Apixaban compared with parenteral heparin and/or vitamin K antagonist in patients with nonvalvular atrial fibrillation undergoing cardioversion: Rationale and design of the EMANATE trial

Cardioversion of atrial fibrillation and atrial flutter revisited: current evidence and practical guidance for a common procedure

Cardioversion is widely used in patients with atrial fibrillation (AF) and atrial flutter when a rhythm control strategy is pursued. We sought to summarize the current evidence on this important area of clinical management of patients with AF including electrical and pharmacological cardioversion, peri-procedural anticoagulation and thromboembolic complications, success rate, and risk factors for recurrence to give practical guidance.

Non Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients Scheduled for Electrical Cardioversion: A Real-Life Propensity Score Matched Study

Aim

The aim of the present study was to assess the safety and effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin K antagonists (VKAs) in atrial fibrillation (AF) patients undergoing electrical cardioversion (EC).

Methods

A propensity score-matched analysis was performed in order to identify two homogeneous groups including AF patients on NOACs and VKAs treatment scheduled for EC. The primary safety endpoint was major bleeding. The composite of stroke, transient ischemic attack (TIA) and systemic embolism (SE) was the primary effectiveness endpoint. The discontinuation rate of anticoagulant therapy was assessed.

Results

A total of 495 AF patients on NOACs therapy and scheduled for EC were compared to 495 VKAs recipients. No statistically significant differences in the incidence of both major bleeding (1.01% versus 1.4%; P= 0.5) and thromboembolic events (0.6% versus 0.8%; P= 0.7) were observed during a mean follow-up of 15 ± 3 months. The discontinuation rate of NOACs was significantly lower compared to VKAs (1.6% versus 3.6%, P=0.04).

Conclusion

We showed a safe and effective clinical profile of NOACs among AF patients scheduled for electrical cardioversion in real-life setting. Patients on NOACs therapy showed a lower discontinuation rate compared to those on VKAs.

Determinants of left atrium thrombi in scheduled cardioversion: an ENSURE-AF study analysis

Aims

ENSURE-AF (NCT 02072434) was the largest prospective randomized clinical trial of anticoagulation for cardioversion in atrial fibrillation (AF), which also provides the largest prospective dataset for transoesophageal echocardiography (TOE) prior to cardioversion. This ancillary analysis investigated determinants of TOE-detected left atrium thrombi (LAT) in patients scheduled for electrical cardioversion (ECV).

Methods and results

The ENSURE-AF multicentre PROBE evaluation trial compared edoxaban 60 mg once daily (QD) with enoxaparin/warfarin in 2199 subjects undergoing ECV of non-valvular AF. Patients were stratified by the use of TOE, anticoagulant experience, and selected edoxaban dose. Electrical cardioversion was cancelled or deferred when TOEdetected LAT. In total, 1183 subjects were stratified to the TOE arm and LAT was reported in 91 (8.2%). In univariate analysis, age ≥75 years (26.4% vs. 16.9%, P = 0.0308), lower weight (86.5 ± 15.0 vs. 90.7 ± 18.0 kg, P = 0.0309), lower creatinine clearance (80.1 ± 30.6 vs. 93.2 ± 33.9 mL/min, P = 0.0007), heart failure (59.3% vs. 43.0%, P = 0.0029), and diuretic treatment (53.9% vs. 40.1%, P = 0.0141) were more prevalent in the LAT group. Non-significant trends were seen for higher mean CHA₂DS₂-VASc score (3.0 ± 1.41 vs. 2.7 ± 1.48, P = 0.0571) and more prevalent anticoagulation use prior to enrolment (60.4% vs. 50.3%, P = 0.0795) in the LAT group. In logistic regression analysis, age (P = 0.0202) and heart failure (P = 0.0064) were independently associated with LAT.

Conclusion

Elective ECV is commonly cancelled or deferred due to TOE-detected LAT in patients with non-valvular AF. Age ≥75 years and heart failure were associated with the presence of LAT.

[Prevention of thromboembolic complications during cardioversion and catheter ablation in patients with atrial fibrillation: review of key randomized trials]

This review focuses on the relevance of sinus rhythm control in patients with atrial fibrillation in real-life clinical practice and specific clinical features of patients with this arrhythmia. The authors presented current guidelines on prevention of thromboembolic complications and a review of results from major clinical studies of direct oral anticoagulants. The search for literature and selection of clinical studies for 2009-2020 were performed on websites of the European and Russian Societies of Cardiology, the All-Russian Scientific Society of Arrhythmologists, and in online databases PubMed, EMBASE, eLibrary, and Google Scholar using the key words atrial fibrillation, anticoagulants, ablation, cardioversion, and efficacy and safety.

Non-vitamin K antagonist oral anticoagulants therapy for atrial fibrillation patients undergoing electrophysiologic procedures

Over the last 10 years since the introduction of non-vitamin K antagonist oral anticoagulants (NOACs) into routine clinical practice our experience with these drugs has increased tremendously, also in the context of patients undergoing electrophysiology procedures. While some open questions remain, the available evidence indicates that for the majority of cases, these interventions can safely be performed on NOACs if study-based standard operating procedures are in place and followed. This review summarizes the most current trial evidence and guidelines on the use of NOACs for patients undergoing cardioversion, atrial fibrillation ablation, and device implantations, based on previous work of the author and others.

Management of periprocedural anticoagulant therapy: a novel individualized approach-a transeusophageal echocardiographic study

Patients with non-valvular atrial fibrillation who are under chronic oral anticoagulant therapy (OAC) treatment frequently require interruption of OAC treatment. By examining the presence of left atrial/left atrial appendage (LA/LAA) thrombus or dense spontaneous echo contrast (SEC) with transesophageal echocardiography (TEE) we aimed to develop an individualized strategy. To test the validity of CHA₂DS₂VASc score based recommendations was our secondary purpose. In this prospective study patients with non-valvular atrial fibrillation on OAC therapy were included. Patients' baseline characteristics, CHA₂DS₂VASc and HASBLED scores, medications, type of invasive procedures and clinical events were recorded. Each patient underwent to TEE examination prior to the invasive procedure. Bridging anticoagulation was recommended only to patients with LA/LAA thrombus. We included 155 patients and mean CHA₂DS₂VASc score of the study population was 3.4 ± 1.4. Seventy-one of them had LA/LAA thrombi or SEC on TEE examination and bridging anticoagulation was applied. OAC treatment was not bridged in 8 of 11 patients with prior cerebrovascular accident and 17 of 31 patients with CHA₂DS₂VASc score of > 4. 57 of 124 patients with CHA₂DS₂VASc score of ≤ 4 required bridging anticoagulation. There were 14 major bleedings decided according to ISTH bleeding classification. Major bleeding was observed only in patients underwent to high-risk bleeding procedure. In conclusion CHA₂DS₂VASc score by itself is not enough for decision-making regarding ischemic risk. Furthermore, since major bleedings occurred only in patients underwent to high-risk bleeding surgery, TEE-based individualisation may be a feasible approach particularly for those with high thromboembolic risk undergoing high-bleeding risk procedure.

Efficacy and Safety of Direct Oral Anticoagulants in Elderly Patients With Atrial Fibrillation: A Network Meta-Analysis

Background: Direct oral anticoagulants (DOACs) have been widely used in patients with atrial fibrillation (AF) for antithrombotic prophylaxis, which were shown to have a favorable risk–benefit profile. However, there are no guidelines for the use of DOACs in elderly patients (aged ≥75 years) with AF, which creates uncertainty about the optimal antithrombotic treatment in these patients.

Methods: After comprehensively searching Embase, PubMed, and Cochrane databases, five phase III randomized controlled trials involving 28,137 elderly participants were included in this study. The efficacy outcome was stroke or systemic embolism, and the safety outcome was major bleeding. We conducted a network meta-analysis by using a Bayesian random-effect model for the first time to evaluate the efficacy and safety of main DOACs (apixaban, edoxaban, rivaroxaban, and dabigatran) and warfarin in elderly patients with AF. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were used to assess the effect of drugs on efficacy and safety. The rank probabilities were used to reflect the hierarchy of drugs, and a larger rank probability value symbolized a better rank of drugs.

Results: In the prophylaxis of stroke or systemic embolism, apixaban was found to be the best among DOACs compared to warfarin (HR, 0.71; 95% CI: 0.33–1.50), though this finding was not statistically significant. Apixaban ranked the best (rank probabilities, 41.2%) in efficacy of drugs, followed by rivaroxaban, edoxaban, dabigatran, and warfarin (rank probabilities, 31.8, 15.9, 10.9, and 0.2%, respectively). In reducing the risk of major bleeding, apixaban was found to be the best among DOACs too, compared to warfarin (HR, 0.64; 95% CI: 0.33–1.30), though this finding was not statistically significant. In safety, apixaban ranked the best (rank probabilities, 71.4%), followed by edoxaban, dabigatran, warfarin, and rivaroxaban (rank probabilities, 21.0, 5.8, 0.9, and 0.8%, respectively).

Conclusions: DOACs showed a lower incidence of stroke/systemic embolism and major bleeding compared with warfarin in antithrombotic therapy in elderly patients (aged ≥75 years), with apixaban being the best of those interventions. Therefore, apixaban should be given priority as an anticoagulant in stroke prevention for elderly patients with AF.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Anticoagulation in the cardiac patient: A concise review

Anticoagulation has multiple roles in the treatment of cardiovascular disease, including in management of acute myocardial infarction, during percutaneous coronary intervention, as stroke prophylaxis in patients with atrial arrhythmias, and in patients with mechanical heart valves. Clinical anticoagulation choices in the aforementioned diseases vary widely, due to conflicting data to support established agents and the rapid evolution of evidence-based practice that parallels more widespread use of novel oral anticoagulants. This review concisely summarizes evidence-based guidelines for anticoagulant use in cardiovascular disease, and highlights new data specific to direct oral anticoagulants.

Apixaban compared to heparin/vitamin K antagonist in patients with atrial fibrillation scheduled for cardioversion: the EMANATE trial

Aim

The primary objective was to compare apixaban to heparin/vitamin K antagonist (VKA) in patients with atrial fibrillation (AF) and ≤48 h anticoagulation prior to randomization undergoing cardioversion.

Methods

One thousand five hundred patients were randomized. The apixaban dose of 5 mg b.i.d. was reduced to 2.5 mg b.i.d. in patients with two of the following: age ≥ 80 years, weight ≤ 60 kg, or serum creatinine ≥ 133 µmol/L. To expedite cardioversion, at the discretion of the investigator, imaging and/or a loading dose of 10 mg (down-titrated to 5 mg) was allowed. The endpoints for efficacy were stroke, systemic embolism (SE), and death. The endpoints for safety were major bleeding and clinically relevant non-major (CRNM) bleeding.

Results

There were 1038 active and 300 spontaneous cardioversions; 162 patients were not cardioverted. Imaging was performed in 855 patients, and 342 received a loading dose of apixaban. Comparing apixaban to heparin/VKA in the full analysis set, there were 0/753 vs. 6/747 strokes [relative risk (RR) 0; 95% confidence interval (95% CI) 0-0.64; nominal P = 0.015], no SE, and 2 vs. 1 deaths (RR 1.98; 95% CI 0.19-54.00; nominal P > 0.999). In the safety population, there were 3/735 vs. 6/721 major (RR 0.49; 95% CI 0.10-2.07; nominal P = 0.338) and 11 vs. 13 CRNM bleeding events (RR 0.83; 95% CI 0.34-1.89; nominal P = 0.685). On imaging, 60/61 with thrombi continued randomized treatment; all (61) were without outcome events.

Conclusions

Rates of strokes, systemic emboli, deaths, and bleeds were low for both apixaban and heparin/VKA treated AF patients undergoing cardioversion.

Clinical Trials.gov number

NCT02100228.

Fitting the right non-vitamin K antagonist oral anticoagulant to the right patient with non-valvular atrial fibrillation: an evidence-based choice

Atrial fibrillation (AF) is the most prevalent arrhythmia and is associated with an increased risk of ischemic stroke (IS) and systemic embolism (SE). Stroke prevention is a key element for the overall management of AF patients. The non-vitamin K antagonist oral anticoagulants (NOACs), such as dabigatran, rivaroxaban, apixaban and edoxaban, are at least as effective as warfarin in reducing IS/SE with a lower rate of major bleeding. Various analyses from the large Phase III randomized trials demonstrated different efficacy and safety of NOACs in specific subgroups of patients. The randomized trials are supplemented by effectiveness and safety data from real-world observational cohorts following the availability of these drugs for use in everyday clinical practice. Given the clinical heterogeneity of AF patients, the available data from trials and real-world studies allow us to fit the right NOAC to the particular patient's characteristics, with the aim of optimizing outcomes for the individual patient. This review article aims to provide a summary of the evidence on the performance of NOACs in AF patients with specific clinical characteristics. Evidence-based suggestions are presented to provide a simple and viable strategy for clinicians for the choice of a particular NOAC. KEY MESSAGE Given the different performance of the new-oral anticoagulants in patients with the different clinical situation, evidence-based choice of fitting the right new-oral anticoagulants to the patients is provided in this review article.

Periprocedural anticoagulation in atrial fibrillation: Update on electrical cardioversion and ablation

In this manuscript, we discuss the most important changes in the field of anticoagulant treatment in patients with atrial fibrillation in the setting of electrical cardioversion or catheter ablation. Moreover, we provide practical guidance as well as information on daily practice.

Non-vitamin K antagonist oral anticoagulants versus warfarin for the prevention of spontaneous echo-contrast and thrombus in patients with atrial fibrillation or flutter undergoing cardioversion: A trans-esophageal echocardiography study

Spontaneous echo-contrast (SEC) and thrombus observed in trans-esophageal echocardiography (TEE) is known as a strong surrogate marker for future risk of ischemic stroke in patients with atrial fibrillation (AF) or atrial flutter (AFL). The efficacy of non-vitamin K antagonist oral anticoagulants (NOAC) compared to warfarin to prevent SEC or thrombus in patients with AF or AFL is currently unknown. AF or AFL patients who underwent direct current cardioversion (DCCV) and pre-DCCV TEE evaluation from January 2014 to October 2016 in a single center were analyzed. The prevalence of SEC and thrombus were compared between patients who received NOAC and those who took warfarin. NOAC included direct thrombin inhibitor and factor Xa inhibitors. Among 1,050 patients who were considered for DCCV, 424 patients anticoagulated with warfarin or NOAC underwent TEE prior to DCCV. Eighty patients who were anticoagulated for less than 21 days were excluded. Finally, 344 patients were included for the analysis (180 warfarin users vs. 164 NOAC users). No significant difference in the prevalence of SEC (44.4% vs. 43.9%; p = 0.919), dense SEC (13.9% vs. 15.2%; p = 0.722), or thrombus (2.2% vs. 4.3%; p = 0.281) was observed between the warfarin group and the NOAC group. In multivariate analysis, there was no association between NOAC and risk of SEC (odds ratio [OR]: 1.4, 95% CI: 0.796–2.297, p = 0.265) or thrombus (OR: 3.4, 95% CI: 0.726–16.039, p = 0.120). In conclusion, effectiveness of NOAC is comparable to warfarin in preventing SEC and thrombus in patients with AF or AFL undergoing DCCV. However, numerical increase in the prevalence of thrombus in NOAC group warrants further evaluation.

Comparison of Anticoagulant Therapy for Atrial Fibrillation - Novel Oral Anticoagulants Versus Vitamin K Antagonists

In patients with non-valvular atrial fibrillation (NVAF), oral anticoagulation is important for prevention of stroke and systemic embolism (SE). While Vitamin K antagonists (VKAs) have historically been the standard of care, these medications are limited by numerous food and drug interactions with onerous requirements for frequent monitoring and dose adjustments. Over the past decade, several novel oral anticoagulants (NOACs) have been developed to directly inhibit factor IIa/thrombin (dabigatran) or activated factor X (apixaban, rivaroxaban, edoxaban). These medications have been shown to be at least as effective as warfarin for stroke prevention in NVAF with more favorable safety profiles. However, their advantages are underscored by a lack of specific antidotes and assays quantifying their anticoagulant effects. This paper addresses the use of NOACs compared to VKAs in patients with NVAF, with a special focus on high-risk populations, including the elderly, those with renal disease, diabetes mellitus, coronary artery disease, and previous stroke. The current literature surrounding special clinical scenarios including the treatment of bleeding, perioperative management, and the use of NOACs in cardioversion and catheter ablation will be also discussed.

Anticoagulation in atrial fibrillation : Current evidence and guideline recommendations

Atrial fibrillation (AF) is the most frequently encountered sustained arrhythmia with a prevalence of 0.5-10%, depending predominantly on age. The arrhythmia is associated with significant morbidity and mortality, mainly due to thromboembolic events including stroke and systemic embolisms. These complications can be effectively prevented with anticoagulation therapy either with vitamin K antagonists (VKA) or with non-vitamin K antagonists (NOAC). VKA therapy is effective in preventing strokes but these medications are difficult to use, are associated with significant bleeding risk, and have pharmacokinetic/dynamic properties that make their use cumbersome. NOACs-either factor II or factor Xa inhibitors-have been developed over the past two decades and have been tested against VKA in large randomized controlled trials. This trial evidence was complemented more recently by increasing real-world data comprising several 100,000 patients. Finally, NOACs have been examined for their use in specific clinical situations, for example, in patients undergoing cardioversion, catheter ablation, or coronary interventions. In all of these clinical scenarios, NOACs have been similarly effective or-in many instances-even superior to treatment with VKA. Recent guidelines, therefore, recommend NOAC therapy for stroke prevention in AF as first-line therapy.

Direct Oral Anticoagulants in Cardioversion: A Review of Current Evidence

OBJECTIVE

Direct oral anticoagulants (DOACs) are recommended for the prevention of stroke or systemic embolism in nonvalvular atrial fibrillation. Dabigatran, rivaroxaban, apixaban, and edoxaban represent possible alternatives to warfarin in the setting of cardioversion. A literature review was conducted to evaluate the safety and efficacy of DOAC use pericardioversion.

DATA SOURCES

A PubMed and MEDLINE search through August 2017 was conducted using the following search terms alone or in various combinations: dabigatran, rivaroxaban, apixaban, edoxaban, betrixaban, DOAC, NOAC, TSOAC, cardioversion.

STUDY SELECTION AND DATA EXTRACTION

All English-language, human studies comparing the safety and efficacy of DOACs with that of other anticoagulants in the setting of cardioversion were eligible for inclusion. References from published articles were reviewed for additional relevant citations for study inclusion. Four retrospective and 2 prospective trials comparing DOACs with warfarin were identified.

DATA SYNTHESIS

The majority of studies included patients undergoing electric cardioversion. Based on current evidence, the DOACs perform similarly to warfarin in the prevention of stroke and systemic embolism, and bleeding rates are comparable.

CONCLUSIONS

DOACs may be an attractive alternative to warfarin because of fast onset of action, potentially reducing delay to cardioversion. More robust studies are needed in patients with renal dysfunction and patients undergoing pharmacological cardioversion.

Evolving cardiovascular uses of direct-acting oral anticoagulants: a paradigm shift on the horizon?

Direct-acting oral anticoagulants (DOACs), by virtue of pharmacological properties perceived as innovative, are changing the therapeutic scenario of patients requiring short- and long-term anticoagulation. The evidence gathered so far (from pre-approval pivotal trials to real-world post-marketing observational data) consistently confirms that DOACs are overall comparable to vitamin-K antagonists (VKAs) in terms of safety, efficacy, effectiveness and unequivocally documents a clinically relevant reduced risk of intracranial bleeding in the settings of non-valvular atrial fibrillation (AF) and venous thromboembolism. The following issues are attracting considerable clinical interest: (a) identifying specific subpopulations of patients with AF most likely to benefit from one of these agents (the so-called tailored therapy), and (b) expanding therapeutic indications 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 still incompletely characterized. In cardiology, the challenging task of selecting a suitable or even the most appropriate DOAC for patients with AF and a particular phenotype prompted experts to provide suggestions based on careful review of subgroups of patients from pivotal RCTs. However, in the past few months, variegated multicenter trials have been published (RE-CIRCUIT, PIONEER-AF-PCI, GEMINI-ACS-1), with potential influence on clinical practice. Therefore, this review aims to update the latest evidence on the evolving therapeutic uses of DOACs in the cardiovascular area, addressing potential impact for clinicians.

Edoxaban: How Does the Newest Agent Fit into the DOAC Landscape?

Edoxaban is the most recently approved factor Xa inhibitor within the class of direct oral anticoagulants (DOACs). Like other DOACs, edoxaban was approved by the US Food and Drug Administration for treatment of venous thromboembolism and prevention of stroke in patients with nonvalvular atrial fibrillation. Similar to other DOACs, edoxaban has fewer drug-drug interactions than warfarin and does not require routine laboratory monitoring. Unlike other DOACs, edoxaban has yet to be approved for secondary or postoperative venous thromboembolism thromboprophylaxis. Currently no antidote for edoxaban is available. To optimally prescribe agents in the DOAC class, it is critical that providers 1) understand how the agents compare; and 2) identify specific settings in which one agent may be preferred over another.

Advances in anticoagulation management of patients undergoing cardioversion of nonvalvular atrial fibrillation

Atrial fibrillation (AF) is a major cause of stroke. The restoration of sinus rhythm through cardioversion, either chemical or electrical is a common practice. Interestingly, there is an incremental increase from the baseline risk for embolisation in the immediate post-cardioversion period, with most events occurring within 10 days from cardioversion. Especially patients with recent onset AF show the lowest rates of antithrombotic therapy, while having a high stroke risk. Despite the increased risk for embolisation, anticoagulation in patients undergoing cardioversion of atrial fibrillation is often inadequate. Moreover, since the implementation of non-vitamin K antagonists oral anticoagulants (DOACs) there are several therapeutic approaches for pericardioversion anticoagulant therapy and not all suits to all patients. In addition, the extensive use of transesophageal echocardiography provides an alternative strategy, especially useful for patients of high haemorrhagic risk. In this review article, we aim to provide an update on the anticoagulation strategies for patients undergoing cardioversion of non-valvular atrial fibrillation in the advent of the use of DOACs.