Impact of stated barriers on proposed warfarin prescription for atrial fibrillation: a survey of Canadian physicians

Prescribing of anticoagulation for atrial fibrillation in primary care

Atrial fibrillation (AF) is common in primary care patients. Many patients who could benefit from anticoagulation do not receive it. The objective of this study was to describe anticoagulation prescribing by primary care physicians. We conducted an observational study in the Cleveland Clinic Health System among patients with AF and ≥ 1 primary care appointment between 2015 and 2018 and their physicians. We estimated differences in the odds of an eligible patient receiving anticoagulation versus not and a DOAC versus warfarin using two mixed effects logistic regression models, adjusted for patient sociodemographic factors, history of falls or dementia, and CHA2DS2-VASc and HAS-BLED scores. We categorized physicians into prescribing tertiles, based on their adjusted prescribing rate, which we included as predictors in the models. Among 5253 patients, 47% received anticoagulation. Of those, 56% received a DOAC. CHA2DS2-VASc and HAS-BLED scores were not associated with anticoagulation prescription. Black race was negatively associated with receiving anticoagulation overall (aOR:0.71; 95%CI:0.56-0.89) and with prescription for a DOAC (aOR:0.65; 95%CI:0.45-0.93). Among 195 physicians, the anticoagulation prescribing rate ranged from 27% to 57% and DOAC rates ranged from 34% to 69%. Physician prescribing tertile was associated with odds of a patient receiving anticoagulation overall (aOR:1.51; 95%CI: 1.13-2.01 for the highest versus lowest tertile), but not DOAC prescriptions. When prescribing anticoagulation, physicians appear not to consider risk of stroke or bleeding but patient race is an important determinant. Seeing a physician with a high anticoagulation prescribing rate was strongly associated with a patient receiving it, suggesting a lack of individualization.

Treatment and persistence with oral anticoagulants among newly diagnosed patients with non-valvular atrial fibrillation: a retrospective observational study in a US commercially insured and Medicare Advantage population

OBJECTIVES

With the approval of new non-vitamin K antagonist oral anticoagulants for stroke prevention in non-valvular atrial fibrillation (NVAF), it is anticipated that their introduction may change NVAF treatment patterns; however, there is limited supporting real-world evidence. This study investigated guideline-recommended oral anticoagulation (OAC) treatment and persistence in newly diagnosed patients with NVAF to understand demographic and clinical characteristics.

DESIGN

Retrospective observational administrative claims study in the USA.

SETTING

Patients with NVAF with ≥1 pharmacy claim for OAC (warfarin, dabigatran, rivaroxaban or apixaban) and no atrial fibrillation diagnosis within 12 months prior to the first claim were identified in the HealthCore Integrated Research Database between 1 November 2010 and 30 November 2013.

PARTICIPANTS

45 092 patients with NVAF were included.

OUTCOMES

The proportion of OAC-treated patients was stratified by CHADS₂ score. Treatment persistence was measured from OAC initiation to discontinuation, end of eligibility or end of study period (30 November 2014), whichever occurred first.

RESULTS

Almost half of the patients (41.1%) received an OAC. The proportion treated differed slightly in baseline stroke risk (CHADS₂<2: 39.8%; CHADS₂=2 or 3: 42.4%; and CHADS₂>3: 40.3%: p<0.001). Treated patients were slightly younger (70±12.2 vs 71±14.3 years; p<0.001), more likely male (59.7% vs 52.5%; p<0.001) and had a slightly elevated stroke risk (CHADS₂: 2.03±1.3 vs 1.98±1.4; p<0.001) and a lower bleeding risk (HEMORR₂HAGES: 2.55±1.8 vs 2.80±1.9; p<0.001) relative to untreated patients. Overall, patients with higher CHADS₂ scores had higher HEMORR₂HAGES scores. The mean follow-up was 2.25 years (2.25±0.85) and 72.7% of patients discontinued OACs; nearly 25% within 3 months and 55% within 12 months. The mean time to discontinuation was 255±249 days.

CONCLUSIONS

The proportion of patients with NVAF who received OAC treatment was lower than previously reported and differed slightly by stroke risk. Patients with an elevated stroke risk had a higher bleeding risk, suggesting that clinicians may incorporate both in the treatment decision.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Evaluating the potential for pharmacists to prescribe oral anticoagulants for atrial fibrillation

Background

Oral anticoagulant therapy (OAC) to prevent atrial fibrillation (AF)-related strokes remains poorly used. Alternate strategies, such as community pharmacist prescribing of OAC, should be explored.

Methods

Approximately 400 pharmacists, half with additional prescribing authority (APA), randomly selected from the Alberta College of Pharmacists, were invited to participate in an online survey over a 6-week period. The survey consisted of demographics, case scenarios assessing appropriateness of OAC (based on the 2014 Canadian Cardiovascular Society AF guidelines) and perceived barriers to prescribing. Regression analysis was performed to determine predictors of knowledge.

Results

A total of 35% (139/397) of pharmacists responded to the survey, and 57% of these had APA. Depending on the case scenario, 55% to 92% of pharmacists correctly identified patients eligible for stroke prevention therapy, but only about a half selected the appropriate antithrombotic agent; there was no difference in the knowledge according to APA status. In multivariable analysis, predictors significantly associated with guideline-concordant prescribing were having the pharmacist interact as part of an interprofessional team (p = 0.04) and direct OAC (DOAC) self-efficacy (confidence in ability to extend, adapt, initiate or alter prescriptions; p = 0.02). Barriers to prescribing OAC for APA pharmacists included a lack of AF and DOAC knowledge and preference for consulting the physician first, but these same pharmacists also identified difficulty in contacting the physician as a major barrier.

Interpretation and Conclusion

Community pharmacists can identify patients who would benefit from stroke prevention therapy in AF. However, physician collaboration and further training on AF and guidelines for prescribing OAC are needed.

Overcoming global challenges in stroke prophylaxis in atrial fibrillation: The role of non-vitamin K antagonist oral anticoagulants

Atrial fibrillation is the world's most common sustained cardiac arrhythmia and is associated with a significantly increased risk of stroke. The global burden of atrial fibrillation is rising, commensurate with the ageing population. Well-controlled vitamin K antagonist-based anticoagulation has been shown to reduce the risk of stroke secondary to atrial fibrillation by two-thirds. However, patients with atrial fibrillation have frequently been denied anticoagulation because of a variety of perceived risks related to bleeding, falls, chronological age, and poor compliance. Even when vitamin K antagonists are used, maximum benefit and safety are only delivered when high quality control of therapy (TTR > 70%) is achieved, which has proven remarkably difficult in many health-care systems and amongst many patient groups. The non-vitamin K antagonist oral anticoagulants (NOACs) offer solutions to many of the challenges of achieving widespread, safe, and effective anticoagulation for stroke prophylaxis in atrial fibrillation, yet their uptake into routine clinical practice remains variable. The evidence supporting their more widespread use to overcome the challenges of stroke prophylaxis for atrial fibrillation is reviewed in this article.

Opportunistic screening for atrial fibrillation in a rural area

INTRODUCTION

Opportunistic screening is an effective means of identifying subjects with Atrial Fibrillation (AF). Previous studies of opportunistic screening have been performed areas with high population density and before the development of novel oral anticoagulant drugs. We performed a study to determine feasibility of AF screening in a predominantly rural, low population density area.

METHODS

Over 6 months, subjects 65 years and older were screened by local General Practitioners using radial pulse palpation confirmed by 12 lead Electrocardiogram. Data were recorded electronically and those with newly identified AF were followed up to examine management post diagnosis.

RESULTS

In total, 7262 subjects were screened and an irregular pulse was found in 916 (12.6%) of whom 735 (10.1%) had known AF and 55 (0.76%) had newly detected AF. Of these 55 patients with newly documented AF, 28 (50.9%) were women, 38 (69.1%) had hypertension and eight (14.5%) had a smoking history. Mean body mass index in subjects with newly documented AF was 28.9 kg/m(2)(SD 5.6) There was no significant difference in gender mix (P =  0.4), smoking history (P  =  0.8) or alcohol history (P  =  0.8) with the overall population. Fifty-one (92.7%) subjects had a CHA2DS2VaSC score  ≥ 2 of whom 33 (64.7%) were eventually anticoagulated and nine (17.6%) commenced on Aspirin. The rate of newly identified patients in AF was lower than in previous reported key studies because of a higher rate of subjects with known AF.

CONCLUSION

Opportunistic AF screening in a rural environment identified a substantial number of new cases, although less than in previous screening studies.

Prescribers' behavior following below- versus above-range international normalized ratio values in warfarin-treated deep vein thrombosis patients

Maintaining acceptable international normalized ratio (INR) control among deep vein thrombosis (DVT) patients taking warfarin is challenging. We evaluated prescribers' behavior to out-of-range INRs in DVT patients following initial INR stabilization. Following INR stabilization, a below-range INR was associated with fewer subsequent measurements and warfarin-dosing adjustments, and a longer time to re-achieve a therapeutic INR compared to an above-range INR.

Contemporary approaches to managing atrial fibrillation: A survey of Australian general practitioners

BACKGROUND

Recent attention to the management of atrial fibrillation (AF) and stroke prevention has emphasised the need to support the use of existing pharmacotherapy through available services and resources, in preference to using the new, more expensive, novel oral anticoagulants. In this regard, general practitioners (GPs) are at the core of care.

AIMS

To survey Australian GPs regarding their approach to managing AF, particularly in relation to stroke prevention therapy, and to identify the range of services to support patient care.

METHODS

A structured questionnaire, comprising quantitative and qualitative responses, was administered to participating GPs within four geographical regions of NSW (metropolitan, regional, rural areas).

RESULTS

Fifty GPs (mean age 53.74±9.94 years) participated. Most (98 per cent) GPs regarded themselves as primarily responsible for the management of AF, only referring patients to specialists when needed. However, only 10 per cent of GPs specialised in "heart/vascular health". Most (76 per cent) GPs offered point-of-care international normalised ratio (INR) testing, with 90 per cent also offering patient support via practice nurses and home visits. Overall, key determinants influencing GPs' initiation of antithrombotic therapy were: "stroke risk"/"CHADS2 score", followed by "patients' adherence/compliance". GPs focused more on medication safety considerations and the day-to-day management of therapy than on the risk of bleeding.

CONCLUSION

Australian GPs are actively engaged in managing AF, and appear to be well resourced. Importantly, there is a greater focus on the benefits of therapy during decision-making, rather than on the risks. However, medication safety considerations affecting routine management of therapy remain key concerns, with patients' adherence to therapy a major determinant in decision-making.