Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation

Nonvitamin K-dependent oral anticoagulants (NOACs) in chronic kidney disease patients with atrial fibrillation

Atrial fibrillation (AF) represents the most common arrhythmia in patients with chronic kidney disease (CKD). As in the general population, in CKD patients AF is associated with an increased risk of thromboembolism and stroke. However, CKD patients, especially those on renal replacement therapy (RRT), also exhibit an increased risk of bleeding, especially from the gastrointestinal tract. Oral anticoagulation is the most effective form of thromboprophylaxis in patients with AF presenting increased risk of stroke. Limited evidence on efficacy, the increased risk of bleeding as well as some concern regarding the use of warfarin in CKD, has often resulted in the underuse of anticoagulation CKD patients. A large body of evidence suggests that non-vitamin K-dependent oral anticoagulant agents (NOACs) significantly reduce the risk of stroke, intracranial hemorrhage, and mortality, with lower to similar major bleeding rates compared with vitamin K antagonist such as warfarin in normal renal function subjects. Hence, they are currently recommended for patients with atrial fibrillation at risk for stroke. However, NOACs metabolism is largely dependent on the kidneys for elimination and little is known in patients with creatinine clearance <25ml/min who were excluded from all pivotal phase 3 NOACs trials. This review focuses on the current pharmacokinetic, observational, and prospective data on NOACs in patients with moderate to advanced chronic kidney disease (creatinine clearance 15-49ml/min) and those on dialysis.

ANMCO Position Paper: direct oral anticoagulants for stroke prevention in atrial fibrillation: clinical scenarios and future perspectives

It is now 4 years since the introduction of the new direct oral anticoagulants into clinical practice. Therefore, the Italian Association of Hospital Cardiologists (ANMCO) has deemed necessary to update the previous position paper on the prevention of thrombo-embolic complications in patients with non-valvular atrial fibrillation, which was published in 2013. All available scientific evidence has been reviewed, focusing on data derived from both clinical trials and observational registries. In addition, all issues relevant to the practical clinical management of oral anticoagulation with the new direct inhibitors have been considered. Specific clinical pathways for optimal use of oral anticoagulation with the new directly acting agents are also developed and proposed for clinical implementation. Special attention is finally paid to the development of clinical algorithms for medium and long-term follow-up of patients treated with new oral direct anticoagulants.

Consensus Document of the Italian Association of Hospital Cardiologists (ANMCO), Italian Society of Cardiology (SIC), Italian Association of Interventional Cardiology (SICI-GISE) and Italian Society of Cardiac Surgery (SICCH): clinical approach to pharmacologic pre-treatment for patients undergoing myocardial revascularization procedures

The wide availability of effective drugs in reducing cardiovascular events together with the use of myocardial revascularization has greatly improved the prognosis of patients with coronary artery disease. The combination of antithrombotic drugs to be administered before the knowledge of the coronary anatomy and before the consequent therapeutic strategies, can allow to anticipate optimal treatment, but can also expose the patients at risk of bleeding that, especially in acute coronary syndromes, can significantly weigh on their prognosis, even more than the expected theoretical benefit. In non ST-elevation acute coronary syndromes patients in particular, we propose a 'selective pre-treatment' with P2Y12 inhibitors, based on the ischaemic risk, on the bleeding risk and on the time scheduled for the execution of coronary angiography. Much of the problems concerning this issue would be resolved by an early access to coronary angiography, particularly for patients at higher ischaemic and bleeding risk.

ANMCO Position Paper: the use of non-vitamin K dependent new oral anticoagulant(s) in pulmonary embolism therapy and prevention

The new oral anticoagulants (NOACs) have radically changed the approach to the treatment and prevention of thromboembolic pulmonary embolism. The authors of this position paper face, in succession, issues concerning NOACs, including (i) their mechanism of action, pharmacodynamics, and pharmacokinetics; (ii) the use in the acute phase with the 'double drug single dose' approach or with 'single drug double dose'; (iii) the use in the extended phase with demonstrated efficacy and with low incidence of bleeding events; (iv) the encouraging use of NOACs in particular subgroups of patients such as those with cancer, the ones under- or overweight, with renal insufficiency (creatinine clearance > 30 mL/min), the elderly (>75 years); (v) they propose a possible laboratory clinical pathway for follow-up; and (vi) carry out an examination on the main drug interactions, their potential bleeding risk, and the way to deal with some bleeding complications. The authors conclude that the use of NOACs both in the acute phase and in the extended phase is equally effective to conventional therapy and associated with fewer major bleeding events, which make their use in patients at higher risk of recurrences safer.

Evolving Treatments for Arterial and Venous Thrombosis: Role of the Direct Oral Anticoagulants

The direct oral anticoagulants (DOACs) represent a major advance in oral anticoagulant therapy and have replaced the vitamin K antagonists as the preferred treatment for many indications. By simplifying long-term anticoagulant therapy and improving its safety, the DOACs have the potential to reduce the global burden of thrombosis. Postmarketing studies suggest that the favorable results achieved with DOACs in the randomized controlled trials can be readily translated into practice, but highlight the need for appropriate patient, drug and dose selection, and careful follow-up. Leveraging on their success to date, ongoing studies are assessing the utility of DOACs for the prevention of thrombosis in patients with embolic stroke of unknown source, heart failure, coronary artery disease, peripheral artery disease, antiphospholipid syndrome, and cancer. The purpose of this article is to (1) review the pharmacology of the DOACs, (2) describe the advantages of the DOACs over vitamin K antagonists, (3) summarize the experience with the DOACs in established indications, (4) highlight current challenges and limitations, (5) highlight potential new indications; and (6) identify future directions for anticoagulant therapy.

Recent Advances in Stroke Prevention in Patients with Atrial Fibrillation and End-Stage Renal Disease

BACKGROUND

Chronic kidney disease (CKD) is associated with a high prevalence of atrial fibrillation (AF), but in this population the risk/benefit ratio of anticoagulant therapy with vitamin K antagonists (VKA) for thromboprophylaxis is uncertain.

SUMMARY

In end-stage renal disease (ESRD) patients undergoing hemodialysis, VKA seem less effective in stroke prevention than in the general population, with an increased risk of major bleeding. Recently, novel oral anticoagulant agents (NOACs) have proven to be effective for stroke prevention in AF and have demonstrated an improved safety profile compared to VKA. Limited data from post hoc analyses of controlled clinical trials suggest the safe and effective use of NOACs in patients with moderate renal impairment (i.e., estimated glomerular filtration rate, eGFR, between 30 and 50 mL/min). The question still remains whether NOACs can be used in patients with an eGFR <30 mL/min, since there are no studies addressing this subject. In fact, patients with CKD stage 4 and 5 were excluded from controlled clinical trials on anticoagulation therapy for stroke prevention in AF. Left atrial appendage (LAA) occlusion represents a nonpharmacological alternative for stroke prevention in patients with AF who are difficult to manage medically. Preliminary data indicate a similar efficacy and safety profile in patients with CKD compared to patients with normal renal function.

KEY MESSAGES

Stroke prevention in patients with ESRD and AF represents a clinical challenge with poor evidence. LAA occlusion may become the standard of care for stroke prevention in patients with ESRD and AF.

Relation of Stroke and Major Bleeding to Creatinine Clearance in Patients With Atrial Fibrillation (from the Fushimi AF Registry)

Creatinine clearance (CrCl) has been widely used to adjust the dosage of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation (AF) and exclude contraindicated patients. However, there are few available real-world data on the relation between CrCl and adverse clinical outcomes in patients with AF. Therefore, we evaluated the clinical characteristics and adverse events in Japanese patients with AF stratified by CrCl. We categorized patients in the Fushimi AF Registry, a large prospective community-based Japanese cohort of patients with AF, into 3 groups as follows: (1) CrCl <30 ml/min, (2) CrCl 30 to 49 ml/min, and (3) CrCl ≥50 ml/min. We evaluated 3,080 patients after a median follow-up of 1,076 days. Comparing with patients with CrCl ≥50 ml/min, patients with AF with CrCl <30 ml/min showed increased risks of stroke/systemic embolism (SE) (hazard ratio [HR] 1.68; 95% confidence interval [CI] 1.04 to 2.65; p = 0.04) and major bleeding (HR, 2.08; 95% CI 1.23 to 3.39; p = 0.008) after adjustment for prespecified factors. Patients with AF with CrCl <30 ml/min were also associated with higher risks of all-cause death, hospitalization for heart failure, myocardial infarction, or the composite of all-cause death and stroke/SE. However, no excess risk of stroke/SE (HR 1.10; 95% CI 0.76 to 1.58; p = 0.6) or major bleeding (HR 0.98; 95% CI 0.63 to 1.48; p = 0.9) was noted for patients with CrCl 30 to 49 ml/min. In conclusion, Japanese patients with AF with CrCl <30 ml/min were closely associated with adverse clinical events including stroke/SE and major bleeding.

Impact of valvular heart disease on oral anticoagulant therapy in non-valvular atrial fibrillation: results from the RAMSES study

The definition of non-valvular atrial fibrillation (NVAF) is controversial. We aimed to assess the impact of valvular heart disease on stroke prevention strategies in NVAF patients. The RAMSES study was a multicenter and cross-sectional study conducted on NVAF patients (ClinicalTrials.gov identifier NCT02344901). The study population was divided into patients with significant valvular disease (SVD) and non-significant valvular disease (NSVD), whether they had at least one moderate valvular disease or not. Patients with a mechanical prosthetic valve and mitral stenosis were excluded. Baseline characteristics and oral anticoagulant (OAC) therapies were compared. In 5987 patients with NVAF, there were 3929 (66%) NSVD and 2058 (34%) SVD patients. The predominant valvular disease was mitral regurgitation (58.1%), followed by aortic regurgitation (24.1%) and aortic stenosis (17.8%). Patients with SVD had higher CHA₂DS₂VASc [3.0 (2.0; 4.0) vs. 4.0 (2.0; 5.0), p < 0.001] and HAS-BLED [2.0 (1.0; 2.0) vs. 2.0 (1.0; 2.0), p = 0.004] scores compared to patients with NSVD. Overall, 2763 (71.2%) of NSVD and 1515 (73.8%) of SVD patients were on OAC therapy (p = 0.035). When the patients with SVD were analyzed separately, the mean CHA₂DS₂VASc and HAS-BLED scores were higher in patients with mitral regurgitation compared to patients with aortic regurgitation and aortic stenosis [4.0 (3.0; 5.0), 3.0 (2.0; 4.0), 3.0 (2.0; 4.0) p < 0.001 and 2.0 (1.0; 3.0), 1.0 (1.0; 2.0), 1.0 (0.0; 2.0) p < 0.001, respectively]. In patients with SVD, 65.7% of mitral regurgitation, 82.6% of aortic regurgitation and 88.0% of aortic stenosis patients were on OAC therapy. One out of three NVAF patients had at least one moderate valvular heart disease with the predominance of mitral regurgitation. Patients with SVD were at greater risk of stroke and bleeding compared to patients with NSVD. Although patients with mitral regurgitation should be given more aggressive anticoagulant therapy due to their higher risk of stroke, they are undertreated compared to patients with aortic valve diseases.

Real-life experience with the specific reversal agent idarucizumab for the management of emergency situations in dabigatran-treated patients: a series of 11 cases

Non-vitamin K antagonist oral anticoagulants (NOACs) have a favorable benefit-risk profile compared with vitamin K antagonists. However, the lack of specific reversal agents has made the management of some patients receiving long-term treatment with NOACs problematic in emergency situations such as major bleeding events or urgent procedures. Idarucizumab, a fully humanized Fab antibody fragment that binds specifically and with high affinity to dabigatran, was recently approved for use in adult patients treated with dabigatran when rapid reversal of its anticoagulant effect is required. Clinical experience with idarucizumab is currently limited. We report 11 real-life clinical cases in which idarucizumab was used after multidisciplinary consultation in a variety of emergency situations including severe postoperative bleeding, emergency high-bleeding-risk surgery (hip/spine surgery and neurosurgery), invasive diagnostic testing (lumbar puncture), intracranial bleeding (pre-pontine subarachnoid hemorrhage and lobar intracerebral hemorrhage) and thrombolysis with recombinant tissue plasminogen activator for acute ischemic stroke. This case series illustrates the role of idarucizumab in improving patient safety in rare emergency situations requiring rapid reversal of the anticoagulant effect of dabigatran, while highlighting the importance of information and education about the availability and appropriate use of this recently approved specific reversal agent.

Italian intersociety consensus on DOAC use in internal medicine

The direct oral anticoagulants (DOACs) are drugs used in clinical practice since 2009 for the prevention of stroke or systemic embolism in non-valvular atrial fibrillation, and for the treatment and secondary prevention of venous thromboembolism. The four DOACs, including the three factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) and one direct thrombin inhibitor (dabigatran) provide oral anticoagulation therapy alternatives to Vitamin K antagonists (VKAs). Despite their clear advantages, the DOACs require on the part of the internist a thorough knowledge of their pharmacokinetic and pharmacodynamic characteristics to ensure their correct use, laboratory monitoring and the appropriate management of adverse events. This document represents a consensus paper on the use of DOACs by representatives of three Italian scientific societies: the Italian Society of Internal Medicine (SIMI), the Federation of the Associations of Hospital Managers (FADOI), and the Society for the Study of Haemostasis and Thrombosis (SISET). This document formulates expert opinion guidance for pragmatic managing, monitoring and reversing the anticoagulant effect of DOACs in both chronic and emergency settings. This practical guidance may help the internist to create adequate protocols for patients hospitalized ion internal medicine wards, where patients are often elderly subjects affected by poly-morbidities and renal insufficiency, and, thus, require particular attention to drug-drug interactions and peri-procedural protocols.

Vitamin K antagonists: relative strengths and weaknesses vs. direct oral anticoagulants for stroke prevention in patients with atrial fibrillation

Vitamin K antagonists (VKAs) have been the mainstay of anticoagulation therapy for more than 50 years. VKAs are mainly used for the prevention of stroke in patients with atrial fibrillation (AF) and the treatment and secondary prevention of venous thromboembolism. In the past 5 years, four new agents-the direct factor Xa inhibitors apixaban, edoxaban and rivaroxaban and the direct thrombin inhibitor dabigatran [collectively known as direct oral anticoagulants (DOACs) or non-VKA oral anticoagulants]-have been approved for these and other indications. Despite these new treatment options, the VKA warfarin currently remains the most frequently prescribed oral anticoagulant. The availability of DOACs provides an alternative management option for patients with AF, especially when the treating physician is hesitant to prescribe a VKA owing to associated limitations, such as food and drug interactions, and concerns about bleeding complications. Currently available real-world evidence shows that DOACs have similar or improved effectiveness and safety outcomes compared with warfarin. Treatment decisions on which DOAC is best suited for which patient to maximize safety and effectiveness should take into account not only clinically relevant patient characteristics but also patient preference. This article reviews and highlights real and perceived implications of VKAs for the prevention of stroke in patients with non-valvular AF, with specific reference to their strengths and weaknesses compared with DOACs.

Exploring indications for the Use of direct oral anticoagulants and the associated risks of major bleeding

Thrombosis is a leading cause of morbidity and mortality in the United States. Arterial and venous thromboses are implicated in the pathogenesis of major disorders, including myocardial infarction, ischemic stroke, and venous thromboembolism. Over the past decade, direct oral anticoagulants (DOACs) (eg, direct thrombin inhibitor and factor Xa [FXa] inhibitors) have been adopted as alternatives to warfarin due to their clinical advantages and efficacy for the treatment of thrombosis. As with all anticoagulants, treatment with DOACs is associated with a risk of major bleeding, including life-threatening gastrointestinal bleeds and intracranial hemorrhages (ICHs). In turn, the burden of bleeding associated with DOAC treatment is itself associated with substantial healthcare costs that are amplified by an increased risk of thromboembolic events and mortality following major bleeding events, especially in patients with ICHs. Given the rapid adoption of the DOACs and projected usage in the large patient population affected by thromboembolic conditions, clinicians are increasingly likely to encounter patients with major bleeding events due to DOAC therapy. Unlike warfarin, effective strategies to manage these bleeds are limited. There is an unmet need for reversal agents for use in the management of patients who receive FXa inhibitors and experience life-threatening bleeding or need emergency surgery. Andexanet alfa and ciraparantag are being evaluated as potential antidotes for both direct and indirect FXa inhibitors.

Financial Impact of Direct-Acting Oral Anticoagulants in Medicaid: Budgetary Assessment Based on Number Needed to Treat

BACKGROUND

Faced with rising healthcare costs, state Medicaid programs need short-term, easily calculated budgetary estimates for new drugs, accounting for medical cost offsets due to clinical advantages.

OBJECTIVE

To estimate the budgetary impact of direct-acting oral anticoagulants (DOACs) compared with warfarin, an older, lower-cost vitamin K antagonist, on 12-month Medicaid expenditures for nonvalvular atrial fibrillation (NVAF) using number needed to treat (NNT).

METHOD

Medicaid utilization files, 2009 through second quarter 2015, were used to estimate OAC cost accounting for generic/brand statutory minimum (13/23%) and assumed maximum (13/50%) manufacturer rebates. NNTs were calculated from clinical trial reports to estimate avoided medical events for a hypothetical population of 500,000 enrollees (approximate NVAF prevalence × Medicaid enrollment) under two DOAC market share scenarios: 2015 actual and 50% increase. Medical service costs were based on published sources. Costs were inflation-adjusted (2015 US$).

RESULTS

From 2009-2015, OAC reimbursement per claim increased by 173 and 279% under maximum and minimum rebate scenarios, respectively, while DOAC market share increased from 0 to 21%. Compared with a warfarin-only counterfactual, counts of ischemic strokes, intracranial hemorrhages, and systemic embolisms declined by 36, 280, and 111, respectively; counts of gastrointestinal hemorrhages increased by 794. Avoided events and reduced monitoring, respectively, offset 3-5% and 15-24% of increased drug cost. Net of offsets, DOAC-related cost increases were US$258-US$464 per patient per year (PPPY) in 2015 and US$309-US$579 PPPY after market share increase.

CONCLUSIONS

Avoided medical events offset a small portion of DOAC-related drug cost increase. NNT-based calculations provide a transparent source of budgetary-impact information for new medications.

Emerging therapeutic uses of direct-acting oral anticoagulants: An evidence-based perspective

Direct-acting oral anticoagulants (DOACs) were claimed to cause a potential paradigm shift in the therapeutic scenario of patients requiring short- and long-term anticoagulation, by virtue of their pharmacological properties, perceived as innovative. The evidence gathered so far (from pre-approval pivotal trials to real-world post-marketing observational data) consistently confirmed that DOACs are overall comparable to vitamin-K antagonists (VKAs) in terms of safety, efficacy and effectiveness and unequivocally documented a consistent and clinically relevant reduced risk of intracranial bleeding in the settings of non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE). Interestingly, two parallel paths can be identified in the current research scenario: A) in the aforementioned consolidated therapeutic indications, an innovative approach is directed towards tailored treatment strategies, to identify patients most likely to benefit from one of the different anticoagulant drugs, in particular subpopulations at increased risk of adverse events (e.g., bleeding); B) in unconventional settings, DOACs are gaining interest for potential use in emerging diseases characterized by arterial and venous thromboembolic risk. In these scenarios, the risk-benefit profile of DOACs, as compared to VKAs or heparins, is less defined. The aim of this review is to critically assess the body of evidence underlying emerging therapeutic uses of DOACs (e.g., heparin-induced thrombocytopenia, anti-phospholipid antibody syndrome), including evolving issues in special populations (e.g., patients with VTE and cancer or cirrhosis). This will be achieved by analyzing the strength (i.e., systematic reviews, randomized clinical trials, observational studies, case report/series) and consistency (i.e., concordance) of both published and unpublished evidence registered in major public repositories.

Reversing the anticoagulation effects of dabigatran

The standard of care for oral anticoagulation therapy has primarily been warfarin, which is limited by its indirect mechanism-of-action, variable kinetics, tolerability, and routine monitoring concerns. The direct-acting oral anticoagulants (DOACs) have predictable pharmacokinetics and pharmacodynamics, and improved safety and efficacy compared to warfarin for the prevention of stroke in patients with nonvalvular atrial fibrillation and prevention or management of venous thromboembolism. Consequential bleeding is a concern with all anticoagulants. Vitamin K is not a rapid reversal agent for warfarin; rather it facilitates synthesis of new vitamin K-dependent clotting factors, which can take longer than 24 h. Other nonspecific agents, including recombinant activated factor VII, three- and four-factor prothrombin complex concentrates (PCC), and activated PCC or Factor Eight Inhibitor Bypassing Activity (FEIBA®), are options based on clinical need. Specific agents to quickly reverse the effects of DOACs have been under development, and idarucizumab, a monoclonal antibody fragment that rapidly binds dabigatran, has been approved for clinical use in cases of dabigatran-related life-threatening bleeding, or if a dabigatran-treated patient needs emergency surgery or an invasive procedure. Idarucizumab specifically and rapidly reverses dabigatran-induced anticoagulation as measured by established coagulation assays. However, this does not guarantee complete hemostasis, especially if a patient has underlying comorbidities such as renal or liver disease, or has experienced recent trauma that requires urgent surgery. In these cases, concomitant supportive therapy and/or administration of concentrated clotting factors may be considered. Emerging data from ongoing trials and clinical experience will further inform providers regarding optimal approaches for anticoagulation reversal.

Antagonizing dabigatran by idarucizumab in cases of ischemic stroke or intracranial hemorrhage in Germany – A national case collection

Background

Idarucizumab is a monoclonal antibody fragment with high affinity for dabigatran that reverses its anticoagulant effects within minutes. It may exhibit the potential for patients under dabigatran therapy suffering ischemic stroke to regain eligibility for thrombolysis with rt-PA and may inhibit lesion growth in patients with intracerebral hemorrhage on dabigatran.

Aims

To provide insights into the clinical use of idarucizumab in patients under effective dabigatran anticoagulation presenting with signs of ischemic stroke or intracranial hemorrhage.

Methods

Retrospective data collected from German neurological/neurosurgical departments administering idarucizumab following product launch from January to August 2016 were used.

Results

Thirty-one patients presenting with signs of stroke received idarucizumab in 22 stroke centers. Nineteen patients treated with dabigatran presented with ischemic stroke and 12 patients suffered from intracranial bleeding. In patients receiving rt-PA thrombolysis following idarucizumab, 79% benefitted from i.v. thrombolysis with a median improvement of five points in NIHSS. No bleeding complications occurred. Hematoma growth was observed in 2 out of 12 patients with intracranial hemorrhage. The outcome was favorable with a median NIHSS improvement of 5.5 points and mRS 0–3 in 67%. Overall, mortality was low with 6.5% (one patient in each group).

Conclusion

Administration of rt-PA after reversing dabigatran activity with idarucizumab in case of ischemic stroke is feasible, easy to manage, effective, and appears to be safe. In dabigatran-associated intracranial hemorrhage, idarucizumab has the potential to prevent hematoma growth and improve outcome. Idarucizumab represents a new therapeutic option for patients under dabigatran treatment presenting with ischemic stroke or intracranial hemorrhage.

Evaluation of the Appropriateness of Direct Oral Anticoagulant Selection and Monitoring in the Outpatient Setting

Background: Direct oral anticoagulants (DOACs) share many indications with warfarin but require less frequent follow-up and monitoring. There is limited data available on the prescribing of DOACs and appropriate laboratory monitoring in a real-world clinical setting. Objective: To determine if patients receiving care at 2 University of Florida (UF) Health Internal Medicine clinics are prescribed DOACs according to Food and Drug Administration (FDA)–approved labeling. Secondary objectives were to determine the percentage of patients receiving appropriate baseline laboratory tests prior to DOAC initiation and the frequency of laboratory monitoring. Methods: This retrospective chart review evaluated patients enrolled at 2 UF Health Internal Medicine practices within the UF Health system who were prescribed a DOAC between April 2014 and April 2015. Adherence to FDA-approved dosing recommendations and baseline laboratory tests were compared to previously published data. This study was approved by the UF Institutional Review Board. Results: A total of 194 patients met inclusion criteria. Ninety-six patients (49.5%) were on a DOAC prior to data collection; 98 patients (50.5%) started a DOAC during data collection. Of the 194 patients, 155 (79.9%) were prescribed DOACs per FDA-approved labeling ( P = .0005); 79 (40.8%) obtained a complete blood count, serum creatinine, and liver function tests prior to DOAC initiation. Conclusions: Prescribing practices were significantly better than published data; however, 1 in 5 patients were not prescribed a DOAC according to FDA-approved labeling. Less than half of the patients started on a DOAC obtained the recommended labs prior to medication initiation.

Gastrointestinal bleeding in patients on novel oral anticoagulants: Risk, prevention and management

Novel oral anticoagulants (NOACs), which include direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitors (rivaroxaban, apixaban and edoxaban), are gaining popularity in the prevention of embolic stroke in non-valvular atrial fibrillation as well as in the prevention and treatment of venous thromboembolism. However, similar to traditional anticoagulants, NOACs have the side effects of bleeding, including gastrointestinal bleeding (GIB). Results from both randomized clinical trials and observations studies suggest that high-dose dabigatran (150 mg b.i.d), rivaroxaban and high-dose edoxaban (60 mg daily) are associated with a higher risk of GIB compared with warfarin. Other risk factors of NOAC-related GIB include concomitant use of ulcerogenic agents, older age, renal impairment, Helicobacter pylori infection and a past history of GIB. Prevention of NOAC-related GIB includes proper patient selection, using a lower dose of certain NOACs and in patients with renal impairment, correction of modifiable risk factors, and prescription of gastroprotective agents. Overt GIB can be managed by withholding NOACs followed by delayed endoscopic treatment. In severe bleeding, additional measures include administration of activated charcoal, use of specific reversal agents such as idarucizumab for dabigatran and andexanent alfa for factor Xa inhibitors, and urgent endoscopic management.

Early secondary prevention after initially ineffective revascularization treatments for acute ischemic stroke due to tandem occlusion

: The most effective treatment of patients with stroke due to tandem occlusion is still unclear. We report the case of a man with stroke due to tandem internal carotid artery/middle cerebral artery occlusion, who underwent initially ineffective intravenous thrombolysis (IVT) and endovascular treatment. Early anticoagulation with apixaban was started after 48 h of IVT, given a newly diagnosed nonvalvular atrial fibrillation. Spontaneous partial recanalization of the cervical internal carotid artery was noted, and carotid endarterectomy was performed 72 h after IVT and 8 h after the last dose of apixaban. Surgery was conducted without any complication and the patient was discharged 7 days after onset with a residual mild hemiparesis. This is the first report of urgent carotid endarterectomy in an anticoagulated patient receiving a direct oral anticoagulant. This case highlights the importance of an early multidisciplinary approach to achieve a successful treatment of stroke due to tandem occlusion.

Switching, Adverse Effects and Use of Over-the-Counter Analgesics among Users of Oral Anticoagulants: A Pharmacy-based Survey

Oral anticoagulants are widely used but information on important aspects in that respect is not available from medical registers or clinical databases. Therefore, we conducted a survey including patients filling a prescription for oral anticoagulants at two large Danish community pharmacies. We collected information concerning the patients' knowledge of their anticoagulant treatment including prior drug switching. Further, patients were asked about use of over-the-counter analgesics, adverse effects and how the treatment affected their everyday life. Among 335 eligible patients, 301 (90%) agreed to participate. Atrial fibrillation was the most common indication (65%), and most patients filled a prescription for a non-vitamin K antagonist oral anticoagulant (NOAC) (58%). Among the 12% (n = 35) of participants who had switched oral anticoagulant treatment, 69% had switched from a vitamin K antagonist (VKA) to a NOAC. Switching was most frequently caused by inconvenience (34%) and adverse effects (23%). Although half of all patients had recently bought over-the-counter analgesics, purchase of ibuprofen and aspirin was rare (6%). More VKA users than NOAC users felt limited in their everyday life because of anticoagulant treatment (18% versus 9%). Among non-incident NOAC users, 21% had experienced adverse effects during their current treatment. Based on first-hand information from a large sample of anticoagulant users, we conclude that the main drug-related issues leading to anticoagulant switching and perceived limitations in everyday life were inconvenience and adverse effects. This varied between drug groups. Further, use of NSAIDs obtained over the counter was rare.

Clinical Stroke prevention in atrial fibrillation

Oral anticoagulation therapy has reduced the risk of ischaemic stroke and improved the outcomes for patients with atrial fibrillation considerably. The emergence of the non-vitamin K oral anticoagulants as alternatives to vitamin K antagonists has significantly changed the practice of stroke prevention in atrial fibrillation. As the main complication with antithrombotic therapy is bleeding, physicians should always balance the risk of ischaemic stroke against intracranial haemorrhage and intervene where appropriate to reduce both risks. Individual approach is often mandatory due to heterogeneity of the risks and patient preferences. The purpose of this review is to summarise the current knowledge of the oral anticoagulation therapy in atrial fibrillation patients and guide physicians with the management of anticoagulants based on data from clinical trials and systematic reviews.

Edoxaban in Atrial Fibrillation and Venous Thromboembolism-Ten Key Questions and Answers: A Practical Guide

Edoxaban is the fourth non-vitamin K antagonist oral anticoagulant now available for clinical use in the prevention of stroke/systemic embolism in atrial fibrillation (AF) and in the treatment of venous thromboembolism (VTE), after the completion of large-scale randomized comparative clinical trials with the vitamin K antagonist warfarin. Edoxaban has some peculiar pharmacological properties and outcome data. Here a group of experts in AF and VTE answers a set of questions on its practical use, trying to define the profile of patients that would be most appropriate for its use.

Current Situation of Medication Adherence in Hypertension

Despite increased awareness, poor adherence to treatments for chronic diseases remains a global problem. Adherence issues are common in patients taking antihypertensive therapy and associated with increased risks of coronary and cerebrovascular events. Whilst there has been a gradual trend toward improved control of hypertension, the number of patients with blood pressure values above goal has remained constant. This has both personal and economic consequences. Medication adherence is a multifaceted issue and consists of three components: initiation, implementation, and persistence. A combination of methods is recommended to measure adherence, with electronic monitoring and drug measurement being the most accurate. Pill burden, resulting from free combinations of blood pressure lowering treatments, makes the daily routine of medication taking complex, which can be a barrier to optimal adherence. Single-pill fixed-dose combinations simplify the habit of medication taking and improve medication adherence. Re-packing of medication is also being utilized as a method of improving adherence. This paper presents the outcomes of discussions by a European group of experts on the current situation of medication adherence in hypertension.

Clinical implications of reversal agents for direct oral anticoagulants

Direct oral anticoagulants (DOACs) are effective in preventing and treating venous thromboembolism, and preventing stroke in atrial fibrillation. Until recently, there has been no specific reversal agent for DOACs. Now, a specific antidote for the direct thrombin inhibitor, dabigatran has been approved for use, and antidotes for factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) are being developed. We review the evidence for currently used and emerging reversal strategies, and discuss possible clinical implications, including increased prescription of DOACs, use of DOACs in clinical situations previously felt to pose too great a risk of bleeding, and use of reversal agents beyond currently approved indications.

Potential Causes and Implications of Low Target Therapeutic Ratio in Warfarin-Treated Patients for Thrombosis Prophylaxis: A Single-Center Experience

Time in therapeutic range (TTR) of international normalized ratio is crucial for the safety and efficacy of anticoagulation with warfarin and it is influenced by many factors. There are limited data about the quality of warfarin therapy and its effects on clinical outcomes in Turkey. The aim of this study is to demonstrate the quality of anticoagulant therapy with warfarin and evaluate the parameters that affect the quality of warfarin therapy. A total of 170 patients with atrial fibrillation (AF; mean age: 62.2 ± 13.3; 69.2% female) treated with warfarin were included in this study. The mean follow-up period was 20 ± 8.4 months. The mean TTR levels of all patients were found to be 54.2% ± 21.4%. The TTR levels were similar in patients with valvular AF (VAF) and nonvalvular AF (NVAF). Logistic regression analysis revealed that elderly, heart failure (HF), and renal dysfunction were independent predictors of lower TTR. There were no significant differences between the VAF and NVAF subgroups regarding the incidence of mortality, stroke, and myocardial infarction. Cox regression analysis revealed that HF, coronary artery disease, and renal dysfunction were independent predictors of clinical outcomes in addition to lower TTR. Our results provide data regarding the quality of anticoagulation with warfarin from a single tertiary center in Istanbul, Turkey. The questions remain in seeking quality improvement in anticoagulation.

[Perioperative anticoagulation with NOAC using the example of rivaroxaban]

BACKGROUND

Recent findings require an update of earlier recommendations on the perioperative management of non Vitamin K antagonist oral anticoagulants (NOAC).

METHOD

The present position paper summarises the outcomes of an expert panel discussion.

RESULTS AND CONCLUSIONS

Based on the pharmacokinetic profile of rivaroxaban, a preoperative interruption of 24-72 hours is recommended depending on the patient's renal function, as well as individual and surgery-related bleeding risks. Similar NOAC-free intervals are recommended for patients with epidural catheters. Elective surgery should be delayed accordingly. A low molecular weight heparin (LMWH) "bridging" (in fact "switching") should be avoided because of an increased bleeding risk. Six to 8 hours after the intervention rivaroxaban can be re-initiated or, in case of more extensive interventions or an increased bleeding risk, after 24-72 hours; if necessary this interval could by bridged with LMWH, e. g. if the thromboembolic risk is considered high. In case of emergency surgery with a rivaroxaban pause of less than 9 hours, one should be prepared for a bleeding management including the use of prothrombin concentrate (PCC). Coagulation tests have no value for predicting perioperative bleeding, in contrast to a standardised bleeding history. As an overall estimate, the PT (Quick) can be determined with a suitable reagent. Currently, rivaroxaban-specific measurements of anti Xa levels are available at few specialised centres only. Moderate to severe haemorrhages can usually be managed by temporary interruption of rivaroxaban in conjunction with local and general haemostatic measures. Life-threatening bleeding events require a specific haemostasis management including the administration of PCC; these events are rare and usually have a favourable prognosis, except for intracranial haemorrhages.

Findings of transoesophageal echocardiogram in appropriately anticoagulated patients with persistent atrial fibrillation prior to planned cardioversion

Background

To evaluate a diagnostic value of transoesophageal echocardiogram (TEE) in appropriately anticoagulated patients with a non-valvular atrial fibrillation (AF) and to establish possible additional indications for TEE; to evaluate the incidence of left atrial (LA) thrombi in appropriately anticoagulated patients in daily clinical practice.

Methods

This retrospective study analyses data of 432 patients who had been anticoagulated by means of oral anticoagulants (OACs) prior to planned cardioversion during the period from 2012 to 2015. Thromboembolic (TE) and bleeding risks were assessed using CHA2DS2-VASc and HAS-BLED scores. Transthoracic and transoesophageal echocardiograms were evaluated. TE complications during 30 days after discharge were assessed.

Results

432 patients were selected, aged from 22 to 89 years (mean 65.0 ±11.5), 277 (64.1%) males and 155 (35.9%) females, 306 (70.8%) on warfarin and 126 (29.2%) on non-vitamin K antagonist oral anticoagulants (NOAC). Mean CHA2DS2-VASc score was 3.5 ±1.5. TEE was performed for 120 (27.8%) patients, more frequently for patients on NOACs and for ones with III° LA enlargement.

TEE revealed LA thrombi in seven (5.8%) of the patients. In warfarin and NOACs groups thrombi were revealed in five (7.0%) and two (4.1%) patients, respectively. TEE did not reveal any thrombi in patients with normal left ventricular (LV) function; however, thrombi were found in two (6.1%) patients with slightly decreased LV function, and in five (17.9%) patients with markedly decreased LV function.

In patients with decreased left ventricular ejection fraction (LVEF) thrombi in LA were found more frequently than in patients with normal and slightly decreased LVEF (17.9% vs 2.2%, p=0.008). CHA2DS2-VASc score of all 7 patients was ≥5. None of the patients after cardioversion had TE complications 30 days after discharge.

Conclusions

The risk of LA thrombi in patients prepared for scheduled cardioversion in line with the guidelines is low. Higher risk of thrombi was present in patients with decreased LVEF (≤40%), CHA2DS2-VASc ≥5. In order to assess more accurately indications to perform TEE for appropriately anticoagulated patients prior to scheduled cardioversion a study with larger number of patients is required.

Effectiveness and safety of reduced dose non-vitamin K antagonist oral anticoagulants and warfarin in patients with atrial fibrillation: propensity weighted nationwide cohort study

Objective To examine clinical effectiveness and safety of apixaban 2.5 mg, dabigatran 110 mg, and rivaroxaban 15 mg compared with warfarin among patients with atrial fibrillation who had not previously taken an oral anticoagulant.Design Propensity weighted (inverse probability of treatment weighted) nationwide cohort study.Setting Individual linked data from three nationwide registries in Denmark.Participants Patients with non-valvular atrial fibrillation filling a first prescription for an oral anticoagulant from August 2011 to February 2016. Patients who filled a prescription for a standard dose non-vitamin K antagonist oral anticoagulant (novel oral anticoagulants, NOACs) were excluded. To control for baseline differences in the population, a propensity score for receipt of either of the four treatment alternatives was calculated to apply an inverse probability treatment weight.Intervention Initiated anticoagulant treatment (dabigatran 110 mg, rivaroxaban 15 mg, apixaban 2.5 mg, and warfarin).Main outcome measures Patients were followed in the registries from onset of treatment for the primary effectiveness outcome of ischaemic stroke/systemic embolism and for the principal safety outcome of any bleeding events.Results Among 55 644 patients with atrial fibrillation who met inclusion criteria, the cohort was distributed according to treatment: apixaban n=4400; dabigatran n=8875; rivaroxaban n=3476; warfarin n=38 893. The overall mean age was 73.9 (SD 12.7), ranging from a mean of 71.0 (warfarin) to 83.9 (apixaban). During one year of follow-up, apixaban was associated with higher (weighted) event rate of ischaemic stroke/systemic embolism (4.8%), while dabigatran, rivaroxaban, and warfarin had event rates of 3.3%, 3.5%, and 3.7%, respectively. In the comparison between a non-vitamin K antagonist oral anticoagulant and warfarin in the inverse probability of treatment weighted analyses and investigation of the effectiveness outcome, the hazard ratios were 1.19 (95% confidence interval 0.95 to 1.49) for apixaban, 0.89 (0.77 to 1.03) for dabigatran, and 0.89 (0.69 to 1.16) for rivaroxaban. For the principal safety outcome versus warfarin, the hazard ratios were 0.96 (0.73 to 1.27) for apixaban, 0.80 (0.70 to 0.92) for dabigatran, and 1.06 (0.87 to 1.29) for rivaroxaban.Conclusion In this propensity weighted nationwide study of reduced dose non-vitamin K antagonist oral anticoagulant regimens, apixaban 2.5 mg twice a day was associated with a trend towards higher rates of ischaemic stroke/systemic embolism compared with warfarin, while rivaroxaban 15 mg once a day and dabigatran 110 mg twice a day showed a trend towards lower thromboembolic rates. The results were not significantly different. Rates of bleeding (the principal safety outcome) were significantly lower for dabigatran, but not significantly different for apixaban and rivaroxaban compared with warfarin.

Incidence of severe renal dysfunction among individuals taking warfarin and implications for non-vitamin K oral anticoagulants

BACKGROUND

The purpose of this study is to assess incidence and risk factors for severe renal dysfunction in patients requiring oral anticoagulation to help guide initial drug choice and provide a rational basis for interval monitoring of renal function for patients prescribed non-vitamin K oral anticoagulants.

METHODS

Patients on warfarin for atrial fibrillation or venous thromboembolism were consecutively enrolled from January 2007 to December 2010. Baseline kidney function was assessed, and patients were followed to their first decline of kidney function to creatinine clearance<30 mL/min. Multivariate regression assessed independent risk factors for the primary outcome. Severe renal impairment based on baseline kidney function was assessed by Kaplan-Meier analyses.

RESULTS

Of 787 patients identified, 34 were excluded for baseline CrCl <30 mL/min. The mean age was 71 years, and 74% and 31% had hypertension and diabetes mellitus, respectively. At baseline, 23% (n=174) had moderate chronic kidney disease (CKD) (CrCl 30-59mL/min), whereas 31% had mild CKD (CrCl 60-89mL/min). Severe renal impairment occurred in 92 patients (12%), 25% of which was seen within 5.3 months. Of those with baseline stage 3 CKD, 37% developed severe renal impairment. Stage 3 CKD conferred a 14-fold increased risk in the development of severe renal dysfunction (odds ratio 14.5, 95% CI 6.7-31.3, P<.001). Coronary artery disease was also associated with severe renal impairment (odds ratio 2.2, 95% CI 1.3-3.8, P=.004).

CONCLUSIONS

Acute and chronic renal dysfunction is common among individuals requiring long-term anticoagulant therapy. Patients with moderate chronic kidney disease and coronary artery disease are at the highest short-term risk of developing severe renal impairment. More frequent monitoring of these patients is warranted.