Characterization of patients with atrial fibrillation not treated with oral anticoagulants

Opportunistic atrial fibrillation screening in primary care in Ireland: results of a pilot screening programme

BACKGROUND

Atrial fibrillation (AF), a common, frequently asymptomatic cardiac arrhythmia, is a major risk factor for stroke. Identification of AF enables effective preventive treatment to be offered, potentially reducing stroke risk by up to two-thirds. There is international consensus that opportunistic AF screening is valuable though uncertainty remains about the optimum screening location and method. Primary care has been identified as a potential location for AF screening using one-lead ECG devices.

METHODS

A pilot AF screening programme is in primary care in the south of Ireland. General practitioners (GPs) were recruited from Cork and Kerry. GPs invited patients ≥65 years to undergo AF screening. The screening comprised a one-lead ECG device, Kardia Mobile, blood pressure check and ascertainment of smoking status. Possible AF on one-lead ECG was confirmed with a 12-lead ECG. GPs also recorded information including medical history, current medication and onward referral. The Keele Decision Support tool was used to assess patients for oral anticoagulation (OAC).

RESULTS

3555 eligible patients, attending 52 GPs across 34 GP practices, agreed to undergo screening. 1720 (48%) were female, 1780 (50%) were hypertensive and 285 (8%) were current smokers. On the one-lead ECG, 3282 (92%) were in normal sinus rhythm, 101 (3%) had possible AF and among 124 (4%) the one-lead ECG was unreadable or unclassified. Of the 101 patients with possible AF, 45 (45%) had AF confirmed with 12-lead ECG, an incidence rate of AF of 1.3%. Among the 45 confirmed AF cases, 27 (60%) were commenced on OAC therapy by their GP.

CONCLUSION

These findings suggest that AF screening in primary care may prove useful for early detection of AF cases that can be assessed for treatment. One-lead ECG devices may be useful in the detection of paroxysmal AF in this population and setting. Current OAC of AF may be suboptimal.

Being precise with anticoagulation to reduce adverse drug reactions: are we there yet?

Anticoagulants are potent therapeutics widely used in medical and surgical settings, and the amount spent on anticoagulation is rising. Although warfarin remains a widely prescribed oral anticoagulant, prescriptions of direct oral anticoagulants (DOACs) have increased rapidly. Heparin-based parenteral anticoagulants include both unfractionated and low molecular weight heparins (LMWHs). In clinical practice, anticoagulants are generally well tolerated, although interindividual variability in response is apparent. This variability in anticoagulant response can lead to serious incident thrombosis, haemorrhage and off-target adverse reactions such as heparin-induced thrombocytopaenia (HIT). This review seeks to highlight the genetic, environmental and clinical factors associated with variability in anticoagulant response, and review the current evidence base for tailoring the drug, dose, and/or monitoring decisions to identified patient subgroups to improve anticoagulant safety. Areas that would benefit from further research are also identified. Validated variants in VKORC1, CYP2C9 and CYP4F2 constitute biomarkers for differential warfarin response and genotype-informed warfarin dosing has been shown to reduce adverse clinical events. Polymorphisms in CES1 appear relevant to dabigatran exposure but the genetic studies focusing on clinical outcomes such as bleeding are sparse. The influence of body weight on LMWH response merits further attention, as does the relationship between anti-Xa levels and clinical outcomes. Ultimately, safe and effective anticoagulation requires both a deeper parsing of factors contributing to variable response, and further prospective studies to determine optimal therapeutic strategies in identified higher risk subgroups.

Implications of Clinical Risk Phenotypes on the Management and Natural History of Atrial Fibrillation: A Report From the GLORIA-AF

Background Clinical risk factors are common among patients with atrial fibrillation (AF), but there are still limited data on their association with oral anticoagulant (OAC) treatment patterns and major outcomes. We aim to analyze the association between clinical risk phenotypes on AF treatment patterns and the risk of major outcomes. Methods and Results The GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation) phase 2 and 3 registries enrolled patients with a recent diagnosis of AF between 2011 and 2016. We defined 4 features of clinical risk among patients with CHA2DS2-VASc ≥2: elderly individuals (aged ≥80 years), chronic kidney disease (estimated glomerular filtration rate <45 mL/min), history of stroke, and history of bleeding. We analyzed the odds of receiving OAC and the risk of OAC discontinuation and adverse events at follow-up according to specific combinations and cumulative burden of these features. Primary outcome was the composite of all-cause death, thromboembolism, and major bleeding. Among 28 891 (mean±SD age, 70.1±10.5 years; 45.5% women) patients included, 10 797 (37.3%) had at least 1 clinical risk feature. OAC use was lower among patients in the elderly group (odds ratio [OR], 0.85 [95% CI, 0.75-0.96]), those with history of both stroke and bleeding (OR, 0.45 [95% CI, 0.35-0.56]), and those with multiple features (OR, 0.71 [95% CI, 0.62-0.82]). Increasing burden of clinical risk features was associated with OAC discontinuation, with highest magnitude in those with ≥3 features (hazard ratio [HR], 1.68 [95% CI, 1.31-2.15]). Groups with increasingly complex clinical risk phenotypes were associated with the occurrence of the primary composite outcome, with the highest figures observed for groups with a history of both stroke and bleeding (adjusted HR, 2.36 [95% CI, 1.83-3.04]) and multiple features (adjusted HR, 2.86 [95% CI, 2.52-3.25]). Conclusions In patients with AF, clinical risk phenotypes are multifaceted and heterogenous, and they are associated with differences in stroke prevention and worse prognosis.

BARRIERS TO GUIDELINE-DIRECTED ANTICOAGULATION IN PATIENTS WITH ATRIAL FIBRILLATION NEW APPROACHES TO AN OLD PROBLEM

Optimising guideline-directed anticoagulation in atrial fibrillation remains a perennial problem despite strong evidence for improved health outcomes with use of guideline-directed anticoagulation. Efforts to improve uptake have been hampered by barriers found at the level of the physician, patient, disease and choices of therapy. Clinician judgement is often clouded by factors such as therapeutic inertia, aversion to bleeding risk and implicit bias. For patients, negative pre-conceptions of therapy, impact of therapy on day-to-day life and the nocebo effect pose significant barriers. Both groups are impacted by poor education. Utility of a single pronged approach directed towards clinicians or patients have demonstrated variable success, with the highest impact appreciated in studies employing shared decision models. Further, there is emerging evidence for use of integrated models of care, which have shown improved efficacy in improving patient outcomes, as well as use of digital platforms such as mobile app-based interventions, which can be of aid to the clinician in improving patient adherence to anticoagulation with translated improved outcomes in clinical trials. Our narrative review article aims to investigate the physician and health system, patient, as well as drug therapy and disease barriers to uptake of guideline-directed anticoagulation in treatment of non-valvular atrial fibrillation.

Development of Complementary Encounter and Patient Decision Aids for Shared Decision Making about Stroke Prevention in Atrial Fibrillation

Introduction

Decision aids (DAs) are helpful instruments used to support shared decision making (SDM). Patients with atrial fibrillation (AF) face complex decisions regarding stroke prevention strategies. While a few DAs have been made for AF stroke prevention, an encounter DA (EDA) and patient DA (PDA) have not been created to be used in conjunction with each other before.

Design

Using iterative user-centered design, we developed 2 DAs for anticoagulation choice and stroke prevention in AF. Prototypes were created, and we elicited feedback from patients and experts via observations of encounters, usability testing, and semistructured interviews.

Results

User testing was done with 33 experts (in AF and SDM) and 51 patients from 6 institutions. The EDA and PDA underwent 1 and 4 major iterations, respectively. Major differences between the DAs included AF pathophysiology and a preparation to meet with the clinician in the PDA as well as different language throughout. Content areas included personalized stroke risk, differences between anticoagulants, and risks of bleeding. Based on user feedback, developers 1) addressed feelings of isolation with AF, 2) improved navigation options, 3) modified content and flow for users new to AF and those experienced with AF, 4) updated stroke risk pictographs, and 5) added structure to the preparation for decision making in the PDA.

Limitations

These DAs focus only on anticoagulation for stroke prevention and are online, which may limit participation for those less comfortable with technology.

Conclusions

Designing complementary DAs for use in tandem or separately is a new method to support SDM between patients and clinicians. Extensive user testing is essential to creating high-quality tools that best meet the needs of those using them.

Highlights

First-time complementary encounter and patient decision aids have been designed to work together or separately.User feedback led to greater structure and different experiences for patients naïve or experienced with anticoagulants in patient decision aids.Online tools allow for easier dissemination, use in telehealth visits, and updating as new evidence comes out.

Exploring clinician perspectives on patients with atrial fibrillation who are not prescribed anticoagulation therapy

Objective

To explore themes underlying why anticoagulants are under-prescribed for stroke prevention in atrial fibrillation (AF) patients from the clinician's perspective and characteristics of those patients.

Methods

Clinicians at the University of Utah Health system were recruited for semi-structured 15-minute interviews. An interview guide focused on anticoagulant prescribing practices for patients with AF. Interviews were transcribed verbatim. Two reviewers independently coded passages corresponding with key themes.

Results

Eleven practitioners were interviewed from cardiology, internal medicine, and family practice. Five themes were found: the role of compliance in anticoagulation decision making, the role of pharmacists in supporting clinicians, the use of shared decision making and risk communication, risk of bleeding as the main barrier to taking anticoagulants, and the variety of reasons patients have for not starting or discontinuing anticoagulants.

Conclusion

Fear of bleeding was the foremost reason underlying anticoagulant underutilization in patients with AF followed by compliance, and patient worries. Communication between patients and clinicians as well as interdisciplinary teamwork are key to understanding and improving anticoagulant prescribing in AF.

Innovation

Our study was the first to assess the role pharmacists play in prescribing clinician's decisions surrounding anticoagulant use in AF. Pharmacists could play an important collaborative role in SDM.

Randomized evaluation of decision support interventions for atrial fibrillation: Rationale and design of the RED-AF study

BACKGROUND

Shared decision making (SDM) improves the likelihood that patients will receive care in a manner consistent with their priorities. To facilitate SDM, decision aids (DA) are commonly used, both to prepare a patient before their clinician visit, as well as to facilitate discussion during the visit. However, the relative efficacy of patient-focused or encounter-based DAs on SDM and patient outcomes remains largely unknown. We aim to directly estimate the comparative effectiveness of two DA's on SDM observed in encounters to discuss stroke prevention strategies in patients with atrial fibrillation (AF).

METHODS

The study aims to recruit 1200 adult patients with non-valvular AF who qualify for anticoagulation therapy, and their clinicians who manage stroke prevention strategies, in a 2x2 cluster randomized multi-center trial at six sites. Two DA's were developed as interactive, online, non-linear tools: a patient decision aid (PDA) to be used by patients before the encounter, and an encounter decision aid (EDA) to be used by clinicians with their patients during the encounter. Patients will be randomized to PDA or usual care; clinicians will be randomized to EDA or usual care.

RESULTS

Primary outcomes are quality of SDM, patient decision making, and patient knowledge. Secondary outcomes include anticoagulation choice, adherence, and clinical events.

CONCLUSION

This trial is the first randomized, head-to-head comparison of the effects of an EDA versus a PDA on SDM. Our results will help to inform future SDM interventions to improve patients' AF outcomes and experiences with stroke prevention strategies.

The burden of undertreatment and non-treatment among patients with non-valvular atrial fibrillation and elevated stroke risk: a systematic review

OBJECTIVE

Global treatment guidelines recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A literature review and synthesis of observational studies were undertaken to identify the body of evidence on untreated and undertreated NVAF and the association with clinical and economic outcomes.

METHODS

An extensive search (1/2010-4/2020) of MEDLINE, the Cochrane Library, conference proceedings, and health technology assessments (HTAs) was conducted. Studies must have evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs (but with possible antiplatelet treatment), while undertreatment was defined as treatment with only antiplatelet agents.

RESULTS

Sixteen studies met our inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0-51.1%, while rates of undertreatment ranged from 10.0-45.1%. The clinical benefits of anticoagulation were reported in the evaluated studies with reductions in stroke and mortality outcomes observed among patients treated with anticoagulants compared to untreated or undertreated patients. Adverse events associated with all bleeding types (i.e. hemorrhagic stroke, major bleeding or gastrointestinal hemorrhaging) were found to be higher for warfarin patients compared to untreated patients in real-world practice. Healthcare resource utilization was found to be lower among patients highly-adherent to warfarin compared to untreated patients.

CONCLUSIONS

Rates of nontreatment and undertreatment among NVAF patients remain high and are associated with preventable cardiovascular events and death. Strategies to increase rates of treatment may improve clinical outcomes.

Impact of Fall Risk and Direct Oral Anticoagulant Treatment on Quality-Adjusted Life-Years in Older Adults with Atrial Fibrillation: A Markov Decision Analysis

BACKGROUND AND OBJECTIVE

The decision to initiate anticoagulation in older adults with atrial fibrillation is complicated by the benefit of ischemic stroke prevention vs the risk of falls resulting in major bleeds. The objective of this study was to assess the impact of different treatments including direct oral anticoagulants on quality-adjusted life-years (QALYs) in patients aged 75 years and older with atrial fibrillation in the context of falls.

METHODS

A Markov decision process was constructed for older patients with atrial fibrillation taking no anti-thrombotic, aspirin, warfarin, rivaroxaban, and apixaban. Input probabilities for clinical events were estimated from the available literature. One-way and two-way sensitivity analyses were performed by measuring the impact of varying input probabilities of clinical events on QALY outcomes.

RESULTS

The base-case scenario estimated that older adults treated with no anti-thrombotic, aspirin, warfarin, rivaroxaban, and apixaban had QALYs of 8.03, 8.69, 10.38, 11.02, and 11.56, respectively. The sensitivity analysis estimated that an older adult would need to fall over 45 (rivaroxaban) and 458 (apixaban) times per year for the QALY of a direct oral anticoagulant to be lower than that of aspirin.

CONCLUSIONS

Older adults with atrial fibrillation benefit from stroke protection of anticoagulants, especially direct oral anticoagulants, even if they are at high risk of falls. Clinicians should not consider fall risk as a deciding factor for withholding anticoagulation in this population of patients.

Prevalence/incidence of atrial fibrillation based on integrated medical/pharmacy claims, and association with co-morbidity profiles/multi-morbidity in a large US adult cohort

BACKGROUND

Identification of published data on prevalent/incidence of atrial fibrillation/flutter (AF) often relies on inpatient/outpatient claims, without consideration to other types of healthcare services and pharmacy claims. Accurate, population-level data that can enable the ongoing monitoring of AF epidemiology, quality of care at affordable cost, and complications are needed. We hypothesised that prevalent/incidence data would vary via the use of integrated medical/pharmacy claims, and associated comorbidities would vary accordingly.

PURPOSE

To examine AF prevalence/incidence and associated individual comorbidity and multi-morbidity profiles for a large US adult cohort spanning across a wide age range for both males/females based on both integrated criteria from both medical/pharmacy claims.

METHODS

We studied a population of 8 343 992 persons across many geographical areas in the US continent from 1 January/2016 to 31 October 2019. The prevalence and incidence of AF were comparatively analysed for different healthcare parameters (eg, emergency room visit, anticoagulant medication, heart rhythm control medication) and for integrated criteria based on medical/pharmacy claims.

RESULTS

Based on integrated medical and pharmacy claims, AF prevalence was 12.7% in the elderly population (≥65 years) and 0.9% in the younger population (<65 years). These prevalence rates are different from estimates provided by the US CDC for those aged ≥65 years (9%) and age <65 years (2%); thus, the prevalence is under-estimated in the elderly population and over-estimated in the younger population. The incidence ratios for elderly females relative to younger females was 15.07 (95%CI 14.47-15.70), a value that is about 50% higher than for elderly males (10.57 (95%CI 10.24-10.92)). Comorbidity risk profile for AF identified on the basis of medical and pharmacy criteria varied by age and gender. The proportion with multi-morbidity (defined as ≥2 long term comorbidities) was 10%-12%.

CONCLUSION

Continued reliance only on outpatient and inpatient claims greatly underestimates AF prevalence and incidence in the general population by over 100%. Multi-morbidity is common amongst AF patients, affecting approximately 1 in 10 patients. AF patients with four or more co-morbidities captured 20%-40% of the AF cohorts depending on age groups and prevalent or incident cases.

Underuse of oral anticoagulants in privately insured patients with atrial fibrillation: A population being targeted by the IMplementation of a randomized controlled trial to imProve treatment with oral AntiCoagulanTs in patients with Atrial Fibrillation (IMPACT-AFib)

BACKGROUND

Many studies showing underuse of oral anticoagulants (OACs) in patients with atrial fibrillation (AF) predated the advent of the non-vitamin K antagonist OACs. We retrospectively examined use of OACs in a large commercially insured population.

METHODS

Administrative claims data from 4 research partners participating in FDA-Catalyst, a program of the Sentinel Initiative, were queried in September 2017. Patients were included if they were ≥30 years old with ≥365 days of medical/pharmacy coverage, and had ≥2 diagnosis codes for AF, a CHA₂DS₂-VASc score ≥2, absence of contraindications to OAC use, and no evidence of OAC use in the 365 days before the index AF diagnosis. The main outcome measures of the current analysis were rates of OAC use in the prior 12 months of cohort identification and factors associated with non-use.

RESULTS

A total of 197,806 AF patients met the eligibility criteria prior to assessment of OAC treatment. Of these, 179,580 (91%) patients were ≥65 years old and 73,286 (37%) patients were ≥80 years old. Half of the patients (98,903) were randomized to the early intervention arm in the IMPACT-AFib trial and constitute the cohort for this analysis. Of these, 32,295 (33%) had no evidence of OAC use in the prior 12 months. Compared with patients with evidence of OAC use in the prior 12 months, patients without OAC use were more likely to be ≥80 years old, women, and have a history of anemia (51% vs 47%) and less likely to have diabetes (41% vs 44%), history of stroke or TIA (15% vs 19%), and history of heart failure (39% vs 48%).

CONCLUSIONS

Despite a high risk of stroke, one-third of privately insured patients with AF and no obvious contraindications to an OAC were not treated with an OAC. There is an unmet need for evidence-based interventions that could lead to greater use of OACs in patients with AF at risk for stroke.

National Physician Survey for Nonvalvular Atrial Fibrillation (NVAF) Anticoagulation Comparing Knowledge, Attitudes and Practice of Cardiologist to PCPs

Introduction:

NVAF is estimated to affect between 6.4 and 7.4 million Americans in 2018, and increases the risk of stroke 5-fold. To mitigate this risk, guidelines recommend anticoagulating AF patients unless their stroke risk is very low. Despite these recommendations, 30.0-60.0% of NVAF patients do not receive indicated anticoagulation. To better understand why this may be, we surveyed PCPs and cardiologists nationwide on their attitudes, knowledge and practices toward managing NVAF with warfarin and direct-acting oral anticoagulants (DOACs).

Methods:

We surveyed 1,000 PCPs and 500 cardiologists selected randomly from a master list of the American Medical Association, using a paper based, anonymous, self-administered, mailed scannable survey. The survey contained questions on key demographics and data concerning attitudes, knowledge and practices related to prescribing DOACs. The surveys went out in the fall/winter of 2017-8 with a $10 incentive gift card. Survey responses were scanned into an Excel database and analyzed using SAS 9.3 (Cary, NC) for descriptive and inferential statistics.

Results:

Two hundred and forty-nine providers (167 PCPs, 82 cardiologists) participated in the study with a response rate of 18.8% (249/1320). Respondent mean years ±SD of experience since completing residency was 23.2 ± 13.8. Relative to cardiologists, less PCPs use CHADsVASC (36.8% vs. 74.4%) (p < 0.0001); more have never used HAS-BLED, HEMORR2HAGES, or ATRIA (38.5% vs. 9.8%) (p < .0001); more felt that their lack of knowledge/experience with DOACs was a barrier to prescribing the agents (p = 0.005); and more reported that they could use additional education on DOACs (87.0% vs. 47.0%) (p < 0.0001). Overall, cardiologists were more concerned about ischemic stroke outcomes, while PCPs were more concerned with GI bleeding. Cardiologists also felt that clinical trial data were most helpful in choosing the most appropriate DOAC for their patients, while PCPs felt that Real World Data was most useful.

Conclusions:

Cardiologists were more concerned with ischemic stroke while anticoagulating patients and utilized screening instruments like CHADsVASC in a majority of their patients. PCPs were concerned with GI bleeds when anticoagulating but nearly 40.0% utilized no screening tools to assess bleeding risk. Our findings show that future education about DOACs would be warranted especially with PCPs.

Potential missed opportunities to prevent ischaemic stroke: prospective multicentre cohort study of atrial fibrillation-associated ischaemic stroke and TIA

OBJECTIVE

We report on: (1) the proportion of patients with known atrial fibrillation (AF); and (2) demographic, clinical or radiological differences between patients with known AF (and not treated) and patients with newly diagnosed AF, in a cohort of patients who presented with ischaemic stroke or transient ischaemic attack (TIA) not previously treated with anticoagulation.

DESIGN

We reviewed cross-sectional baseline demographic and clinical data from a prospective observational cohort study, (CROMIS-2).

SETTING

Patients were recruited from 79 hospital stroke centres throughout the UK and one centre in the Netherlands.

PARTICIPANTS

Patients were eligible if they were adults who presented with ischaemic stroke or TIA and AF and had not been previously treated with oral anticoagulation.

MAIN OUTCOME MEASURES

Proportion of patients with known AF before index ischaemic stroke or TIA from a cohort of patients who have not been previously treated with oral anticoagulation. Secondary analysis includes the comparison of CHA2DS2-VASc and HAS-BLED scores and other demographics and risk factors between those with newly diagnosed AF and those with previously known AF.

RESULTS

Of 1470 patients included in the analysis (mean age 76 years (SD 10)), 622 (42%) were female; 999 (68%) patients had newly diagnosed AF and 471 (32%) patients had known AF. Of the 471 patients with known AF, 68% had a strong indication for anticoagulation and 89% should have been considered for anticoagulation based upon CHA2DS2-VASc score. Patients with known AF were more likely to have a prior history of dementia (4% vs 2%, p=0.02) and had higher HAS-BLED scores (median 3 vs 2). CHA2DS2-VASc, other risk factors and demographics were similar.

CONCLUSIONS

About 1/3 of patients who present with stroke and have AF who have not been treated with oral anticoagulation have previously known AF. Of these patients, at least 68% were not adequately treated with oral anticoagulation.

TRIAL REGISTRATION NUMBER

NCT02513316.

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.

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.

Incidence, type of atrial fibrillation and risk factors for stroke: a population-based cohort study

Purpose

The aims of this study were to estimate the incidence of atrial fibrillation and atrial flutter (AF), to assess the presence of provoking factors and risk factors for stroke and systemic embolism, and to determine the type of AF in patients with first-diagnosed AF.

Patients and methods

This cohort study was performed in northern Sweden between January 1, 2011 and December 31, 2012. Diagnosis registries were searched for the International Classification of Diseases-10 code for AF (I48) to identify cases of incident AF. All AF diagnoses were electrocardiogram-verified. Data pertaining to provoking factors, type of AF and presence of risk factors for stroke and systemic embolism according to the CHA₂DS₂-VASc score were obtained from medical records.

Results

The incidence of AF in the entire population was 4.0 per 1,000 person-years. The incidence was 27.5 per 1,000 person-years in patients aged ≥80 years. A total of 21% of all patients had a provoking factor in association with the first-diagnosed episode of AF. The CHA₂DS₂-VASc score was 2 or higher in 81% of the patients. Permanent AF was the most common type of AF (29%).

Conclusion

There was a considerable increase in the incidence of AF with age, and a provoking factor was found in one-fifth. The most common type of AF was permanent AF. Four in five patients had a CHA₂DS₂-VASc score of 2 or more.