Novel anticoagulants: general overview and practical considerations for dental practitioners

Management of patients receiving novel antithrombotic treatment in endodontic practice: Review and clinical recommendations

Cardiovascular diseases are a major component of non-communicable diseases and death, with thrombosis constituting the most common underlying pathosis of the three major cardiovascular disorders: ischaemic heart disease (acute coronary syndrome), stroke and venous thromboembolism (VTE). The introduction of direct oral anticoagulants (DOACs) in recent years has necessitated a more complex approach to periprocedural and perioperative anticoagulation management and the need for revised management strategies and protocols. Currently, patients taking classic oral anticoagulants are advised to stop taking the drugs and have their INR values checked 72 h prior to dental surgery (e.g., apical surgery, tooth extraction, and periodontal surgery) and checked again 24 h prior to the procedure to ensure it is within the therapeutic range. However, the current incorporation of these novel DOACs in routine medical practice requires changes in the way patients are managed preoperatively in dentistry, and specifically in endodontic surgery. The methodology applied in this review included searching for relevant articles in the PubMed database using keywords listed in the Entree Terms databases. Articles published on human blood clotting mechanism, antithrombotic drugs, as well as treatment guidelines and recommendations for dentistry were retrieved. In addition, textbooks and guidelines that may not have surfaced in the online search were searched manually. The aim of this paper was to review the mechanisms of action of classic and novel antithrombotic medications and their impact on endodontic treatment and the management of local haemostasis in endodontics.

Is telephone follow-up useful in preventing post-extraction bleeding in patients on antithrombotic treatment?

Background

The aim of the study was to investigate the usefulness of telephone follow-up in preventing post-extraction bleeding and improving wound healing in patients on chronic antithrombotic treatment.

Material and Methods

A prospective randomized clinical trial was carried out on 256 patients (test group = 128; control group = 128). The exact two-tailed Fisher test and the two-tailed non-parametric Mann-Whitney test were used for statistical analysis.

Results

The incidence of post-extraction bleeding was 15.6% and there was no difference between test and control groups. However, the study group was significantly, though weakly, associated with the severity of bleeding. Patient satisfaction with post-operative follow-up differed significantly between patients who had and those who did not have post-extraction bleeding.

Conclusions

Telephone follow-up after tooth extraction may play a role in the prevention of severe post-operative bleeding as well as in monitoring and managing the surgical wound.

Key words:Post-operative instructions, patient satisfaction, wound healing.

Tooth extraction without discontinuation of oral antithrombotic treatment: A prospective study

OBJECTIVE

To identify which variable, among those related to surgeries, to patients, or to antithrombotic treatments, could be considered as a bleeding indicator, and to analyze effectiveness of the local hemostatic protocols used, incidence of bleeding and healing index, depending on the number of extracted teeth, and patient antithrombotic treatment.

METHODS

Patients who underwent tooth extractions without interruption or reduction of antithrombotic treatment were prospectively followed. The exact two-tailed Fisher test was used to investigate the relationship between presence/absence of bleeding and type of hemostatic material. The effect of variables on the probability of bleeding and healing index was assessed by means of a multivariate logistic regression.

RESULTS

Two hundred and fifty-four procedures were analyzed. The incidence of bleeding was 15.75%. Severe bleeding occurred in only 6 patients (2.34%). The number of involved dental quadrants and pre-surgical antibiotic treatments were found to be positively related with bleeding. The use of vasoconstrictors during surgery resulted in a reduction of healing index scores.

CONCLUSIONS

Tooth extractions in patients on antithrombotic treatment were found to be free from significant bleeding although the involvement of more than 1 quadrant in the same procedure should be avoided.

Direct oral anticoagulants in oral surgery: a prospective cohort

BACKGROUND

Quantitative assessment of bleeding in dental extractions is rarely reported in the literature. The assessment of bleeding might provide additional evidence to predict and minimize postoperative outcomes. The aim of this study was to evaluate the pattern of bleeding in individuals taking direct oral anticoagulants (DOACs) submitted to dental extractions.

METHODS

Intraoperative bleeding was evaluated by using total collected bleeding corrected by absorbance reading (dental bleeding score). To monitoring bleeding episodes from the day of surgery, this cohort was followed up until the seventh postoperative day.

RESULTS

Forty-five procedures were performed in three comparative groups, patients under DOACs, individuals taking vitamin K antagonists (VKAs) and without anticoagulant therapy. No bleeding events were observed in procedures carried out in individuals of the DOAC group. Additional hemostatic measures were required in two procedures in the VKA group and one in the non-anticoagulated group. The dental bleeding scores obtained for the DOAC and VKA groups were similar.

CONCLUSIONS

Our data suggest that the DOAC therapy did not result in increased bleeding outcomes in this sample.

Inhibitory effects of dabigatran etexilate, a direct thrombin inhibitor, on osteoclasts and osteoblasts

INTRODUCTION

Anticoagulants are widely used in orthopedic surgery to decrease the risk of deep vein thrombosis. While significant bone impairment is induced by long-term heparin therapy, little is known about the effects of direct oral anticoagulants (DOACs). Herein, we investigated the effects of dabigatran etexilate (Pradaxa®), a DOAC inhibitor of thrombin, on bone cells using in vitro and ex vivo cell culture models.

MATERIALS AND METHODS

Osteoblasts and osteoclasts exposed to different concentrations of dabigatran etexilate and untreated cells were assayed for cell differentiation and activity. Favorable osteogenic conditions for osteoblasts were tested using titanium with nanotopography (Ti-Nano). In addition, mice treated with a dabigatran etexilate solution had bone marrow cells analyzed for the ability to generate osteoclasts.

RESULTS

Dabigatran etexilate at concentrations of 1 μg/mL and 2 μg/mL did not impact osteoclast or osteoblast viability. The drug inhibited osteoclast differentiation and activity as observed by the reduction of TRAP+ cells, resorption pits and gene and protein expression of cathepsin K. Consistently, osteoclasts from mice treated with dabigatran showed decreased area, resorptive activity, as well as gene and protein expression of cathepsin K. In osteoblast cultures, grown both on polystyrene and Ti-Nano, dabigatran etexilate reduced alkaline phosphatase (ALP) activity, matrix mineralization, gene expression of ALP and osteocalcin.

CONCLUSIONS

Dabigatran etexilate inhibited osteoclast differentiation in ex vivo and in vitro models in a dose-dependent manner. Moreover, the drug reduced osteoblast activity even under optimal osteogenic conditions. This study provides new evidence regarding the negative overall impact of DOACs on bone cells.

Safety of tooth extraction in patients receiving direct oral anticoagulant treatment versus warfarin: a prospective observation study

The aim of this study was to compare the safety of tooth extraction in patients receiving direct oral anticoagulants (DOACs) or warfarin without cessation of their antithrombotic treatment. This prospective observational study included 367 patients undergoing tooth extraction (119 receiving DOACs and 248 receiving warfarin). All extractions in DOAC patients were performed 6-7h after taking DOACs in consideration of the half-life in blood under continued antithrombotic treatment. To examine the potential postoperative bleeding risk related to the time of extraction and the drug concentration of blood, activated partial thromboplastin time (APTT) in dabigatran and prothrombin time (PT) in rivaroxaban were measured three times after administration. A total of 390 tooth extractions were performed: 128 in the DOAC patients and 262 in warfarin patients. Postoperative bleeding occurred in four extractions (3.1%) in the DOAC group and in 23 (8.8%) in the warfarin group. There was no statistically significant difference between the two groups (odds ratio: 2.362, 95% confidence interval (CI) 0.819-6.815, p=0.112). APTT and PT prolongation in almost all cases decreased with time after taking the medicine. Our findings suggest that interruption of DOAC therapy is not necessary for tooth extraction if the procedure is performed at least 6h after the last dose.

Direct Oral Anticoagulants and Medical Comorbidities in Patients Needing Dental Extractions: Management of the Risk of Bleeding

PURPOSE

The purpose of this study was to measure the frequency of bleeding during and after tooth extraction in patients exposed to direct oral anticoagulants (DOACs) and identify risk factors for prolonged or excessive bleeding.

MATERIALS AND METHODS

This retrospective cohort study involved 100 patients who underwent tooth extractions according to the European Heart Rhythm Association protocol: continuation of DOAC therapy for extractions of up to 3 teeth in the same session performed at the (presumed) time of DOAC trough concentration. We respected an interval of at least 4 hours between extraction and last DOAC intake. The outcome of interest was incidence of mild, moderate, and severe bleeding during the intervention and in the 7-day follow-up period. Data analysis considered the presence of comorbidities as the primary predictor for bleeding; additional predictors were age, gender, type of comorbidity, indication for DOAC therapy, DOAC agent, and extraction of contiguous teeth.

RESULTS

Of the patients, 64 had comorbidities (diabetes in 50%). The distributions of demographic, clinical, and dental variables were similar for patients with and without comorbidities. We observed 4 bleeding episodes (1 moderate episode 1 hour after the extraction and 3 mild episodes the day after the extraction) in the comorbidity group and none in the non-comorbidity group (4 of 64 vs 0 of 36, P = .29; overall bleeding rate, 4 of 100). The factor significantly triggering bleeding in patients with comorbidity was extractions of couples and triplets of multirooted teeth (P = .004).

CONCLUSIONS

Tooth extractions in patients with comorbidities taking DOACs may be safely managed as long as they are performed at least 4 hours after the last DOAC intake and do not involve 2 or 3 contiguous premolars and molars.

Direct oral anticoagulants: A retrospective study of bleeding, behavior, and documentation

OBJECTIVE

To examine the effects of direct oral anticoagulants (DOACs) on bleeding complications following dental surgeries.

SUBJECTS AND METHODS

This 6-year retrospective study collected data from records of patients undergoing oral surgical procedures within a university setting. An electronic health record database was searched using current procedural terminology codes for oral surgical procedures. Information regarding patient, procedural factors, and postoperative complications were extracted. Data were analyzed by Fisher's exact test.

RESULTS

Of patients who had a procedural code associated with oral surgery, only 0.11% (12/11,320) took a DOAC. Twelve patients (10 males, age ranging from 44 to 90 years) underwent 17 surgeries by nine different practitioners involving 98 extractions, 14 alveoloplasties, two tuberosity reductions, and two tori removals. In nine cases, the DOAC was discontinued a mean of 52.5 hrs prior to surgery (range 12-120 hrs). Bleeding complications were not reported for patients whose drug was discontinued or continued. Documentation of drug continuation/discontinuation was poor.

CONCLUSIONS

Bleeding was not observed with direct oral anticoagulation use in this oral surgery cohort. Drug discontinuation/continuation was not a factor in bleeding outcomes, and direct oral anticoagulation interruption was variable and poorly documented.

Management of dental patients receiving antiplatelet therapy or chronic oral anticoagulation: A review of the latest evidence

The perioperative management of patients treated with antithrombotic medications who undergo surgical procedures represents a common clinical problem. Dental interventions are usually associated with a low risk of bleeding; however, the dental implications of new antithrombotic agents are not yet fully understood. The present review is based on the latest evidence and recommendations published on the periprocedural management of dental patients treated with single or dual antiplatelet therapy, vitamin K antagonists, or direct oral anticoagulants for a variety of indications.

Postoperative bleeding risk of direct oral anticoagulants after oral surgery procedures: a systematic review and meta-analysis

Direct oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban; DOACs) have been introduced to improve safety and superior therapeutic value compared to their predecessors such as warfarin or enoxaparin. The aim of this systematic review and meta-analysis was to assess the postoperative bleeding risk of DOACs during oral surgery procedures. Systematic searches were performed in electronic databases including PubMed, Scopus, Web of Science and Cochrane Library. Thirteen studies were included in the qualitative synthesis: two retrospective case-control studies, five prospective case-control studies, three cross-sectional studies, two case series and a case report; while only six studies were statistically analysed. The risk ratio of postoperative bleeding in DOACs patients was significantly greater than in healthy patients (3.04; 95% confidence interval (CI)=1.31-7.04). This is especially true for rivaroxaban (4.13; 95% CI=1.25-13.69), and less so for dabigatran which presented a risk ratio similar to that of healthy patients (1.00; 95% CI=0.21-4.82). However, further research is required to support these results. Both apixaban and edoxaban were excluded from statistical analysis due to the lack of clinical studies.

Direct oral anticoagulants and its implications in dentistry. A review of literature

BACKGROUND

Four novel direct oral anticoagulants (DOACs) named dabigatran, rivaroxaban, edoxaban and apixaban have been recently introduced to overcome some of the drawbacks of existing anticoagulants. They have less interactions and do not require routine monitoring. However, there is not enough scientific data about the protocol to apply in these patients on DOACs undergoing dental treatment. Thus is necessary to evaluate the potential bleeding risk of these drugs, the possibility of thromboembolic events occurring if they are withdrawn or the need to change to heparin previously.

MATERIAL AND METHODS

A comprehensive search of the PubMed, Scopus and ISI Web of Science databases was conducted to identify studies that evaluated the relationship between direct oral anticoagulants and dental procedures. The quality of the reported information was assessed following the PRISMA statement.

RESULTS

Eleven studies that met the inclusion criteria were included in the review: 2 randomized clinical trials, 3 prospective studies, 3 retrospective studies, 2 case series and 1 case report.

CONCLUSIONS

DOACs are safe drugs in terms of bleeding. The possible postoperative bleeding complications are manageable with conventional haemostasis measurements. The bridging approach with heparin does not seem to be recommended. Consensus among the professionals involved in the management of the patient is fundamental in invasive dental treatments and in complex patients. Key words:Oral anticoagulants, DOAC, NOAC, dabigatran, rivaroxaban, apixaban, edoxaban, bleeding, oral surgery.

New horizons in anticoagulation: Direct oral anticoagulants and their implications in oral surgery

BACKGROUND

Thrombotic disorders remain a leading cause of death in the Western World. For decades, vitamin K antagonists used in the prevention of this pathology, such as warfarin or sintrom, were the only oral agents available for long-term anticoagulation, in spite of their disadvantages.

MATERIAL AND METHODS

An electronic database search was carried out on MedLine and The Cochrane Library Plus, without restrictions on the type of study nor dates, in English and Spanish. Abstracts were reviewed, and complete articles if necessary, considering all articles that included recommendations on DOACs and oral surgery.

RESULTS

In recent years, the so-called "new oral anticoagulants" have been introduced in clinical practice to treat those patients whose medical conditions require long-term anticoagulant treatment, replacing traditional oral anticoagulants.

CONCLUSIONS

The new oral anticoagulants represent new therapeutic options, with a number of advantages such as poor interaction with food, minor drug interactions, and do not require periodic dose adjustments or routine controls. The purpose of this review is to establish an update on the new oral anticoagulants: Dabigatran, Rivarozaban, Apixaban and Edoxaban.

Risks of postextraction bleeding after receiving direct oral anticoagulants or warfarin: a retrospective cohort study

OBJECTIVE

The effect of direct oral anticoagulants (DOACs) on the risk of bleeding after tooth extraction remains unclear. This study aimed to evaluate the incidence of postextraction bleeding among patients who received DOAC and vitamin K antagonists (VKAs), such as warfarin.

DESIGN

This study was a retrospective cohort analysis. Incidence rates and propensity score-matched regression models were used to compare the risks of bleeding after tooth extractions involving DOACs and VKAs.

SETTING

The study took place in a single university hospital in Japan.

PARTICIPANTS

Between April 2013 and April 2015, 543 patients underwent a total of 1196 simple tooth extractions.

PRIMARY OUTCOME MEASURE

The primary outcome measure was the occurrence of postextraction bleeding, which was defined as bleeding that could not be stopped by biting down on gauze and required medical treatment between 30 min and 7 days after the extraction.

RESULTS

A total of 1196 tooth extractions (634 procedures) in 541 patients fulfilled the study criteria, with 72 extractions (41 procedures) involving DOACs, 100 extractions (50 procedures) involving VKAs and 1024 extractions (543 procedures) involving no anticoagulants. The incidences of postextraction bleeding per tooth for the DOAC, VKA and no anticoagulant extractions were 10.4%, 12.0% and 0.9%, respectively. The incidences of postextraction bleeding per procedure for DOACs, VKAs and no anticoagulants were 9.7%, 10.0% and 1.1%, respectively. In comparison to the VKA extractions, the DOAC extractions did not significantly increase the risk of postextraction bleeding (OR 0.69, 95% CIs 0.24 to 1.97; p=0.49).

CONCLUSIONS

The risk of postextraction bleeding was similar for DOAC and VKA extractions.

Delayed bleeding after implant surgery in patients taking novel oral anticoagulants: a case report

The use of novel oral anticoagulants (NOACs) has increased in recent times in an effort to overcome the shortcomings of warfarin. They are being used primarily for the prevention of thrombosis caused by atrial fibrillation and offer the advantages of having fewer drug interactions than warfarin, no dietary restrictions, and no requirement for regular blood tests. Although there is reportedly less postoperative bleeding even if the drug is not discontinued during procedures that can cause local bleeding, such as dental procedures, no well-designed clinical studies have assessed postoperative bleeding associated with the use of these drugs. This article reports a case of a 74-year-old male patient who was taking rivaroxaban. The patient underwent a dental implant procedure after discontinuing rivaroxaban for one day and subsequently suffered delayed bleeding on postoperative day 6. Accordingly, this article also reports that the use of NOACs may also lead to delayed bleeding.

Preoperative Preparation and Planning of the Oral and Maxillofacial Surgery Patient

Every patient is different and has the potential to respond unfavorably to anesthetic and surgical intervention. Preparation is the key to optimizing patient outcome.

Dental management of patients taking novel oral anticoagulants (NOAs): Dabigatran

Background

A new group of oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban) with clear advantages over classic dicoumarin oral anticoagulants (warfarin and acenocoumarol) has been developed in recent years. Patients being treated with oral anticoagulants are at higher risk for bleeding when undergoing dental treatments.

Material and Methods

A literature search was conducted through April 2016 for publications in the ISI Web of Knowledge, PubMed and Cochrane Library using the keywords “dabigatran”, “rivaroxaban”, “apixaban”, “edoxaban”, “new oral anticoagulants”, “novel oral anticoagulants”, “bleeding” and “dental treatment”.

Results

There is no need for regular coagulation monitoring of patients on dabigatran therapy. Whether or not to temporarily discontinue dabigatran must be assessed according to the bleeding risk involved in the dental procedure to be performed.

Conclusions

The number of patients under treatment with new oral anticoagulants will increase in the coming years. It is essential to know about the pharmacokinetics and pharmacodynamics of new oral anticoagulants and about their interactions with other drugs. It is necessary to develop clinical guidelines for the perioperative and postoperative management of these new oral anticoagulants in oral surgical procedures, and to carefully evaluate the bleeding risk of dental treatment, as well as the thrombotic risk of suppressing the new oral anticoagulant.

Key words:Dabigatran, rivaroxaban, apixaban, edoxaban, novel oral anticoagulants, bleeding.

Managing patients taking edoxaban in dentistry

Background

Anticoagulation therapy is used in several conditions to prevent or treat thromboembolism. A new group of oral anticoagulants with clear advantages over classic dicoumarin oral anticoagulants (warfarin and acenocoumarol) has been developed in recent years. The Food and Drug Administration has approved edoxaban, dabigatran, rivaroxaban and apixaban. Their advantages include: predictable pharmacokinetics, drug interactions and limited food, rapid onset of action and short half-life. However, they lack a specific reversal agent.

Material and Methods

This paper examines the available evidence regarding rivaroxaban and sets out proposals for clinical guidance of dental practitioners treating these patients in primary dental care. A literature search was conducted through July 2016 for publications in PubMed and Cochrane Library using the keywords “edoxaban”, “dabigatran”, “rivaroxaban”, “apixaban”, “new oral anticoagulants”, “novel oral anticoagulants”, “bleeding” and “dental treatment” with the “and” boolean operator in the last 10 years.

Results

The number of patients taking edoxaban is increasing. There is no need for regular coagulation monitoring of patients on edoxaban therapy. For patients requiring minor oral surgery procedures, interruption of edoxaban is not generally necessary. Management of patients on anticoagulation therapy requires that dentists can accurately assess the patient prior to dental treatments.

Conclusions

Their increased use means that oral care clinicians should have a sound understanding of the mechanism of action, pharmacology, reversal strategies and management of bleeding in patients taking edoxaban. There is a need for further clinical studies in order to establish more evidence-based guidelines for dental patients requiring edoxaban.

Key words:Edoxaban, dabigatran, rivaroxaban, apixaban, novel oral anticoagulants, bleeding.

Cell-to-cell communication in guided bone regeneration: molecular and cellular mechanisms

This overview provides insights into the molecular and cellular mechanisms involved in guided bone regeneration, in particular focusing on aspects presented in the 3D movie, Cell-To-Cell Communication in Guided Bone Regeneration. The information presented here is based almost exclusively on genetic mouse models in which single genes can be deleted or overexpressed, even in a specific cell type. This information needs to be extrapolated to humans and related to aspects relevant to graft consolidation under the clinical parameters of guided bone regeneration. The overview follows the ground tenor of the Cell-To-Cell Communication series and focuses on aspects of cell-to-cell communication in bone regeneration and guided bone regeneration. Here, we discuss (1) the role of inflammation during bone regeneration, including (2) the importance of the fibrin matrix, and (3) the pleiotropic functions of macrophages. We highlight (4) the origin of bone-forming osteoblasts and bone-resorbing osteoclasts as well as (5) what causes a progenitor cell to mature into an effector cell. (6) We touch on the complex bone adaptation and maintenance after graft consolidation and (7) how osteocytes control this process. Finally, we speculate on (8) how barrier membranes and the augmentation material can modulate graft consolidation.

Novel anticoagulants - an update on the latest developments and management for clinicians treating patients on these drugs

There are several novel anticoagulant agents that are being increasingly used as an alternative to warfarin, with these drugs being reported to be at least as effective if not better. Their increased use means that oral care clinicians should have a sound understanding of the mechanism of action, pharmacology, reversal strategies and management of bleeding in patients taking these drugs. Surprisingly, there is little published in the current literature specific to professionals involved in oral health care. In this review, we provide an overview of these drugs and discuss the management of patients who need an oral procedure based on currently available literature and clinical trials.

Direct Oral Anticoagulants in Dental Patients Including the Frail Elderly Population

Direct oral anticoagulants (DOACs) have led to a paradigm shift in the field of anticoagulation, providing safe and convenient anticoagulation without the need for regular blood testing. Currently, there are three major DOACs available-Factor Xa inhibitors (apixaban and rivaroxaban) and direct thrombin inhibitors (dabigatran)-that are available for use in atrial fibrillation and venous thromboembolism. While these agents have been shown to be as effective as warfarin, with a similar or better bleeding profile, there remains some concern of the use of these drugs in vulnerable populations, such as the frail elderly patients; particularly since reversal agents and drug monitoring are not routinely available. We aim to provide a review of the use of DOACs and the impact of DOACs on dental treatment in the elderly population.