority of patients presenting with persistently patent ductus arteriosus. Reocclusion has been found feasible in those with continuous murmurs (nine of nine) and should be offered early because it is unlikely for spontaneous closure to occur in this group. It appears prudent to follow those with small residual shunting because further spontaneous closure can occur.