The Tasmanian atrial fibrillation study: Transition to direct oral anticoagulants 2011-2015

Use of thromboprophylaxis guidelines and risk stratification tools in atrial fibrillation: A survey of general practitioners in Australia

RATIONALE AND OBJECTIVES

Clinical guidelines produced by cardiology societies (henceforth referred to simply as 'clinical guidelines') recommend thromboprophylaxis with oral anticoagulants (OACs) in patients with atrial fibrillation (AF) who have moderate-to-high stroke risk. However, deviations from these recommendations are observed, especially in the primary healthcare setting. The primary aims of this study were to evaluate the self-reported use of AF clinical guidelines and risk stratification tools among Australian general practitioners (GPs), and their perceptions regarding the available resources.

METHOD

We conducted an online survey of Australian GPs. Descriptive statistics were used to summarise the findings.

RESULTS

Responses from 115 GPs were included for analysis. Respondents reported various ways of accessing thromboprophylaxis-related information (n = 113), including clinical guidelines (13.3%), 'Therapeutic Guidelines^© ' (37.2%) and Royal Australian College of General Practitioners websites (16.8%). Of those who reported reasons against accessing information from clinical guidelines (n = 97), the most frequent issues were: too many AF guidelines to choose from (34.0%; 33/97), different guidelines for different diseases (32.0%; 31/97), time-consuming to read guidelines (21.6%; 21/97), disagreements between different guideline recommendations (20.0%; 19/97), conflict with criteria for government subsidy (17.5%; 17/97) and GPs' busy schedules (15.5%; 15/97). When assessing patients' risk of stroke (n = 112) and bleeding (n = 111), the majority of the respondents reported primarily relying on a formal stroke risk (67.0%) and bleeding risk (55.0%) assessment tools, respectively. Respondents reported using formal stroke and bleeding risk assessment tools mainly when newly initiating patients on therapy (72.4%; 76/105 and 65.3%; 65/101, respectively).

CONCLUSION

Among our small sample of Australian GPs, most did not access thromboprophylaxis-related information directly from AF-specific clinical guidelines developed by cardiology societies. Although the majority reported using formal stroke and bleeding assessment tools, these were typically used on OAC initiation only. More focus is needed on formal risk reassessment as clinically indicated and at regular review.

Anticoagulant prescribing for atrial fibrillation and risk of incident dementia

OBJECTIVE

The aim of this study was to investigate the association between oral anticoagulant type (direct oral anticoagulants (DOACs) vs vitamin K antagonists (VKAs)) and incident dementia or mild cognitive impairment (MCI) among patients with newly diagnosed atrial fibrillation (AF).

METHODS

Using linked electronic health record (EHR) data from the Clinical Practice Research Datalink in the UK, we conducted a historical cohort study among first-time oral anticoagulant users with incident non-valvular AF diagnosed from 2012 to 2018. We compared the incidence of (1) clinically coded dementia and (2) MCI between patients prescribed VKAs and DOACs using Cox proportional hazards regression models, with age as the underlying timescale, accounting for calendar time and time on treatment, sociodemographic and lifestyle factors, clinical comorbidities and medications.

RESULTS

Of 39 200 first-time oral anticoagulant users (44.6% female, median age 76 years, IQR 68-83), 20 687 (53%) were prescribed a VKA and 18 513 (47%) a DOAC at baseline. Overall, 1258 patients (3.2%) had GP-recorded incident dementia, incidence rate 16.5 per 1000 person-years. DOAC treatment for AF was associated with a 16% reduction in dementia diagnosis compared with VKA treatment in the whole cohort (adjusted HR 0.84, 95% CI: 0.73 to 0.98) and with a 26% reduction in incident MCI (adjusted HR 0.74, 95% CI: 0.65 to 0.84). Findings were similar across various sensitivity analyses.

CONCLUSIONS

Incident EHR-recorded dementia and MCI were less common among patients prescribed DOACs for new AF compared with those prescribed VKAs.

Non-adherence to Thromboprophylaxis Guidelines in Atrial Fibrillation: A Narrative Review of the Extent of and Factors in Guideline Non-adherence

Atrial fibrillation is the most common arrhythmia. It increases the risk of thromboembolism by up to fivefold. Guidelines provide evidence-based recommendations to effectively mitigate thromboembolic events using oral anticoagulants while minimizing the risk of bleeding. This review focuses on non-adherence to contemporary guidelines and the factors associated with guideline non-adherence. The extent of guideline non-adherence differs according to geographic region, healthcare setting, and risk stratification tools used. Guideline adherence has gradually improved over recent years, but a significant proportion of patients are still not receiving guideline-recommended therapy. Physician-related and patient-related factors (such as patient refusals, bleeding risk, older age, and recurrent falls) also contribute to guideline non-adherence, especially to undertreatment. Quality improvement initiatives that focus on undertreatment, especially in the primary healthcare setting, may help to improve guideline adherence.

Factors influencing oral anticoagulant use in patients newly diagnosed with atrial fibrillation

BACKGROUND

We investigated factors that influenced oral anticoagulant (OAC) initiation and choice in Australian general practice patients newly diagnosed with AF.

METHODS

Using an Australian nationally representative general practice dataset, MedicineInsight, we identified patients newly diagnosed with AF between January 2009 and April 2019. Logistic regression analyses were used to examine factors associated with OAC initiation and choice.

RESULTS

A total of 63 212 patients with AF (53.7% males, mean age 72.4 years) were identified. Nearly two-thirds of these patients (40 854 [64.6%]) were initiated on an OAC, at a median time of 6 days after the documented diagnosis date. The proportion of patients who were initiated an OAC increased from 44.8% in 2009 to 72.2% in 2019 (P < .001). High risk of stroke (CHA₂ DS₂ -VASc, adjusted odds ratio (AOR), 4.39 [95% CI, 3.99-4.83]), low risk of bleeding (ORBIT, AOR, 1.87 [95% CI, 1.72-2.03]), not having a recorded history of dementia (AOR, 1.81 [95% CI, 1.65-1.98]) and male sex (AOR, 1.29 [95% CI, 1.22-1.35]) were independently associated with OAC initiation. Direct-acting oral anticoagulant (DOAC) use increased from 11.9% in 2011 to 94.0% of all OAC initiations in April 2019 (P < .001).

CONCLUSIONS

The proportion of newly diagnosed patients with AF initiated on OAC increased markedly following the introduction of the DOACs. Of those initiated, 9 in 10 were receiving a DOAC at the end of the study period. There is potential underuse in women and individuals with dementia.

Ten-Year Trends in the Use of Oral Anticoagulants in Australian General Practice Patients With Atrial Fibrillation

Objective: Appropriate use of oral anticoagulants (OACs) reduces the risk of stroke in patients with atrial fibrillation (AF). The study characterized the prescribing of OACs in people with AF in the Australian primary care setting over 10 years.

Design: Retrospective population study.

Setting and Participants: We performed 10 sequential cross-sectional analyses of patients with a recorded diagnosis of AF between 2009 and 2018 using national general practice data. The proportion of patients with AF who were prescribed an OAC based on their stroke risk was examined.

Primary and secondary outcomes: The primary outcome was the proportion of high stroke risk patients who were prescribed an OAC over a decade. The secondary outcome was variation in OAC prescribing among general practices.

Results: The sample size of patients with AF ranged from 9,874 in 2009 to 41,751 in 2018. The proportion who were prescribed an OAC increased from 39.5% (95% CI 38.6–40.5%) in 2009 to 52.0% (95% CI 51.5–52.4%) in 2018 (p for trend < 0.001). During this time, the proportion of patients with AF and high stroke risk who were prescribed an OAC rose from 41.7% (95% CI 40.7–42.8%) to 55.2% (95% CI 54.7–55.8%; p for trend < 0.001) with the direct-acting oral anticoagulants accounting for over three-quarters of usage by 2018. There was substantial variation in OAC prescribing between general practices. In 2018, the proportion of moderate to high stroke risk patients who were prescribed an OAC was 38.6% (95% CI 37.2–40.1%) in the lowest practice site quintiles and 65.6% (95% CI 64.5–66.7%) in the highest practice site quintiles.

Conclusions: Over the 10 years, OAC prescribing in high stroke risk patients with AF increased by one-third. There was considerable variation in OAC prescribing between general practices.

Missed Opportunities to Initiate Oral Anticoagulant in Atrial Fibrillation: Insights from Australian Acute Coronary Syndrome Registries

BACKGROUND

Many patients with atrial fibrillation (AF) do not receive oral anticoagulant (OAC) therapy. The aims of this study were to 1) document receipt of OAC among patients with a history of AF admitted with an acute coronary syndrome (ACS); and to 2) determine whether hospital admission was associated with an improvement in prescription of OAC therapy.

METHODS

Using Australian data from the Cooperative National Registry of Acute Coronary Care, Guideline Adherence and Clinical Events (CONCORDANCE) and Global Registry of Acute Coronary Events (GRACE) registries, 1,479 patients with a history of AF presenting with an ACS were separated into two groups: aspirin monotherapy/no therapy (No OAC) or oral anticoagulant ± aspirin (OAC). Clinical characteristics and in-hospital treatments and outcomes were compared.

RESULTS

Of 1,479 patients, 532 (36%) with a history of AF presented on OAC with the remainder receiving antiplatelet (n=580 [39%]) or no antithrombotic therapy (n=367 [25%]). Treatment with OAC prior to presentation increased during the 18 years of the study (27% to 56%, p=0.0002). Ninety-five per cent (95%) of the OAC group had a CHA2DS2-VA score >1 vs 88% of the No OAC group (p<0.001). Patients receiving OAC had a lower prevalence of bleeding risk factors than no OAC patients (p<0.001). Only 39% of this cohort was discharged on an OAC, although this increased during the observational period (26-61%, p≤0.0001).

CONCLUSION

In patients presenting with an ACS with a history of AF, receipt of OAC has improved over time but remains suboptimal. There is minimal escalation in provision of OAC therapy during hospital care, indicating missed opportunities to address this evidence practice gap.

The Quality of Advice Provided by Pharmacists to Patients Taking Direct Oral Anticoagulants: A Mystery Shopper Study

Pharmacists report being less confident in their knowledge of direct acting oral anticoagulants (DOACs) than of vitamin K antagonists, which may influence their ability to detect and manage complications arising from DOAC use. In a mystery shopper study, patient agents were sent into community pharmacies with symptom or product-related requests related to common complications that might arise during treatment with oral anticoagulants, with each visit being assessed for the preferred outcome. Only 10/41 (24.4%) visits resulted in the preferred outcome. A complete history-taking process, obtaining a medical history, patient characteristics and pharmacist involvement were strong predictors of the preferred outcome being achieved. The preferred outcome was not consistently achieved without pharmacist involvement. The potential for strategies that support comprehensive pharmacist involvement in over-the-counter requests should be considered to ensure the provision of optimal care to patients taking high-risk medications such as DOACs.

Atrial Fibrillation Screen, Management, and Guideline-Recommended Therapy in the Rural Primary Care Setting: A Cross-Sectional Study and Cost-Effectiveness Analysis of eHealth Tools to Support All Stages of Screening

BACKGROUND

Internationally, most atrial fibrillation (AF) management guidelines recommend opportunistic screening for AF in people ≥65 years of age and oral anticoagulant treatment for those at high stroke risk (CHA₂DS₂‐VA≥2). However, gaps remain in screening and treatment.

METHODS AND RESULTS

General practitioners/nurses at practices in rural Australia (n=8) screened eligible patients (≥65 years of age without AF) using a smartphone ECG during practice visits. eHealth tools included electronic prompts, guideline‐based electronic decision support, and regular data reports. Clinical audit tools extracted de‐identified data. Results were compared with an earlier study in metropolitan practices (n=8) and nonrandomized control practices (n=69). Cost‐effectiveness analysis compared population‐based screening with no screening and included screening, treatment, and hospitalization costs for stroke and serious bleeding events. Patients (n=3103, 34%) were screened (mean age, 75.1±6.8 years; 47% men) and 36 (1.2%) new AF cases were confirmed (mean age, 77.0 years; 64% men; mean CHA₂DS₂‐VA, 3.2). Oral anticoagulant treatment rates for patients with CHA₂DS₂‐VA≥2 were 82% (screen detected) versus 74% (preexisting AF)(P=NS), similar to metropolitan and nonrandomized control practices. The incremental cost‐effectiveness ratio for population‐based screening was AU$16 578 per quality‐adjusted life year gained and AU$84 383 per stroke prevented compared with no screening. National implementation would prevent 147 strokes per year. Increasing the proportion screened to 75% would prevent 177 additional strokes per year.

CONCLUSIONS

An AF screening program in rural practices, supported by eHealth tools, screened 34% of eligible patients and was cost‐effective. Oral anticoagulant treatment rates were relatively high at baseline, trending upward during the study. Increasing the proportion screened would prevent many more strokes with minimal incremental cost‐effectiveness ratio change. eHealth tools, including data reports, may be a valuable addition to future programs.

REGISTRATION

URL: https://www.anzctr.org.au. Unique identifier: ACTRN12618000004268.

The Tasmanian Atrial Fibrillation Study (TAFS): Differences in Stroke Prevention According to Sex

Background: There are limited Australian data on sex differences in oral anticoagulant (OAC) prescribing in atrial fibrillation (AF) and ongoing debate regarding the optimal approach to stroke risk assessment and OAC prescribing in female patients with AF. Objective: The purpose of this study was to investigate sex differences in the prescribing of OACs in patients with AF stratified by stroke risk and in the rate of adverse outcomes. Methods: A retrospective analysis of patients admitted to the Royal Hobart Hospital (Tasmania, Australia) with nonvalvular AF between January 2011 and July 2015 was conducted. Rates of antithrombotic prescribing according to sex and stroke risk were assessed along with a multivariate analysis for predictors of OAC prescribing. Rates of thromboembolism, bleeding, and all-cause mortality were assessed according to sex. Results: A total of 2090 patients were included (44.7% female). Women with a CHA2DS2-VA score ≥2 were less likely to receive an OAC compared with men (56.7% vs 62.2%, P = 0.023). Female sex was an independent negative predictor of OAC prescribing (adjusted odds ratio = 0.83; 95% CI = 0.69-0.99; P = 0.041). There were no sex differences in the incidence rates of thromboembolism, bleeding, or all-cause mortality in patients newly commenced on antithrombotic therapy. Conclusion and Relevance: Female patients with a high stroke risk were less likely to receive guideline-recommended treatment. This study provides new information on prescribing trends within the Australian setting and highlights the opportunity to improve the management of female patients with AF and 1 or more additional stroke risk factors.

Ischaemic stroke and transient ischaemic attack on anticoagulants: outcomes in the era of direct oral anticoagulants

Clinical and imaging characteristics of patients receiving direct oral anticoagulants presenting with transient ischaemic attack or stroke are lacking. A retrospective review of all patients who presented to a high-volume primary stroke centre with acute stroke symptoms while prescribed an oral anticoagulant between January 2012 and June 2017. Clinical, radiological characteristics and functional outcomes were examined. Anticoagulated patients diagnosed with stroke or transient ischaemic attack shared similar disease and outcome characteristics irrespective of anticoagulants used. One-third of warfarin patients with sub-therapeutic international normalised ratios were treated with thrombolytics but no direct oral anticoagulants level was performed in any of the patients, with only one treated by intravenous thrombolysis.

eHealth Tools to Provide Structured Assistance for Atrial Fibrillation Screening, Management, and Guideline-Recommended Therapy in Metropolitan General Practice: The AF - SMART Study

Background

This eHealth implementation study aimed to evaluate strategies to promote opportunistic atrial fibrillation (AF) screening using electronic screening prompts and improve treatment using electronic decision support (EDS) software.

Methods and Results

An electronic screening prompt appeared whenever an eligible patient's (aged ≥65 years, no AF diagnosis) medical record was opened in participating general practices. General practitioners and practice nurses offered screening using a smartphone ECG, with validated AF algorithm. Guideline‐based EDS was provided to assist treatment decisions. Deidentified data were collected from practices using a data extraction tool. General practices (n=8) across Sydney, Australia, screened for a median of 6 months. A total of 1805 of 11 476 (16%) eligible patients who attended were screened (44% men, mean age 75.7 years). Screening identified 19 (1.1%) new cases of AF (mean age, 79 years; mean CHA₂DS₂‐VASc, 3.7; 53% men). General practitioners (n=30) performed 70% of all screenings (range 1–448 patients per general practitioner). The proportion of patients with AF who had CHA₂DS₂‐VASc ≥2 for men or ≥3 for women prescribed oral anticoagulants was higher for those diagnosed during the study: 15 of 18 (83%) for screen‐detected and 39 of 46 (85%) for clinically detected, compared with 933 of 1306 (71%) patients diagnosed before the study (P<0.001). The EDS was accessed 111 times for patients with AF and for 4 of 19 screen‐detected patients.

Conclusions

The eHealth tools showed promise. Adherence to guideline‐based oral anticoagulant prescription was significantly higher in patients diagnosed during the study period, although the EDS was only used in a minority. While the proportion of eligible patients screened and EDS use was relatively low, further refinements may improve uptake in clinical practice.

Clinical Trial Registration

URL: www.anzctr.org.au. Unique identifier: ACTRN12616000850471.

Treatment Expectations, Convenience, and Satisfaction with Anticoagulant Treatment: Perceptions of Patients in South-East Queensland, Australia

Background: Warfarin has long been the only oral anticoagulant (OAC) available, but options now include non-vitamin K antagonists. Prescribing an OAC may be influenced by patient factors and preferences influenced by dosing, monitoring, and adverse effects, which may ultimately impact patient satisfaction and convenience. The aim of this study was to explore the perception of OAC treatment by Australian patients in terms of treatment expectations, convenience, and satisfaction. Methods: The Perception of Anticoagulant Treatment Questionnaire was distributed to patients dispensed OAC medication from three pharmacies in South-East Queensland. Responses to questions using a five-point Likert scale were collated and mean results utilised to assess expectations, convenience, and satisfaction, including an analysis across demographic groups. Results: A total of 56 (26.8%) surveys were returned, with the majority of respondent’s male (58.2%). Highest mean scores for treatment expectation were for an OAC that was easy to take (4.85 ± 0.79) and that could be taken care of by the respondents themselves (4.11 ± 1.14). The mean overall score for convenience was 68.90 ± 11.44% and for satisfaction 69.43 ± 16.58%. Significantly higher mean convenience scores were found in females and patients with atrial fibrillation. Conclusions: Patients’ highest expectations were for an OAC that would be easy to take, and overall satisfaction and convenience was around 69%. Factors including demographics can influence perceptions of therapy, and addressing individual preferences for OAC therapy may increase ratings of satisfaction and convenience.

Adherence to Oral Anticoagulants in Atrial Fibrillation: An Australian Survey

Background:

The aim of this study was to investigate the proportion of patients who have suboptimal adherence to oral anticoagulant (OAC), identify the predictors of adherence, and determine whether patient-related factors vary across adherence levels in Australia.

Methods:

Respondents were recruited for an online survey using Facebook. Survey instruments included the Morisky Medication Adherence Scale, the Anticoagulation Knowledge Tool, the Perception of Anticoagulant Treatment Questionnaires, and a modified Cancer Information Overload scale. Predictors of medication adherence were identified using ordinal regression analysis.

Results:

Of the 386 responses eligible for analysis, only 54.9% reported a high level of adherence. Participants aged 65 years or younger were less likely to have high adherence compared to older participants (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.33-0.88; P = .013), while females were more likely to be highly adherent compared to males (OR, 1.69; 95% CI, 1.08-2.64; P = .023). The analyses showed that age, gender, treatment satisfaction, information overload, concerns about making mistake when taking OACs, and cost of medication were significant predictors of adherence.

Conclusion:

Self-reported suboptimal adherence to OAC is common among patients with atrial fibrillation. A focus on supporting people who are at higher risk of suboptimal adherence is needed to maximize the benefit of OAC therapy in this population.

Thromboembolism and Mortality in the Tasmanian Atrial Fibrillation Study

BACKGROUND

Although utilization of anticoagulation in patients with atrial fibrillation (AF) has increased in recent years, contemporary data regarding thromboembolism and mortality incidence rates are limited outside of clinical trials. This study aimed to investigate the impact of the direct oral anticoagulants (DOACs) on the clinical outcomes of patients with AF included in the Tasmanian Atrial Fibrillation Study.

METHODS

The medical records of all patients with a primary or secondary diagnosis of AF who presented to public hospitals in Tasmania, Australia, between 2011 and 2015, were retrospectively reviewed. We investigated overall thromboembolic events (TEs), ischemic stroke/transient ischemic attack (IS/TIA), and mortality incidence rates in patients admitted to the Royal Hobart Hospital, the main teaching hospital in the state. We compared outcomes in 2 time periods: prior to the availability of DOACs (pre-DOAC; 2011 to mid-2013) and following their general availability after government subsidization (post-DOAC; mid-2013 to 2015).

RESULTS

Of the 2390 patients with AF admitted during the overall study period, 942 patients newly prescribed an antithrombotic medication (465 and 477 from the pre-DOAC and post-DOAC time periods, respectively) were followed. We observed a significant decrease in the incidence rates of overall TE (3.2 vs 1.7 per 100 patient-years [PY]; P < .001) and IS/TIA (2.1 vs 1.3 per 100 PY; P = .022) in the post-DOAC compared to the pre-DOAC period. All-cause mortality was significantly lower in the post-DOAC period (2.9 vs 2.2 per 100 PY, P = .028). Increasing age, prior stroke, and admission in the pre-DOAC era were all risk factors for TE, IS/TIA, and mortality in this study population. The risk of IS/TIA was more than doubled (hazard ratio: 2.54; 95% confidence interval: 1.17-5.52) in current smokers compared to ex- and nonsmokers.

CONCLUSION

Thromboembolic event and all-cause mortality rates were lower following the widespread availability of DOACs in this population.

Changes in Oral Anticoagulant Prescribing for Stroke Prevention in Patients With Atrial Fibrillation

Suboptimal guideline adherence and underuse of anticoagulants in patients with atrial fibrillation (AF) have been reported worldwide. This study aimed to compare anticoagulation practice in Australia during the pre- and postdirect oral anticoagulant (DOAC) eras. Between January 2011 and July 2015, patients with nonvalvular AF (NVAF) admitted to the Royal Hobart Hospital, Tasmania, Australia, were retrospectively reviewed. The pre- and post-DOAC era cohorts included admissions from January 2011 to July 2013 and August 2013 to July 2015, respectively. Overall, 2,118 patients met our inclusion criteria. The overall rate of anticoagulation increased from 52.5% in the pre-DOAC era to 60.7% in the post-DOAC era (p <0.001). Moreover, prescribing of OACs among high-risk patients improved significantly (63.1% vs 55.2%, p = 0.001). OAC overprescribing in low-risk patients did not change significantly between the 2 cohorts (35.0% vs 42.9% in the pre- and post-DOAC eras, respectively, p = 0.59). In multivariate analysis, DOAC era (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.17 to 1.68 and CHA₂DS₂-VASc ≥2 (OR 1.95, 95% CI 1.36 to 2.80) were independent predictors of OAC prescribing in both eras and the whole study period. Conversely, aging and previous bleeding were inversely associated with OAC prescribing. In conclusion, there has been a significant increase in OAC prescribing in the post-DOAC era, potentially driven by the widespread availability of DOACs. However, OAC underuse in high-risk patients and overuse in low-risk patients was apparent throughout our study. These findings highlight the need to identify the drivers of anticoagulant underuse and overuse and address them accordingly.

Bleeding-related admissions in patients with atrial fibrillation receiving antithrombotic therapy: results from the Tasmanian Atrial Fibrillation (TAF) study

PURPOSE

Limited data are available from the Australian setting regarding bleeding in patients with atrial fibrillation (AF) receiving antithrombotic therapy. We aimed to investigate the incidence of hospital admissions due to bleeding and factors associated with bleeding in patients with AF who received antithrombotic therapy.

METHODS

A retrospective cohort study was conducted involving all patients with AF admitted to the Royal Hobart Hospital, Tasmania, Australia, between January 2011 and July 2015. Bleeding rates were calculated per 100 patient-years (PY) of follow-up, and multivariable modelling was used to identify predictors of bleeding.

RESULTS

Of 2202 patients receiving antithrombotic therapy, 113 presented to the hospital with a major or minor bleeding event. These patients were older, had higher stroke and bleeding risk scores and were more often treated with warfarin and multiple antithrombotic therapies than patients who did not experience bleeding. The combined incidence of major and minor bleeding was significantly higher in warfarin- versus direct-acting oral anticoagulants (DOAC)- and antiplatelet-treated patients (4.1 vs 3.0 vs 1.2 per 100 PY, respectively; p = 0.002). Similarly, the rate of major bleeding was higher in patients who received warfarin than in the DOAC and antiplatelet cohorts (2.4 vs 0.4 vs 0.6 per 100 PY, respectively; p = 0.001). In multivariate analysis, increasing age, prior bleeding, warfarin and multiple antithrombotic therapies were independently associated with bleeding.

CONCLUSION

The overall rate of bleeding in this cohort was low relative to similar observational studies. The rate of major bleeding was higher in patients prescribed warfarin compared to DOACs, with a similar rate of major bleeding for DOACs and antiplatelet agents. Our findings suggest potential to strategies to reduce bleeding include using DOACs in preference to warfarin, and avoiding multiple antithrombotic therapies in patients with AF.