Managing anticoagulated patients
Michele West and Garry Sime give an overview of new SDCEP guidance on managing and treating dental patients taking anticoagulants or antiplatelet drugs
More than 500,000 people in Scotland currently take one or more anticoagulants or antiplatelet drugs to treat or prevent thrombotic events1. It is, therefore, very likely that at some point most dentists will encounter such patients, under circumstances where they require dental treatment likely to cause bleeding.
The primary concern for those performing dental procedures on this patient group is likely to be the potential for bleeding complications due to the drugs’ effects on clot formation, and the practitioner’s aim will be to manage the bleeding risk through the use of appropriate treatment planning and haemostatic measures. However, given the variety of these drugs and the other factors that can influence bleeding risk, deciding on the best course of action for an individual patient is often not straightforward.
Various guidelines exist nationally and internationally, providing advice and recommendations for the dental treatment of patients taking the most commonly used of the drugs, including the oral anticoagulant warfarin and the antiplatelet agents aspirin and clopidogrel2-7. These drugs have been in use for a number of years, allowing for the accumulation of significant dental clinical experience and evidence to underpin best practice.
The relative seriousness of the different outcomes is a very important factor to be considered
However, since 2008, several new anticoagulant and antiplatelet drugs have entered the UK market and are being increasingly prescribed for cardiac and thrombotic conditions. Dabigatran, rivaroxaban and apixaban belong to the group of so-called novel oral anticoagulants, or NOACs (also known as direct oral anticoagulants; DOACs, or target specific oral anticoagulants; TSOACs)8. These are a newer class of oral anticoagulants that act in a different way to warfarin, by directly inhibiting specific components of the anticoagulation cascade. New antiplatelet drugs prasugrel and ticagrelor also became available at around the same time and are usually prescribed in combination with aspirin as dual antiplatelet therapies.
The availability and increasing use of these new anticoagulants and antiplatelet drugs has driven the need for new guidelines to assist dental practitioners in the management of patients taking them. Currently, local guidelines from different Scottish health boards make conflicting recommendations for the treatment of patients taking NOACs, with divergence of opinion on whether the NOACs should be interrupted for invasive dental procedures or not. This has the potential to lead to variation in dental treatment for the patients taking these anticoagulants. The conflicting advice is also a source of concern and confusion for dentists and has resulted in calls for a single national guideline on the topic9.
In response to the identification of this topic as a priority in oral healthcare, the Scottish Dental Clinical Effectiveness Programme (SDCEP) has developed new guidance on the ‘Management of Dental Patients Taking Anticoagulants or Antiplatelet Drugs’.
The aim of the guidance is to provide advice covering both the new and the conventional drugs, with clear recommendations for the management of invasive dental treatment for this patient group. The guidance was published in August 2015 and printed copies have been distributed widely to members of the dental profession in Scotland.
The main guidance document includes information on each of the drug groups and provides practical advice and recommendations to inform the assessment of bleeding risk and decision making for treatment planning. A quick reference guide, which provides the main recommendations and advice in an easily accessible flow-chart format, is also available.
Additional tools have been developed to support the implementation of the guidance, including printable patient information leaflets specific for the different drug types. A form for recording the contact details of key medical, dental and emergency care contacts, which can be kept on hand by dentists for use should the need arise, is also provided.
The aim of the patient information leaflets is to make patients aware of the importance of informing their dentist about all medical conditions that they have and all of the medications they are taking, even if these are non-prescribed. Ideally, these leaflets should be provided to patients identified as taking anticoagulants or antiplatelet drugs before they require an invasive procedure.
Additionally, the leaflets provide information about how the patient’s dental treatment may be affected by their drugs so as to manage their expectations with regards to the extra precautions that may be taken and to provide a basis for communication between the patient and their dentist. Also available are post-treatment advice sheets, with space for recording local emergency contact details, which can be adapted as required by dental practices and provided to patients.
The guidance and all of the supporting documents are freely available via the SDCEP website (www.sdcep.org.uk).
Development of the guidance
SDCEP’s approach to the development of this guidance was to engage the clinical knowledge, expertise and experience of a multidisciplinary group of individuals with a wide range of perspectives to provide a balanced view on the clinical questions to be addressed.
This guidance development group was chaired by Garry Sime, a senior dental officer and specialist in special care dentistry based at Broxden Dental Centre in Perth. The other 17 members of the advisory group included dental consultants of various specialities, comprising oral surgery, oral medicine, special care dentistry, oral and maxillofacial surgery and restorative dentistry. A cardiologist, a haematologist, two senior pharmacists and a general medical practitioner provided medical and pharmaceutical expertise and opinion. Three primary care dental practitioners, including one from Orkney to ensure that issues relevant for remote and rural locations were fully considered, and a dental therapist represented the views of end-users.
Importantly, the guidance development group also included a patient representative who, in addition to having personal experience of anticoagulant use, is a patient contact for the anticoagulation charity ACE (Anticoagulation Europe) and so was well placed to represent patient views and perspectives.
Scoping research with dental practitioners and patients was carried out at the outset of the project to explore their experiences and views to inform the development and content of the guidance. This research was carried out by TRiaDS (Translation Research in a Dental Setting; www.triads.org.uk), who work in partnership with SDCEP and have long-standing experience of carrying out research projects, within an established framework, to support and inform the development and implementation of SDCEP guidance10.
The TRiaDS research confirmed that, while dental practitioners were generally confident in their approach to treating patients taking warfarin or the commonly used antiplatelet drugs, there was considerable variation in the dentists’ knowledge and confidence for the treatment of patients taking the newer drugs. Variation in referral decisions was also identified. Furthermore, accurate medical history taking emerged as a significant issue from both the perspective of the dentists and the patients. Difficulties in obtaining accurate details were highlighted by dentists and uncertainty in whether this information had been collected and recorded was highlighted by patients.
The evidence to inform the clinical questions addressed in the guidance was obtained through systematic searching of the literature. SDCEP was fortunate to be able to employ the expert skills and experience of the Cochrane Oral Health Group for this task (www.ohg.cochrane.org).
The recommendations developed by the group were based on considered judgements of the evidence, where available, clinical experience and expert opinion, and on the perspectives of patients and practitioners. The balance of risks, the values and preferences of patients, and the practicalities of the proposed treatment options were all taken into consideration. In line with an increasing number of national and international guideline developers, SDCEP uses the GRADE approach (Grading of Recommendations, Assessment, Development and Evaluation; www.gradeworkinggroup.org) for assigning evidence levels and developing recommendations.
Following this approach, the evidence quality and strength of each of the key recommendations presented in the SDCEP guidance are stated clearly, so that dental practitioners can be aware of how clear-cut the recommendations are when planning treatment on an individual patient basis.
Prior to publication, the guidance was scrutinised through a national consultation process and it is endorsed by the Dental Faculty of the Royal College of Physicians and Surgeons of Glasgow and the Faculties of Dental Surgery of the Royal College of Surgeons of Edinburgh and the Royal College of Surgeons of England. Public Health England also supports the guidance recommendations.
The balance of risks
The overarching consideration when performing an invasive procedure on a patient taking any anticoagulant or antiplatelet drug is the balance of the risk of a bleeding complication if the medication is continued versus the risk of a thrombotic event if the patient’s medication is interrupted. There is insufficient evidence from which to obtain an accurate measure of the relative risks of these events for each of the different anticoagulant and antiplatelet drugs or combinations. However, the relative seriousness of the different outcomes is a very important factor to be considered in the judgements leading to the development of recommendations.
Bleeding complications following a dental procedure are usually understood to mean excessive, prolonged or delayed bleeding, or bleeding that requires unplanned measures such as repacking and suturing. In extreme and rare cases, the patient may need to attend hospital for a medical intervention such as a transfusion. While it is acknowledged that a bleeding complication following dental treatment may be a worrying or distressing situation for both patient and practitioner, these events are rarely life threatening. In contrast, a stroke caused by a thromboembolism can have a catastrophic effect on the patient, with the potential to cause serious disability and even death.
Evidence reported over the last 50 years for patients taking warfarin was analysed in a recent review article11. Of more than 5,000 patients having in excess of 11,000 dental surgical procedures carried out without interruption of their warfarin medication, only 31 (0.6 per cent) experienced a bleeding complication which required more than local haemostatic measures. In many of these cases, the patients had other medical complications such as being on combined anticoagulant/antiplatelet therapies or having excessively high post-operative INR levels which, in some instances, was attributed to antibiotic usage.
On the other hand, the records for more than 2,500 patients whose warfarin therapy was interrupted or reduced prior to a dental procedure reported that 22 (0.8 per cent) experienced a thromboembolic event, six of which proved fatal.
Furthermore, the majority of studies identified in a recent systematic review found no significant difference in bleeding complications following dental procedures when comparing patients who had continued taking warfarin with those who had modified their drug intake or were not taking any anticoagulants12. This evidence also supports the argument to not interrupt warfarin therapy for dental treatment.
Although some guidelines initially advocated warfarin interruption for dental procedures, it is no longer considered best practice to do so. Most current guidelines, including the new guidance from SDCEP, recommend that invasive dental treatments should be carried out without warfarin interruption, as long as the patient’s INR is of an acceptable level. This recommendation is consistent with documented patient preference, with evidence suggesting that patients place a higher value on avoiding a thromboembolism than avoiding a bleeding complication following a dental procedure when considering the potential outcomes of each13.
Accumulated data from studies of patients taking antiplatelet drugs also indicates that serious bleeding complications experienced while continuing their antiplatelet medication for dental procedures are rare (estimated at 0.2 per cent)14. As with warfarin, none of the bleeding complications have been reported to result in a fatality.
The evidence also indicates that there is an increased risk of a thrombotic complication if antiplatelet medications are interrupted14. The estimates vary and depend on the condition for which the patient is being treated and the duration of interruption. It is likely that the risk is highest for patients on dual antiplatelet therapy following a coronary stent.
What about the NOACs?
While the recommendations for dental patients taking warfarin or antiplatelet drugs can be informed by evidence and accumulated clinical experience, this is not the case for the newer drugs, particularly the NOACs. There is, as yet, no direct evidence reporting on the impact of the NOACs on bleeding outcomes following dental procedures. Instead, the likely effects on bleeding can only be indirectly inferred from the evidence that relates to other types of bleeding.
Large trials conducted by the manufacturers of apixaban, dabigatran and rivaroxaban found comparable rates of spontaneous bleeding events for each compared to patients taking warfarin15-17. However, how relevant these results are as predictors for bleeding following dental procedures is not clear.
Current advice from the manufacturers of the NOACs is to interrupt the medication for one to four days (depending on the drug and the patient) prior to any kind of surgical procedure. However, not all types of surgery will cause the same levels of bleeding or carry the same risk of bleeding complications.
Although not yet the case for the NOACs, the distinction in terms of extent and controllability of bleeding between general surgical and dental surgical procedures is now acknowledged for warfarin. The product sheets provided by manufacturers of warfarin provide separate advice for surgery and dental surgery, with continuation of anticoagulation therapy recommended for the latter18.
The SDCEP guidance recommendations
Key recommendations made by the new SDCEP guidance, in common with many other guidelines, are that neither warfarin nor antiplatelet drugs should be interrupted for dental procedures.
Because of the lack of evidence on which to base the recommendations for the NOACs, further deliberation was carried out by the guidance development group in formulating their advice. Particular emphasis was placed on the potential seriousness of the outcomes for bleeding complications versus thromboembolic events.
The outcome was that for the NOACs, the SDCEP guidance takes a dual approach and advises that drug treatment is: (i) continued for more minor dental procedures, which are judged to have a low risk of bleeding complications; and (ii) briefly interrupted for more invasive and extensive dental surgery.
The opinion of the group was that the interruption of a patient’s NOAC medication was justified, but only for dental procedures with a higher risk of bleeding complications, and as long as the drug interruption was kept to a minimum.
The recommendation given in the guidance is to advise patients to miss (or delay, depending on the drug) their morning dose of NOAC on the day of treatment, giving a window of 12-24 hours (drug dependent) of drug interruption prior to their dental surgery. Because of the short-half lives of the NOACs (~12 hours), levels of anticoagulation fall quickly and can also be reinstated quickly, minimising the length of time that a patient is sub-therapeutically anticoagulated.
For the relatively low-risk dental procedures, it was judged that, taking the balance of likely risk of a severe bleeding complication versus a thromboembolic event and all other factors into account, these procedures can be carried out without drug interruption. However, as a precaution, the guidance advises that for these dental procedures, initial treatment should be limited so that the extent and controllability of bleeding can be assessed before proceeding further with the treatment.
Future research and recommendations
As with all guidelines, the recommendations for the new drugs will have to be reviewed in due course and revised if new evidence or experience emerges and indicates that this is appropriate.
It is very important that any adverse events occurring when providing dental treatment to patients taking the newer anticoagulant or antiplatelet drugs are recorded to inform future recommendations.
The national Yellow Card Scheme (www.yellowcard.mhra.gov.uk) collects data on adverse drug events, but this does, of course, rely on these being reported by practitioners and in sufficient detail. High-quality research studies are urgently required to investigate the impact of the drugs on bleeding complications after invasive dental procedures, and with longer patient follow-up, the effect on thrombotic events.
Another new oral anticoagulant, edoxaban, and an antiplatelet drug, vorapaxar, are now on the horizon, with both recently gaining EU marketing approval. Further drugs are also in the pipeline. Again, data on the impact of these for patients having dental treatment will be of great value to inform future guidelines for the management of such patients.
About the authors
Dr Michele West is a research and development manager with the Scottish Dental Clinical Effectiveness Programme (SDCEP) based in Dundee at the Dental Education Centre. She was the project lead for the development of SDCEP’s new dental clinical guidance for the ‘Management of Dental Patients Taking Anticoagulants or Antiplatelet Drugs’.
Garry Sime is a Specialist in Special Care Dentistry. He is currently working in NHS Tayside as the Senior Dental Officer for Outreach at Broxden Dental Centre in Perth. He was the chair of the guidance development group for the recently published SDCEP guidance document ‘Management of Dental Patients Taking Anticoagulants or Antiplatelet Drugs’.
To get in touch or for further information, email email@example.com
The information given in this article on the recommendations provided in the ‘Management of Dental Patients Taking Anticoagulants or Antiplatelet Drugs’ guidance is only a brief overview. For more detailed information about these recommendations and advice for following them, the dental practitioner should refer to the full guidance, which is available at www.sdcep.org.uk
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