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

Prescribing of direct oral anticoagulants and warfarin to older people with atrial fibrillation in UK general practice: a cohort study

BACKGROUND

Anticoagulation for stroke prevention in atrial fibrillation (AF) has, historically, been under-used in older people. The aim of this study was to investigate prescribing of oral anticoagulants (OACs) for people aged ≥ 75 years in the UK before and after direct oral anticoagulants (DOACs) became available.

METHODS

A cohort of patients aged ≥ 75 years with a diagnosis of AF was derived from the Clinical Practice Research Datalink (CPRD) between January 1, 2003, and December 27, 2017. Patients were grouped as no OAC, incident OAC (OAC newly prescribed) or prevalent OAC (entered study on OAC). Incidence and point prevalence of OAC prescribing were calculated yearly. The risk of being prescribed an OAC if a co-morbidity was present was calculated; the risk difference (RD) was reported. Kaplan-Meier curves were used to explore persistence with anticoagulation. A Cox regression was used to model persistence with warfarin and DOACs over time.

RESULTS

The cohort comprised 165,596 patients (66,859 no OAC; 47,916 incident OAC; 50,821 prevalent OAC). Incidence of OAC prescribing increased from 111 per 1000 person-years in 2003 to 587 per 1000 person-years in 2017. Older patients (≥ 90 years) were 40% less likely to receive an OAC (RD -0.40, 95% CI -0.41 to -0.39) than younger individuals (75-84 years). The likelihood of being prescribed an OAC was lower with a history of dementia (RD -0.34, 95% CI -0.35 to -0.33), falls (RD -0.17, 95% CI -0.18 to -0.16), major bleeds (RD -0.17, 95% CI -0.19 to -0.15) and fractures (RD -0.13, 95% CI -0.14 to -0.12). Persistence with warfarin was higher than DOACs in the first year (0-1 year: HR 1.25, 95% CI 1.17-1.33), but this trend reversed by the third year of therapy (HR 0.75, 95% CI 0.63-0.89).

CONCLUSIONS

OAC prescribing for older people with AF has increased; however, substantial disparities persist with age and co-morbidities. Whilst OACs should not be withheld solely due to the risk of falls, these results do not reflect this national guidance. Furthermore, the under-prescribing of OACs for patients with dementia or advancing age may be due to decisions around risk-benefit management.

TRIAL REGISTRATION

EUPAS29923 . First registered on: 27/06/2019.

Anticoagulation trends in adults aged 65 years and over with atrial fibrillation: a cohort study

Objective

To describe patterns of anticoagulation prescription and persistence for those aged ≥65 years with atrial fibrillation (AF).

Methods

Descriptive cohort study using electronic general practice records of patients in England, who attended an influenza vaccination aged ≥65 years and were diagnosed with AF between 2008 and 2018. Patients were stratified by 10-year age group and year of diagnosis. Proportion anticoagulated, type of anticoagulation (direct oral anticoagulant (DOAC) or warfarin) initiated at diagnosis and persistence with anticoagulation over time are reported.

Results

42 290 patients (49% female), aged 65–74 (n=11 722), 75–84 (n=19 055) and 85+ (n=11 513) years at AF diagnosis are included. Prescription of anticoagulation at diagnosis increased over the time period from 55% to 86% in people aged 65–74 years, from 54% to 86% in people aged 75–84 years and from 27% to 75% in people aged 85 years and over. By 2018, 92% of patients with newly diagnosed AF were started on a DOAC. Survivor function for 5-year persistence in patients prescribed DOAC was 0.80 (95% CI 0.77 to 0.82) and for warfarin 0.71 (95% CI 0.70 to 0.72). Survivor function for any anticoagulation at 5 years was 0.79 (95% CI 0.78 to 0.81), 0.73 (95% CI 0.72 to 0.75) and 0.58 (95% CI 0.59 to 0.64) for people aged 65–74, 75–84 and 85+ years, respectively.

Conclusions

Rates of anticoagulation in AF in those aged ≥65 years have increased from 2008 to 2018, over which time period there has been a shift from initiating anticoagulation with warfarin to DOAC. Persistence with anticoagulation is higher in people on DOACs than on warfarin and in people aged <85 years.

Percutaneous Left Atrial Appendage Occlusion: A View From the UK

AF is associated with an increased risk of thromboembolic events, which is usually managed with oral anticoagulation therapy. However, despite a broad range of anticoagulant options and improved uptake in anticoagulation over the past decade, there are some limitations to this approach. Percutaneous left atrial appendage occlusion has been shown to be an effective alternative in this setting, and population data suggest a clear demand for this procedure. Over the past decade, several important changes to the commissioning and delivery of this service have occurred in the UK. In this article, the authors describe the use of percutaneous left atrial appendage occlusion in the UK and discuss the challenges that lie ahead.

Temporal variation in the diagnosis of resolved atrial fibrillation and the influence of performance targets on clinical coding: cohort study

OBJECTIVES

To investigate whether the introduction of performance targets for anticoagulation in atrial fibrillation (AF) was associated with a change in use of the 'resolved AF' code.

DESIGN

Retrospective cohort studies.

SETTING

Data from The Health Improvement Network, a UK database of electronic patient records, from 2000 to 2016.

PARTICIPANTS

250 788 adult patients aged ≥18 years with a diagnosis of AF, including 14 757 with an incident diagnosis of 'resolved AF'.

MAIN OUTCOME MEASURES

Annual and monthly incidence of 'resolved AF' from 2000 to 2016. Among patients with 'resolved AF', for each year we calculated median duration of the preceding AF diagnosis and the proportion prescribed anticoagulants prior to 'resolved AF'.

RESULTS

Incidence of 'resolved AF' increased from 5.7 to 26.3 per 1000 person-years between 2005 and the introduction of AF performance targets in 2006. Compared with the years prior to the introduction of the performance targets, incidence has remained higher in every year since their implementation. Since 2007, monthly incidence has been highest between January and March. Between 2005 and 2006, median duration between AF and 'resolved AF' diagnoses increased from 276 days (9 months) to 1343 days (3 years 8 months). Among 'resolved AF' patients with CHA₂DS₂-VASc score ≥1, 81.9% (95% CI 81.1 to 82.6) had no current anticoagulant prescription, and 62.3% (95% CI 61.4 to 63.2) had no record of any anticoagulant prescription.

CONCLUSION

The introduction of AF performance targets was followed by a large increase in use of the 'resolved AF' code, particularly in the months immediately before practices make their anticoagulant performance target submissions. Although most AF patients are prescribed anticoagulants, few patients diagnosed with 'resolved AF' are prescribed anticoagulants and most have never been prescribed them. Untreated patients are much more likely to be coded as having 'resolved AF'.

GARFIELD-AF model for prediction of stroke and major bleeding in atrial fibrillation: a Danish nationwide validation study

OBJECTIVES

To externally validate the accuracy of the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) model against existing risk scores for stroke and major bleeding risk in patients with non-valvular AF in a population-based cohort.

DESIGN

Retrospective cohort study.

SETTING

Danish nationwide registries.

PARTICIPANTS

90 693 patients with newly diagnosed non-valvular AF were included between 2010 and 2016, with follow-up censored at 1 year.

PRIMARY AND SECONDARY OUTCOME MEASURES

External validation was performed using discrimination and calibration plots. C-statistics were compared with CHA₂DS₂VASc score for ischaemic stroke/systemic embolism (SE) and HAS-BLED score for major bleeding/haemorrhagic stroke outcomes.

RESULTS

Of the 90 693 included, 51 180 patients received oral anticoagulants (OAC). Overall median age (Q1, Q3) were 75 (66-83) years and 48 486 (53.5%) were male. At 1-year follow-up, a total of 2094 (2.3%) strokes/SE, 2642 (2.9%) major bleedings and 10 915 (12.0%) deaths occurred. The GARFIELD-AF model was well calibrated with the predicted risk for stroke/SE and major bleeding. The discriminatory value of GARFIELD-AF risk model was superior to CHA₂DS₂VASc for predicting stroke in the overall cohort (C-index: 0.71, 95% CI: 0.70 to 0.72 vs C-index: 0.67, 95% CI: 0.66 to 0.68, p<0.001) as well as in low-risk patients (C-index: 0.64, 95% CI: 0.59 to 0.69 vs C-index: 0.57, 95% CI: 0.53 to 0.61, p=0.007). The GARFIELD-AF model was comparable to HAS-BLED in predicting the risk of major bleeding in patients on OAC therapy (C-index: 0.64, 95% CI: 0.63 to 0.66 vs C-index: 0.64, 95% CI: 0.63 to 0.65, p=0.60).

CONCLUSION

In a nationwide Danish cohort with non-valvular AF, the GARFIELD-AF model adequately predicted the risk of ischaemic stroke/SE and major bleeding. Our external validation confirms that the GARFIELD-AF model was superior to CHA₂DS₂VASc in predicting stroke/SE and comparable with HAS-BLED for predicting major bleeding.

Left Atrial Appendage Epicardial Clip (AtriClip): Essentials and Post-Procedure Management

Left atrial appendage exclusion is a viable alternative to anticoagulation for stroke risk reduction in atrial fibrillation patients. In this article we address the essentials and post-procedural management of left atrial appendage exclusion using the AtriClip.

Atrial fibrillation in patients with active malignancy and use of anticoagulants: Under-prescription but no adverse impact on all-cause mortality

Prescription of anticoagulants (ACs) in patients with cancer and atrial fibrillation (AF) is challenging and the impact on survival is not defined. In this study data prospectively collected in Oncology Units were retrospectively evaluated. Among 4664 patients admitted for malignancy, 394 patients (8.4%) had documented AF (mean age of 74 ± 9) and AC was prescribed to 155 patients (40%). Neither the type of cancer, the stage of the disease (metastatic or not) nor the ongoing treatments were significantly associated with prescription of AC, which was independently associated with BMI (OR 1.10; CI 95% 1.03-1.17; p = .003), valvular heart disease (OR 3.76; CI95% 1.59-8.87; p = .002), and previous venous thromboembolism (OR 6.67; 95%CI 2.67-16.70; p < .001). During a median follow-up of 212 days, survival from all-cause death was 37%, 28% and 18% at 6 months, 1 and 2 years, respectively. Only variables related to neoplastic disease or to patient clinical complexity were independently associated with mortality. A CHA₂DS₂VASc ≥ 4 was significantly associated with mortality (HR 1.33; 95%CI 1.06-1.67; p = .013). Treatment with ACs was not significantly related to mortality, neither in the whole cohort of patients, nor in patients with metastatic malignancies. In conclusion the prescription of ACs in patients with AF and active cancer was suboptimal, with one fourth of the patients not treated with ACs and one third using LMWH at prophylactic, non-therapeutic doses. Only few variables (BMI, valvular heart disease and previous venous thromboembolism) predicted prescription of ACs. Prescription of ACs was not associated with all-cause mortality, even in the subgroup with metastasis.

Barriers to a software reminder system for risk assessment of stroke in atrial fibrillation: a process evaluation of a cluster randomised trial in general practice

BACKGROUND

Oral anticoagulants reduce the risk of stroke in patients with atrial fibrillation (AF), but are underused. AURAS-AF (AUtomated Risk Assessment for Stroke in AF) is a software tool designed to identify eligible patients and promote discussions within consultations about initiating anticoagulants.

AIM

To investigate the implementation of the software in UK general practice.

DESIGN AND SETTING

Process evaluation involving 23 practices randomly allocated to use AURAS-AF during a cluster randomised trial.

METHOD

An initial invitation to discuss anticoagulation was followed by screen reminders appearing during consultations until a decision had been made. The reminders required responses, giving reasons for cases where an anticoagulant was not initiated. Qualitative interviews with clinicians and patients explored acceptability and usability.

RESULTS

In a sample of 476 patients eligible for the invitation letter, only 159 (33.4%) were considered suitable for invitation by their GPs. Reasons given were frequently based on frailty, and risk of falls or haemorrhage. Of those invited, 35 (22%) started an anticoagulant (7.4% of those originally identified). A total of 1695 main-screen reminders occurred in 940 patients. In 883 instances, the decision was taken not to initiate and a range of reasons offered. Interviews with 15 patients and seven clinicians indicated that the intervention was acceptable, though the issue of disruptive screen reminders was raised.

CONCLUSION

Automated risk assessment for stroke in atrial fibrillation and prompting during consultations are feasible and generally acceptable, but did not overcome concerns about frailty and risk of haemorrhage as barriers to anticoagulant uptake.

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.

Prevalence and treatment of atrial fibrillation in UK general practice from 2000 to 2016

OBJECTIVE

Atrial fibrillation (AF) is the most common cardiac arrhythmia and an important risk factor for stroke. Treatment with anticoagulants substantially reduces risk of stroke. Current prevalence and treatment rates of AF in the UK as well as changes in recent years are not known. The aim of this analysis was to determine trends in age-sex specific prevalence and treatment of AF in the UK from 2000 to 2016.

METHODS

17 sequential cross-sectional analyses were carried out between 2000 and 2016 using a large database of electronic primary care records of patients registered with UK general practitioners. These determined the prevalence of patients diagnosed with AF, the stroke risk of those with AF and the proportion of AF patients currently receiving anticoagulants. Stroke risk was assessed using CHA₂DS₂-VASc score.

RESULTS

Age-sex standardised AF prevalence increased from 2.14% (95% CI 2.11% to 2.17%) in 2000 to 3.29% (95% CI 3.27% to 3.32%) in 2016. Between 2000 and 2016, the proportion of patients with AF prescribed anticoagulants increased from 35.4% (95% CI 34.7% to 36.1%) to 75.5% (95% CI 75.1% to 75.8%) in those with high stroke risk (p for change over time <0.001) and from 32.8% (95% CI 30.5% to 35.2%) to 47.1% (95% CI 45.4% to 48.7%) in those with moderate stroke risk (p<0.001). In patients with low risk of stroke, the proportion decreased from 19.9% (95% CI 17.8% to 22.2%) to 9.7% (95% CI 8.4% to 11.1%) (p<0.001). Anticoagulant prescribing performance varied between practices; in 2016, the proportion of eligible patients treated was 82.9% (95% CI 82.2% to 83.7%) and 62.0% (95% CI 61.0% to 63.0%) in the highest-performing and lowest-performing practice quintiles, respectively. There was poor agreement in individual practice performance over time from 2006 to 2016: linear-weighted κ=0.10 (95% CI 0.02 to 0.19).

CONCLUSIONS

From 2000 to 2016, the prevalence of recorded AF has increased in all age groups and both sexes. Anticoagulant treatment of eligible patients with AF has more than doubled, with marked improvements since 2011, alongside a reduction in the use of anticoagulants in ineligible patients with AF.

Risk of stroke and transient ischaemic attack in patients with a diagnosis of resolved atrial fibrillation: retrospective cohort studies

OBJECTIVES

To determine rates of stroke or transient ischaemic attack (TIA) and all cause mortality in patients with a diagnosis of "resolved" atrial fibrillation compared to patients with unresolved atrial fibrillation and without atrial fibrillation.

DESIGN

Two retrospective cohort studies.

SETTING

General practices contributing to The Health Improvement Network, 1 January 2000 to 15 May 2016.

PARTICIPANTS

Adults aged 18 years or more with no previous stroke or TIA: 11 159 with resolved atrial fibrillation, 15 059 controls with atrial fibrillation, and 22 266 controls without atrial fibrillation.

MAIN OUTCOME MEASURES

Primary outcome was incidence of stroke or TIA. Secondary outcome was all cause mortality.

RESULTS

Adjusted incidence rate ratios for stroke or TIA in patients with resolved atrial fibrillation were 0.76 (95% confidence interval 0.67 to 0.85, P<0.001) versus controls with atrial fibrillation and 1.63 (1.46 to 1.83, P<0.001) versus controls without atrial fibrillation. Adjusted incidence rate ratios for mortality in patients with resolved atrial fibrillation were 0.60 (0.56 to 0.65, P<0.001) versus controls with atrial fibrillation and 1.13 (1.06 to 1.21, P<0.001) versus controls without atrial fibrillation. When patients with resolved atrial fibrillation and documented recurrent atrial fibrillation were excluded the adjusted incidence rate ratio for stroke or TIA was 1.45 (1.26 to 1.67, P<0.001) versus controls without atrial fibrillation.

CONCLUSION

Patients with resolved atrial fibrillation remain at higher risk of stroke or TIA than patients without atrial fibrillation. The risk is increased even in those in whom recurrent atrial fibrillation is not documented. Guidelines should be updated to advocate continued use of anticoagulants in patients with resolved atrial fibrillation.