Balancing bleeding and thrombotic risk with new oral anticoagulants in patients with atrial fibrillation

Atrial fibrillation (AF) markedly increases the risk of stroke. Warfarin is highly effective for the prevention of stroke in such patients, but it is difficult to use and causes bleeding. Three new oral anticoagulants have been approved for stroke prevention in AF patients, and are at least as effective as warfarin with better bleeding profiles. These new agents have changed and simplified our approach to stroke prevention, as the threshold for initiation of oral anticoagulation is lower. All patients with AF should be risk assessed using the CHA₂DS₂-VASc score, and all patients with a score of 1 or above (except women with female sex as their only risk factor on the CHA₂DS₂-VASc score) should be considered for oral anticoagulation with one of the new agents. Formal bleeding risk assessment is essential, and can be done by using the well-validated HAS-BLED score.     

Warfarin for atrial fibrillation in community‐based practise

Summary. Background: Previous studies of anticoagulation for atrial fibrillation (AF) have predominantly occurred in academic settings or randomized trials, limiting their generalizability.Objective: To describe the management of patients with AF anticoagulated with warfarin in community‐based practise.Methods: We enrolled 3396 patients from 101 community‐based practises in 38 states. Data included demographics, comorbidities, and International Normalized Ratio (INR) values. Outcomes included time in therapeutic INR range (TTR), stroke, and major hemorrhage.Results: The mean TTR was 66.5%, but varied widely among patients: 37% had TTR above 75%, while 34% had TTR below 60%. The yearly rates of major hemorrhage and stroke were 1.90 per 100 person‐years and 1.00 per 100 person‐years. Four percent of patients (n = 127) were intentionally targeted to a lower INR, and spent 42.7% of time with an INR below 2.0, compared to 18.8% for patients with a 2.0–3.0 range (P < 0.001). Mean TTR for new warfarin users (57.5%) remained below that of prevalent users through the first six months. Patients with interruptions of warfarin therapy had lower TTR than all others (61.6% vs. 67.2%, P < 0.001), which corrected after deleting low peri‐procedural INR values (67.0% vs. 67.4%, P = 0.73).Conclusions: Anticoagulation control varies widely among patients taking warfarin for AF. TTR is affected by new warfarin use, procedural interruptions, and INR target range. In this community‐based cohort of predominantly prevalent warfarin users, rates of hemorrhage and stroke were low. The risk versus benefit of a lower INR target range to offset bleeding risk remains uncertain.     

Pharmacoeconomics of anticoagulation therapy for stroke prevention in atrial fibrillation: a review

INTRODUCTION: Atrial fibrillation (AF) increases the risk of ischemic stroke 5-fold and may not only be responsible for as many as 15% of all strokes that occur but also for larger and more disabling strokes than those attributable to other causes which increase the associated costs of care. Anticoagulation with warfarin in the target INR of 2.5 is a major clinical challenge in real-life practice, given that the complex relationship between warfarin dosage and response is readily altered by a variety of factors such as concurrent medications, illnesses, genetic influences, and dietary/lifestyle changes. Consequently, INR values are out of the target range approximately half of the time in real-life studies compared to clinical trial setting. Current anticoagulation therapies are less likely to be cost-effective in routine clinical practice and need improvement. The aim of this review is to discuss the pharmacoeconomic consequences of this management strategy by analysing the optimal treatment option within specific age and risk groups, confirming current guidelines for a health economic perspective and considering the economic impact on health care policy. METHODS: An electronic search of the Medline/PubMed database from 1966 to 2005 was performed to identify articles dealing with all pharmacoeconomic aspects of stroke prevention in atrial fibrillation. The following search terms were used: 'atrial fibrillation', 'stroke', 'cost', 'warfarin'. RESULTS: Treatment with warfarin is cost-effective (versus aspirin or no therapy) in patients with AF at moderate-to-high risk of stroke. The cost-effectiveness of anticoagulation therapy is driven by the achieved risk reduction rather than the potential benefits estimated from clinical trials. Failure to maintain optimal anticoagulation places patients at risk of complications, the management of which is a significant cost driver. CONCLUSION: Improvement could be achieved by optimising physicians and patient's knowledge driven through prevention campaigns by health care policy.     

Acute anticoagulation adjustment in patients with atrial fibrillation at risk for stroke: approaches,strategies, risks and benefits

The acute management of anticoagulation in patients with atrial fibrillation to prevent stroke and other thromboembolic complications includes the use of individualized strategies tailored to the patient and based on the situation (cardioversion, surgeries, dental procedures, cardiac interventions, other invasive procedures and initiation of, or adjustment to, warfarin dosing). The vast range of choices can cause confusion and few randomized controlled clinical trials in this area provide adequate guidance. Chronic anticoagulation management is more straightforward since clinical evidence is ample, randomized clinical trial data provides cogent informaiton and guidelines have been established. Acute management of anticoagulation in patients with atrial fibrillation to prevent thromboembolic complications is often unrecognized but is emerging as a crucial, but challenging, and increasingly complex aspect of the care of patients with atrial fibrillation. This review addresses issues regarding such patients who may be at risk for stroke and require acute adjustments of anticoagulation (in light of, or in lieu of, chronic anticoagulation). Several promising new strategies are considered in light of established medical care. This analysis provides practical recommendations based on available data and presents results from recent investigations that may provide insight into future strategies.     

Adherence to oral anticoagulation in ischemic stroke patients with atrial fibrillation

BackgroundNon-vitamin K antagonist oral anticoagulants (NOAC) have superior safety and comparable efficacy profile compared to vitamin-K antagonists (VKAs), with more convenient dosing schemes. However, issues with adherence to the NOACs remain unsolved.AimsWe sought to investigate the adherence to oral anticoagulation (OAC) and baseline factors associated with poor adherence after ischaemic stroke in patients with atrial fibrillation (AF).MethodsWe recruited hospitalised patients (2013–2019) from two prospective stroke registries in Larissa and Helsinki University Hospitals and invited survived patients to participate in a telephone interview. We assessed adherence with the Adherence to Refills and Medications Scale (ARMS) and defined poor adherence as a score of over 17. In addition to demographics, individual comorbidities, and stroke features, we assessed the association of CHA₂DS₂-VASc and SAMe-TT₂R₂ scores with poor adherence.ResultsAmong 396 patients (median age 75.0 years, interquartile range [IQR] 70–80; 57% men; median time from ischaemic stroke to interview 21 months [IQR 12–33]; median ARMS score 17 [IQR 17–19]), 56% of warfarin users and 44% of NOAC users reported poor adherence. In the multivariable regression model adjusted for site, sex, and age, poor adherence was independently associated with tertiary education, absence of heart failure, smoking history, use of VKA prior to index stroke, and prior ischaemic stroke. CHA₂DS₂-VASc and SAMe-TT₂R₂ scores were not associated with poor adherence.ConclusionsAdherence was poor in half of AF patients who survived an ischaemic stroke. Independent patient-related factors, rather than composite scores, were associated with poor adherence in these patients.

KEY MESSAGES

• Adherence was poor in half of the atrial fibrillation patients who survived an ischaemic stroke.
• Independent patient-related factors rather than composite scores were associated with poor adherence.
• The findings support the importance of recognising adherence support as a crucial part of holistic patient care recommended by recent AF guideline.

     

Stroke risk assessment for atrial fibrillation: hospital-based stroke risk assessment and intervention program

Background: Despite the proven effectiveness of antithrombotic therapy for atrial fibrillation (AF), the treatment remains suboptimal. The aim of this study was to implement and evaluate a system to improve the appropriate use of antithrombotics for stroke prevention in AF utilizing a clinical pharmacist as a stroke risk assessor. Method: Hospital in‐patients with AF were prospectively identified and they received a formal stroke risk assessment from a pharmacist. The patients’ risk of stroke was assessed and documented according to Australian guidelines and a recommendation regarding antithrombotic therapy was made to the medical team on a specially designed stroke risk assessment form. Results: One hundred and thirty‐four stroke risk assessments were performed during the intervention period. For those patients at high risk of stroke and with no contraindication present (warfarin‐eligible patients), 98% were receiving warfarin on discharge from hospital compared to 74% on admission (P < 0·001). Of the 50 (37%) assessments that recommended a change of therapy, 44 (88%) resulted in a change in the patient’s current antithrombotic therapy compared to their admission therapy. Thirty (68%) of the assessments resulted in an ‘upgrade’ to more‐effective treatment options for example from no therapy to any agent or from aspirin to warfarin. Discussion and Conclusion: The pharmacist‐led stroke risk assessment program resulted in a significant increase in the proportion of patients receiving appropriate thromboprophylaxis for stroke prevention in AF. The methods used in this study should be evaluated in a larger trial, in multiple hospitals, with different pharmacists performing the intervention.     

Value of pacemaker atrial diagnostic data in patients with paroxysmal atrial fibrillation: an opportunity to improve rates of warfarin utilization

Atrial diagnostic data within implantable devices provide an opportunity to assess the frequency and quantity of atrial fibrillation (AF) episodes (AF burden) and its impact on appropriate warfarin anticoagulation. Cardiologists were given clinical scenarios to review with different types of pacemaker diagnostic data in an elderly patient with risk factors for stroke. AF specific data was associated with increased warfarin utilization, but only at intermediate rates. Potential reasons and clinical implications are discussed.     

Nonsteroidal anti-inflammatory drugs and bleeding risk in anticoagulated patients with atrial fibrillation

Although nonsteroidal anti-inflammatory drugs (NSAIDs) have generally conferred increased gastrointestinal bleeding risk, the data for bleeding risks with these drugs in anticoagulated atrial fibrillation (AF) patients per se were much more limited. Recent evidence shows that concomitant use of NSAIDs in anticoagulated AF patients carries a real risk of serious bleeding, as well as thromboembolism. Thus, physicians should clearly exercise extra caution with NSAIDs in patients with AF, especially if they are anticoagulated. Also, AF patients with NSAIDs should also undergo regular clinical review, and clinicians should regularly reassess the need for NSAID use. Finally, as a part of regular clinical assessment, bleeding risk should be routinely assessed, and the HAS-BLED score is now recommended in many guidelines for this purpose.     

老年心房颤动患者华法林长期抗凝治疗的效果与安全性

目的：探讨老年心房颤动（房颤）患者华法林长期抗凝治疗的疗效、安全性和华法林剂量的动态变化,为经验性抗凝治疗提供依据。方法选取心血管专科门诊每月进行规律随访的抗凝治疗时间＞12个月、年龄≥65岁的持续性房颤患者52例,根据随访记录统计患者出血、脑梗死的情况以及华法林的用药剂量。结果经心电图确诊的持续性房颤患者52例,其中男30例,女22例,平均年龄（72．5±5．6）岁,平均随访时间（23．20±11．35）个月;在随访期间,未出现颅内出血等严重威胁生命的出血,轻度出血10例,其中牙龈出血2例、鼻出血1例、咯血2例、结膜出血3例和双下肢皮肤瘀斑 2例;52例患者出现脑梗死 1例（1．9％）;在长达24个月的随访时间中,房颤患者华法林抗凝治疗的剂量无显著变化,达到充分抗凝的平均剂量为3．6 mg／d左右。结论房颤患者长期抗凝治疗安全有效,其平均维持剂量约为3．6 mg／d,但需要规律检测国际标准化比值。