Prophylaxis against Infective Endocarditis:NICE Guidelines
PROPHYLAXIS AGAINST INFECTIVE ENDOCARDITIS:NICE GUIDELINES
22nd April 2008
Dear Editor,
It is our opinion that patients will be harmed if these guidelines
are taken up by dental, medical and surgical colleagues on recommendations
from NICE.1 The advice is contrary to the views of the majority of
practising cardiologists and cardiac surgeons in the UK who are
responsible for managing those unfortunate enough to develop infective
endocarditis (IE) as a result of a failure to offer preventative measures
to patients who are particularly susceptible. In our survey of 520
cardiologists and cardiac surgeons in the UK carried out 12 months ago,
94.2% felt that patients “at risk” of IE should receive antibiotic
prophylaxis (ABP) prior to dental procedures in an attempt to try and
prevent IE.2
In November 2007, we detailed our criticisms to NICE in response to
the publication of the unwieldy and voluminous draft document that was
virtually unreadable, unclear and disorganised. A summary of our opinion
was published on the British Cardiac Society website.3 In this draft
document, numerous summaries of data from the literature were presented
which associate IE with various dental, surgical and interventional
procedures but conclusions were then illogically drawn by the authors that
patients “at risk” did not need to receive ABP. The conclusions were not
supported by evidence from the literature but were simply the opinion of
those responsible for this misleading publication. The authors tried to
justify their conclusions by quoting estimates of risk for patients with
particular cardiac defects, and estimates of risks for certain procedures.
We regard this as a meaningless exercise and such guestimates cannot be
accepted as the science on which to base advice which is illogical.
Pathology has taught us that IE cannot occur without bacteraemia and a
susceptible endocardial lesion or intravascular foreign body in-situ. The
consequences of this are ignored by the authors because randomised
clinical trials do not exist to support the case for antibiotic
prophylaxis (ABP). We agree that the conditions that need to exist for an
endocardial vegetation to develop in a patient include a susceptible
cardiac lesion with endocardium that is in such a state to enable bacteria
to adhere to it, bacteraemia itself sufficient to allow seeding of the
endocardium and the ability of the bacteria to resist the body’s immune
defense mechanisms to eradicate the infection. This understanding explains
why not every patient “at risk” who undergoes a bacteraemia-producing
procedure goes on to develop IE and why those who do, present at various
intervals from the interventional procedure. To recommend not trying to
eradicate or minimise predictable bacteraemia associated with these
procedures in patients “at-risk”, especially when thousands of case
reports have been published in the literature linking them with IE is in
our view illogical and perverse. The authors have chosen to ignore such
reports and their significance. In the UK, 83.3% of cardiac specialists
believe that case reports of bacteraemia associated with invasive
procedures constitute “evidence” to support the need to try and prevent IE
associated with those procedures in cardiac patients at risk. Moreover,
74.6% felt that case reports of IE associated with invasive/interventional
procedures constituted “evidence” sufficient enough to warrant ABP for
those patients at risk who were undergoing those procedures.2 The value
and importance of case reports in helping us to understand disease
mechanisms, pathogenesis and treatment strategies should not be
underestimated and thankfully most editors of peer-review journals still
take this view. There is also evidence in the literature that bacteraemia
may persist for > 1 hour after procedures.4 Although we accept that ABP
will not be successful all the time there is also evidence that
bacteraemia can be abolished or minimised by ABP5 - but this too has been
conveniently ignored. We all have to accept that although day-to-day tasks
such as eating and tooth brushing are associated with bacteraemia, it is
impractical to use ABP for these events even though occasionally these
episodes may indeed be responsible for IE in patients at risk. We must
therefore strongly support the need for good dental hygiene and regular
dental care for such patients in order to try and minimise their risk of
IE.
Surprisingly, there is no mention in the draft document of the
devastating consequences of IE – the serious systemic upset, the
devastating vasculitic and embolic extracardiac complications and the
destructive cardiac effects that result in the need for urgent or
emergency cardiac surgery in patients who are very sick. The prolonged in-
hospital stay – much of which will be in intensive care, the prolonged
need for high-dose, expensive parenteral antibiotics, serial
haematological, biochemical, microbiological and cardiac investigations
and the input required from other specialists to deal with the
complications of IE are also ignored. The long-lasting devastating effects
of the embolic complications particularly those associated with the CNS
such as embolic/haemorrhagic stroke and cerebral abscess including
hemiplegia, paraplegia, aphasia and visual loss are disastrous in patients
of any age but particularly in the younger patient who has a career and
family responsibilities which may be wiped out in an instance.
The ideas that the risk of antibiotic-associated adverse events exceeds
the benefit that ABP has to offer “at risk” patients who undergo a dental,
gastrointestinal or genitourinary tract procedure and that ABP is likely
to be responsible for the development of antibiotic resistance among micro
-organisms are neither borne out in clinical practice nor supported by any
evidence in the literature. These are not good enough reasons to abandon
ABP for these susceptible individuals.
The opening sentence of the NICE draft document “This guideline
offers best practice advice on antimicrobial prophylaxis against infective
endocarditis before an interventional procedure …..” cannot be further
from the truth. Moreover, the “Quick reference guide” is illogical, will
be ignored by those physicians, dentists and surgeons responsible for
managing patients “at risk” of IE and will remain an embarrassment to the
authors.
References
1. Prophylaxis against Infective Endocarditis: Antimicrobial
prophylaxis against infective endocarditis in adults and children
undergoing interventional procedures. Quick reference guide. National
Institute for Health and Clinical Excellence (NICE) clinical guideline 64.
www.nice.org.uk
2. Ramsdale DR. Against the motion: “Prophylactic antibiotic therapy
to prevent endocarditis after dental procedures is unnecessary and
inappropriate”. BCS Annual Scientific Conference, Glasgow. June 6th 2007.
3. Ramsdale DR. Response to draft document by NICE on “Antibiotic
Prophylaxis against Infective Endocarditis in adults and children”, 27th
November 2007. www.bcs.com/pages/news
4. Tomas I, Alvarez M, Limeres J, Potel C, Medina J, Diz P.
Prevalence, duration and aetiology of bacteraemia following dental
extractions. Oral Dis 2007;13:56-62.
5. Lockhart PB, Brennan MT, Kent ML, Norton HJ, Weinrib DA. Impact of
amoxicillin prophylaxis on the incidence, nature and duration of
bacteraemia in children after intubation and dental procedures.
Circulation 2004;109:2878-84.
Yours sincerely,
Dr David R Ramsdale FRCP MD and Dr Nicholas D Palmer MRCP MD
Consultant Cardiologists,
Mr John A C Chalmers FRCS and Mr Brian Fabri FRCS
Consultant Cardiac Surgeons
From: The Cardiothoracic Centre, Thomas Drive, Liverpool, UK. L14
3PE.
Competing interests:
None declared
Competing interests:
No competing interests
24 April 2008
David R Ramsdale
Consultant Cardiologist
Dr Nicholas Palmer, Mr John Chalmers, Mr Brian Fabri
Rapid Response:
Prophylaxis against Infective Endocarditis:NICE Guidelines
PROPHYLAXIS AGAINST INFECTIVE ENDOCARDITIS:NICE GUIDELINES
22nd April 2008
Dear Editor,
It is our opinion that patients will be harmed if these guidelines are taken up by dental, medical and surgical colleagues on recommendations from NICE.1 The advice is contrary to the views of the majority of practising cardiologists and cardiac surgeons in the UK who are responsible for managing those unfortunate enough to develop infective endocarditis (IE) as a result of a failure to offer preventative measures to patients who are particularly susceptible. In our survey of 520 cardiologists and cardiac surgeons in the UK carried out 12 months ago, 94.2% felt that patients “at risk” of IE should receive antibiotic prophylaxis (ABP) prior to dental procedures in an attempt to try and prevent IE.2
In November 2007, we detailed our criticisms to NICE in response to the publication of the unwieldy and voluminous draft document that was virtually unreadable, unclear and disorganised. A summary of our opinion was published on the British Cardiac Society website.3 In this draft document, numerous summaries of data from the literature were presented which associate IE with various dental, surgical and interventional procedures but conclusions were then illogically drawn by the authors that patients “at risk” did not need to receive ABP. The conclusions were not supported by evidence from the literature but were simply the opinion of those responsible for this misleading publication. The authors tried to justify their conclusions by quoting estimates of risk for patients with particular cardiac defects, and estimates of risks for certain procedures. We regard this as a meaningless exercise and such guestimates cannot be accepted as the science on which to base advice which is illogical. Pathology has taught us that IE cannot occur without bacteraemia and a susceptible endocardial lesion or intravascular foreign body in-situ. The consequences of this are ignored by the authors because randomised clinical trials do not exist to support the case for antibiotic prophylaxis (ABP). We agree that the conditions that need to exist for an endocardial vegetation to develop in a patient include a susceptible cardiac lesion with endocardium that is in such a state to enable bacteria to adhere to it, bacteraemia itself sufficient to allow seeding of the endocardium and the ability of the bacteria to resist the body’s immune defense mechanisms to eradicate the infection. This understanding explains why not every patient “at risk” who undergoes a bacteraemia-producing procedure goes on to develop IE and why those who do, present at various intervals from the interventional procedure. To recommend not trying to eradicate or minimise predictable bacteraemia associated with these procedures in patients “at-risk”, especially when thousands of case reports have been published in the literature linking them with IE is in our view illogical and perverse. The authors have chosen to ignore such reports and their significance. In the UK, 83.3% of cardiac specialists believe that case reports of bacteraemia associated with invasive procedures constitute “evidence” to support the need to try and prevent IE associated with those procedures in cardiac patients at risk. Moreover, 74.6% felt that case reports of IE associated with invasive/interventional procedures constituted “evidence” sufficient enough to warrant ABP for those patients at risk who were undergoing those procedures.2 The value and importance of case reports in helping us to understand disease mechanisms, pathogenesis and treatment strategies should not be underestimated and thankfully most editors of peer-review journals still take this view. There is also evidence in the literature that bacteraemia may persist for > 1 hour after procedures.4 Although we accept that ABP will not be successful all the time there is also evidence that bacteraemia can be abolished or minimised by ABP5 - but this too has been conveniently ignored. We all have to accept that although day-to-day tasks such as eating and tooth brushing are associated with bacteraemia, it is impractical to use ABP for these events even though occasionally these episodes may indeed be responsible for IE in patients at risk. We must therefore strongly support the need for good dental hygiene and regular dental care for such patients in order to try and minimise their risk of IE.
Surprisingly, there is no mention in the draft document of the devastating consequences of IE – the serious systemic upset, the devastating vasculitic and embolic extracardiac complications and the destructive cardiac effects that result in the need for urgent or emergency cardiac surgery in patients who are very sick. The prolonged in- hospital stay – much of which will be in intensive care, the prolonged need for high-dose, expensive parenteral antibiotics, serial haematological, biochemical, microbiological and cardiac investigations and the input required from other specialists to deal with the complications of IE are also ignored. The long-lasting devastating effects of the embolic complications particularly those associated with the CNS such as embolic/haemorrhagic stroke and cerebral abscess including hemiplegia, paraplegia, aphasia and visual loss are disastrous in patients of any age but particularly in the younger patient who has a career and family responsibilities which may be wiped out in an instance. The ideas that the risk of antibiotic-associated adverse events exceeds the benefit that ABP has to offer “at risk” patients who undergo a dental, gastrointestinal or genitourinary tract procedure and that ABP is likely to be responsible for the development of antibiotic resistance among micro -organisms are neither borne out in clinical practice nor supported by any evidence in the literature. These are not good enough reasons to abandon ABP for these susceptible individuals.
The opening sentence of the NICE draft document “This guideline offers best practice advice on antimicrobial prophylaxis against infective endocarditis before an interventional procedure …..” cannot be further from the truth. Moreover, the “Quick reference guide” is illogical, will be ignored by those physicians, dentists and surgeons responsible for managing patients “at risk” of IE and will remain an embarrassment to the authors.
References
1. Prophylaxis against Infective Endocarditis: Antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures. Quick reference guide. National Institute for Health and Clinical Excellence (NICE) clinical guideline 64. www.nice.org.uk
2. Ramsdale DR. Against the motion: “Prophylactic antibiotic therapy to prevent endocarditis after dental procedures is unnecessary and inappropriate”. BCS Annual Scientific Conference, Glasgow. June 6th 2007.
3. Ramsdale DR. Response to draft document by NICE on “Antibiotic Prophylaxis against Infective Endocarditis in adults and children”, 27th November 2007. www.bcs.com/pages/news
4. Tomas I, Alvarez M, Limeres J, Potel C, Medina J, Diz P. Prevalence, duration and aetiology of bacteraemia following dental extractions. Oral Dis 2007;13:56-62.
5. Lockhart PB, Brennan MT, Kent ML, Norton HJ, Weinrib DA. Impact of amoxicillin prophylaxis on the incidence, nature and duration of bacteraemia in children after intubation and dental procedures. Circulation 2004;109:2878-84.
Yours sincerely,
Dr David R Ramsdale FRCP MD and Dr Nicholas D Palmer MRCP MD Consultant Cardiologists,
Mr John A C Chalmers FRCS and Mr Brian Fabri FRCS Consultant Cardiac Surgeons
From: The Cardiothoracic Centre, Thomas Drive, Liverpool, UK. L14 3PE.
Competing interests: None declared
Competing interests: No competing interests