The Guideline-Policy Gap in Direct-Acting Oral Anticoagulants Usage in Atrial Fibrillation: Evidence, Practice, and Public Policy Considerations

Does prescribing apixaban or rivaroxaban versus warfarin for patients diagnosed with atrial fibrillation save health system costs? A multivalued treatment effects analysis

BACKGROUND

Non-valvular atrial fibrillation (AF) is a common heart arrhythmia in the elderly population. AF patients are at high-risk of ischemic strokes, but oral anticoagulant (OAC) therapy reduces such risks. Warfarin had been the standard OAC for AF patients, however its effectiveness is highly variable and dependent on close monitoring of the anticoagulant response. Newer OACs such as rivaroxaban and apixaban address these drawbacks but are more costly. It is uncertain which OAC therapy for AF is cost-saving from the healthcare system perspective.

METHODS

We followed a cohort of patients in Ontario, Canada, aged ≥ 66 who were newly diagnosed with AF and prescribed OACs between 2012 and 2017. We used a two-stage estimation procedure. First, we account for the patient selection into OACs using a multinomial logit regression model and estimated propensity scores. Second, we used an inverse probability weighted regression adjustment approach to determine cost-saving OAC options. We also examined component-specific costs (i.e., drug, hospitalization, emergency department and physician) to understand the drivers of cost-saving OACs.

RESULTS

We found that compared to warfarin, rivaroxaban and apixaban treatments were cost-saving options, with per-patient 1-year healthcare cost savings at $2436 and $1764, respectively. These savings were driven by cost-savings in hospitalization, emergency department visits, and physician visits, outweighing higher drug costs. These results were robust to alternative model specifications and estimation procedures.

CONCLUSIONS

Treating AF patients with rivaroxaban and apixaban than warfarin reduces healthcare costs. OAC reimbursement policies for AF patients should consider rivaroxaban or apixaban over warfarin as the first-line treatment.

Early experiences with edoxaban for stroke prevention in atrial fibrillation in the Southeast Asia region

Edoxaban, a once-daily, direct-acting oral anticoagulant, is approved to prevent stroke or systemic embolism in non-valvular atrial fibrillation (NVAF) and treat venous thromboembolism. The clinical benefit of edoxaban for stroke prevention in Asian patients with NVAF has been demonstrated in clinical and real-world studies. We share early clinical experiences with once-daily edoxaban and discuss its evidence-based use in patients with NVAF in Southeast Asia through several cases of patients at high risk, including frail patients, elderly patients with multiple comorbidities and patients with increased bleeding risk. These cases demonstrate the effectiveness and safety of once-daily edoxaban in patients with NVAF in Southeast Asia.

Geographic and temporal variation in the treatment and outcomes of atrial fibrillation: a population-based analysis of national quality indicators

BACKGROUND

Assessment of potential geographic variation in quality indicators of atrial fibrillation care may identify opportunities for improvement in the quality of atrial fibrillation care. The objective of this study was to assess for potential geographic variation in the quality of atrial fibrillation care in Alberta, Canada.

METHODS

In a population-based cohort of adults (age ≥ 18 yr) with incident nonvalvular atrial fibrillation (NVAF) diagnosed between Apr. 1, 2008, and Mar. 31, 2016, in Alberta, we investigated the variation in national quality indicators of atrial fibrillation care developed by the Canadian Cardiovascular Society. Specifically, we assessed the geographic and temporal variation in the proportion of patients with initiation of oral anticoagulant therapy, persistence with therapy, ischemic stroke and major bleeding outcomes 1 year after atrial fibrillation diagnosis using linked administrative data sets. We defined stroke risk using the CHADS₂ score. We assessed geographic variation using small-area variation statistics and geospatial data analysis.

RESULTS

Of the 64 093 patients in the study cohort (35 019 men [54.6%] and 29 074 women [45.4%] with a mean age of 69 [standard deviation 15.9] yr), 36 199 were at high risk for stroke and 14 411 were at moderate risk. Within 1 year of NVAF diagnosis, 20 180 patients (55.7%) in the high-risk group and 6448 patients (44.7%) in the moderate-risk group were prescribed anticoagulation. A total of 2187 patients (3.4%) had an ischemic stroke, and 2996 patients (4.7%) experienced a major bleed. There was substantial regional variation observed in initiation of oral anticoagulant therapy but not in the proportion of patients with ischemic stroke or major bleeding. Among the 64 Health Status Areas in Alberta, therapy initiation rates ranged from 22.6% to 71.2% among patients at high stroke risk and from 22.7% to 55.8% among those at moderate stroke risk, with clustering of lower therapy initiation rates in rural northern regions.

INTERPRETATION

The rate of initiation of oral anticoagulant therapy among adults with incident atrial fibrillation was less than 60% in patients in whom oral anticoagulant therapy would be considered guideline-appropriate care. The large geographic variation in oral anticoagulant prescribing warrants additional study into patient, provider and health care system factors that contribute to variation and drive disparities in high-quality, equitable atrial fibrillation care.

Optimizing adherence and persistence to non-vitamin K antagonist oral anticoagulant therapy in atrial fibrillation

Atrial fibrillation (AF) is associated with an increased risk of stroke, which can be prevented by the use of oral anticoagulation. Although non-vitamin K antagonist oral anticoagulants (NOACs) have become the first choice for stroke prevention in the majority of patients with non-valvular AF, adherence and persistence to these medications remain suboptimal, which may translate into poor health outcomes and increased healthcare costs. Factors influencing adherence and persistence have been suggested to be patient-related, physician-related, and healthcare system-related. In this review, we discuss factors influencing patient adherence and persistence to NOACs and possible problem solving strategies, especially involving an integrated care management, aiming for the improvement in patient outcomes and treatment satisfaction.

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.

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.

Patient satisfaction after conversion from warfarin to direct oral anticoagulants for patients on extended duration of anticoagulation for venous thromboembolism - The SWAN Study

Background

Warfarin is an anticoagulant medication proven effective in the initial treatment and secondary prevention of venous thromboembolism. Anti-Xa direct oral anticoagulants are alternatives to warfarin; however there is limited data assessing satisfaction after switching from warfarin to an anti-Xa direct oral anticoagulant in patients for treatment of venous thromboembolism.

Objectives

To assess medication satisfaction in patients requiring anticoagulation for venous thromboembolism after conversion from warfarin to an anti-Xa direct oral anticoagulant.

Methods

A retrospective cohort study with prospective assessment of satisfaction and review of adverse events following anti-Xa direct oral anticoagulant replacement of warfarin for treatment of venous thromboembolism. Out of 165 patients who had switched from warfarin to rivaroxaban or apixaban from an outpatient haematology practice, 126 patients consented for a survey of patient’s relative satisfaction of anti-Xa direct oral anticoagulant therapy compared with previous warfarin therapy using the Anti-Clot Burden and Benefits Treatment Scale and SWAN Score.

Results

The mean Anti-Clot Burden and Benefits and SWAN Score was 93% (56/60) and 83% (24.8/30) respectively reflecting high satisfaction with anti-Xa direct oral anticoagulants. 120 patients stated preference for anti-Xa direct oral anticoagulants over warfarin. Leading perceptions driving this was the reduction in frequency of medical contact and fewer bleeding side effects. Thirteen patients (10.3%) experienced an adverse event after the anti-Xa direct oral anticoagulant switch (majority were non-major bleeding) but most remained on anti-Xa direct oral anticoagulant treatment after management options were implemented with continued high satisfaction scores.

Conclusions

Patient satisfaction with anti-Xa direct oral anticoagulant therapy for the treatment and prevention of venous thromboembolism after switching from warfarin in routine clinical practice appeared high. Improved patient convenience including reduced frequency of medical contact and fewer unpredictable side effects were perceived as significant advantages of anti-Xa direct oral anticoagulants compared to warfarin.

Trends in anticoagulant prescribing: a review of local policies in English primary care

Background

Oral anticoagulants are prescribed for stroke prophylaxis in patients with atrial fibrillation, which is the most common heart arrhythmia worldwide. The vitamin K antagonist (VKA) warfarin is a long-established anticoagulant. However, newer direct oral anticoagulants (DOACs) have been recently introduced as an alternative. Given the prevalence of atrial fibrillation, anticoagulant choice has substantial clinical and financial implications for healthcare systems. In this study, we explore trends and geographic variation in anticoagulant prescribing in English primary care. Because national guidelines in England do not specify a first-line anticoagulant, we investigate the association between local policies and prescribing data.

Methods

Primary care prescribing data of anticoagulants for all NHS practices from 2014 to 2019 in England was obtained from the ePACT2 database. Public formularies were accessed online to obtain local anticoagulation prescribing policies for 89.5% of clinical commissioning groups (CCGs). These were categorized according to their recommendations: no local policies, warfarin as first-line, or identification of a preferred DOAC (but not a preferred anticoagulant). Local policies were cross-tabulated with pooled prescribing data to measure the strength of association with Cramér’s V.

Results

Nationally, prescribing of DOACs increased from 9% of all anticoagulants in 2014 to 74% in 2019, while that of warfarin declined accordingly. Still, there was significant local variation. Across geographical regions, DOACs ranged from 53 to 99% of all anticoagulants. Most CCGs (73%) did not specify a first-line choice, and 16% recommended warfarin first line. Only 11% designated a preferred DOAC. Policies with a preferred DOAC indeed correlated with increased prescribing of that DOAC (Cramér’s V = 0.25, 0.27, 0.38 for rivaroxaban, apixaban, edoxaban respectively). However, local policies showed a negligible relationship with the classes of anticoagulants prescribed—DOAC or VKA (Cramér’s V = 0.01).

Conclusions

Nationally, the use of DOACs to treat atrial fibrillation has increased rapidly. Despite this, significant geographical variation in uptake remains. This study provides insights on how local policies relate to this variation. Our findings suggest that, in the absence of a nationally recommended first-line anticoagulant, local prescribing policies may aid in deciding between individual DOACs, but not in adjudicating between DOACs and vitamin K antagonists (i.e. warfarin) as general classes.

Systematic review of interventions to improve safety and quality of anticoagulant prescribing for therapeutic indications for hospital inpatients

PURPOSE

Anticoagulation-associated adverse drug events are common in hospitalised patients and result in morbidity, mortality, increased length of hospital stay and higher costs of care. Many are preventable. We reviewed the literature to identify and assess interventions intended to improve safety or quality anticoagulant prescribing.

METHODS

A systematic search of EMBASE, MEDLINE, the Cochrane Library, Pretty Darn Quick-Evidence and Health Systems Evidence was undertaken to identify controlled studies assessing system-level interventions to improve prescribing of oral or parenteral therapeutic anticoagulation for any indication in hospitalised adults. Data were extracted for safety and quality outcomes, with studies grouped by intervention type for meta-analysis and narrative review.

RESULTS

Of 10,640 records screened, 19 trials evaluating 12,742 participants were included for analysis. No study specifically evaluated prescribing of low molecular weight heparins (LMWHs) or direct acting oral anticoagulants (DOACs). Our findings suggest that physician-led anticoagulation consultation services may reduce bleeding rates in high-risk patients. On meta-analysis, decision supported warfarin dosing resulted in higher proportion of time with international normalised ratio in therapeutic range (p = 0.0007). Studies of other clinical decision support systems and heparin monitoring systems did not demonstrate improved safety, and quality findings were inconsistent. Systematic education and feedback programs were not efficacious.

CONCLUSIONS

There is currently insufficient high-quality evidence to recommend any reviewed intervention, though several warrant closer evaluation. Adequately powered controlled trials assessing safety outcomes and evidence-based quality markers in high-risk patient groups and studies of interventions to improve safety of LMWH and DOAC prescribing are needed.