Predictors of warfarin use in atrial fibrillation in the United States: a systematic review and meta-analysis

Ten-Year Trend of Oral Anticoagulation Use in Postoperative and Nonpostoperative Atrial Fibrillation in Routine Clinical Practice

BACKGROUND

The study aimed to describe the patterns and trends of initiation, discontinuation, and adherence of oral anticoagulation (OAC) in patients with new-onset postoperative atrial fibrillation (POAF), and compare with patients newly diagnosed with non-POAF.

METHODS AND RESULTS

This retrospective cohort study identified patients newly diagnosed with atrial fibrillation or flutter between 2012 and 2021 using administrative claims data from OptumLabs Data Warehouse. The POAF cohort included 118 366 patients newly diagnosed with atrial fibrillation or flutter within 30 days after surgery. The non-POAF cohort included the remaining 315 832 patients who were newly diagnosed with atrial fibrillation or flutter but not within 30 days after a surgery. OAC initiation increased from 28.9% to 44.0% from 2012 to 2021 in POAF, and 37.8% to 59.9% in non-POAF; 12-month medication adherence increased from 47.0% to 61.8% in POAF, and 59.7% to 70.4% in non-POAF. The median time to OAC discontinuation was 177 days for POAF, and 242 days for non-POAF. Patients who saw a cardiologist within 90 days of the first atrial fibrillation or flutter diagnosis, regardless of POAF or non-POAF, were more likely to initiate OAC (odds ratio, 2.92 [95% CI, 2.87-2.98]; P <0.0001), adhere to OAC (odds ratio, 1.08 [95% CI, 1.04-1.13]; P <0.0001), and less likely to discontinue (odds ratio, 0.83 [95% CI, 0.82-0.85]; P <0.0001) than patients who saw a surgeon or other specialties.

CONCLUSIONS

The use of and adherence to OAC were higher in non-POAF patients than in POAF patients, but they increased over time in both groups. Patients managed by cardiologists were more likely to use and adhere to OAC, regardless of POAF or non-POAF.

Regional and Demographic Disparities in Atrial Fibrillation Mortality in the USA

BACKGROUND

Despite the burden of atrial fibrillation/flutter (AF/AFL) in the USA, an assessment of contemporary mortality trends is scarce in the literature. This study aimed to assess the temporal trends in AF/AFL deaths among US adults by age, sex, race/ethnicity, and census region from 1999 to 2020.

METHODS

National mortality data was abstracted from the National Center for Health Statistics to identify decedents whose underlying cause of death was cardiovascular disease and multiple cause of death, AF/AFL. Joinpoint regression assessed mortality trends, and we calculated the average percentage changes (APC) and average annual percentage changes in mortality rates. Results were presented as effect estimates and 95% confidence intervals (95% CI).

RESULTS

Between 1999 and 2020, 657,126 adults died from AF/AFL in the USA. Contemporary trends have worsened overall except among individuals from the Northeast region for whom the rates have remained stationary since 2015 (APC = 0.1; 95% CI, - 1.0, 1.1). Regional and demographic disparities were observed, with higher rates noted among younger persons below 65 years of age, women (APC = 2.1; 95% CI, 1.7, 2.5), and non-Hispanic Blacks (APC = 4.5; 95% CI, 3.9, 5.2).

CONCLUSIONS

The temporal trends in AF/AFL mortality in the USA have exhibited a worsening pattern in recent years, with regional and demographic disparities. Further investigations are warranted to explore the determinants of AF/AFL mortality in the US population and identify factors that may explain the observed differences. Understanding these factors will facilitate efforts to promote improved and equitable health outcomes for the population.

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Country and health expenditure are major predictors of withholding anticoagulation in atrial fibrillation patients at high risk of stroke

BACKGROUND

Guidelines for patients with atrial fibrillation (AF) at high thromboembolic risk recommend oral anticoagulants (OACs) for preventing stroke and systemic embolism (SE). The reasons for guideline non-adherence are still unclear.

AIM

The aim is to identify clinical, demographic and non-patient characteristics associated with withholding OAC in patients with AF at high stroke risk.

METHODS

Patients in the Global Anticoagulant Registry in the FIELD-AF, newly diagnosed with AF between March 2010 and August 2016, and with CHA2DS2-VASc Score≥2 (excluding sex), were grouped by OAC treatment at enrolment. Factors associated with OAC non-use were analysed by multivariable logistic regression.

RESULTS

Of 40 416 eligible patients, 12 126 (30.0%) did not receive OACs at baseline. Globally, OAC prescription increased over time, from 60.4% in 2010-2011 to 74.7% in 2015-2016. Country of enrolment was the major predictor for OAC withholding (χ2-df=2576). Clinical predictors of OAC non-use included type of AF (χ2-df=404), history of bleeding (χ2-df=263) and vascular disease (χ2-df=99). OACs were used most frequently around the age of 75 years and decreasingly with younger as well as older age beyond 75 years (χ2-df=148). Non-cardiologists (χ2-df=201) and emergency room physicians (χ2-df=14) were less likely to prescribe OACs. OAC prescription correlated positively with country health expenditure.

CONCLUSIONS

Approximately one out of three AF patients did not receive OAC, while eligible according to the guidelines. Country of enrolment was the major determinant of anticoagulation strategy, while higher country health expenditure was associated with lower likelihood of withholding anticoagulation.

Time trends in antithrombotic therapy prescription patterns: Real-world monocentric study in hospitalized patients with atrial fibrillation

BACKGROUND

Since 2010, the European Society of Cardiology has extended prescription criteria for oral antithrombotic therapy (OAT) in atrial fibrillation (AF). Direct oral anticoagulants (DOACs) were upgraded from an IIAa recommendation in 2012 to an IA in 2016. In real-world scenarios, however, OAC prescription is still suboptimal, mainly for DOACs.

AIM

To evaluate OAT temporal prescription patterns in a cohort of patients hospitalized with AF in a Cardiology Department.

METHODS

A retrospective observational study was conducted on a cohort of hospitalized patients in a secondary setting (Trapani, Italy) from 2010 to 2021 with AF as the main or secondary diagnosis. For 4089 consecutive patients, the variables extracted from the Cardiology department database were: Sex, age, time of hospitalization, antithrombotic therapy (warfarin, acenocoumarol, apixaban, dabigatran, edoxaban, rivaroxaban, aspirin, clopidogrel, other antiplatelet agents, low molecular weight heparin, and fondaparinux), diagnosis at discharge and used resources. Basal features are presented as percentage values for categorized variables and as mean +/- SD for categorized once.

RESULTS

From January 1st, 2010 to October 6th, 2021, 25132 patients were hospitalized in our department; 4089 (16.27%, mean age 75.59+/-10.82) were discharged with AF diagnosis; of them, 2245 were males (54.81%, mean age 73.56+/-11.45) and 1851 females (45.19%, mean age 78.06+/-9.47). Average length of stay was 5.76+/-4.88 days; 154 patients died and 88 were moved to other Departments/Structures. AF was the main diagnosis in 899 patients (21.94%). The most frequent main diagnosis in patients with AF was acute myocardial infarction (1973 discharges, 48.19%). The most frequent secondary cardiac diagnosis was chronic coronary syndrome (1864 discharges, 45.51%), and the most frequent secondary associated condition was arterial hypertension (1010 discharges, 24.66%). For the analysis of antithrombotic treatments, the final sample included 3067 patients, after excluding in-hospital deaths, transferred out or self-discharged patients, as well as discharges lacking indications for prescribed treatments. OAC treatment increased significantly (35.63% in 2010-2012 vs 61.18% in 2019-2021, +25.55%, P < 0.0001), in spite of any antiplatelet agent use. This rise was due to increasing use of DOACs, with or without antiplatelet agents, from 3.04% in 2013-2015 to 50.06% in 2019-2021 (+47.02%, P < 0.0001) and was greater for factor Xa inhibitors, especially apixaban. In addition, treatment with a vitamin K antagonist, in spite of any antiplatelet agent use, decreased from 35.63% in 2010-2012 to 11.12% in 2019-2021 (-24.48%, P < 0.0001), as well as any antiplatelet therapy, alone or in double combination, (49.18% in 2010-2012 vs 34.18% in 2019-2021, -15.00%, P < 0.0001); and patients not receiving antithrombotic therapy declined with time (14.58% in 2010-2012 vs 1.97% in 2021, P < 0.0001).

CONCLUSION

Real-world patients with AF are elderly and affected by cardiovascular and non-cardiovascular diseases. The percentage of patients on OAT and DOACs increased. These data suggest a slow, gradual guidelines implementation process.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Prescribing Patterns of Direct-Acting Oral Anticoagulants in Patients With Atrial Fibrillation and Chronic Kidney Disease: A Retrospective Cohort Analysis

BACKGROUND

The association of patient and prescriber characteristics with use of warfarin versus direct-acting oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) and chronic kidney disease (CKD) is not well studied.

METHODS

The 20% Centers for Medicare & Medicaid Services Parts A, B, and D claims data from 2010 to 2017 were used to identify patients with stage 3, 4, or 5 CKD and AF who received a DOAC (apixaban, dabigatran, rivaroxaban) or warfarin. Prescribers were categorized as cardiologists, primary care providers (PCPs), and others. Using logistic regression, we estimated odds ratios (ORs) for the association of baseline characteristics and prescriber specialty with first use of a DOAC, relative to warfarin.

RESULTS

We identified 22,739 individuals with CKD who were newly initiated on oral anticoagulation for AF. New DOAC prescriptions increased from 490 in 2011 to 3261 in 2017, and displaced warfarin over time (1849, 2011; 945, 2017). By Q4 of 2014, cardiologists prescribed DOACs as initial treatment more frequently than warfarin, but non-cardiologists did not do so until 2015. As of 2017, apixaban was the most widely prescribed anticoagulant, comprising 56% and 50% of prescriptions by cardiologists and non-cardiologists, respectively. PCPs (OR 0.54, 0.51-0.58) and other providers (OR 0.55, 0.51-0.59) were less likely than cardiologists to prescribe DOACs.

CONCLUSIONS

DOAC prescriptions, particularly apixaban, increased over time and gradually displaced warfarin. The total number of patients with AF and CKD receiving anticoagulation increased over time. Cardiologists increased DOAC prescriptions more rapidly than non-cardiologists.

Incidence and Mortality Trends of Atrial Fibrillation/Atrial Flutter in the United States 1990 to 2017

Atrial fibrillation (AF) and flutter (AFL) are the most common clinically significant arrhythmias in older adults with an increasing disease burden due to an aging population. However, up-to-date trends in disease burden and regional variation remain unknown. In an observational study utilizing the Global Burden of Disease (GBD) database, age-standardized mortality and incidence rates for AF overall and for each state in the United States (US) from 1990 to 2017 were determined. All analyses were stratified by gender. The relative change in age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) over the observation period were determined. Trends were analyzed using Joinpoint regression analysis. The mean ASIR per 100,000 population for men was 92 (+/-8) and for women was 62 (+/-5) in the US in 2017. The mean ASDR per 100,000 population for men was 5.8 (+/-0.3) and for women was 4.4 (+/-0.4). There were progressive increases in ASIR and ASDR in all but 1 state. The states with the greatest percentage change in incidence were New Hampshire (+13.5%) and Idaho (+16.0%) for men and women, respectively. The greatest change regarding mortality was seen in Mississippi (+26.3%) for men and Oregon (+53.8%) for women. In conclusion these findings provide updated evidence of increasing AF and/or AFL incidence and mortality on a national and regional level in the US, with women experiencing greater increases in incidence and mortality rates. This study demonstrates that the public health burden related to AF in the United States is progressively worsening but disproportionately across states and among women.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

The role of biomarkers and neuroimaging in ischemic/hemorrhagic risk assessment for cardiovascular/cerebrovascular disease prevention

Stroke prevention in patients with atrial fibrillation is arguably one of the fastest developing areas in preventive medicine. The increasing use of direct oral anticoagulants and nonpharmacologic methods such as left atrial appendage closure for stroke prevention in these patients has increased clinicians' options for optimal care. Platelet antiaggregants are also commonly used in other ischemic cardiovascular and or cerebrovascular conditions. Long term use of oral anticoagulants for atrial fibrillation is associated with elevated risks of major bleeds including especially brain hemorrhages, which are known to have extremely poor outcomes. Neuroimaging and other biomarkers have been validated to stratify brain hemorrhage risk among older adults. A thorough understanding of these biomarkers is essential for selection of appropriate anticoagulant or left atrial appendage closure for stroke prevention in patients with atrial fibrillation. This article will address advances in the stratification of ischemic and hemorrhagic stroke risk among patients with atrial fibrillation and other conditions.

Antiplatelet patterns and outcomes in patients with atrial fibrillation not prescribed an anticoagulant after stroke

BACKGROUND

To determine association of discharge antiplatelet therapy prescription with 1-year outcomes among patients with AF admitted with acute ischemic stroke and discharged without oral anticoagulation.

METHODS

In a retrospective cohort study from the Get With The Guidelines-Stroke registry, we identified all Medicare fee-for-service beneficiaries 65 years or older with AF or atrial flutter admitted with acute ischemic stroke and discharged without oral anticoagulation from April 2003 through December 2014, and we determined association of discharge antiplatelet therapy prescription with 1-year outcomes using Medicare claims data. Primary outcomes were 1-year mortality and composite endpoint of major adverse cardiovascular/neurologic/bleeding events (MACNBE).

RESULTS

Of 64,228 subjects (median [interquartile range] age, 84 [78-89] years; 62.5% female), 54,621 (85.0%) were discharged with antiplatelet therapy, and 9607 (15.0%) were discharged with no antithrombotic therapy. The unadjusted rates of 1-year mortality were lower among patients receiving antiplatelet therapy (37.3%) than among those receiving no antithrombotic therapy (48.1%); unadjusted rates of MACNBE were lower for those receiving antiplatelet therapy (45.5%) compared with those receiving no antithrombotic therapy (55.2%). After adjusting for potential confounders, antiplatelet therapy prescription was associated with reduced 1-year mortality (adjusted hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.62-0.66, P < .001) and MACNBE (adjusted HR 0.69, 95% CI 0.67-0.71, P < .001).

CONCLUSIONS

Among Medicare beneficiaries with AF admitted for acute ischemic stroke but not discharged on oral anticoagulant therapy, antiplatelet therapy, compared with no antithrombotic therapy, was associated with reduced 1-year mortality and MACNBE.

Frailty, Cognitive Impairment, and Anticoagulation Among Older Adults with Nonvalvular Atrial Fibrillation

BACKGROUND/OBJECTIVES

Oral anticoagulation (OAC) is challenging in older patients with nonvalvular atrial fibrillation (NVAF) who are often frail and have cognitive impairment. We examined the characteristics of older NVAF patients associated with higher odds of physical and cognitive impairments. We also examined if these high-risk patients have different OAC prescribing patterns and their satisfaction with treatment because it may impact optimal management of their NVAF.

METHODS

The patients in the Systematic Assessment of Geriatric Elements in Atrial Fibrillation (SAGE-AF study cohort 2016-2018) had NVAF, were aged 65 and older, and eligible for the receipt of OAC. Measures included frailty (Fried Frailty scale), cognitive impairment (Montreal Cognitive Assessment Battery), OAC prescribing and type (direct oral anticoagulant [DOAC] or vitamin K antagonist [VKA]), depressive symptoms (Patient Health Questionnaire-9), bleeding, stroke risk, and treatment benefit (Anti-Clot Treatment Scale).

RESULTS

Patients (n = 1,244) were 49% female, aged 76 (standard deviation = 7) years. A total of 14% were frail, and 42% had cognitive impairment. Frailty and cognitive impairment co-occurred in 9%. Odds of having both impairments versus none were higher with depression (odds ratio [OR] = 4.62; 95% confidence interval [CI] = 2.59-8.26), older age (OR = 1.56; 95% CI = 1.29-1.88), lower education (OR = 3.81; 95%CI = 2.13-6.81), race/ethnicity other than non-Hispanic White (OR = 7.94; 95% CI = 4.34-14.55), bleeding risk (OR = 1.43; 95% CI = 1.12-1.81), and stroke risk (OR = 1.35; 95% CI = 1.13-1.62). OAC prescribing was not associated with CI and frailty status. Among patients taking OACs (85%), those with both impairments were more likely to take DOAC than VKA (OR = 1.69; 95% CI = 1.01-2.80). Having both impairments (OR = 1.87; 95% CI = 1.08-3.27) or cognitive impairment (OR = 1.56; 95% CI = 1.09-2.24) was associated with higher odds of reporting lower treatment benefit.

CONCLUSION

In a large cohort of older NVAF patients, half were frail or cognitively impaired, and 9% had both impairments. We highlight the characteristics of patients who may benefit from cognitive and physical function screenings to maximize treatment and enhance prognosis. Finally, the co-occurrence of impairment was associated with low perceived benefit of treatment that may impede optimal management.

Impact of liver disease on oral anticoagulant prescription and major adverse events in patients with atrial fibrillation: analysis from a population-based cohort study

AIMS 

Data on the impact of liver disease (LD) in patients with atrial fibrillation (AF) and the role of oral anticoagulant (OAC) drugs for stroke prevention are limited.

METHODS AND RESULTS 

A retrospective observational population-based cohort study on the administrative health databases of Lombardy region Italy. All AF patients ≥40 years admitted to hospital from 2000 to 2018 were considered. Atrial fibrillation and LD diagnosis were established using ICD9-CM codes. Use of OAC was determined with Anatomical Therapeutic Chemical codes. Primary study outcomes were stroke, major bleeding, and all-cause death. Among 393 507 AF patients, 16 168 (4.1%) had concomitant LD. Liver disease AF patients were significantly less treated with OAC. Concomitant LD was associated with an increased risk in all the study outcomes [hazard ratio (HR): 1.18, 95% confidence interval (CI): 1.11-1.25 for stroke; HR: 1.57, 95% CI: 1.47-1.66 for major bleeding; HR: 1.41, 95% CI: 1.39-1.44 for all-cause death]. Use of OAC in patients with AF and LD resulted in a reduction in stroke (HR: 0.80, 95% CI: 0.70-0.92), major bleeding (HR: 0.86, 95% CI: 0.74-0.99), and all-cause death (HR: 0.77, 95% CI: 0.73-0.80), with similar results according to subgroups. A net clinical benefit (NCB) analysis suggested a positive benefit/risk ratio in using OAC in AF patients with LD (NCB: 0.408, 95% CI: 0.375-0.472).

CONCLUSION

In AF patients, concomitant LD carries a significantly higher risk for all clinical outcomes. Use of OAC in AF patients with LD was associated with a significant favourable benefit/risk ratio, even in high-risk patient subgroups.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Left atrial appendage closure: A therapy uniquely suited for specific populations of patients with atrial fibrillation

Atrial fibrillation (AF) is the most common clinically relevant arrhythmia and confers a fivefold increased risk for stroke. Cardioembolic stroke secondary to AF is a devastating event, but is largely preventable with appropriate oral anticoagulation (OAC). The PROTECT and PREVAIL trials demonstrated that the WATCHMAN left atrial appendage closure (LAAC) device in combination with short-term warfarin therapy is noninferior to long-term warfarin with respect to a composite endpoint of stroke, cardiovascular death, and systemic embolism. Importantly, the WATCHMAN confers a significant reduction in life-threatening bleeding compared to OAC. Although direct-acting oral anticoagulant (DOAC) are superior to warfarin in eligible patients, several important AF populations exist in whom left atrial appendage (LAA) closure may be preferable to DOAC. Populations warranting strong consideration of LAAC include patients with contraindications to DOAC, end-stage renal disease, prior intracranial hemorrhage, recurrent gastrointestinal bleeding, and patients undergoing transcatheter aortic valve replacement or left atrial electrical isolation. Device-related thrombosis is an important complication of LAAC, and DOAC may be preferential to warfarin for prevention and treatment of this complication remains unexplored. Prospective clinical trials comparing DOAC to LAAC in these unique populations are either ongoing or needed.

Oral Anticoagulation in Patients With Liver Disease

Patients with liver disease are at increased risks of both thrombotic and bleeding complications. Many have atrial fibrillation (AF) or venous thromboembolism (VTE) necessitating oral anticoagulant agents (OACs). Recent evidence has contradicted the assumption that patients with liver disease are "auto-anticoagulated" and thus protected from thrombotic events. Warfarin and non-vitamin K-antagonist OACs have been shown to reduce thrombotic events safely in patients with either AF or VTE. However, patients with liver disease have largely been excluded from trials of OACs. Because all currently approved OACs undergo metabolism in the liver, hepatic dysfunction may cause increased bleeding. Thus, the optimal anticoagulation strategy for patients with AF or VTE who have liver disease remains unclear. This review discusses pharmacokinetic and clinical studies evaluating the efficacy and safety of OACs in patients with liver disease and provides a practical, clinically oriented approach to the management of OAC therapy in this population.

Evaluating the implementation of a quality improvement process in General Practice using a realist evaluation framework

RATIONALE, AIMS, AND OBJECTIVES

Underuse of anticoagulants in atrial fibrillation is known to increase the risk of stroke and is an international problem. The National Institute for Health Care and Excellence guidance CG180 seeks to reduce atrial fibrillation related strokes through prescriptions of Non-vitamin K antagonist Oral Anticoagulants. A quality improvement programme was established by the West of England Academic Health Science Network (West of England AHSN) to implement this guidance into General Practice. A realist evaluation identified whether the quality improvement programme worked, determining how and in what circumstances.

METHODS

Six General Practices in 1 region, became the case study sites. Quality improvement team, doctor, and pharmacist meetings within each of the General Practices were recorded at 3 stages: initial planning, review, and final. Additionally, 15 interviews conducted with the practice leads explored experiences of the quality improvement process. Observation and interview data were analysed and compared against the initial programme theory.

RESULTS

The quality improvement resources available were used variably, with the training being valued by all. The initial programme theories were refined. In particular, local workload pressures and individual General Practitioner experiences and pre-conceived ideas were acknowledged. Where key motivators were in place, such as prior experience, the programme achieved optimal outcomes and secured a lasting quality improvement legacy.

CONCLUSION

The employment of a quality improvement programme can deliver practice change and improvement legacy outcomes when particular mechanisms are employed and in contexts where there is a commitment to improve service.

Gender Differences in Efficacy and Safety of Direct Oral Anticoagulants in Atrial Fibrillation: Systematic Review and Network Meta-analysis

BACKGROUND

Studies indicate that women with atrial fibrillation (AF) are less likely to receive anticoagulants despite their higher risk of stroke compared with men.

OBJECTIVE

To evaluate whether the efficacy and safety of direct oral anticoagulants (DOACs) differ in women with AF as compared with men. Our secondary aim was to examine gender differences regarding the safety and efficacy of specific DOACs.

DATA SOURCES

MEDLINE, EMBASE, Cochrane, and ClinicalTrials.gov were searched through March 2017.

STUDY SELECTION AND DATA EXTRACTION

Randomized clinical trials that reported on major bleeding and stroke with DOACs in women and men with AF were included. Meta-analysis and network meta-analysis was performed.

DATA SYNTHESIS

Five trials met the inclusion criteria. Among 66 389 patients, 37.8% were women. Women treated with DOACs were at higher risk of stroke and systemic embolism compared with men (RR = 1.19; 95% CI = 1.04-1.35; I² = 10%) but there was a significantly lower risk of major bleeding in women compared with men (RR = 0.86; 95% CI = 0.78-0.94; I² = 0%). Network meta-analyses suggested differences between various DOACs in men and women.

LIMITATIONS

Patient-level data enabling control for differences in baseline risk and head-to-head comparisons between DOACs were not available. Relevance to Patient Care and Clinical Practice: Undertreatment with DOACs among women cannot be justified.

CONCLUSION

Women treated with DOACs had a lower rate of major bleeding and higher rate of stroke and systemic emboli compared with men. Further investigation of DOACs, including differences between the DOACs in specific populations is warranted.

Effectiveness and Safety of Apixaban, Dabigatran, and Rivaroxaban Versus Warfarin in Frail Patients With Nonvalvular Atrial Fibrillation

Background

Frailty predicts poorer outcomes and decreased anticoagulation use in patients with nonvalvular atrial fibrillation. We sought to assess the effectiveness and safety of apixaban, dabigatran and rivaroxaban versus warfarin in frail nonvalvular atrial fibrillation patients.

Methods and Results

Using US MarketScan claims data from November 2011 to December 2016, we identified frail oral anticoagulant‐naïve nonvalvular atrial fibrillation patients with ≥12 months of continuous insurance coverage before oral anticoagulant initiation. Frailty status was determined using the Johns Hopkins Claims‐based Frailty Indicator score (≥0.20 indicating frailty). Users of apixaban, dabigatran, or rivaroxaban were separately 1:1 matched to warfarin users via propensity‐scores, with residual absolute standardized differences <0.1 being achieved for all covariates after matching. Patients were followed for up to 2 years or until an event, insurance disenrollment or end of follow‐up. Rates of stroke or systemic embolism and major bleeding were compared using Cox regression and reported as hazard ratios (HRs) and 95% confidence intervals (CIs). In total, 2700, 2784, and 5270 patients were included in the apixaban, dabigatran, and rivaroxaban 1:1 matched analyses to warfarin. At 2 years, neither apixaban nor dabigatran were associated with differences in the hazard of stroke or systemic embolism (HR=0.78; 95% CI=0.46–1.35 and HR=0.94; 0.60–1.45) or major bleeding (HR=0.72; 95% CI=0.49–1.06 and HR=0.87; 95% CI=0.63–1.19) versus warfarin. Rivaroxaban was associated with reduced stroke or systemic embolism at 2 years (HR=0.68; 95% CI=0.49–0.95) without significantly altering major bleeding risk (HR=1.07; 95% CI=0.81–1.32).

Conclusions

Our study found rivaroxaban but not apixaban or dabigatran to be associated with reduced SSE versus warfarin in frail nonvalvular atrial fibrillation patients. No direct‐acting oral anticoagulants demonstrated a significant difference in major bleeding versus warfarin.

Incidence and characteristics of major bleeding among rivaroxaban users with renal disease and nonvalvular atrial fibrillation

OBJECTIVE

Patients with nonvalvular atrial fibrillation (AF) and renal disease (RD) who receive anticoagulation therapy appear to be at greater risk of major bleeding (MB) than AF patients without RD. As observed in past studies, anticoagulants are frequently withheld from AF patients with RD due to concerns regarding bleeding. The objective of this study was to evaluate the incidence and pattern of MB in those with RD, as compared to those without RD, in a population of rivaroxaban users with nonvalvular AF.

METHODS

Electronic medical records of over 10 million patients from the Department of Defense Military Health System were queried to identify rivaroxaban users with nonvalvular AF. A validated algorithm was used to identify MB-related hospitalizations. RD was defined through diagnostic codes present within 6 months prior to the bleeding date for MB cases and end of study participation for non-MB patients. Data were collected on patient characteristics, comorbidities, MB management, and outcomes.

RESULTS

Overall, 44,793 rivaroxaban users with nonvalvular AF were identified. RD was present among 6,921 patients (15.5%). Patients with RD had a higher rate of MB than those without RD, 4.52 per 100 person-years versus 2.54 per 100 person-years, respectively. The fatal bleeding outcome rate (0.09 per 100 person-years) was identical between those with and without RD.

CONCLUSION

In this post-marketing study of 44,793 rivaroxaban users with nonvalvular AF, RD patients experienced a higher MB rate than those without RD. The higher rate of MB among those with RD may be due to the confounding effects of comorbidities.

Revisiting sex differences in outcomes in non-valvular atrial fibrillation: a population-based cohort study

Aims

In patients with non-valvular atrial fibrillation (NVAF), it is uncertain whether the higher risk of ischaemic stroke in women reported in some studies is due to residual confounding. We assessed this association using standard time-fixed and more accurate time-dependent adjustment for confounders.

Methods and results

Using the computerized databases of the Régie de l'assurance maladie du Québec (RAMQ), we identified a cohort of patients with NVAF during 2000-2009 and RAMQ medication coverage. Cox proportional hazards models were used to estimate the hazard ratio (HR) of ischaemic stroke, death, and bleeding, associated with sex, adjusting for time-fixed covariates at cohort entry. This was compared with adjustment for time-dependent covariates using an age and time-matched nested case-control analysis. The cohort included 147 622 patients. During a mean follow-up of 2.9 years 11 326 patients had a stroke (incidence rate 2.6 per 100 per year). Using time-fixed adjustment for confounders, women had a moderately higher risk of ischaemic stroke than men (HR 1.16 (Confidence interval (CI) 95% 1.11-1.21). Matching on age and using time-dependent adjustment for confounders, women were not at higher risk of stroke than men (Rate Ratio 1.01; 95% CI 0.97-1.05). Mortality and bleeding rates were lower in women compared with men in both analyses.

Conclusion

In NVAF, women were not at higher risk of thromboembolic events than men in our study. The small increased risk reported in previous studies may be related to residual confounding, in particular from insufficient control for age.

Influence of Age on Warfarin Dose, Anticoagulation Control, and Risk of Hemorrhage

OBJECTIVE

We assessed the influence of age on warfarin dose, percentage time in target range (PTTR), and risk of major hemorrhage.

DESIGN

Warfarin users recruited into a large prospective inception cohort study were categorized into three age groups: young (younger than 50 yrs), middle aged (50-70 yrs), and elderly (older than 70 yrs). The influence of age on warfarin dose and PTTR was assessed using regression analysis; risk of major hemorrhage was assessed using proportional hazards analysis. Models were adjusted for demographic, clinical, and genetic factors.

SETTING

Two outpatient anticoagulation clinics.

PARTICIPANTS

A total of 1498 anticoagulated patients.

OUTCOMES

Warfarin dose (mg/day), PTTR, major hemorrhage.

RESULTS

Of the 1498 patients, 22.8% were young, 44.1% were middle aged, and 33.1% were elderly. After accounting for clinical and genetic factors, compared with young warfarin users, warfarin dose requirements were 10.6% lower among the middle aged and an additional 10.6% lower for the elderly. Compared with young patients, middle-aged and elderly patients spent more time in target international normalized ratio (INR) range (p<0.0001), despite having fewer INR assessments (p<0.0001). Compared with young warfarin users, absolute risk of hemorrhage was marginally higher among the middle aged (p=0.08) and significantly higher among the elderly (p=0.016). Compared with young warfarin users, after adjustment, the relative risk of hemorrhage increased by 31% for each age category (p=0.026).

CONCLUSIONS

In a real-world setting, despite achieving better anticoagulation control, elderly patients had a higher risk of major hemorrhagic events. As the population ages and the candidacy for oral anticoagulation increases, strategies that mitigate the elevated risk of hemorrhage need to be identified.

Atrial Fibrillation for the Neurologist: Preventing both Ischemic and Hemorrhagic Strokes

PURPOSE OF REVIEW

This review aims to help neurologists managing atrial fibrillation (AF) patients who had an ischemic stroke and/or with intracranial hemorrhage (ICH) markers, therefore at high embolic/hemorrhagic risks.

RECENT FINDINGS

Implantable loop recorders have substantially improved the accuracy of AF detection. Recent research yielded a set of powerful neuroimaging markers that can stratify ICH risk. Direct oral anticoagulants (DOAC) are easier to use with a lower ICH risk than warfarin in a general AF population. Finally, the FDA-approved left atrial appendage closure (LAAC) with the WATCHMAN device provides an option without the need for life-long anticoagulation. In this review, we introduce the concept of preventing both ischemic and hemorrhagic strokes in AF patients through accurate AF diagnosis and stratification of both embolic and ICH risks. LAAC can be considered in patients at higher hemorrhagic risks while warfarin/DOAC use should be individualized in the majority of AF patients at a low risk of bleeding.

Temporal trends in antithrombotic treatment of real-world UK patients with newly diagnosed atrial fibrillation: findings from the GARFIELD-AF registry

OBJECTIVE

To investigate evolving patterns in antithrombotic treatment in UK patients with newly diagnosed non-valvular atrial fibrillation (AF).

DESIGN

Prospective, multicentre, international registry.

SETTING

186 primary care practices in the UK.

PARTICIPANTS

3482 participants prospectively enrolled in four sequential cohorts (cohort 2 (C2) n=830, diagnosed September 2011 to April 2013; cohort 3 (C3) n=902, diagnosed April 2013 to June 2014; cohort 4 (C4) n=850, diagnosed July 2014 to June 2015; cohort 5 (C5) n=900, diagnosed June 2015 to July 2016). Participants had newly diagnosed non-valvular AF and at least one risk factor for stroke, were aged ≥18, and provided informed consent.

MAIN OUTCOME MEASURES

Antithrombotic treatment initiated at diagnosis, overall and according to stroke and bleeding risks. Stroke risk was retrospectively calculated using CHA₂DS₂-VASc (cardiac failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled)-vascular disease, age 65-74 and sex category (female)) and bleeding risk using HAS-BLED (hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, elderly (>65), drugs/alcohol concomitantly (1 point each)).

RESULTS

42.7% were women and the mean age was 74.5 years. The median CHA₂DS₂-VASc score was 3 in all cohorts and the median HAS-BLED score was 2 in all cohorts. There was a statistically significant increase in the use of anticoagulant therapy from C2 to C5 (C2 54.7%, C3 60.3%, C4 73.1%, C5 73.9%; P value for trend <0.0001). The increase in the use of anticoagulant was mainly in patients with CHA₂DS₂-VASc ≥2. The use of vitamin K antagonists (VKAs)±antiplatelet (AP) drugs decreased from C2 to C5 (C2 53.3%, C3 52.1%, C4 50.3%, C5 30.6%), while the use of non-vitamin K antagonist oral anticoagulants (NOACs)±AP increased (C2 1.3%, C3 8.0%, C4 22.7%, C5 43.3%). The use of AP only decreased (C2 36.4%, C3 25.5%, C4 11.9%, C5 10.5%), as did the combination therapy of VKA+AP (C2 13.6%, C3 11.0%, C4 9.6%, C5 5.8%).

CONCLUSION

There has been a progressive increase in the proportion of patients newly diagnosed with AF receiving guideline-recommended therapy in the UK, potentially driven by the availability of NOACs.

TRIAL REGISTRATION NUMBER

NCT01090362; Pre-results.

A post-marketing assessment of major bleeding in total hip and total knee replacement surgery patients receiving rivaroxaban

BACKGROUND

Rivaroxaban is a novel oral anticoagulant indicated for prophylaxis against deep vein thrombosis and pulmonary embolism in patients undergoing total hip replacement (THR) or total knee replacement (TKR) surgery.

OBJECTIVE

To evaluate major bleeding (MB) in THR/TKR patients receiving post-operative rivaroxaban.

METHODS

Electronic medical records of nearly 10 million US Department of Defense (DoD) beneficiaries were queried from 1 January 2013 through 30 June 2015. Using the validated Cunningham case-finding algorithm, post-surgical MB events in rivaroxaban users were identified and analyzed. The incidence of MB was determined, and descriptive statistics were used to compare patient characteristics and other covariates in those with and without MB. Two additional methods were used to explore and identify bleeding cases that were not considered MB events per the study case-finding algorithm.

RESULTS

A total of 12,429 patients received THR and/or TKR surgery, and were post-operatively prescribed rivaroxaban. Nine patients had MB, yielding an incidence proportion of 0.07% (95% CI 0.02-0.13). The alternative case-finding methods found bleeding incidences of 0.46% and 0.21%, though it is not clear whether these are clinical MB cases, since the alternative methods were not validated.

CONCLUSIONS

The incidence of MB in this retrospective analysis is lower than that observed in the clinical trials of rivaroxaban. Whether this is due to lower real-world MB rates or challenges with case-finding algorithms is unclear.

The role of contraindications in prescribing anticoagulants to patients with atrial fibrillation: a cross-sectional analysis of primary care data in the UK

BACKGROUND

Underuse of anticoagulants in atrial fibrillation (AF) is an international problem, which has often been attributed to the presence of contraindications to treatment. No studies have assessed the influence of contraindications on anticoagulant prescribing in the UK.

AIM

To determine the influence of contraindications on anticoagulant prescribing in patients with AF in the UK.

DESIGN AND SETTING

Cross-sectional analysis of primary care data from 645 general practices contributing to The Health Improvement Network, a large UK database of electronic primary care records.

METHOD

Twelve sequential cross-sectional analyses were carried out from 2004 to 2015. Patients with a diagnosis of AF aged ≥35 years and registered for at least 1 year were included. Outcome measure was prescription of anticoagulant medication.

RESULTS

Over the 12 study years, the proportion of eligible patients with AF with contraindications who were prescribed anticoagulants increased from 40.1% (95% confidence interval [CI] = 38.3 to 41.9) to 67.2% (95% CI = 65.6 to 68.8), and the proportion of those without contraindications prescribed anticoagulants increased from 42.1% (95% CI = 41.6 to 42.6) to 67.7% (95% CI = 67.2 to 68.1). In patients with a recent history of major bleeding or aneurysm, prescribing rates increased from 44.3% (95% CI = 42.2 to 46.5) and 34.8% (95% CI = 29.4 to 40.6) in 2004 to 71.7% (95% CI = 69.9 to 73.5) and 63.2% (95% CI = 58.3 to 67.8) in 2015, respectively, comparable with rates in patients without contraindications.

CONCLUSION

The presence or absence of recorded contraindications has little influence on the decision to prescribe anticoagulants for the prevention of stroke in patients with AF. The study analysis suggests that, nationally, 38 000 patients with AF with contraindications are treated with anticoagulants. This has implications for patient safety.

Trends in the prevalence and management of pre-stroke atrial fibrillation, the South London Stroke Register, 1995-2014

Background

Previous studies have found low use of anticoagulation prior to stroke, in people with atrial fibrillation (AF). This study examined data on patients with AF-related stroke from a population-based stroke register, and sought to examine changes in management of AF prior to stroke, and reasons for suboptimal treatment, in those who were known to be at a high risk of stroke.

Methods

The South London Stroke Register (SLSR) is an ongoing population-based register recording first-in-a-lifetime stroke. Trends in the prevalence of AF, and antithrombotic medication prescribed before the stroke, were investigated from 1995 to 2014. Multivariable logistic regression analyses were conducted to assess the factors associated with appropriate management.

Results

Of the 5041 patients on the register, 816 (16.2%) were diagnosed with AF before their stroke. AF related stroke increased substantially among Black Carribean and Black African patients, comprising 5% of the overall cohort in 1995–1998, increasing to 25% by 2011–2014 (p<0.001). Anticoagulant prescription in AF patients at high-risk of stroke (CHADS2 score [> = 2]) increased from 9% (1995–1998) to 30% (2011–2014) (p<0.001). Antiplatelet prescription was more commonly prescribed throughout all time periods (43% to 64% of high-risk patients.) Elderly patients (>65) were significantly less likely to be prescribed an anticoagulant, with ethnicity, gender and deprivation showing no association with anticoagulation.

Conclusions

Most AF-related strokes occurred in people who could have been predicted to be at high risk before their stroke, yet were not prescribed optimal preventative treatment. The elderly,despite being at highest stroke risk, were rarely prescribed anticoagulants.

Quality of care in patients with atrial fibrillation in primary care: a cross-sectional study comparing clinical and claims data

Objectives: Atrial fibrillation (AF) is a common cardiac arrhythmia with increased risk of thromboembolic stroke. Oral anticoagulation (OAC) reduces stroke risk by up to 68%. The aim of our study was to evaluate quality of care in patients with AF in a primary health care setting with a focus on physician guideline adherence for OAC prescription and heart rate- and rhythm management. In a second step we aimed to compare OAC rates based on primary care data with rates based on claims data. Methods: We included all GP practices in the region Vorpommern-Greifswald, Germany, which were willing to participate (N=29/182, response rate 16%). Claims data was derived from the regional association of statutory health insurance physicians. Patients with a documented AF diagnosis (ICD-10-GM-Code ICD I48.-) from 07/2011-06/2012 were identified using electronic medical records (EMR) and claims data. Stroke and bleeding risk were calculated using the CHA2DS2-VASc and HAS-BLED scores. We calculated crude treatment rates for OAC, rate and rhythm control medications and adjusted OAC treatment rates based on practice and claims data. Adjusted rates were calculated including the CHA2DS2-VASc and HAS-BLED scores and individual factors affecting guideline based treatment. Results: We identified 927 patients based on EMR and 1,247 patients based on claims data. The crude total OAC treatment rate was 69% based on EMR and 61% based on claims data. The adjusted OAC treatment rates were 90% for patients based on EMR and 63% based on claims data. 82% of the AF patients received a treatment for rate control and 12% a treatment for rhythm control. The most common reasons for non-prescription of OAC were an increased risk of falling, dementia and increased bleeding risk. Conclusion: Our results suggest that a high rate of AF patients receive a drug therapy according to guidelines. There is a large difference between crude and adjusted OAC treatment rates. This is due to individual contraindications and comorbidities which cannot be documented using ICD coding. Therefore, quality indicators based on crude EMR data or claims data would lead to a systematic underestimation of the quality of care. A possible overtreatment of low-risk patients cannot be ruled out.

No Decline in the Risk of Stroke Following Incident Atrial Fibrillation Since 2000 in the Community: A Concerning Trend

Background

While atrial fibrillation is a recognized risk factor for stroke, contemporary data on trends in stroke incidence after the diagnosis of atrial fibrillation are scarce.

Methods and Results

Olmsted County, MN residents with incident atrial fibrillation or atrial flutter (collectively referred to as AF) from 2000 to 2010 were identified. Cox regression determined associations of year of AF diagnosis with ischemic stroke and transient ischemic attack (TIA) occurring through 2013. Among 3247 AF patients, 321 (10%) had an ischemic stroke/TIA over a mean of 4.6 years (incidence rate [95% CI] per 100 person‐years: 2.14 [1.91–2.38]). Two hundred thirty‐nine (7%) of 3265 AF patients experienced an ischemic stroke (incidence rate: 1.54 [1.35–1.75]). The risk of both outcomes remained unchanged over time after adjusting for demographics and comorbidities (hazard ratio [95% CI] per year of AF diagnosis: 1.00 [0.96–1.04] for ischemic stroke/TIA; 1.01 [0.96–1.06] for ischemic stroke only). In analyses restricted to patients with prescription information, the rates of anticoagulation use did not change over time, reaching 50.8% at 1 year after AF diagnosis. Further adjustment for anticoagulation use did not alter the temporal trends in stroke incidence (hazard ratio [95% CI] per year of AF diagnosis: 1.06 [0.97–1.15] for ischemic stroke/TIA; 1.08 [0.98–1.20] for ischemic stroke only).

Conclusions

Strokes/TIAs are frequent after AF, occurring in 10% of patients after 5 years of follow‐up. The occurrence of stroke/TIA did not decline over the last decade, which may be influenced by a leveling off of anticoagulation use. This concerning trend has major public health implications.

Cost-Effectiveness of Novel Oral Anticoagulants for Stroke Prevention in Non-Valvular Atrial Fibrillation

Recently, novel oral anticoagulants (NOACs) have been approved for stroke prevention in patients with atrial fibrillation (AF). Although these agents overcome some disadvantages of warfarin, they are associated with increased costs. In this review, we will provide an overview of the cost-effectiveness of NOACs for stroke prevention in AF. Our comments and conclusions are limited to studies directly comparing all available NOACs within the same framework. The available cost-effectiveness analyses suggest that NOACs are cost-effective compared to warfarin, with apixaban likely being most favorable. However, significant limitations in these models are present and should be appreciated when interpreting their results.

Long-term vitamin K antagonists treatment patterns of Non-Valvular Atrial Fibrillation (NVAF): a population-based cohort study

Background

Recent trends in vitamin K antagonists (VKA) use in non-valvular atrial fibrillation (NVAF) are useful to evaluate the potential improvement in management of NVAF since the introduction of new oral anticoagulants. Our objective was therefore to describe the contemporary VKA treatment patterns following NVAF diagnosis.

Methods and Results

We used the computerized databases of the Régie de l’assurance maladie du Québec (RAMQ), responsible for administering the universal health care services for all its residents, to identify a population-based cohort of 135,241 patients with an incident diagnosis of NVAF during 2000–2009 and RAMQ medication coverage.

Following NVAF diagnosis, 47.1 % of the patients were prescribed VKA, 35.5 % received an antiplatelet only, and 17.4 % did not initiate antithrombotic therapy. The proportion of patients initiating VKA within 3 months of diagnosis increased from 33 % to 39 % over the 10-year study period, mainly driven by a higher proportion of treated patients aged 80 or more (from 29 % to 41 %). At the end of the study period, women were prescribed VKA as frequently as men, except in the subgroup of patients with a low risk of ischemic stroke. The median time from VKA initiation to the first discontinuation varied greatly according to the definition of discontinuation, ranging from 11 months to 5.7 years.

Conclusion

Although VKA remain underused after NVAF diagnosis, there has been an increase in VKA treatment over the last decade, particularly among older patients. Also the gap in treatment between men and women has been closing within the last decade. Once initiated, most VKA interruptions were temporary rather than definitive.

Underuse of anticoagulation in patients with atrial fibrillation

Atrial fibrillation (AF) is a major risk factor for ischemic stroke. Guidelines recommend anticoagulation for patients with intermediate and high stroke risk (CHA2DS2-VASc score ≥ 2). Underuse of anticoagulants among eligible patients remains a persistent problem. Evidence demonstrates that the psychology of the fear of causing harm (omission bias) results in physicians' hesitancy to initiate anticoagulation and an inaccurate estimation of stroke risk. The American Heart Association (AHA) initiated the Get With The Guidelines-AFIB (GWTG-AFIB) module in June 2013 to enhance guideline adherence for treatment and management of AF. Better quality of care for AF patients can be provided by increasing adherence to anticoagulation guidelines and improving patient compliance with anticoagulation therapy through education and established protocols. Nonvitamin K antagonist oral anticoagulants may facilitate better patient adherence due to ease of administration and reduced monitoring burden. In this review, we discuss the reasons for underuse, omission bias contributing to underuse, and different strategies to address this issue.

Bleeding Outcomes After Left Atrial Appendage Closure Compared With Long-Term Warfarin: A Pooled, Patient-Level Analysis of the WATCHMAN Randomized Trial Experience

OBJECTIVES

The purpose of this study was to compare the relative risk of major bleeding with left atrial appendage (LAA) closure compared with long-term warfarin therapy.

BACKGROUND

LAA closure is an alternative approach to chronic oral anticoagulation for the prevention of thromboembolism in patients with atrial fibrillation (AF).

METHODS

We conducted a pooled, patient-level analysis of the 2 randomized clinical trials that compared WATCHMAN (Boston Scientific, Natick, Massachusetts) LAA closure with long-term warfarin therapy in AF.

RESULTS

A total of 1,114 patients were included, with a median follow-up of 3.1 years. The overall rate of major bleeding from randomization to the end of follow-up was similar between treatment groups (3.5 events vs. 3.6 events per 100 patient-years; rate ratio [RR]: 0.96; 95% confidence interval [CI]: 0.66 to 1.40; p = 0.84). LAA closure significantly reduced bleeding >7 days post-randomization (1.8 events vs. 3.6 events per 100 patient-years; RR: 0.49; 95% CI: 0.32 to 0.75; p = 0.001), with the difference emerging 6 months after randomization (1.0 events vs. 3.5 events per 100 patient-years; RR: 0.28; 95% CI: 0.16 to 0.49; p < 0.001), when patients assigned to LAA closure were able to discontinue adjunctive oral anticoagulation and antiplatelet therapy. The reduction in bleeding with LAA closure was directionally consistent across all patient subgroups.

CONCLUSIONS

There was no difference in the overall rate of major bleeding in patients assigned to LAA closure compared with extended warfarin therapy over 3 years of follow-up. However, LAA closure significantly reduced bleeding beyond the procedural period, particularly once adjunctive pharmacotherapy was discontinued. The favorable effect of LAA closure on long-term bleeding should be considered when selecting a stroke prevention strategy for patients with nonvalvular AF. (WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy [PREVAIL]; NCT01182441).

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.

Choosing the right drug to fit the patient when selecting oral anticoagulation for stroke prevention in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is a growing health problem that is associated with a significantly increased risk of stroke and thromboembolism. Oral anticoagulant (OAC) therapy reduces the risk of stroke and all-cause mortality in patients with AF. OAC therapy is commonly given as a well-controlled vitamin K antagonist (VKA; e.g. warfarin) and can reduce the risk of stroke in AF patients by almost two-thirds. However, the widespread use of VKAs has been hampered by the unpredictable pharmacokinetic and pharmacodynamic properties of the drugs and justifiable concerns about the consequent risk of haemorrhage. The non-VKA OACs (NOACs) have revolutionized thromboprophylaxis in AF by providing therapeutic options with predictable pharmacodynamic and pharmacokinetic properties that are as efficacious as warfarin in the prevention of stroke and thromboembolism but are more convenient to use. In this review, we provide a patient-centred framework to assist clinicians in recommending the right OAC therapy to fit the individual patient with AF, including methods for stratifying the risk of stroke and haemorrhage and the chances of achieving tight control of VKA anticoagulation, and we discuss the properties of the NOACs that favour their use in particular patient cohorts.

[Anticoagulation in the aged patient with atrial fibrillation: What are prescribing cardiologists, geriatricians and general practitioners?]

OBJECTIVE

To assess prescribing of anticoagulants in atrial fibrillation (AF) in the elderly, both a quantitative point of view (rate of anticoagulation) and qualitative (type of anticoagulation). Determinants of prescribing and non-prescribing were also analysed.

METHODS

Prospective survey of practice, based on one clinical case and questionnaire conducted in 60 practitioners (20 cardiologists [C], 20 geriatricians [G] and 20 general practitioners [GP]).

RESULTS

In reading the clinical case, 88.3% of physicians would have initiated a treatment; three types of treatments would have been chosen: AVK (68.3%), ODA (20.0%) and platelet antiaggregant (11.7%). Criteria taken into account to initiate anticoagulation varied according to the specialty. Cardiologists considered more the age criteria (C: 95.0%, G: 75.0%, MG: 60.0%; P<0.05), diabetes (C: 90.0%, G: 60.0%, MG: 55.0%; P<0.05), hypertension (C: 85.0%, G: 55.0%, MG: 60.0%; P<0.05) and female gender (C: 80.0%, G: 35.0%, MG: 25.0%; P<0.05). The quality of renal function was however a more secondary criteria (C: 15.0%, G: 5.0%, MG: 0.0%; P<0.05). General practitioners considered most frequently the presence of underlying heart disease (C: 35.0%, G: 5.0%, MG: 45.0%; P<0.05) as well as usual cardiovascular risk factors (overweight, dyslipidaemia; P<0.05). Risk of bleeding, however, was observed by 76.7% of physicians in the clinical situation presented (C: 70.0%, G: 75.0%, MG: 85.0%; P<0.05).

CONCLUSION

This survey confirms that the FA remains under anticoagulated in the elderly and the barriers to the prescription of oral anticoagulation are often without rational basis.

Addressing Disparities in Stroke Prevention for Atrial Fibrillation: Educational Opportunities

Disparities in atrial fibrillation (AF)-related stroke and mortality persist, especially racial disparities, within the US "Stroke Belt." This study identified barriers to optimal stroke prevention to develop a framework for clinician education. A comprehensive educational needs assessment was developed focusing on clinicians within the Stroke Belt. The mixed qualitative-quantitative approach included regional surveys and one-on-one clinician interviews. Identified contributors to disparities included implicit racial biases, lack of awareness of racial disparities in AF stroke risk, and lack of effective multicultural awareness and training. Additional barriers affecting disparities included patient medical mistrust and clinician-patient communication challenges. General barriers included lack of consistency in assessing stroke and anticoagulant-related bleeding risk, underuse of standardized risk assessment tools, discomfort with novel anticoagulants, and patient education deficiencies. Effective cultural competency training is one strategy to reduce disparities in AF-related stroke and mortality by improving implicit clinician bias, addressing medical mistrust, and improving clinician-patient communication.