Pre-admission warfarin use in patients with acute ischemic stroke and atrial fibrillation: The appropriate use and barriers to oral anticoagulant therapy

Use of oral anticoagulants and its associated factors among nonvalvular atrial fibrillation patients with new-onset acute ischemic stroke: A report from the China Atrial Fibrillation Registry study

Background

The adherence of oral anticoagulant (OAC) therapy among nonvalvular atrial fibrillation (NVAF) patients with acute ischemic stroke (AIS) in China during recent years was unclear, and the possible factors that influenced the initiation and persistent use of OAC were needed to be explored.

Methods

A total of 1085 NVAF patients, who experienced new‐onset and nonfatal AIS from August 2011 to December 2020 during follow‐ups in the China Atrial Fibrillation Registry (China‐AF), were enrolled. Information including patients' demographic characteristics, medical history, medication usage, which were collected before and after the index stroke, were used in the analysis.

Results

OAC was initiated in 40% (434/1085) NVAF patients within 3 months after new‐onset AIS. High‐reimbursement‐rate insurance coverage (odds ratio [OR]: 1.51, 95% confidence interval [CI]: 1.03–2.22, p = .036), 3‐month‐peri‐stroke AF episodes (OR: 2.63, 95% CI: 1.88–3.69, p < .001), and pre‐stroke OAC usage (OR: 8.92, 95% CI: 6.01–13.23, p < .001), were positively associated with initiation of OAC within 3 months after new‐onset AIS, while age (OR: 0.98, 95% CI: 0.96–1.00, p = .024), female (OR: 0.63, 95% CI: 0.44–0.90, p = .012) and higher modified HASBLED score (OR: 0.45, 95% CI: 0.37–0.55, p < .001) were negatively associated with it. Among 3‐month‐post‐stroke OAC users, history of radiofrequency ablation (hazard ratio: 1.65, 95% CI: 1.16–2.35; p = .006) was positively associated with non‐persistence of OAC usage.

Conclusions

In China, the proportion of NVAF patients who initiated OAC therapy since new‐onset AIS was still low. More efforts are needed on improving patients' adherence to anticoagulant therapy.

The Guideline-Policy Gap in Direct-Acting Oral Anticoagulants Usage in Atrial Fibrillation: Evidence, Practice, and Public Policy Considerations

Atrial fibrillation has a high disease burden-both in prevalence and associated consequences. Despite anticoagulation being an effective treatment in atrial fibrillation, stroke prevention is slow to reflect evidence-based practice. Real-world data reveal a substantial portion of patients who would benefit from anticoagulation, yet do not receive it adequately or at all. A large part of this suboptimal treatment is due to the underutilization of direct oral anticoagulants (DOACs). In response to abundant evidence published over a short timeframe, international guidelines have adopted DOAC usage ahead of policy and fund holders. This paper reviews the evidence and values that influence published guidelines, patient-physician decision making, and policy framework on DOAC usage. An important factor is the access gap between patients who qualify for DOAC according to evidence-based guidelines and the subset of this cohort who are eligible for DOAC based on government funded policy. We analyse the Canadian health system in detail-including drug approval and funding process. Health care systems in other countries are explored, with emphasis on similar universal health care systems that may help overcome barriers common to Canada. We will discuss strategies to: (1) improve awareness of the risk and preventability of stroke; (2) enable physicians to provide evidence-based DOAC usage; (3) empower patients to improve adherence and persistence; (4) collect real-life data that encourages patient self-monitoring, physician outcomes auditing, and building evidence that is useful for policy makers; and (5) use postmarketing data in negotiating shared risk management between pharmaceuticals and government to improve access to DOACs.

The safety of NOACs in atrial fibrillation patient subgroups: A narrative review

AIM

Four non-vitamin K oral anticoagulants (NOACs) have been evaluated in clinical trials for the prevention of stroke in patients with atrial fibrillation (AF). Although each of the NOACs have been shown to be at least non-inferior to warfarin for efficacy and safety outcomes, controversy remains over the relative safety of each NOAC inpatient subgroups. This narrative review provides an overview of phase III data on NOAC trials for the prevention of stroke in AF, with a focus on reporting the safety of each agent in key patient subgroups based on age, gender, accumulated risk factors, and primary or secondary prevention of stroke.

METHODS

A comprehensive literature search was completed and, where data permit, analyses of phase III trials of the NOACs are presented for each patient subgroup.

RESULTS

Analyses of key safety outcomes from NOAC trials were completed using primary trial data, including major bleeding and all-cause mortality. The safety of NOACs was generally consistent and favourable compared with warfarin according to patient age, gender, previous history of stroke, and the presence of risk factors for stroke.

CONCLUSIONS

The safety of the NOACs compared with warfarin was generally favourable across different patient subgroups, including those perceived to be at "high risk" for adverse outcomes. However, certain NOACs may be preferable to warfarin in some subgroups, based on indirect analyses.

Optimal choice of pharmacological therapy – Prevention of stroke and assessment of bleeding risk in patients with atrial fibrillation

Background:

The aim of the study was to highlight the importance of adequate anticoagulant therapy and the correlation of higher risk of stroke.

Methods:

This study analyzed data obtained from 103 patients with diagnosis of atrial fibrillation (AF) (39 of them had a stroke). Patients were divided into groups according to the CHADS₂, CHA₂DS₂-VASc, and HASBLED scores.

Results:

An analysis showed that anticoagulant drugs were more often prescribed to subjects <75 years of age (P = 0.001). Patients with a higher CHADS₂ score had a higher CHA₂DS₂-VASc score and vice versa (rho = 0.513; P = 0.0001). According to the CHA₂DS₂-VASc, 91.3% of the patients examined were prescribed an anticoagulant medication as a therapy at discharge from the hospital. The result was statistically significant compared to the practice where an anticoagulant was prescribed to 55.9% of high-risk subjects as estimated by the CHA₂DS₂-VASc score (P < 0.05). Our results also show that rivaroxaban is more commonly prescribed as a discharge therapy than warfarin (χ² = 12.401; P = 0.0001). Furthermore, a significantly higher number of patients who were being prescribed aspirin (38.5%) had a stroke compared to 12.8% of patients who were being prescribed warfarin (χ² = 12.259; P = 0.0001).

Conclusions:

Novel oral anticoagulants (NOACs) seem to be a better choice as a pharmacological therapy in the treatment of AF, due to a lack of adequate monitoring of patients’ international normalized ratio (INR) values. CHA₂DS₂-VASc and HASBLED scores must be used as a part of routine clinical diagnostics when dealing with patients with AF.

Exploring patient–provider decision-making for use of anticoagulation for stroke prevention in atrial fibrillation: Results of the INFORM-AF study

Background:

Atrial fibrillation is associated with stroke, yet approximately 50% of patients are not treated with guideline-directed oral anticoagulants (OACs).

Aims:

Given that the etiology of this gap in care is not well understood, we explored decision-making by patients and physicians regarding OAC use for stroke prevention in atrial fibrillation.

Methods and results:

We conducted a descriptive qualitative study among providers ( N=28) and their patients with atrial fibrillation for whom OACs were indicated ( N=25). We used purposive sampling across three outpatient settings in which atrial fibrillation patients are commonly managed: primary care ( n=14), geriatrics ( n=10), and cardiology ( n=4). Eligible patients were stratified by those prescribed OAC ( n=13) and not prescribed OAC ( n=12). Semi-structured, in-depth interviews assessed decision-making regarding risk and OAC use. Classical content analysis was used to code narratives and identify themes. Results among patients consisted of the overarching theme of trust in provider recommendations. Sub-themes included: awareness of increased risk of stroke with atrial fibrillation; willingness to accept medications recommended by their physician; and low demand for explanatory decision aids. Among physicians, the overarching theme was decisional conflict regarding the balance between stroke and bleeding risk, and the optimal medication to prescribe. Subthemes included: absence of decision aids for communication; and misperceptions around the assessment and management of stroke risk with atrial fibrillation.

Conclusions:

Patient involvement in decision-making around OAC use did not occur in this study of patients with atrial fibrillation. Improved access to decision aids may increase patient engagement in the decision-making process of OAC use for stroke prevention.

Cost-effectiveness of dabigatran etexilate for the prevention of stroke and systemic embolism in atrial fibrillation: A Canadian payer perspective

Oral dabigatran etexilate is indicated for the prevention of stroke and systemic embolism in patients with atrial fibrillation (AF) in whom anticoagulation is appropriate. Based on the RE-LY study we investigated the cost-effectiveness of Health Canada approved dabigatran etexilate dosing (150 mg bid for patients <80 years, 110 mg bid for patients ≥80 years) versus warfarin and “real-world” prescribing (i.e. warfarin, aspirin, or no treatment in a cohort of warfarin-eligible patients) from a Canadian payer perspective. A Markov model simulated AF patients at moderate to high risk of stroke while tracking clinical events [primary and recurrent ischaemic strokes, systemic embolism, transient ischaemic attack, haemorrhage (intracranial, extracranial, and minor), acute myocardial infarction and death] and resulting functional disability. Acute event costs and resulting long-term follow-up costs incurred by disabled stroke survivors were based on a Canadian prospective study, published literature, and national statistics. Clinical events, summarized as events per 100 patient-years, quality-adjusted life years (QALYs), total costs, and incremental cost effectiveness ratios (ICER) were calculated. Over a lifetime, dabigatran etexilate treated patients experienced fewer intracranial haemorrhages (0.49 dabigatran etexilate vs. 1.13 warfarin vs. 1.05 “real-world” prescribing) and fewer ischaemic strokes (4.40 dabigatran etexilate vs. 4.66 warfarin vs. 5.16 “real-world” prescribing) per 100 patient-years. The ICER of dabigatran etexilate was $10,440/QALY versus warfarin and $3,962/QALY versus “real-world” prescribing. This study demonstrates that dabigatran etexilate is a highly cost-effective alternative to current care for the prevention of stroke and systemic embolism among Canadian AF patients.

Atrial Fibrillation as an Ischemic Stroke Clinical and Economic Burden Modifier: A 15-Year Nationwide Study

BACKGROUND

Atrial fibrillation (AF) is a major risk factor for ischemic stroke (IS). Patients with AF may undergo preventive therapy. Although the AF impact in the clinical burden of IS has been studied, information is lacking in Southern Europe and there are no studies about the impact in potential years of life lost. Moreover, no nationwide or long-term study analyzed the economic burden of IS stratified by AF.

OBJECTIVE

To study the impact of AF in the clinical and economic burden of IS.

METHODS

We conducted a retrospective study using nationwide administrative data for all public hospitalizations in mainland Portugal from 2000 to 2014. We considered IS hospitalizations stratified by the presence of AF as secondary diagnosis.

RESULTS

Of the total 275,173 IS hospitalizations, 22.6% reported AF. The total number of IS hospitalizations increased from 14,836 in 2000 to 19,561 in 2014 (32% increase), with an increase of 138% in the AF group (from 2,411 to 5,727). In-hospital mortality decreased from 13.6% to 11.5% and was consistently higher in the AF group (17.3% vs. 11.1%). Mean charges were also higher in the AF group (€2297 vs. €2191). Age-adjusted potential years of life lost rate was higher in the group without AF (39.6 vs. 7.5).

CONCLUSIONS

AF-associated IS hospitalizations more than doubled in the studied 15-year period. Also, AF was responsible for higher in-hospital mortality and hospitalization charges. These facts highlight the need for early detection of AF and preventive treatment to limit IS occurrence, its associated burden, and poorer health outcomes.

Low Use of Oral Anticoagulant Prescribing for Secondary Stroke Prevention: Results From the Ontario Stroke Registry

BACKGROUND

Oral anticoagulation reduces the risk of stroke in atrial fibrillation but is often underused.

OBJECTIVES

To identify factors associated with oral anticoagulant prescribing and adherence after stroke or transient ischemic attack (TIA).

RESEARCH DESIGN

Retrospective cohort study using linked Ontario Stroke Registry and prescription claims data.

SUBJECTS

Consecutive patients with atrial fibrillation and ischemic stroke/TIA admitted to 11 stroke centers in Ontario, Canada between 2003 and 2011.

MEASURES

We used modified Poisson regression models to determine predictors of anticoagulant prescribing and multiple logistic regression to determine predictors of 1-year adherence.

RESULTS

Of the 5781 patients in the study cohort, 4235 (73%) were prescribed oral anticoagulants at discharge. Older patients were less likely to receive anticoagulation [adjusted relative risk (aRR) for each additional year=0.997; 95% confidence interval (CI), 0.995-0.998], as were those with TIA compared with ischemic stroke (aRR=0.904; 95% CI, 0.865-0.945), prior gastrointestinal bleed (aRR=0.778; 95% CI, 0.693-0.873), dementia (aRR=0.912; 95% CI, 0.856-0.973), and those from a long-term care facility (aRR=0.810; 95% CI, 0.737-0.891). After limiting the sample to those without obvious contraindications to anticoagulation, age, dementia, and long-term care residence continued to be associated with lower prescription of oral anticoagulants. One-year adherence to therapy was similar across most patient groups.

CONCLUSIONS

Age, dementia, and long-term care residence are predictors of lower oral anticoagulant use for secondary stroke prevention and represent key target areas for quality improvement initiatives.

Use of Oral Anticoagulant Therapy in Older Adults with Atrial Fibrillation After Acute Ischemic Stroke

OBJECTIVES

To explore barriers to anticoagulation in older adults with atrial fibrillation (AF) at high risk of stroke and to identify opportunities for interventions that might increase use of oral anticoagulants (OACs).

DESIGN

Retrospective cohort study.

SETTING

Two large community-based AF cohorts.

PARTICIPANTS

Individuals with ischemic stroke surviving hospitalization (N = 1,405, mean age 79).

MEASUREMENTS

Using structured chart review, reasons for nonuse of OAC were identified, and 1-year poststroke survival was assessed. Logistic regression was used to identify correlates of OAC nonuse.

RESULTS

Median CHA₂ DS₂ -VASc score was 5, yet 44% of participants were not prescribed an OAC at discharge. The most-frequent (nonmutually exclusive) physician reasons for not prescribing OAC included fall risk (26.7%), poor prognosis (19.3%), bleeding history (17.1%), participant or family refusal (14.9%), older age (11.0%), and dementia (9.4%). Older age (odds ratio (OR) = 8.96, 95% confidence interval (CI) = 5.01-16.04 for aged ≥85 vs <65) and disability (OR = 12.58, 95% CI = 5.82-27.21 for severe vs no deficit) were the most-important independent predictors of nonuse of OACs. By 1 year, 42.5% of those not receiving an OAC at discharge had died, versus 19.1% of those receiving an OAC (P < .001), far higher than recurrent stroke rates.

CONCLUSION

Despite very high stroke risk, more than 40% of participants were not discharged with an OAC. Dominant reasons included fall risk, poor prognosis, older age, and dementia. These individuals' high 1-year mortality rate confirmed their high level of comorbidity. To improve anticoagulation decisions and outcomes in this population, future research should focus on strategies to mitigate fall risk, improve assessment of risks and benefits of anticoagulation in individuals with AF, and determine whether newer anticoagulants are safer in complex elderly and frail individuals.

Under-prescribing of Prevention Drugs and Primary Prevention of Stroke and Transient Ischaemic Attack in UK General Practice: A Retrospective Analysis

BACKGROUND

Stroke is a leading cause of death and disability; worldwide it is estimated that 16.9 million people have a first stroke each year. Lipid-lowering, anticoagulant, and antihypertensive drugs can prevent strokes, but may be underused.

METHODS AND FINDINGS

We analysed anonymised electronic primary care records from a United Kingdom (UK) primary care database that covers approximately 6% of the UK population. Patients with first-ever stroke/transient ischaemic attack (TIA), ≥18 y, with diagnosis between 1 January 2009 and 31 December 2013, were included. Drugs were considered under-prescribed when lipid-lowering, anticoagulant, or antihypertensive drugs were clinically indicated but were not prescribed prior to the time of stroke or TIA. The proportions of strokes or TIAs with prevention drugs under-prescribed, when clinically indicated, were calculated. In all, 29,043 stroke/TIA patients met the inclusion criteria; 17,680 had ≥1 prevention drug clinically indicated: 16,028 had lipid-lowering drugs indicated, 3,194 anticoagulant drugs, and 7,008 antihypertensive drugs. At least one prevention drug was not prescribed when clinically indicated in 54% (9,579/17,680) of stroke/TIA patients: 49% (7,836/16,028) were not prescribed lipid-lowering drugs, 52% (1,647/3,194) were not prescribed anticoagulant drugs, and 25% (1,740/7,008) were not prescribed antihypertensive drugs. The limitations of our study are that our definition of under-prescribing of drugs for stroke/TIA prevention did not address patients' adherence to medication or medication targets, such as blood pressure levels.

CONCLUSIONS

In our study, over half of people eligible for lipid-lowering, anticoagulant, or antihypertensive drugs were not prescribed them prior to first stroke/TIA. We estimate that approximately 12,000 first strokes could potentially be prevented annually in the UK through optimal prescribing of these drugs. Improving prescription of lipid-lowering, anticoagulant, and antihypertensive drugs is important to reduce the incidence and burden of stroke and TIA.

Adherence to Guidelines for Antithrombotic Therapy in Patients with Atrial Fibrillation According to CHADS2 Score before and after Stroke: A Multicenter Observational Study from Korea

Background and Purpose

A substantial proportion of patients with atrial fibrillation (AF) are not treated optimally; however, the inappropriateness of drug therapy has never been evaluated before or after a stroke event. We investigated the adherence to guidelines for therapy in AF patients hospitalized with acute ischemic stroke (AIS) before stroke onset and at discharge, with the aim of identifying the factors associated with inappropriate therapy.

Methods

AIS patients with AF hospitalized within 7 days of onset were identified from a prospective nine-center stroke registry database. Two cohorts were defined: patients diagnosed with AF prior to the stroke event (admission cohort) and patients diagnosed with AF at discharge from hospital (discharge cohort). Any of the following conditions were regarded as nonadherence to guidelines in this study: use of anticoagulant or nonuse of antithrombotics with CHADS2 score=0, nonuse of antithrombotics with CHADS2 score=1, or nonuse of anticoagulant with CHADS2 score ≥2.

Results

Overall, 406 patients were enrolled in the admission cohort and 518 in the discharge cohort. The rates of nonadherence before a stroke event and at discharge were 77.8% and 33.3%, respectively. These rates varied widely for both cohorts, with interhospital differences being statistically significant. Multivariable analysis revealed that old age, stroke history, and congestive heart failure were associated with nonadherence before stroke. At discharge, males, coronary heart disease, inappropriate antithrombotic use before stroke, and functional disability at discharge were associated with nonadherence.

Conclusions

This study shows that antithrombotic use in AIS patients with AF might be not optimal before and after stroke in Korea.

Paroxysmal atrial fibrillation and the hazards of under-treatment

BACKGROUND AND PURPOSE

Oral anticoagulants are highly efficacious for the prevention of stroke in atrial fibrillation, and are the preferred treatment by current guidelines. The purpose of our study was to assess the utilization of antithrombotic drugs in atrial fibrillation patients at the time of ischemic stroke and the factors associated with their use.

METHODS

We enrolled 759 consecutive patients admitted with ischemic stroke at Boston Medical Center, Geisinger Health System, and the University of Alabama. To be eligible, patients had to have electrocardiographically-confirmed atrial fibrillation at the time of admission or within 6 months of the index stroke. All stroke events and electrocardiograms were validated by study physicians. Patients with newly diagnosed atrial fibrillation were not eligible.

RESULTS

The mean age was 78 years, 43% were male, 19% black, and the mean CHADS2 score is 3.0. Atrial fibrillation was paroxysmal in 31%. At presentation, 181 (24%) patients were taking warfarin only, 96 (13%) both warfarin and aspirin, 294 (39%) aspirin alone, and 189 (25%) no antithrombotic therapy. The mean international normalized ratio was 1.6. Among patients with paroxysmal atrial fibrillation, one in five was taking warfarin. Although increasing stroke risk was associated with a greater likelihood of warfarin use, only 39% of highest risk CHADS2 3-6 were taking warfarin at the time of stroke.

CONCLUSIONS

Among high-risk individuals with atrial fibrillation, only 37% were taking warfarin at the time of stroke. Paroxysmal atrial fibrillation was associated with the highest risk of not receiving warfarin.

Do NOACs Improve Antithrombotic Therapy in Secondary Stroke Prevention in Nonvalvular Atrial Fibrillation?

Guidelines recommended oral anticoagulant (OAC) for ischemic stroke patients related to atrial fibrillation (AF). But, underprescription or underdose of warfarin was observed worldwide. We aimed to explore if the use of antithrombotic therapy in nonvalvular AF (NVAF) ischemic stroke patients improved after novel oral anticoagulants (NOACs) became available. Between January 2011 to December 2013, 360 acute ischemic stroke patients related to NVAF were recruited. Patients were categorized into 2 groups based on the date (July 2012) of NOACs' availability. There were 184 patients recruited before July 2012, and whereas 176 patients after July 2012. Demographic data, interested factors, and the percentage of patient on OAC were compared. One month after discharge, percentage of OAC utilization was significantly higher (29% versus 41%; P = 0.022) as well as effective anticoagulation (22.2% versus 80.6%; P < 0.001); warfarin utilization was significantly less (28.3% versus 11%; P < 0.001) after NOACs became available. Antiplatelet agent utilization was high in 2 groups (57% versus 52%; P = 0.36). Age (odd ratios [OR] 0.947; 95% confidence intervals [CI] 0.912-0.984; P = 0.005), Barthel index (OR 1.012; 95% CI 1.000-1.025; P = 0.05), and NOACs' availability (OR 1.857; 95% CI 1.086-3.175; P = 0.024) were the significant factors affecting the use of OAC. A higher percentage of NVAF ischemic stroke patients returning for their 1-month follow-up were treated with NOACs than with warfarin. The use of antithrombotic therapy improved after NOACs became available. But, the majority of the patients were still received antiplatelet agent for emboli stroke prevention.

A case-based approach to implementing guidelines for stroke prevention in patients with atrial fibrillation: balancing the risks and benefits

Atrial fibrillation (AF) puts patients at risk of complications, including stroke. Warfarin therapy has been the mainstay of antithrombotic treatment for reducing the risk of stroke in AF. However, warfarin has limitations that have motivated development of several novel oral anticoagulants (NOACs), including dabigatran, rivaroxaban, apixaban, and edoxaban. Clinical trials demonstrate that the NOACs offer efficacy and safety that are equivalent to, or better than, those of warfarin for reducing the risk of stroke in patients with nonvalvular AF. This review examines stroke risk reduction in patients with AF from the perspective of the clinician balancing the risks and benefits of treatment options, evaluates the most recent guidelines, and discusses 2 hypothetical patient cases to better illustrate how clinicians may apply available data in the clinical setting. We reviewed guidelines for the reduction of stroke risk in AF and data from clinical trials on the NOACs. Choosing antithrombotic treatment involves assessing the benefits of therapy versus its risks. Risk indexes, including CHADS2, CHA2DS2-VASc, and HAS-BLED can help determine how to treat patients with AF. Current guidelines suggest using these risk indexes to customize treatment to individual patients. Many current treatment guidelines also incorporate recommendations for the use of NOACs as an alternative to warfarin. As additional data emerge and guidelines are updated, these recommendations will likely evolve. In the interim, clinicians may consider published guidelines and clinical trial results on NOACs. Real-world experience will provide clinicians with additional insight into their treatment decisions.

An automated clinical alert system for newly-diagnosed atrial fibrillation

OBJECTIVE

Clinical decision support systems that notify providers of abnormal test results have produced mixed results. We sought to develop, implement, and evaluate the impact of a computer-based clinical alert system intended to improve atrial fibrillation stroke prophylaxis, and identify reasons providers do not implement a guideline-concordant response.

MATERIALS AND METHODS

We conducted a cohort study with historical controls among patients at a tertiary care hospital. We developed a decision rule to identify newly-diagnosed atrial fibrillation, automatically notify providers, and direct them to online evidence-based management guidelines. We tracked all notifications from December 2009 to February 2010 (notification period) and applied the same decision rule to all patients from December 2008 to February 2009 (control period). Primary outcomes were accuracy of notification (confirmed through chart review) and prescription of warfarin within 30 days.

RESULTS

During the notification period 604 notifications were triggered, of which 268 (44%) were confirmed as newly-diagnosed atrial fibrillation. The notifications not confirmed as newly-diagnosed involved patients with no recent electrocardiogram at our institution. Thirty-four of 125 high-risk patients (27%) received warfarin in the notification period, compared with 34 of 94 (36%) in the control period (odds ratio, 0.66 [95% CI, 0.37-1.17]; p = 0.16). Common reasons to not prescribe warfarin (identified from chart review of 151 patients) included upcoming surgical procedure, choice to use aspirin, and discrepancy between clinical notes and the medication record.

CONCLUSIONS

An automated system to identify newly-diagnosed atrial fibrillation, notify providers, and encourage access to management guidelines did not change provider behaviors.

Antithrombotic therapy in elderly patients with non-valvular atrial fibrillation: a pilot study

Objective

Non-valvular atrial fibrillation (NVAF) is one common arrhythmia in the elderly. However, use of antithrombotic therapy in this population is not well known in the People’s Republic of China. This study aimed at investigating antithrombotic therapy status in elderly patients with NVAF in our hospital.

Methods

A cross-sectional study of consecutive geriatric patients aged ≥60 years with NVAF who discharged from our hospital between January 2012 and December 2013 were collected. CHA₂DS₂-VASc score (cardiac failure or dysfunction, hypertension, age ≥75 [doubled], diabetes, stroke or transient ischemic attack [doubled], vascular disease, age 65–74, and sex category [female]) was used to analyze antithrombotic indication.

Results

We consecutively collected data of 1,000 discharged elderly patients (≥60 years) with NVAF (mean age 75.3±8.0 years, 75 years or older 54.7%, female 42.7%). The proportion of paroxysmal atrial fibrillation and non-paroxysmal atrial fibrillation (persistent or permanent) patients were 39.4% and 60.6%, respectively. Among 1,000 patients, 29.1% received oral anticoagulant therapy (OAT), including warfarin (27.8%) and novel oral anticoagulants (1.3%), 39.5% of patients received antiplatelet therapy, and 31.4% received neither therapy. Based on CHA₂DS₂-VASc score for stroke risk stratification, 68.9% patients with score ≥1 and 70.2% patients with score ≥2 received antithrombotic therapy, while the rates of OAT were 29.1% and 29.5%, respectively. Among patients with high stroke risk, those with paroxysmal atrial fibrillation were less likely to receive OAT compared with the patients with non-paroxysmal atrial fibrillation (19.5% vs 35.7%, P<0.001). The patients ≥75 years old had lower rate of OAT than the patients <75 years old (25.8% vs 34.8%, P=0.003). The patients with coronary artery disease had lower rate of OAT than the patients without coronary artery disease (24.4% vs 33.4%, P=0.003). Sex and history of stroke or transient ischemic attack had no effect on the use of OAT (30.8% vs 27.9%, P=0.326 and 28.8% vs 29.8%, P=0.761, respectively).

Conclusion

OAT in elderly patients with NVAF in our hospital is underused, especially in those patients with higher risk of stroke.

CHADS2 and CHA2DS2Vasc-Score in Peripheral Systemic Embolism

Objectives: We analysed the characteristics of patients with an acute peripheral embolic event considering the possible use of the CHADS2-Score and the CHA₂DS₂Vasc-Score Patients and Methods: We retrospectively analyzed 163 cases of acute peripheral arterial embolism treated in the Department of Vascular Medicine of the HELIOS Klinik Krefeld, Germany, from 2008 to 2011. We retrospectively screened the medical form for information regarding atrail fibrillation (AF) and the risk factors necessary to calculate the CHADS₂ and CHA₂DS₂vasc score. Results: Arterial hypertension and age > 75 years were the most frequent risk factors. Mean CHADS₂ score was similar in males and females (2.3 ± 1.5 and 2.3 ± 1.4). 66% of the males and 63.3% of the females scored 2 and more points. Mean CHA₂DS₂Vasc score was 3.6 ± 2.0 in males and 4.6 ± 1.9 in females. 85.2% of the males and 95.4% of the females scored more than 2 points. In the medical forms AF was documented in 79 (48%) patients, of which 23 (43 %) were males and 56 (51%) females. Mean CHADS₂ score and mean CHA₂DS₂Vasc score were slightly higher in those with AF compared to the total group, but not significantly different. The rate of patients with 2 and more points increased for both scores: CHADS₂ score: males 82.6% and females 76.8%, CHA₂DS₂Vasc: males 100% and females 98.2%. Almost half of the patients with AF had had anticoagulation with phenprocoumon before (males 12 (52%), females 24 (43%), but only every 10th was within the therapeutic range (INR ≥2) Conclusion: The number of those with AF is high amongst patients with acute peripheral embolism. According to the CHADS₂ and CHA₂DS₂Vasc score, most of these patients had an indication for oral anticoagulation independent form the embolic event.

Novel oral anticoagulants for stroke prevention in atrial fibrillation: a focus on the older patient

Atrial fibrillation (AF) is a common arrhythmia that is associated with an increased risk of stroke, particularly in the elderly. Traditionally, a vitamin K antagonist such as warfarin is prescribed for stroke prevention. Warfarin is effective at lowering stroke risk but has several limitations due to food restrictions, drug interactions, and a narrow therapeutic window. Various novel oral anticoagulants (NOACs) are available or under development to provide alternative treatment options. This article reviews the efficacy and safety of three NOACs (dabigatran etexilate, rivaroxaban, and apixaban) in addition to warfarin and aspirin, for prevention of stroke in patients with AF, focusing on the elderly population. Results of clinical trials demonstrate that the efficacy of NOACs for stroke prevention in patients with AF is as good as or better than that of warfarin. The NOACs are also associated with an equivalent or lower risk of bleeding. Regardless of the medication chosen, older patients with AF must be treated cautiously due to an increased risk of stroke and bleeding, as well as potential challenges related to drug interactions and monitoring requirements. NOACs may be suitable alternatives to warfarin for stroke prevention in older patients due to several advantages, including a faster onset of action, few drug or food interactions, and no requirement for regular monitoring. However, dose adjustments may be required for certain patients, such as those with severe renal impairment or in the setting of drug interactions.

The use of anticoagulants in the management of atrial fibrillation among general practices in England

Objectives

To investigate the use of oral anticoagulants (AC) and antiplatelet agents (AP) in the management of atrial fibrillation (AF) among patients in primary care in England.

Design

Epidemiological study.

Setting

1857 general practices in England representing a practice population of 13.1 million registered patients.

Patients

231 833 patients with a history of AF.

Main outcome measures

The primary outcome was AC and AP use by CHADS₂ score and age groups <30 years, 30–49 years, 50–64 years, 65–79 years and >79 years.

Results

231 833 patients with a history of AF were identified, giving a prevalence among uploading practices of 1.76%. Prevalence of AF varied markedly between practices, related to differing practice age profiles. The total number of patients with AF in a practice was strongly predicted by the number of patients aged 65 years and over in the practice. 57.0% of the AF population had a CHADS₂ score ≥2 and 83.7%≥1. 114 212 (49.3%) patients received AC therapy. AC uptake increased with increasing CHADS₂ score up to a score of 3, but thereafter reached a plateau. Among 132 099 patients with a CHADS₂ score ≥2, 72 211 (54.7%) received an AC, 14 987(11.3%) were recorded as having a contraindication or having declined AC therapy, leaving 44 901 (34.0%) not on AC therapy and without a recorded contraindication or recorded refusal. Among patients not prescribed an AC, 79.9% were prescribed an AP. The use of AC declined in the elderly (for CHADS₂≥2, 47.4% of patients ≥80 years, compared with 64.5% for patients aged <80 years, p<0.001). By contrast, AP uptake was more prevalent among elderly patients.

Conclusions

Over one-third of patients with AF and known risk factors who are eligible for AC do not receive them. There is a high use of AP among patients not receiving AC. Uptake of AC is particularly poor among patients aged 80 years and over.

Reasons for non-use of proven pharmacotherapeutic interventions: systematic review and framework development

RATIONALE, AIMS AND OBJECTIVES

The quality of patient care and safety is dependent on addressing both errors of commission (e.g. overuse of medications) and errors of omission (e.g. patients receiving too little care). Despite guidelines recommending the use of certain proven pharmacotherapeutic interventions, a large gap exists between the patients that have an indication for, and those that actually receive such interventions. To address how the rate of implementation of proven interventions can be improved is dependent on a comprehensive knowledge of the factors contributing to their underuse. The aim of the review is to create an evidence-based framework of reasons why eligible patients do not receive proven pharmacotherapeutic interventions.

METHODS

A systemic review of the published reasons for non-use based on the Cochrane methodology.

RESULTS

The systematic review identified 67 articles meeting the inclusion criteria. The reasons for non-use were extracted from the studies and a framework was created from the results.

CONCLUSIONS

The factors associated with lack of implementation of proven pharmacotherapeutic interventions are complex and heterogeneous but can be understood from the perspectives of clinicians, patients and health care delivery systems. Efforts to increase the utilization of proven interventions should focus on disease/intervention-specific programmes that take into account the identified modifiable clinician, patient and system factors.

Stroke prevention in elderly patients with atrial fibrillation: challenges for anticoagulation

Elderly patients with atrial fibrillation (AF), who constitute almost half of all AF patients, are at increased risk of stroke. Anticoagulant therapies, especially vitamin K antagonists (VKA), reduce the risk of stroke in all patients including the elderly but are frequently under-used in older patients. Failure to initiate VKA in elderly AF patients is related to a number of factors, including the limitations of current therapies and the increased risk for major haemorrhage associated with advanced age and anticoagulation therapy. Of particular concern is the risk of intracranial haemorrhages (ICH), which is associated with high rates of mortality and morbidity. Novel oral anticoagulant agents that are easier to use and might offer similar or better levels of stroke prevention with a similar or reduced risk of bleeding should increase the use of antithrombotic therapy in the management of elderly AF patients. Amongst these new agents, the recently approved direct thrombin inhibitor dabigatran provides effective stroke prevention with a significant reduction of ICH, and enables clinicians to tailor the dose according to age and haemorrhagic risk.

Performance of stroke risk scores in older people with atrial fibrillation not taking warfarin: comparative cohort study from BAFTA trial

OBJECTIVE

To compare the predictive power of the main existing and recently proposed schemes for stratification of risk of stroke in older patients with atrial fibrillation.

DESIGN

Comparative cohort study of eight risk stratification scores.

SETTING

Trial of thromboprophylaxis in stroke, the Birmingham Atrial Fibrillation in the Aged (BAFTA) trial.

PARTICIPANTS

665 patients aged 75 or over with atrial fibrillation based in the community who were randomised to the BAFTA trial and were not taking warfarin throughout or for part of the study period.

MAIN OUTCOME MEASURES

Events rates of stroke and thromboembolism.

RESULTS

54 (8%) patients had an ischaemic stroke, four (0.6%) had a systemic embolism, and 13 (2%) had a transient ischaemic attack. The distribution of patients classified into the three risk categories (low, moderate, high) was similar across three of the risk stratification scores (revised CHADS(2), NICE, ACC/AHA/ESC), with most patients categorised as high risk (65-69%, n = 460-457) and the remaining classified as moderate risk. The original CHADS(2) (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes, previous Stroke) score identified the lowest number as high risk (27%, n = 180). The incremental risk scores of CHADS(2), Rietbrock modified CHADS(2), and CHA(2)DS(2)-VASc (CHA(2)DS(2)-Vascular disease, Age 65-74 years, Sex) failed to show an increase in risk at the upper range of scores. The predictive accuracy was similar across the tested schemes with C statistic ranging from 0.55 (original CHADS(2)) to 0.62 (Rietbrock modified CHADS(2)), with all except the original CHADS(2) predicting better than chance. Bootstrapped paired comparisons provided no evidence of significant differences between the discriminatory ability of the schemes.

CONCLUSIONS

Based on this single trial population, current risk stratification schemes in older people with atrial fibrillation have only limited ability to predict the risk of stroke. Given the systematic undertreatment of older people with anticoagulation, and the relative safety of warfarin versus aspirin in those aged over 70, there could be a pragmatic rationale for classifying all patients over 75 as "high risk" until better tools are available.

Optimizing use of current anticoagulants

Although warfarin has been the mainstay of oral anticoagulation therapy for decades, evidence-based methods for improving the quality of warfarin therapy remain underused. The arrival of new anticoagulants that do not require routine laboratory monitoring and lack the significant dietary and drug interaction potential that are seen with warfarin is an important evolutionary step in the management of thromboembolic disease. However, it will be years before the efficacy and long-term safety of these new agents are defined. Newer oral anticoagulants will be more expensive than generic warfarin. This article examines various approaches to optimize the clinical use of warfarin. For patients able to achieve stable anticoagulation control, warfarin remains an important therapeutic option, delivering similar clinical outcomes at a fraction of the cost to the health care system.

Underuse of oral anticoagulants in atrial fibrillation: a systematic review

BACKGROUND

Atrial fibrillation is associated with substantial mortality and morbidity from stroke and thromboembolism. Despite an efficacious oral anticoagulation therapy (warfarin), atrial fibrillation patients at high risk for stroke are often under-treated. This systematic review compares current treatment practices for stroke prevention in atrial fibrillation with published guidelines.

METHODS

Literature searches (1997-2008) identified 98 studies concerning current treatment practices for stroke prevention in atrial fibrillation. The percentage of patients eligible for oral anticoagulation due to elevated stroke risk was compared with the percentage treated. Under-treatment was defined as treatment of <70% of high-risk patients.

RESULTS

Of 54 studies that reported stroke risk levels and the percentage of patients treated, most showed underuse of oral anticoagulants for high-risk patients. From 29 studies of patients with prior stroke/transient ischemic attack who should all receive oral anticoagulation according to published guidelines, 25 studies reported under-treatment, with 21 of 29 studies reporting oral anticoagulation treatment levels below 60% (range 19%-81.3%). Subjects with a CHADS(2) (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >or=2 also were suboptimally treated, with 7 of 9 studies reporting treatment levels below 70% (range 39%-92.3%). Studies (21 of 54) using other stroke risk stratification schemes differ in the criteria they use to designate patients as "high risk," such that direct comparison is not possible.

CONCLUSIONS

This systematic review demonstrates the underuse of oral anticoagulation therapy for real-world atrial fibrillation patients with an elevated risk of stroke, highlighting the need for improved therapies for stroke prevention in atrial fibrillation.

Reasons for undertreatment with oral anticoagulants in frail geriatric outpatients with atrial fibrillation: a prospective, descriptive study

OBJECTIVES

The main aims of the study were to explore whether oral anticoagulation (OAC) for atrial fibrillation (AF) in geriatric outpatients is prescribed in accordance with international (American College of Cardiology/American Heart Association/European Society of Cardiology [ACC/AHA/ESC]) and Dutch national guidelines for the general practitioner (GP) and to identify whether age and selected co-morbid conditions are associated with undertreatment. As a secondary objective, we wanted to establish how many patients discontinue OAC because of major bleeding.

METHODS

In 2004, at the first visit of all patients to the geriatric day clinic of the Slotervaart Hospital in Amsterdam, the Netherlands, demographic data, Mini-Mental State Examination score, medical history, Charlson Comorbidity Index score, and data on medication use and changes were documented. The presence of AF was established by assessment of medical history information obtained by the GP, the history taken from patients and their caregivers, and the results of clinical evaluation, including ECG findings. Associations between the use of OAC, demographic data and co-morbid conditions registered in the Dutch NHG (Nederlands Huisartsen Genootschap [Dutch College of General Practitioners]) standard for GPs as risk factors for stroke or contraindications to the use of OAC were analysed. The reasons for discontinuing OAC were assessed after 4 years by requesting the information from the anticoagulation services or the GP.

RESULTS

At the time of the initial visit, 17.5% of the 807 outpatients had chronic AF (n = 135) or were known to have paroxysmal AF (n = 6). The mean age of the 141 patients in this cohort was 84.3 years (SD 6.2 years). Co-morbid conditions increasing the risk of stroke were present in 129 patients (91.5%). Contraindications to the use of OAC were observed in 118 patients (83.7%). Of the 116 patients with AF in their history before their visit, 57.8% were being treated with OAC at the time of their visit. After comprehensive geriatric assessment, 73 (51.8%) of the 141 patients with chronic or paroxysmal AF were continued on OAC. Of the 141 patients with chronic or paroxysmal AF, 110 (78.0%) had both extra stroke risk factors and contraindications to the use of OAC. Only increasing age was significantly and independently associated with not being prescribed anticoagulants (p < 0.001). At the 4-year follow-up, OAC had been discontinued in 5.5% of patients because of major bleeding; three patients (4.1%) taking OAC had died as a result of major bleeding, and one other patient had discontinued treatment because of a major, non-lethal bleeding episode.

CONCLUSION

Applying the NHG standard for appropriate prescription, and disregarding age as a risk factor or contraindication, in this population, 14 of 141 patients (9.9%) were inappropriately prescribed OAC, salicylates or no prophylaxis. Since only patient age was associated with not prescribing OAC in this study, higher age still seems to be considered the most important contraindication to anticoagulation therapy. Implementation of better models for stratifying bleeding risk in the frail elderly is needed. After 4 years, the cumulative rate of bleeding causing discontinuation of anticoagulation therapy in this usual-care study of frail older patients was not alarmingly higher than in other usual-care studies.

Improving adherence to treatment guidelines: a blueprint

Patients with chronic diseases often require complex medication regimens to meet evidence-based treatment guidelines. However, translating evidence-based recommendations into clinical care has proven to be difficult. Several factors-patient adherence, disease complexity, competing medical issues, guideline dissemination, and clinical inertia-are thought to contribute to this problem. In this manuscript, we describe a multidisciplinary ambulatory approach to improve the care of patients with chronic conditions. Our goal was to design an intervention that focused on improving the prescription rates of medications known to reduce cardiovascular-related events and hospital admissions for patients with diabetes mellitus, coronary artery disease, heart failure, chronic kidney disease, or stroke. We also describe the critical lessons we have learned in implementing our intervention, including the successes and barriers we encountered during the project.

Clinical outcomes of acute stroke patients with atrial fibrillation

Evaluation of: Kazumi K, Yasuyuki I, Kensaku S, Takeshi I, Shinji Y, Junya A. IV-tPA therapy in acute stroke patients with atrial fibrillation. J. Neurol. Sci. 276(1-2), 6-8 (2009). Stroke is the leading cause of disability and the second most common cause of death worldwide. The care and treatment of stroke patients have evolved over the last two decades, with increasing use of thrombolysis (e.g., intravenous tissue plasminogen activator in acute stroke patients), which has improved survival and recovery following stroke. The article under evaluation offers a greater insight into the relationship of clinical outcome of stroke and atrial fibrillation after tissue plasminogen activator infusion.

Trend in incidence of cardiovascular risk factors in elderly and over-aged stroke patients between 2003 and 2007 in Greece

The aim of this study is to identify the main cardiovascular risk factors (CRFs) in patients over 65 years with ischemic stroke. This is a retrospective study in 175 patients that were hospitalized in our department due to ischemic stroke in the period 2006-2007. The patients were divided in two groups: Group I--elderly (65-80 years) and Group II--over-aged (>or=81 years). The results were compared with a similar study performed in our department in the period 2002-2003 in 160 ischemic stroke patients. Statistical analysis was made by the chi2-test. Hypertension, either alone or in combination with other CRFs, constitutes the main CRF. Diabetes mellitus (DM) is not frequently the sole CRF but its coexistence with other CRFs ranks DM as the second most important CRF, with the largest percentage in the elderly. Dyslipipidemia is 4th CRF in order following the coronary heart disease (CHD). Taking into account that the provision of acute therapeutic intervention in elderly and over-aged ischemic stroke patients is in most cases difficult, because of their age and the high risk of thrombolysis in these patients, there is increased need to focus on primary prevention of ischemic stroke by treating associated CRF.

Admission international normalized ratio and acute infarct volume in ischemic stroke

OBJECTIVE

The level of anticoagulation at the time of stroke onset may influence the size, composition, and dissolution rate of the occlusive clot. We explored the relation between admission international normalized ratio (INR) and acute infarct volume in patients with ischemic stroke.

METHODS

We studied 93 consecutive patients with preadmission warfarin use who had INR measurement and diffusion-weighted imaging performed within 24 hours of stroke onset. Ninety-three etiologic stroke subtype-matched patients without prior warfarin use served as control patients. Linear regression analysis was used to test for independence of INR as a predictor of infarct volume.

RESULTS

In patients with preadmission warfarin use, admission INR was inversely correlated with lesion volume on diffusion-weighted imaging (r = -0.38). This relation was retained after adjustment for potential covariates (p = 0.014). INR less than 2.0 was associated with 3.5-fold (95% confidence interval, 2.9-4.2) greater lesion volume on diffusion-weighted imaging as compared with INR of 2.0 or more. Patients who were on therapeutic INR (>or=2.0) had smaller infarcts compared with patients without preadmission warfarin use (p = 0.001). Admission INR was inversely correlated with acute perfusion defect (r = -0.33), chronic infarct volume (r = -0.42), National Institutes of Health Stroke Scale score at admission (r = -0.27), and modified Rankin score at discharge (r = -0.28).

INTERPRETATION

These results suggest that preadmission warfarin use associated with therapeutic level of anticoagulation can offer a benefit in limiting the extent of ischemic injury in an event of acute stroke.

Potentially Preventable Strokes in High-Risk Patients With Atrial Fibrillation Who Are Not Adequately Anticoagulated

Background and Purpose— Warfarin is the most effective stroke prevention medication for high-risk individuals with atrial fibrillation, yet it is often underused. This study examined the magnitude of this problem in a large contemporary, prospective stroke registry.

Methods— We analyzed data from the Registry of the Canadian Stroke Network, a prospective database of consecutive patients with stroke admitted to 12 designated stroke centers in Ontario (2003 to 2007). We included patients admitted with an acute ischemic stroke who (1) had a known history of atrial fibrillation; (2) were classified as high risk for systemic emboli according to published guidelines; and (3) had no known contraindications to anticoagulation. Primary end points were the use of prestroke antithrombotic medications and admission international normalized ratio.

Results— Among patients admitted with a first ischemic stroke who had known atrial fibrillation (n=597), strokes were disabling in 60% and fatal in 20%. Preadmission medications were warfarin (40%), antiplatelet therapy (30%), and no antithrombotics (29%). Of those taking warfarin, three fourths had a subtherapeutic international normalized ratio (<2.0) at the time of stroke admission. Overall, only 10% of patients with acute stroke with known atrial fibrillation were therapeutically anticoagulated (international normalized ratio ≥2.0) at admission. In stroke patients with a history of atrial fibrillation and a previous transient ischemic attack or ischemic stroke (n=323), only 18% were taking warfarin with therapeutic international normalized ratio at the time of admission for stroke, 39% were taking warfarin with subtherapeutic international normalized ratio, and 15% were on no antithrombotic therapy.

Conclusions— In high-risk patients with atrial fibrillation admitted with a stroke, and who were candidates for anticoagulation, most were either not taking warfarin or were subtherapeutic at the time of ischemic stroke. Many were on no antithrombotic therapy. These findings should encourage greater efforts to prescribe and monitor appropriate antithrombotic therapy to prevent stroke in individuals with atrial fibrillation.