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Preference of North Carolina (USA) paediatric cardiologists
for the American Heart Association guidelines for prevention
of infectious endocarditis prior to invasive dental procedures
Michael W. Roberts*, Jessica Y. Lee and Elman G. Frantz
Department of Pediatric Dentistry, University of North Carolina School of Dentistry, Chapel Hill, USA.
*Corresponding author:
Michael W. Roberts
[email protected]
Editor approved:
Pablo Varela-Centelles
University of Santiago de
Compostela, Spain
Received: 20 October 2014
Revised: 03 December 2014
Accepted: 12 December 2014
Published: 18 December 2014
© 2014 Roberts et al; licensee
Vernon Innovative Publishers.
http://creativecommons.org/
licenses/by/4.0.
Abstract
Purpose: An updated Prevention of Infective Endocarditis guideline was published
by the American Heart Association (AHA) in 2007. Our study examined whether
paediatric cardiologists in North Carolina preferred the previous 1997 or the more
recent 2007 guideline recommendations prior to invasive dental procedures.
Methods: A cross-sectional study design was used to assess guideline preference
among sixty-eight identified paediatric cardiologist in North Carolina (USA). The
survey instrument contained questions relative to their preference for the AHA 1997
or 2007 guidelines, their age and sex, number of years in practice, practice profile and
location.
Results: Completed surveys were received from 32 paediatric cardiologists
(4 females/28 males) for a response rate of 47%. There was no difference found
between genders or in the number of years in practice in their prescribing preferences
relative to antibiotic prophylaxis before invasive dental procedures. All but one (97%)
preferred the 2007 guidelines but numerous exceptions were noted. Most of the
responding paediatric cardiologists (27/32) were associated with a university/hospital,
and practicing in an urban setting (19/32).
Conclusions: An overwhelming majority of paediatric cardiologists in North
Carolina who responded to our survey endorsed the 2007 AHA guidelines. However,
exceptions were identified by some study respondents.
Keywords: Infective endocarditis, cardiology, dental, antibiotic prophylaxis
Introduction
I
nfective endocarditis (IE), formerly known as bacterial endocarditis, is fortunately a relatively
uncommon life threatening disease. However, even though there have been advances in diagnosis,
surgical techniques, and management of complications, high morbidity and mortality rates related
to IE continues to exist in at-risk individuals.
IE is the result of a complex interaction between blood-borne pathogens with matrix molecules
and platelets at the site of endocardial cell damage. Turbulent blood flow produced by certain congenital or acquired heart disease predisposes the deposition of platelets and fibrin on the surface
of the heart valve. This initially causes a thrombotic endocarditis on the cardiac valve surface and
adherence of bacteria in the bloodstream to the thrombosis resulting in a vegetation and proliferation of the bacteria. Many of the clinical manifestations of IE are the result of the patient’s immune
response to the microorganisms with pathogenic potential.
Oral mucosal surfaces are covered by extensive and complex microflora including streptococcus
viridans. A break in the mucosal surface permits many organisms to enter the blood stream. Only
a few studies have been published that address the magnitude of bacteremia following a dental
How to cite this article:
Roberts, MW., Lee, JY. and Frantz, EG. (2014). Preference of North Carolina (USA) paediatric cardiologists for the American Heart
Association guidelines for prevention of infectious endocarditis prior to invasive dental procedures. Archives of Oral and Dental Research, 1:4.
Retrieved from http://www.vipoa.org/oraldent
Archives of Oral and Dental Research
procedure but it is relatively low [1-3]. There is no published the administration of antibiotics has the risk of increasing the
evidence that the longer the bacteremia exists the greater the possibility of resistant strains of organisms developing. Indeed,
an alarming number of resistant strains of streptococci viridians
chance of IE.
The first American Heart Association (AHA) guidelines were have emerged over time. In addition, the possibility of developing
published in 1955 regarding prevention of rheumatic fever and an allergy to the antibiotic by the patient does exist [14]. The
bacterial endocarditis through control of streptococcal infections recommendations regarding preventive antibiotic prophylaxis
[4]. There have been numerous revisions and recommendations have over the years become complex often resulting in confusion
published since [5-11]. In 1997, the AHA recommended among both health care providers and at-risk patients [15].
In 2007, the AHA published updated antibiotic prophylaxis
antibiotic prophylaxis for prevention of bacterial endocarditis
for both patients at high and moderate risk prior to certain guidelines for infective endocarditis that limited the prescription
of antibiotics prior to defined invasive dental procedures and to
dental procedure [12,13] Table 1.
Since the 1997 AHA guidelines were published, numerous only patients at high risk [16,17] Table 1. Although there were
studies have questioned the antibiotic recommendations differences, between the 1997 and the 2007 guidelines, both
regarding prophylaxis prior to invasive dental procedures. recommended antibiotic prophylaxis for at-risk patients prior
Authorities have noted that most incidences of IE were the to all dental procedures that involve manipulation of gingival or
result of bacteremia occurring from routine daily activities (i.e., the periapical region of teeth, or perforation of the oral mucosa.
tooth brushing) and not the result of an invasive medical/dental However, the AHA 2007 guidelines were considerably more
procedure. Previous recommendations regarding antibiotic limiting than the association’s earlier versions.
To make substantial changes in the recommendations
prophylaxis were based primarily on what appeared to be a
reasonable attempt to avoid a life-threating infection. However, regarding whether antibiotic prophylaxis was indicated prior
to dental procedures in IE at-risk patients posed certain risks
and potential consequences. These included reversing longTable 1. Cardiac conditions for which prophylaxis for dental
standing expectations and practice patterns, causing confusion
procedures is recommended.
among patients with cardiac risk factors, making fewer patients
1997 AHA Guidelines
eligible for prophylaxis, reducing malpractice claims related to
IE infections [16], and would hopefully stimulate prospective
High-risk category
studies to better inform future guidelines. On the basis of the
• Prosthetic cardiac valves, including bioprosthetic and
homograft valves
2007 guidelines, many fewer patients are recommended for IE
prophylaxis prior to invasive dental procedures.
• Previous bacterial endocarditis
Previous investigations have focused on physicians’ prefer• Complex cyanotic congenital heart disease (e.g., single
ventricle states, transposition of the great arteries,
ences to changes in clinical practice guidelines but none have
tetralogy of Fallot)
examined this in the context of the AHA guideline changes
• Surgically constructed systemic pulmonary shunts or conduits
regarding IE antibiotic prophylaxis. The risk for IE associated
Moderate-risk category
with a dental procedure in a patient with underlying cardiac
• Most other congenital cardiac malformations (other than above
condition is at best an estimate, but has been suggested to be
and below)
1:95,000-1.1 million depending upon the cardiac condition
• Acquired valvar dysfunction (e.g., rheumatic heart disease)
[17-19]. Anecdotal information has suggested that not all pae• Hypertrophic cardiomyopathy
diatric cardiologists agreed with the 2007 AHA changes in the
guidelines regarding IE prophylaxis. The purpose of this study
• Mitral valve prolapse with valvar regurgitation and/or
thickened leaflets
was to assess the IE prophylaxis preference prior to invasive
2007 AHA Guidelines
dental procedures among a group of paediatric cardiologists
in the United States (US).
• Prosthetic cardiac valve
• Previous infective endocarditis
• Congenital heart disease (CHD)
• Unrepaired cyanotic CHD, including palliative shunts and
conduits
• Completely repaired congenital heart defect with prosthetic
material or device, whether placed by surgery or by catheter
intervention, during the first six months after the procedure
• Repaired CHD with residual defects at the site or adjacent to
the site of a prosthetic patch or prosthetic device (which inhibit
endothelialization)
• Cardiac transplantation recipients who develop cardiac
valvulopathy
Roberts et al. 2014
Methods
This survey was targeted toward paediatric cardiologists in
North Carolina (USA) to determine their preferred practice in
prescribing antibiotic prophylaxis prior to dental procedures
for patients at risk for IE. No identifying patient information
was requested. The names of paediatric cardiologists practicing in North Carolina were obtained from the North Carolina
Medical Board, American Board of Pediatrics and by internet
search. Prior to data collection, the development of a survey
instrument was completed in two phases: 1) guideline review
and 2) expert panel review. The expert panel consisted of two
2
Archives of Oral and Dental Research
paediatric dentists, one of whom is an expert in survey design
and a paediatric cardiologist. The data collection followed a
three step process. The survey, along with a self-addressed envelope, was mailed to the 68 identified paediatric cardiologists
(13 females and 55 males) Table 2. The name of the paediatric
cardiologist who completed the survey was not linked to the
survey once it was returned. A second copy of the survey was
sent to those who did not respond to the first solicitation or
redirected if the first mailing was returned as undeliverable. If
no response was received from these two mailings, the nonresponding paediatric cardiologist was phoned by a member of
the study in attempt to gather the information requested on the
survey. The ages of the cardiologists and their years in practice
were obtained in order that maturity and experience could be
assessed as potential confounding factors in guideline preference. The primary outcome measure was practice preferences
among a group of paediatric cardiologists. The Wilcoxon Rank
Sum Test was used to evaluate the response data. This study was
approved by the University of North Carolina IRB #13-2949,
dated September 23, 2013.
Results
Completed surveys were returned by 32 paediatric cardiologists
(4 females/28 males) for a response rate of 47%. The response
rate for females was 31% and 51% for males. Practice setting
and description are presented in Table 3. Nineteen paediatric
cardiologists reported to have an urban practice, 9 suburban and
4 rural. Twenty-seven of the responders practiced in a university/
hospital setting. The remaining reported private/community
practices. Neither age nor years in practice were significantly
different for male and female respondents (Wilcoxon Rank Sum
test: p=0.21 for age and years of practice) Table 4.
When the paediatric cardiologists were asked whether they
preferred the 1997 or the 2007 AHA guideline, an overwhelming
97% (all but one) preferred the 2007 version Table 5. However,
a number of the respondents did report practice exceptions. A
list of these exceptions is displayed in Table 6.
Discussion
This is the first study to examine the preferences of paediatric cardiologists in the United States since the 2007 changes
in the AHA guidelines for infective endocarditis antibiotic
prophylaxis. Interestingly, the National Institute for Health and
Care Excellence (NICE) published guidelines in 2008 in the
United Kingdom (UK) that recommended complete cessation
of antibiotic prophylaxis for prevention of IE [20]. However,
the European Society of Cardiology continued to recommend
antibiotic prophylaxis prior to invasive dental procedures for
high-risk patients [21].
Nevertheless, similar investigations on the preference of the
Table 2. Survey instrument.
Please circle or write your answer to the following:
1. ____ Check here if you do not practice pediatric cardiology in North Carolina. Do not complete the survey but do return
it in the enclosed envelope.
2. For your at risk cardiac patients, which one of the above guidelines (1997 or 2007) do you prefer to follow for preventative
antibiotic prophylaxis prior to your patients having and invasive dental procedure?
1997
2007
No preference
3. If you prefer to follow the 1997 rather than the most recent 2007 antibiotic prophylaxis guidelines, why?
Easier to understand and follow
More comfortable with old guidelines
Did not appreciate that there was a difference between the two guidelines
Other: _____________________________________________________________
4. Are there exceptions to your usual antibiotic prophylaxis recommendations?
Yes
No
If yes, what are these exceptions: ________________________________________
5. What is your age? ______
6. What is your sex? Male ______ Female ______
7. What is your practicing setting? Urban ______
Rural ______
Suburban ______
8. How best to describe your practice? Private/community ______ University/hospital ______
9. How many years have you practiced as a pediatric cardiologist? ______
Roberts et al. 2014
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Table 3. Practice setting and description.
Practice setting
N
Rural
Suburban Urban
Females
4
1
0
3
Males
28
3
9
16
Practice description
N
Private/
Community
Females 4
0
Males
28
5
University/
Hospital
4
23
Table 4. Age and years in practice.
Age in years
N
P25
Median P75
p-value
Females
4
36.50
38.00
45.50
0.21
Males
28
40.00
45.50
52.00
--
Years practicing as a paediatric cardiologist
N
P25
Median P75
p-value
Females
4
3.00
5.50
12.50
0.21
Males
28
5.00
12.00
20.00
--
P25, P75=percentiles; Wilcoxon Rank Sum test
Table 5. AHA guideline preference.
N
1997 Guideline 2007 Guideline
Females 4
0
4
Males
28
1
27
Table 6. Exceptions given when not following the 2007
AHA guidelines.
All single ventricle patients, even those with no fenestration are
prescribed IE prophylaxis. (1)
If I have assumed the patient’s care and the previous cardiologist,
or dentist, recommended IE and the patient (parent) is reluctant to
change this regimen, then occasionally I will continue IE
prophylaxis even if they don’t meet the 2007 guidelines. (5)
All patients with pacemaker/implantable cardioverter defibrillator.
(1)
Patients that are status/post tetralogy of Fallot repair if residual
pulmonary stenosis/insufficiency exists and valve was manipulated.
(1)
All post-heart transplant patients. (1)
If the patient’s paediatrician or dentist express concern if no
antibiotics are prescribed. (1)
Acyanotic complex congenital heart disease (i.e. Fontan without
fenestration, baffle leaks). (1)
If parent prefers/demands antibiotic prophylaxis. (4)
Cyanotic heart defects even after repair and post repair surgery
turbulence. (1)
(X)=number of times cited by a responding paediatric cardiologist
Roberts et al. 2014
NICE IE guidelines versus other guidelines amongst dentists,
cardiologists and patient have since been address in the UK and
Ireland [22-25]. The validity of any of the various conflicting
recommendations has not been confirmed by a randomized
clinical trial [26]. While previously, a retrospective study initially
failed to show an increase over and above the rising trend of the
incidence of IE in England two years on from the publication of
the NICE guidelines, along with nearly a 79% reduction in the
number of prophylactic antibiotic dental prescriptions, [27] a
more recent, sophisticated analysis has reported an increased
incidence above the rising trend of IE among high and lower
risk patients in England, together with a 90% reduction in
prescribed antibiotic prophylaxis prescriptions over the last
five years [28]. Although this study has statistically confirmed
a temporal association between the onset of NICE’s 2008 IE
guidelines and the increase in the number of cases developing
this disease, caution has been advocated before jumping to any
conclusions on a cause and affect association [28]. Prospective randomized controlled studies have been therefore been
advocated to address the issue, recognizing that failing to do
so perpetuate the confusion among both patients and health
providers [29].
The 1997 AHA guidelines regarding recommended antibiotic
prophylaxis prior to invasive dental procedures were based on a
few case control studies, clinical observations, and expert opinion.
The rationale for the guidelines was to avoid a life threatening
infection, where prevention would be preferable to treatment.
The 2007 guidelines regarding antibiotic prophylaxis for identified cardiac issues prior to invasive dental procedures reflected
changes from the 1997 version due to a lack of evidence to support
some of the earlier recommendations [16,17]. However, there
have been challenges to these conclusions. Some cardiologists
believe that patients with cardiac issues (especially those with
mitral valve prolapse) should be allowed to choose whether to
take or not take antibiotics prior to an invasive dental procedure
after being informed of the current (2007) recommendations
until additional clinical evidence is available [30].
So far, earlier studies have not found an increased incidence
of endocarditis since the 2007 AHA guidelines were introduced
and would appear to support the more recent recommendations [31,32]. Other studies have reported that bacteraemia
after tooth brushing is significantly greater in patients with
poor oral hygiene and periodontal disease [33,34]. This would
suggest that improving oral hygiene may be a more effective
means of reducing the incidence of IE caused by oral bacteria
than prescribing antibiotic prophylaxis prior to invasive dental
procedures [35].
The results of our study should be considered in the light of
some limitations. Because the survey was self-completed and
submitted, responses may be susceptible to response bias. Another limitation of our study is the power of the study. Although
a few trends were evident, the sample size was small.
Despite these limitations, this study has several strengths
including it being the first to report on this important topic
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Archives of Oral and Dental Research
of clinical relevance in the US. Only a little is known about 5. Rammelkamp, CH Jr., Breese, BB. And Griffeath, HI., et al.
(1957). (Committee on Prevention of Rheumatic Fever and
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139A-43A.
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10.Shulman, ST., Amren, DP. And Bisno, AL., et al. (1984).
by some study respondents.
(Committee on Rheumatic Fever and Infective Endocarditis,
2. There was no difference between female and male paediatric
American Heart Association). Prevention of bacterial
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tibiotic prophylaxis prior to dental procedures.
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Dajani, A. S., Bisno, A. L., Chung, K. J., Durack, D. T., Freed,
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M., Gerber, M. A., Karchmer, A. W., Millard, H. D., Rahimtoola,
S., Shulman, S. T. and et al. (1990). Prevention of bacterial
Competing interests
endocarditis. Recommendations by the American Heart
The authors declare that they have no competing interests.
Association. JAMA, 264, 2919-22.
12.
Dajani, A. S., Taubert, K. A., Wilson, W., Bolger, A. F., Bayer, A.,
Authors’ contributions
Ferrieri, P., Gewitz, M. H., Shulman, S. T., Nouri, S., Newburger, J.
All authors made significant contributions to this paper.
W., Hutto, C., Pallasch, T. J., Gage, T. W., Levison, M. E., Peter, G.
and Zuccaro, G., Jr. (1997). Prevention of bacterial endocarditis.
Acknowledgement
Recommendations by the American Heart Association. JAMA,
The study was supported by unrestricted funds in the UNC-School
277, 1794-801.
of Dentistry, Department of Pediatric Dentistry. None of the authors
had any potential conflicts of interest associated with the study. The
13.Dajani, A. S., Taubert, K. A. and Wilson, E., et al. (1997).
authors wish to acknowledge the assistance of David Best and Ceib
Prevention of bacterial endocarditisw. Recommendations by the
Phillips, PhD, for their assistance with the statistical analysis, and
American Heart Association. JADA, 128, 11422-51.
Stevey Cline for her assistance in data collection and recording.
14.Ashrafian, H. and Bogle, R. G. (2007). Antimicrobial prophylaxis
for endocarditis: emotion or science? Heart, 93, 5-6.
15.Chate, R. A. (2008). An infective endocarditis audit illustrates
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