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Thromboembolism is the crucial cause of ischemic stroke in patients with atrial fibrillation (AF). Anticoagulation therapy with vitamin K antagonists, such as warfarin, have been proven to be effective for stroke prevention in AF. Nonetheless, the use of warfarin may be limited due to increased risk of bleeding, the potential interaction with multiple foods and drugs, and the need for routine coagulation monitoring. Over the last decade anticoagulants, such as dabigatran and rivaroxaban, have been developed and have shown superiority compared to warfarin for preventing stroke in patients with nonvalvular AF in large randomized trials. In addition, on account of the risk of thrombus formation in the left atrial appendage (LAA), many nonpharmacologic approaches have been developed to reduce stroke risk in patients with AF who are not candidates for anticoagulant therapy. Surgical, epicardial, and endovascular techniques for LAA closure are being investigated currently. Both novel pharmacotherapy and nonpharmacologic approaches for stroke prevention will be detailed in this review.  相似文献   

3.
Helbing T  Bode C  Moser M 《Hamostaseologie》2012,32(3):195-202
Rivaroxaban (Xarelto(?)) is a new anticoagulant for the prevention and treatment of thromboembolic disorders. Rivaroxaban inhibits coagulation factor Xa directly, has high oral bioavailability, shows low propensity for drug-drug interactions and requires no routine coagulation monitoring. In patients undergoing elective knee or hip replacement surgery rivaroxaban (10 mg/d) is highly effective to prevent venous thromboembolism. In patients with non-valvular atrial fibrillation rivaroxaban (20 mg/d) has been approved to prevent stroke or systemic embolism. The favourable benefit-risk profile of rivaroxaban in the treatment of deep vein thrombosis (DVT) was shown in EINSTEIN-DVT and led to its clinical approval (twice daily 15 mg for 3 weeks, followed by 20 mg/d). Based on ATLAS-ACS-TIMI-51 which has shown that rivaroxaban (2.5 mg twice daily) reduced thrombotic cardiovascular events and mortality in patients with a recent acute coronary syndrome, the approval of low dose rivaroxaban has been submitted for this indication. Taken together, rivaroxaban may become an effective alternative to standard anticoagulants in the prevention and treatment of thromboembolic disorders.  相似文献   

4.
Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.  相似文献   

5.
Atrial fibrillation (AF) is associated with an increased risk of ischemic stroke or systemic embolism compared with normal sinus rhythm. These strokes may efficiently be prevented in patients with risk factors using oral anticoagulant therapy, with either vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) (i.e., direct thrombin inhibitors or direct factor Xa inhibitors). Owing to their specific risk profiles, some AF populations may have increased risks of both thromboembolic and bleeding events. These AF patients may be denied oral anticoagulants, whilst evidence shows that the absolute benefits of oral anticoagulants are greatest in patients at highest risk. NOACs are an alternative to VKAs to prevent stroke in patients with “non-valvular AF”, and NOACs may offer a greater net clinical benefit compared with VKAs, particularly in these high-risk patients. Physicians have to learn how to use these drugs optimally in specific settings. We review concrete clinical scenarios for which practical answers are currently proposed for use of NOACs based on available evidence for patients with kidney disease, elderly patients, women, patients with diabetes, patients with low or high body weight, and those with valve disease.  相似文献   

6.
For decades, warfarin has remained the standard oral anticoagulation for stroke prevention in atrial fibrillation (AF). Three novel oral anticoagulants (NOACs) have been recently approved for stroke prevention in non-valvular AF: dabigatran, rivaroxaban and apixaban. Better pharmacological and clinical profiles make these newcomers a preferable alternative over warfarin. Current AF guidelines do not endorse NOACs over warfarin, or one NOAC over another. Indeed, choice of the anticoagulation regimen should be personalized based on the relative efficacy and safety of different agents across subgroups stratified by thrombotic and bleeding risk, as well as on other clinical factors, including anticoagulation control on warfarin, drug interactions, compliance and need for coagulation monitoring. This review appraises i) the randomized evidence on approved NOACs versus warfarin in AF across subgroups stratified by risk factors of stroke and bleeding and by the anticoagulation level reached on warfarin; and ii) clinical factors impacting on the anticoagulation regimen selection.  相似文献   

7.
Atrial fibrillation (AF) is the most common cardiac arrhythmia. It is estimated that 1 in 4 individuals aged 40 years or above will develop at least 1 episode of AF during their lifetime. Stroke is a leading cause of serious, long-term disability and death, and a major socioeconomic burden in developed countries. The major risk factor for thromboembolic stroke is AF. Oral antithrombotic treatment for AF patients has been limited to vitamin K antagonists for more than 60 years. Treatment with warfarin can reduce, but fails to abolish thromboembolic stroke associated with AF. Despite anticoagulation, patients with AF are at increased stroke risk. Furthermore, warfarin has important limitations namely, the limited time in therapeutic range, the need for INR monitoring, risk of major bleeding including stroke, and drug interactions. Recently there have been very exciting and important new advances in thromboprophylaxis for AF. Novel oral agents have been developed and evaluated clinically. These include direct thrombin inhibitors (dabigatran etexilate), oral selective factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) and PAR-1 inhibitors (vorapaxar and atopaxar). Some of the new drugs have demonstrated promising results in the clinical studies, they are convenient in use and do not require monitoring. The downsides are lack of antidotes or specific blood assays to monitor the anticoagulant effect. This review evaluates traditional and novel approaches to thromboprophylaxis in patients with AF.  相似文献   

8.
Ischemic stroke, a major complication of atrial fibrillation (AF), is believed to result from atrial thrombus formation caused by ineffective atrial contraction. Oral anticoagulant therapy effectively reduces the risk of ischemic stroke in patients with AF; this therapy is recommended for patients with any frequency or duration of AF and other risk factors for stroke, such as increased age (>75 years), hypertension, prior stroke, left ventricular dysfunction, diabetes, or heart failure. Recently published data comparing rate-control and rhythm-control strategies in AF emphasized the importance of maintaining an international normalized ratio higher than 2.0 during warfarin therapy and the need for continuing anticoagulant therapy to prevent stroke in high-risk patients, even if the strategy is rhythm control. Hemorrhagic complications can be minimized by stringent control of the international normalized ratio (particularly in elderly patients) and appropriate therapy for comorbidities such as hypertension, gastric ulcer, and early-stage cancers. Undertreatment of patients with AF is a continuing problem, particularly in the elderly population. Patients perceived as likely to be noncompliant, such as the functionally impaired, are less likely to receive warfarin therapy. However, stroke prevention with anticoagulants is cost-effective and improves quality of life, despite the challenges of maintaining appropriate anticoagulation with monitoring and warfarin dose titration. New medications in development with more predictable dosing and fewer drug-drug interactions may reduce the complexities of achieving optimal anticoagulation and increase the practicality of long-term anticoagulant therapy for patients with AF at risk of stroke.  相似文献   

9.
Stroke prevention in atrial fibrillation (AF) has been challenging over decades, mostly due to a number of difficulties associated with oral vitamin K antagonists (VKAs), which have been the most effective stroke prevention treatment for a long time. The oral direct thrombin inhibitors (e.g., dabigatran) and oral direct inhibitors of factor Xa (e.g., rivaroxaban, apixaban) have emerged recently as an alternative to VKAs for stroke prevention in AF. These drugs act rapidly, and have a predictable and stable dose-related anticoagulant effect with a few clinically relevant drug-drug interactions. The novel oral anticoagulants are used in fixed doses with no need for regular laboratory monitoring of anticoagulation intensity. However, each of these drugs has distinct pharmacological properties that could influence optimal use in clinical practice. The following phase 3 randomized trials with novel oral anticoagulants versus warfarin for stroke prevention in AF have been completed: the Randomized Evaluation of Long-term Anticoagulant therapy (RE-LY) trial with dabigatran, the Rivaroxaban Once daily oral direct Factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trial with rivaroxaban, and the Apixaban for Reduction of Stroke and Other Thromboembolism Events in Atrial Fibrillation (ARISTOTLE) trial with apixaban. Moreover, the Apixaban Versus Acetylsalicylic Acid to prevent Strokes (AVERROES) trial included patients with AF who have failed or were unsuitable for warfarin, and compared apixaban versus aspirin for stroke prevention in AF. Overall, apixaban has two large trials for stroke prevention in AF showing benefits not only over warfarin, but also over aspirin among those patients who have failed or refused warfarin. In the ARISTOTLE trial, apixaban was superior to warfarin in the reduction of stroke or systemic embolism, major bleeding, intracranial hemorrhage, and all-cause mortality, with a similar reduction in the rate of ischemic stroke and better tolerability. When compared with aspirin in the AVERROES trial, apixaban was associated with more effective reduction of stroke, a similar risk of major bleeding, and better tolerability. In this review article, the authors summarize the current knowledge on novel oral anticoagulants and discuss the clinical aspects of their use for stroke prevention in AF, with particular emphasis on apixaban.  相似文献   

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心房颤动(房颤)在人群中的发病率逐年升高,成为临床中最常见的心律失常之一。脑栓塞是房颤最主要的并发症。抗凝治疗仍然是预防房颤脑卒中的主要手段,但无论是华法林还是新型抗凝药都有一定的局限性,存在相关的风险及禁忌,且依从性差。鉴于非瓣膜病性房颤患者90%以上的血栓来源于左心耳(LAA),故对于一些栓塞风险高的房颤患者,经皮左心耳封堵术已成为长期华法林替代治疗以降低新发脑卒中风险的另一选择。  相似文献   

12.
Approximately 1 in 3–4 patients presenting with an ischemic stroke will also have atrial fibrillation (AF), and AF-related strokes can be effectively prevented using oral anticoagulant therapy (OAC), either with well-controlled vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs). In addition, OAC use (both VKAs and NOACs) is associated with a 26% reduction in all-cause mortality (VKAs) or an additional 10% mortality reduction with NOACs relative to VKAs. The decision to use OAC in individual AF patient is based on the estimated balance of the benefit from ischemic stroke reduction against the risk of major OAC-related bleeding [essentially intracranial hemorrhage (ICH)]. Better appreciation of the importance of VKAs’ anticoagulation quality [a target time in therapeutic range (TTR) of ≥70%] and the availability of NOACs (which offer better safety compared to VKAs) have decreased the estimated threshold for OAC treatment in AF patients towards lower stroke risk levels. Still, contemporary registry-based data show that OAC is often underused in AF patients at increased risk of stroke. The uncertainty whether to use OAC may be particularly pronounced in AF patients with a single additional stroke risk factor, who are often (mis)perceived as having a “borderline” or insufficient stroke risk to trigger the use of OAC. However, observational data from real-world AF cohorts show that the annual stroke rates in such patients are higher than in patients with no additional stroke risk factors, and OAC use has been associated with reduction in stroke, systemic embolism, or death in comparison to no therapy or aspirin, with no increase in the risk of bleeding relative to aspirin. In this review article, we summarize the basic principles of stroke risk stratification in AF patients and discuss contemporary real-world evidence on OAC use and outcomes of OAC treatment in AF patients with a single additional stroke risk factor in various real-world AF cohorts.  相似文献   

13.
Atrial fibrillation (AF) is said to be an epidemic, affecting 1%–1.5% of the population in the developed world. The clinical significance of AF lies predominantly in a 5‐fold increased risk of stroke. Strokes associated with AF are usually more severe and confer increased risk of morbidity, mortality, and poor functional outcome. Despite the advent of promising experimental therapies for selected patients with acute stroke, pharmacological primary prevention remains the best approach to reducing the burden of stroke.

New antithrombotic drugs include both parenteral agents (e.g. a long‐acting factor Xa inhibitor idraparinux) and oral anticoagulants, such as oral factor Xa inhibitors and direct oral thrombin inhibitors (ximelagatran, dabigatran). Ximelagatran had shown significant potential as a possible replacement to warfarin therapy, but has been withdrawn because of potential liver toxicity. Its congener dabigatran appears to have a better safety profile and has recently entered a phase III randomized clinical trial in AF. Oral factor Xa inhibitors (rivaroxaban, apixaban, YM150) inhibit factor Xa directly, without antithrombin III mediation, and may prove to be more potent and safe.

Selective inhibitors of specific coagulation factors involved in the initiation and propagation of the coagulation cascade (factor IXa, factor VIIa, circulating tissue factor) are at an early stage of development. Additional new agents with hypothetical, although not yet proven, anticoagulation benefits include nematode anticoagulant peptide (NAPc2), protein C derivatives, and soluble thrombomodulin.

A battery of novel mechanical approaches for the prevention of cardioembolic stroke has recently been evaluated, including various models of percutaneous left atrial appendage occluders which block the connection between the left atrium and the left atrial appendage, minimally invasive surgical isolation of the left atrial appendage, and implantation of the carotid filtering devices which divert large emboli from the internal to the external carotid artery, preventing the embolic material from reaching intracranial circulation.

Despite recent advances and promising new approaches, prevention of recurrent AF may be one of the best protections against AF‐related stroke and may reduce the prevalence of stroke by almost 25%. Improved pharmacological and nonpharmacological rhythm control strategies for AF as well as primary prevention of AF with ‘upstream’ therapy and risk factor modification are likely to produce a larger effect on the reduction of stroke rates in the general population than will specific interventions.  相似文献   

14.
Atrial fibrillation (AF) is the most common cardiac arrhythmia. The prevalence of AF is 0.4% in the general population and increases with age up to 6-8% in octogenarians. In Switzerland, approximately 68,000 persons are in atrial fibrillation, and in the EU countries 3.5 millions. Atrial fibrillation disturbs synchronous mechanical atrial activity and impairs the haemodynamics. This can give rise to thrombus formation, mostly in the left atrial appendage, and embolism to the systemic circulation. Clinical manifestations are most often neurological such as transient ischaemic attacks or ischaemic strokes, on average 5% per year. Of all strokes, one in every six occurs in patients with AF. Antiarrhythmic therapy is useful to improve cardiac rate and function in AF. However, to reduce first or recurrent emboli, antithrombotic therapy is of paramount importance. Adjusted-dose warfarin reduces first or recurrent strokes by about 60%. When patients with non-valvular AF are anticoagulated, the odds against ischaemic stroke and intracranial bleeding favour an INR between 2.0 and 3.0. Acetylsalicylic acid is less efficacious than warfarin in AF patients, reducing the risk of stroke by about 20%. Therefore, anticoagulation is the current treatment modality in AF patients at high or intermediate risk, i.e. patients with history of transient ischaemic attack or stroke, those aged > 65 years, those with a history of hypertension, diabetes, heart failure or structural heart disease, valvular disease or significant systolic dysfunction. Antiplatelet agents should be used only for young (< 65 years) AF patients at low risk.  相似文献   

15.
目的回顾性分析心房颤动(房颤)患者的抗凝治疗与卒中情况。 方法调查2015年8月1日至2017年6月30日苏北人民医院住院房颤患者301例的病例资料,记录性别、年龄、主要诊断、合并疾病情况、CHA2DS2-VASc评分、HAS-BLED评分、INR值、华法林剂量、新型口服抗凝剂(NOAC)、阿司匹林使用情况、血栓栓塞事件、出血事件情况,分析抗凝治疗的规范性及其与临床后果的关系。 结果住院房颤患者平均年龄(72±11)岁,房颤类型以非瓣膜型房颤为主,占93.7%(282/301),58.8%的房颤患者采用口服华法林抗凝治疗,4%接受NOAC抗凝治疗。华法林抗凝治疗组缺血性卒中发生率显著低于未抗凝治疗组差异具有统计学意义(13.0% vs 20.5%,P=0.025)。瓣膜型和非瓣膜型房颤患者华法林抗凝治疗后INR达标(INR 2.0~3.0)的比率分别为15.8%和7.1%。 结论为了达到更好的房颤患者卒中预防效果,需进一步加强华法林抗凝治疗的教育和监测。  相似文献   

16.
Atrial fibrillation (AF) affects more than 3 million Americans and is expected to reach epidemic proportions as the US population ages. The presence of AF increases lifetime stroke risk nearly 5-fold. Conventionally, patients at moderate or high risk of stroke have been prescribed antiplatelet agents or vitamin K antagonists to reduce the risk, but each has significant limitations. Accordingly, the development of new oral anticoagulants (direct thrombin inhibitors [DTIs] and factor Xa inhibitors) has attracted significant interest. The DTI dabigatran etexilate was recently shown to provide superior risk reduction to warfarin for stroke and systemic embolism for patients with nonvalvular AF and recently gained US Food and Drug Administration approval for this indication. Dabigatran etexilate is the first new agent for this indication in the United States in more than 50 years. Herein, we outline the options for stroke prevention in AF in the new oral anticoagulant era. The efficacy and practical obstacles surrounding the use of warfarin are summarized. We then review the mechanism of action, efficacy, and safety of dabigatran-including clinically relevant pharmacokinetics. Practical issues of initiation, conversion of anticoagulant therapy, and recommendations for dabigatran use in patients at high risk of bleeding and other special populations are discussed. We conclude by proposing a role for dabigatran in the armamentarium of drugs available for the management of stroke risk in AF.  相似文献   

17.

Background

Emergency department (ED) clinicians are not typically involved in the long-term management of patients' anticoagulation therapy, but they are responsible for decision making for emergency conditions requiring anticoagulation, such as acute venous thromboembolism (VTE). In addition, emergency physicians are often faced with patients who present first to the ED with conditions that may prompt long-term anticoagulation upon hospital discharge, such as atrial fibrillation (AF), or who have acute or potential bleeding complications from anticoagulation.

Objective

In this review, clinical trials of new oral anticoagulants evaluated for treatment of VTE and stroke prophylaxis in AF, as well as practical management aspects, will be discussed. In addition, clinical trials evaluating the adjunctive use of the new oral anticoagulants with antiplatelet therapy in patients who have experienced acute coronary syndrome will be explored.

Discussion

Both dabigatran etexilate and rivaroxaban have successfully completed phase III trials for acute VTE treatment and are currently approved for the reduction of risk of stroke and systemic embolism in patients with nonvalvular AF. In a recently completed phase III trial, apixaban also demonstrated promising efficacy and safety in that indication. Rivaroxaban represents the only new anticoagulant to date to have shown promising phase III results as an adjunct to antiplatelet therapy after acute coronary syndrome.

Conclusion

Knowledge of the appropriate clinical use and safety concerns of the new anticoagulants is imperative as they become more frequently prescribed, and their potential uses in the ED setting represent an important aspect of continuing education for emergency physicians.  相似文献   

18.

Objective

To compare key features of the new oral anticoagulants (NOACs)—dabigatran, rivaroxaban, and apixaban—and to address questions that arise when comparing the NOACs.

Sources of information

PubMed was searched for recent (January 2008 to week 32 of 2013) clinical studies relating to NOAC use for stroke prevention in atrial fibrillation (AF) and for the treatment of acute venous thromboembolism (VTE).

Main message

All NOACs are at least as effective as warfarin for stroke prevention in patients with nonvalvular AF, and are at least as safe in terms of bleeding risk according to 3 large trials. Meta-analyses of these trials have shown that, compared with warfarin therapy, NOACs reduced total mortality, cardiovascular mortality, and intracranial bleeding, and there was a trend toward less overall bleeding. Practical advantages of NOACs over warfarin include fixed once- or twice-daily oral dosing without the need for coagulation monitoring, and few known or defined drug or food interactions. Potential drawbacks of NOACs include a risk of bleeding that might be increased in patients older than 75 years, increased major gastrointestinal bleeding with high-dose dabigatran, increased dyspepsia with dabigatran, the lack of a routine laboratory test to reliably measure anticoagulant effect, and the lack of an antidote for reversal. No direct comparisons of NOACs have been made in randomized controlled trials, and the choice of NOAC is influenced by individual patient characteristics, including risk of stroke or VTE, risk of bleeding, and comorbidity (eg, renal dysfunction).

Conclusion

The NOACs represent important alternatives in the management of patients with AF and VTE, especially for patients who have difficulty accessing regular coagulation monitoring. The companion to this article addresses common “what if” questions that arise in the long-term clinical follow-up and management of patients receiving NOACs.  相似文献   

19.
Atrial fibrillation (AF) is a major cause of ischemic stroke, especially in the elderly. There are currently enough data to support the notion that anticoagulation with warfarin or dabigatran is far superior to aspirin in the prevention of stroke or systemic embolism in AF. Aspirin is the preferred modality in patients who are either not candidates for anticoagulation, such as patients with increased risk for bleeding, low-risk patients based on the CHADS2 score or patients who have difficulty in maintaining a therapeutic international normalized ratio. There is no dispute on the recommendations regarding stroke prevention in high-risk patients (CHADS2 risk score of 2 and beyond) with AF. However, there is some controversy regarding the appropriate strategy (anticoagulation vs aspirin) for stroke prevention in low-risk patients (CHA2DS2-VASc score of 0-1). Novel oral anticoagulant drugs (direct thrombin inhibitors and Factor Xa inhibitors) might further diminish the role of aspirin for stroke prevention in AF due to their superior efficacy, lack of need for monitoring of therapeutic effects and lower bleeding risk when compared with warfarin, especially in patients with stable vascular disease.  相似文献   

20.
Several large prospective randomized trials have demonstrated that anticoagulation with warfarin reduces the risk of thromboembolic stroke in high risk patients with chronic AF by approximately 70%. Large numbers of patients with permanent pacemakers have AF, and anticoagulation rates in this population have not been described. In a prospective analysis of 110 consecutive patients attending the pacemaker clinic of a large university hospital, we assessed the number of patients with AF and the proportion of these patients who were receiving anticoagulation to prevent thromboembolic stroke. Where necessary, temporary pacemaker reprogramming to low ventricular rates was utilized to facilitate the diagnosis of AF. Fifty-three of the 110 patients (48%) were diagnosed with AF, all of whom (100%) had accepted high risk factors for thromboembolic stroke. Only eight of the 53 (15%) had been anticoagulated with warfarin. Thirty-six of the 53 patients (68%) diagnosed with AF had no prior documented diagnosis of chronic AF, and the majority had no symptoms suggesting AF. A single lead II ECG was insufficient in 67 of the 110 patients (61%) to diagnose the underlying atrial rhythm; the remainder required 12-lead ECGs or temporary pacemaker reprogramming to low ventricular rates to diagnose the underlying atrial rhythm. AF is common in patients with permanent pacemakers. It is commonly asymptomatic, and anticoagulation is markedly underutilized in reducing stroke risk in these patients. Attention to the possibility of AF in paced patients should allow prompt diagnosis and allow both the initiation of anticoagulation in order to reduce thromboembolic stroke risk and consideration for cardioversion of AF to sinus rhythm.  相似文献   

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