Discontinuation of non-Vitamin K antagonist oral anticoagulants in patients with non-valvular atrial fibrillation: a population-based cohort study using primary care data from The Health Improvement Network in the UK

Left Atrial Appendage Closure Compared With Oral Anticoagulants for Patients With Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has been suggested as an alternative to long-term oral anticoagulation for nonvalvular atrial fibrillation, but comparative data remain scarce. We aimed to assess ischemic and bleeding outcomes of LAAC compared with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) for the prevention of cardioembolic events in patients with atrial fibrillation.

METHODS AND RESULTS

Embase and MEDLINE were searched for randomized trials comparing LAAC, VKAs, and DOACs. The primary efficacy end point was any stroke or systemic embolism. Treatment effects were calculated from a network meta-analysis and ranked according to the surface under the cumulative ranking curve. Seven trials and 73 199 patients were included. The risk of the primary end point was not statistically different between LAAC versus VKAs (odds ratio [OR], 0.92 [95% CI, 0.62-1.50]) and LAAC versus DOACs (OR, 1.11 [95% CI, 0.71-1.73]). LAAC and DOACs resulted in similar risk of major or minor (OR, 0.93 [95% CI, 0.61-1.42]) and major bleeding (OR, 0.92 [95% CI, 0.58-1.46]); however, after exclusion of procedural bleeding, bleeding risk was significantly lower in those undergoing LAAC. Both LAAC and DOACs reduced the risk of all-cause death  compared with VKAs (LAAC versus VKAs: OR, 0.70 [95% CI, 0.53-0.91]; DOACs versus VKAs: OR, 0.90 [95% CI, 0.85-0.95], respectively). DOACs ranked as the best treatment for stroke or systemic embolism prevention (66.9%) and LAAC for reducing major bleeding (63.9%) and death (96.4%).

CONCLUSIONS

As a nonpharmacological alternative to oral anticoagulation for atrial fibrillation, LAAC showed similar efficacy and safety compared with VKAs or DOACs. Prospective confirmation from larger studies is warranted.

Recurrent Ischemic Stroke in Patients With Atrial Fibrillation While Receiving Oral Anticoagulants

Importance

Patients with atrial fibrillation (AF) can have an ischemic stroke (IS) despite oral anticoagulant (OAC) treatment. Knowledge regarding the association between OAC discontinuation and the subsequent risk of recurrent IS in patients with AF is limited.

Objectives

To determine the risk of recurrent IS in patients with AF receiving OAC and to evaluate the association between OAC discontinuation and the risk of recurrent IS.

Design, Setting, and Participants

This is a nationwide cohort study of patients aged 50 years or older in Denmark who had AF and an IS (entry IS) and were initiating or restarting subsequent OAC treatment after being discharged between January 2014 and December 2021. Patients were followed up for recurrent IS until June 2022. Within this study cohort, a nested case-control analysis was performed in which patients with recurrent IS were matched to patients receiving OAC who had not yet experienced a stroke. Data were analyzed from May 25, 2023, to April 18, 2024.

Exposure

Use of OAC at the time of recurrent IS or the equivalent date in matched controls based on redeemed prescriptions.

Main Outcomes and Measures

The primary outcome was recurrent IS. Crude and adjusted cumulative incidences of recurrent IS and all-cause mortality were calculated in cohort analyses, and adjusted odds ratios (aORs) were determined for recurrent IS associated with OAC discontinuation in nested case-control analyses.

Results

The study cohort included 8119 patients (4392 [54.1%] male; mean [SD] age, 78.4 [9.6] years; median (IQR) CHA2DS2-VASc score, 4.0 [3.0-5.0]). Over a mean (SD) follow-up of 2.9 (2.2) years, 663 patients had a recurrent IS, of whom 533 (80.4%) were receiving OAC at the time of their recurrent IS. The crude cumulative incidence of recurrent IS at 1 year was 4.3% (95% CI, 5.9%-7.1%), and the crude cumulative incidence of all-cause mortality was 15.4% (95% CI, 14.7%-16.2%). Adjusted analysis showed similar results. Patients who discontinued OACs had a higher risk of recurrent IS (89 cases [13.4%], 180 controls [6.8%]; aOR, 2.13; 95% CI, 1.57-2.89) compared with patients still receiving OAC.

Conclusions and Relevance

The risks of recurrent IS and mortality were high in patients with AF despite secondary prevention with OAC, and OAC discontinuation doubled the risk of recurrent IS compared with patients who continued OAC. This finding highlights the importance of OAC continuation and the need for improved secondary stroke prevention in patients with AF.

Clinical benefits of oral anticoagulants in atrial fibrillation patients with dementia: a systematic review and meta-analysis

Background

The management of atrial fibrillation (AF) with oral anticoagulants (OAC) is generally recommended to reduce the risk of stroke. However, the decision to prescribe these medications for patients with AF and dementia remains controversial.

Methods

A systematic review and meta-analysis of retrospective cohort studies were conducted. The search encompassed PubMed, Cochrane Library, Web of Science, and Embase databases from inception until May 1st, 2023, with language limited to English. Eligible studies included comparisons between exposure to OAC vs. non-OAC in the AF population with dementia or cognitive impairment. Studies that compared the effects of direct oral anticoagulants (DOAC) and vitamin-K antagonists were also included. The primary outcome was all-cause mortality, and the secondary outcomes were ischemic stroke and major bleeding. This study was registered with PROSPERO (No. CRD42023420678).

Results

A total of five studies (N = 21,962 patients) met the eligibility criteria and were included in this review. The follow-up duration ranged from 1 to 4 years. Meta-analysis demonstrated that OAC treatment was associated with a lower risk of all-cause mortality in AF patients with dementia with a hazard ratio (HR) of 0.79 and a 95% confidence interval (CI) ranging from 0.68 to 0.92, compared to non-OAC treatment. No statistical differences were observed in the risk of major bleeding (HR = 1.12, 95% CI: 0.88-1.42) or ischemic stroke (HR = 0.77, 95% CI: 0.58-1.00). Three studies reported comparisons between DOAC and warfarin; however, pooled analysis was not performed due to heterogeneity.

Conclusion

The use of OACs in individuals diagnosed with both AF and dementia holds the potential to reduce all-cause mortality rates, thereby improving the overall clinical prognosis within this specific population.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023420678, PROSPERO identifier, CRD42023420678.

Effect of clinic-based single-lead electrocardiogram rhythm assessment on oral anticoagulation prescriptions in patients with previously diagnosed atrial fibrillation

Background

Despite benefits of oral anticoagulation (OAC), many individuals with diagnosed atrial fibrillation (AF) do not receive OAC.

Objective

The purpose of this study was to assess whether cardiac rhythm assessment for AF impacted use of OAC in patients with previously diagnosed AF.

Methods

VITAL-AF was a cluster randomized controlled trial conducted in 16 primary care practices assessing the efficacy of AF rhythm assessment with single-lead electrocardiogram in routine care. Patients 65 years and older were offered rhythm assessment at visits. In this secondary analysis, we evaluated rhythm assessment uptake and compared initiation and discontinuation of OAC in patients with previously diagnosed AF from intervention and control arms over 1 year.

Results

The study included 4593 patients with previously diagnosed AF (2250 intervention; 2343 control). In the intervention arm, 2022 (89.9%) completed rhythm assessment (median 2 visits with rhythm assessment) and 40.1% had ≥1 "Possible AF" result. Initiation of OAC was similar in the intervention (17.7%) and control (19.1%) arms but was influenced by the rhythm assessment result: higher with a "Possible AF" (26.1%; adjusted odds ratio [aOR] 1.62; 95% confidence interval [CI] 1.04-2.51), and lower with a "Normal" result (9.9%; aOR 0.45; 95% CI 0.29-0.71) compared to control. OAC discontinuation was similar in the intervention (6.3%) and control (7.2%) arms, with lower discontinuation with a "Possible AF" result (3.8%; aOR 0.51; 95% CI 0.32-0.81).

Conclusions

Including patients with previously diagnosed AF in a point-of-care rhythm assessment strategy did not increase overall OAC use compared to the control arm. However, the rhythm assessment result influenced both initiation and discontinuation of OAC.

Persistence to rivaroxaban therapy for stroke prevention in clinical practice in Italy: Rationale and design of the RITMUS-AF prospective observational cohort study

Background

Non-valvular atrial fibrillation (NVAF) is a cardiac rhythm disturbance that increases the risk of stroke and is highly prevalent in Europe and Italy, increasingly with advancing age. Oral anticoagulation is a key component of stroke prevention in patients with NVAF, yet withdrawal or interruption of anticoagulation may transiently increase the risk of embolic events. Treatment persistence to anticoagulation is an important metric but one that is not well studied in patients with NVAF in Italy. The RITMUS-AF study aims to evaluate the persistence with rivaroxaban treatment for stroke prevention in patients with NVAF in Italy.

Methods

RITMUS-AF is a prospective, observational cohort study of patients with NVAF in hospital cardiology departments with a non-vitamin K antagonist oral anticoagulant surveillance program across all 20 regions of Italy. The study population comprises consecutively screened, consenting patients with NVAF naïve to and newly treated with rivaroxaban for stroke prevention in routine clinical practice. The target enrollment is 800 patients; each patient will be followed for a maximum duration of 24 months. The primary endpoint is the proportion of patients who discontinue rivaroxaban treatment. Secondary endpoints are reasons for rivaroxaban discontinuation, dose changes and reasons for changes, switches to alternative therapies and the reasons for these decisions, and self-reported adherence. Data analyses will be exploratory and descriptive.

Conclusion

RITMUS-AF will help to address the limited data in Italian clinical practice on treatment persistence and reasons for drug interruptions in patients with NVAF on rivaroxaban.

Oral anticoagulant switching in patients with atrial fibrillation: a scoping review

INTRODUCTION

Oral anticoagulants (OACs) prevent stroke in patients with atrial fibrillation (AF). Several factors may cause OAC switching.

OBJECTIVES

To examine the phenomenon of OAC switching in patients with AF, including all available evidence; frequency and patterns of switch, clinical outcomes, adherence, patient-reported outcomes, reasons for switch, factors associated with switch and evidence gaps.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, Embase and Web of Science, up to January 2022.

RESULTS

Of the 116 included studies, 2/3 examined vitamin K antagonist (VKA) to direct-acting OAC (DOAC) switching. Overall, OAC switching was common and the definition of an OAC switch varied across. Switching from VKA to dabigatran was the most prevalent switch type, but VKA to apixaban has increased in recent years. Patients on DOAC switched more to warfarin than to other DOACs. OAC doses involved in the switches were hardly reported and patients were often censored after the first switch. Switching back to a previously taken OAC (frequently warfarin) occurred in 5%-21% of switchers.The risk of ischaemic stroke and gastrointestinal bleeding in VKA to DOAC switchers compared with non-switchers was conflicting, while there was no difference in the risk of other types of bleeding. The risk of ischaemic stroke in switchers from DOAC versus non-switchers was conflicting. Studies evaluating adherence found no significant changes in adherence after switching from VKA to DOAC, however, an increase in satisfaction with therapy were reported. Reasons for OAC switch, and factors associated with OAC switch were mostly risk factors for stroke and bleeding. Clinical outcomes, adherence and patient-reported outcomes were sparse for switches from DOACs.

CONCLUSIONS

OAC switching is common in patients with AF and patients often switch back to an OAC they have previously been on. There are aspects of OAC switching that have received little study, especially in switches from DOACs.

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.

Pre- and post-stroke oral antithrombotics and mortality in patients with ischaemic stroke

BACKGROUND

Reducing stroke occurrence requires the effective management of cardiovascular and other stroke risk factors.

PURPOSE

To describe pre- and post-stroke medication use, focusing on antithrombotic therapy and mortality risk, in individuals hospitalised for ischaemic stroke (IS) in the United Kingdom.

METHOD

Using primary care electronic health records from the United Kingdom, we identified patients hospitalised for IS (July 2016-September 2019) and classed them into three groups: atrial fibrillation (AF) diagnosed pre-stroke, AF diagnosed post-stroke, and non-AF stroke (no AF diagnosed pre-/post-stroke). We determined use of cardiovascular medications in the 90 days pre- and post-stroke and calculated mortality rates.

RESULTS

There were 3201 hospitalised IS cases: 76.2% non-AF stroke, 15.7% AF pre-stroke, and 8.1% AF post-stroke. Oral anticoagulant (OAC) use increased between the pre- and post-stroke periods as follows: 54.3%-78.7% (AF pre-stroke group), 2.3%-84.8% (AF post-stroke group), and 3.4%-7.3% (non-AF stroke group). Corresponding increases in antiplatelet use were 30.8%-35.4% (AF pre-stroke group) 38.5%-47.5% (AF post-stroke group), and 37.5%-87.3% (non-AF stroke group). Among all IS cases, antihypertensive use increased from 66.8% pre-stroke to 78.8% post-stroke; statin use increased from 49.6%-85.2%. Mortality rates per 100 person-years (95% CI) were 17.30 (14.70-20.35) in the AF pre-stroke group and 9.65 (8.81-10.56) among all other stroke cases.

CONCLUSION

Our findings identify areas for improvement in clinical practice, including optimising the level of OAC prescribing to patients with known AF, which could potentially help reduce the future burden of stroke.

Using primary care data to assess comparative effectiveness and safety of apixaban and rivaroxaban in patients with nonvalvular atrial fibrillation in the UK: an observational cohort study

OBJECTIVE

To compare real-world effectiveness and safety of direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation (AFib) for prevention of stroke.

STUDY DESIGN AND SETTING

A comparative cohort study in UK general practice data from The Health Improvement Network database.

PARTICIPANTS AND INTERVENTIONS

Before matching, 5655 patients ≥18 years with nonvalvular AFib who initiated at least one DOAC between 1 July 2014 and 31 December 2020 were included. DOACs of interest included apixaban, rivaroxaban, edoxaban and dabigatran, with the primary comparison between apixaban and rivaroxaban. Initiators of DOACs were defined as new users with no record of prescription for any DOAC during 12 months before index date.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was stroke (ischaemic or haemorrhagic). Secondary outcomes included the occurrence of all-cause mortality, myocardial infarction (MI), transient ischaemic attacks (TIA), major bleeding events and a composite angina/MI/stroke (AMS) endpoint.

RESULTS

Compared with rivaroxaban, patients initiating apixaban showed similar rates of stroke (HR: 0.93; 95% CI 0.64 to 1.34), all-cause mortality (HR: 1.03; 95% CI 0.87 to 1.22), MI (HR: 0.95; 95% CI 0.54 to 1.68), TIA (HR: 1.03; 95% CI 0.61 to 1.72) and AMS (HR: 0.96; 95% CI 0.72 to 1.27). Apixaban initiators showed lower rates of major bleeding events (HR: 0.60; 95% CI 0.47 to 0.75).

CONCLUSIONS

Among patients with nonvalvular AFib, apixaban was as effective as rivaroxaban in reducing rate of stroke and safer in terms of major bleeding episodes. This head-to-head comparison supports conclusions drawn from indirect comparisons of DOAC trials against warfarin and demonstrates the potential for real-world evidence to fill evidence gaps and reduce uncertainty in both health technology assessment decision-making and clinical guideline development.

Adherence and persistence to oral anticoagulants in patients with atrial fibrillation: A Belgian nationwide cohort study

Background

Since non-vitamin K antagonist oral anticoagulants (NOACs) do not require coagulation monitoring, concerns of lower adherence and persistence to NOACs than vitamin K antagonists (VKAs) have been raised. Moreover, little is known on the frequency of permanent cessation and switching between anticoagulants in patients with atrial fibrillation (AF). Therefore, persistence, reinitiation, switching and adherence to oral anticoagulants (OACs) were investigated.

Materials and methods

AF patients with a first OAC prescription claim between 2013 and 2019 were identified in Belgian nationwide data. Persistence, reinitiation and switching were estimated using Kaplan-Meier analyses. Adherence was investigated using the proportion of days covered (PDC). Predictors for non-adherence and non-persistence were identified by multivariable logistic regression.

Results

Among 277,782 AF patients, 69.6% NOAC and 37.2% VKA users were persistent after 1 year, whereas 44.3% and 18.9% after 5 years, respectively. After one year, 67.1% rivaroxaban, 68.1% dabigatran, 69.8% apixaban, and 76.9% edoxaban users were persistent. Among subjects having discontinued NOAC or VKA treatment, 75.4% and 46.1% reinitiated any OAC within 5 years, respectively. VKAs were more frequently switched to NOACs than vice versa (17.6% versus 2.5% after 1 year). After 1 year, a high PDC (≥ 90%) was observed in 87.8% apixaban, 88.6% dabigatran, 91.3% rivaroxaban, and 94.7% edoxaban users (90.2% NOAC users). Adherence and persistence were higher in older, female subjects, while lower in subjects with dementia or hyperpolypharmacy.

Conclusion

Adherence and persistence to NOACs were high. However, 10% of subjects were non-adherent after 1 year and one-fourth did not reinitiate anticoagulation within 5 years after NOAC discontinuation.

Drug Utilization Pattern of Oral Anticoagulants in Patients with Atrial Fibrillation: A Nationwide Population-Based Study in Korea

INTRODUCTION

Treatment persistence for anticoagulant therapy is important in preventing thromboembolism in nonvalvular atrial fibrillation (NVAF) patients. Understanding drug utilization pattern and treatment changes in oral anticoagulant (OAC) users may facilite better NVAF management. Thus, our study aimed to examine OAC treatment patterns preceding events leading to switch or discontinuation and medication adherence in Korean NVAF patients.

METHODS

We conducted a drug utilization study on all Korean patients with atrial fibrillation (AF) newly prescribed OACs between July 2015 and November 2016 using the national claims data. We assessed treatment changes such as switching and discontinuation from index OAC and relevant events preceding the change and examined patient characteristics as predictors of changes that occurred among OAC users. Medication adherence was compared among OAC users by calculating the medication possession ratio (MPR).

RESULTS

A total of 48,389 NVAF patients were identified who initiated OACs within the study period. Most initiated nonvitamin K antagonist oral anticoagulants (NOACs) (22% apixaban, 24% dabigatran, 37% rivaroxaban), and 18% initiated warfarin. The frequency of switch to another OAC was 8.8% for apixaban, 16.1% for dabigatran, 6.6% for rivaroxaban, and 19.1% for warfarin. The frequency of discontinuation was lower for apixaban (22.9%), dabigatran (26.3%), and rivaroxaban (25.7%) than warfarin (31.6%). Compared to warfarin, NOAC users were less likely to switch treatment. Thromboembolic event was the most common clinical event preceding switch from warfarin to NOAC and from NOAC to warfarin. Discontinuation of OAC was often preceded by a bleeding event. Patients who initiated apixaban showed significantly higher mean MPR compared to those on dabigatran and warfarin.

CONCLUSION

In real-world practice in Korea, we have observed treatment change to be common in OAC users. Our results indicate better medication adherence with NOACs than with warfarin. (ClinicalTrials.gov registration number NCT03572972).

Time Trends and Treatment Pathways in Prescribing Individual Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation: An Observational Study of More than Three Million Patients from Europe and the United States

BACKGROUND

Data directly comparing trends in the use of different oral anticoagulants (OACs) among patients with atrial fibrillation (AF) from different countries are limited. We addressed this using a large-scale network cohort study in the United States (US), Belgium, France, Germany, and the United Kingdom (UK).

METHODS

We used nine databases (claims or electronic health records) that had been converted into the Observational Medical Outcomes Partnership Common Data Model with analysis performed using open-source analytical tools. We identified adults with AF and a first OAC prescription, either vitamin K antagonist (VKA) or direct oral anticoagulant (DOAC), from 2010 to 2017. We described time trends in use, continuation, and switching.

RESULTS

In 2010, 87.5%-99.8% of patients started on a VKA. By 2017, the majority started on a DOAC: 87.0% (US), 88.3% (Belgium), 93.1% (France), 88.4% (Germany), and 86.1%-86.7% (UK). In the UK, DOACs became the most common starting OAC in 2015, 2-3 years later than elsewhere. Apixaban was the most common starting OAC by 2017, 50.2%-57.8% (US), 31.4% (Belgium), 45.9% (France), 39.5% (Germany), and 49.8%-50.5% (UK), followed by rivaroxaban, 24.8%-32.5% (US), 25.7% (Belgium), 38.4% (France), 24.9% (Germany), and 30.2%-31.2% (UK). Long-term treatment was less common in the US than in Europe, especially the UK. A minority of patients switched from their index OAC in the short and long term.

CONCLUSIONS

From 2010 to 2017, VKA use had significantly declined and DOAC use had significantly increased in the US and Europe. Apixaban was the most prescribed OAC in 2017, followed by rivaroxaban.

Risks associated with discontinuation of oral anticoagulation in newly diagnosed patients with atrial fibrillation: Results from the GARFIELD-AF Registry

BACKGROUND

Oral anticoagulation (OAC) in atrial fibrillation (AF) reduces the risk of stroke/systemic embolism (SE). The impact of OAC discontinuation is less well documented.

OBJECTIVE

Investigate outcomes of patients prospectively enrolled in the Global Anticoagulant Registry in the Field-Atrial Fibrillation study who discontinued OAC.

METHODS

Oral anticoagulation discontinuation was defined as cessation of treatment for ≥7 consecutive days. Adjusted outcome risks were assessed in 23 882 patients with 511 days of median follow-up after discontinuation.

RESULTS

Patients who discontinued (n = 3114, 13.0%) had a higher risk (hazard ratio [95% CI]) of all-cause death (1.62 [1.25-2.09]), stroke/systemic embolism (SE) (2.21 [1.42-3.44]) and myocardial infarction (MI) (1.85 [1.09-3.13]) than patients who did not, whether OAC was restarted or not. This higher risk of outcomes after discontinuation was similar for patients treated with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) (p for interactions range = 0.145-0.778). Bleeding history (1.43 [1.14-1.80]), paroxysmal vs. persistent AF (1.15 [1.02-1.29]), emergency room care setting vs. office (1.37 [1.18-1.59]), major, clinically relevant nonmajor, and minor bleeding (10.02 [7.19-13.98], 2.70 [2.24-3.25] and 1.90 [1.61-2.23]), stroke/SE (4.09 [2.55-6.56]), MI (2.74 [1.69-4.43]), and left atrial appendage procedures (4.99 [1.82-13.70]) were predictors of discontinuation. Age (0.84 [0.81-0.88], per 10-year increase), history of stroke/transient ischemic attack (0.81 [0.71-0.93]), diabetes (0.88 [0.80-0.97]), weeks from AF onset to treatment (0.96 [0.93-0.99] per week), and permanent vs. persistent AF (0.73 [0.63-0.86]) were predictors of lower discontinuation rates.

CONCLUSIONS

In GARFIELD-AF, the rate of discontinuation was 13.0%. Discontinuation for ≥7 consecutive days was associated with significantly higher all-cause mortality, stroke/SE, and MI risk. Caution should be exerted when considering any OAC discontinuation beyond 7 days.

Switching of oral anticoagulants in patients with non-valvular atrial fibrillation: A narrative review

Approval of direct-acting oral anticoagulants (DOACs) for stroke prevention in atrial fibrillation (AF) was an important milestone, providing a wider range of treatment options and creating the possibility for drug switching after initiation. In addition to improved utilisation of oral anticoagulants (OACs) for stroke prevention, reports of switching among OACs are growing in the literature; switching may influence clinical outcomes, healthcare costs and patient satisfaction. This review aimed to summarise the current literature on the pattern of OAC switching in patients with AF, including reasons for switching and clinical consequences following switching. A literature search was conducted in PubMed, Scopus, and Embase on Jun 27, 2020. We included 39 articles published after 2013, following the introduction of apixaban. The review found that switching among OACs was common in clinical practice, significantly varying with the type of OAC. Studies reporting the reason for switching and clinical outcomes were comparatively limited. The decision to switch was often related to safety issues (usually bleeding), poor anticoagulation control and ease-of-use. Patient characteristics, clinical conditions and drug interactions were found to be associated with switching from OACs. Findings regarding bleeding outcomes following switching were inconsistent, possibly confounded by the rationale for switching and the switching protocol. Noting the limited number of studies included and their relatively short follow-up periods, switching did not have a significant impact on the risk of stroke and other thrombotic outcomes. Further prospective studies are needed to understand better potential rationales for switching and the clinical outcomes.

Comparison of Direct Oral Anticoagulant Use for the Treatment of Non-Valvular Atrial Fibrillation in Pivotal Clinical Trials vs. the Real-World Setting: A Population-Based Study from Southern Italy

Patients enrolled into pivotal randomized controlled trials (RCTs) may differ substantially from those treated in a real-world (RW) setting, which may result in a different benefit–risk profile. The aim of the study was to assess the external validity of pivotal RCT findings concerning direct oral anticoagulants (DOACs) for the treatment of nonvalvular atrial fibrillation (NVAF) by comparing patients recruited in RCTs to those treated with DOACs registered in a southern Italian local health unit (LHU) in the years 2013–2017. The Palermo LHU claims database was used to describe the baseline characteristics of incident DOAC users (washout > 1 year) with NVAF compared with those of enrolled patients in DOAC pivotal RCTs. In the RW, DOAC treatment discontinuation was calculated during the follow-up and compared with DOAC treatment discontinuation of enrolled patients in DOAC pivotal RCTs. Rates of effectiveness and safety outcomes during the follow-up were calculated in an unmatched and in a simulated RCT population, by matching individual incidental RW and RCT DOAC users (excluding edoxaban users) on age, sex, and CHADS₂ score. Overall, 42,336 and 7092 incident DOAC users with NVAF were identified from pivotal RCTs and from the RW setting, respectively. In RCTs, DOAC use was more common among males (62.6%) compared with an almost equal sex distribution in the RW. RCT patients were younger (mean age ± standard deviation: 70.7 ± 9.2 years) than RW patients (76.0 ± 8.6 years). Compared with RCTs, a higher proportion of RW dabigatran users (30.4% vs. 19.6%) and a lower proportion of RW apixaban (15.9% vs. 25.3%) and rivaroxaban (20.4% vs. 23.7%) users discontinued the treatment during the follow-up (p-value < 0.001). The rate of ischemic stroke was lower in RW high-dose dabigatran users (unmatched/-matched population: 0.40–0.11% per year) than in the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) population (0.93% per year). Major bleeding rates were lower in RW users than in RCT users. In conclusion, except for dabigatran, a lower proportion of DOAC discontinuers was observed in the real-world than in pivotal RCT settings. This study provides reassurance to practicing physicians that DOAC use appears to be effective in stroke prevention and is likely safer in RW patients than in RCT enrolled patients. These results may be related to a lower burden of comorbidities despite more advanced age in the RW population compared to the pivotal RCT population.

Current status of oral anticoagulant adherence in Japanese patients with atrial fibrillation: A claims database analysis

BACKGROUND

Direct oral anticoagulants (DOACs) are widely used for stroke prevention in patients with non-valvular atrial fibrillation (NVAF). We investigated the adherence of DOACs for years known to be associated with the effectiveness in Japanese NVAF patients, using a claim database.

METHOD

We performed a retrospective evaluation of NVAF patients in a claims database in Japan, who initiated dabigatran, rivaroxaban, and apixaban between April 2011 and June 2016. Drug persistence was assessed by Kaplan-Meier method for the initially-prescribed DOAC and all DOACs including switched ones. Proportion of days covered (PDC) was also evaluated in patients with persistent prescription and compared among DOACs.

RESULTS

In the total of 671 patients, rivaroxaban (47%) was more prescribed than dabigatran (28%) and apixaban (25%). Drug persistence at 3 years was higher in rivaroxaban (69%) than dabigatran (57%) and apixaban (67%). Including switching to other DOACs, persistence of DOACs was 72% at 3 years without significant differences between index-DOACs. In multivariate Cox regression analysis, absence of hypertension, and prior history of cancer were significantly associated with the drug discontinuation of all DOACs. The mean PDC was ~ 95% and the frequency of high-adherent patients (PDC ≥0.80) was more than 90%, which similarly persisted at 3 years and showed no significant differences between index DOACs.

CONCLUSION

In a real-world Japanese claim data analysis, about 70% of patients under DOAC showed persistence with anticoagulation therapy at 3 years. High adherence to DOACs assessed by PDC (over 90%) persisted to 3 years regardless of the types of DOACs.

Discontinuation of oral anticoagulation in atrial fibrillation and risk of ischaemic stroke

OBJECTIVE

To evaluate associations between oral anticoagulant (OAC) discontinuation and risk of ischaemic stroke (IS) among patients with atrial fibrillation (AF).

METHODS

We undertook a population-based cohort study with nested case-control analysis using UK primary care electronic health records (IQVIA Medical Research Data-UK) and linked registries from the Region of Southern Denmark (RSD). Patients with AF (76 882 UK, 41 526 RSD) were followed to identify incident IS cases during 2016-2018. Incident IS cases were matched by age and sex to controls. Adjusted ORs for OAC discontinuation (vs current OAC use) were calculated using logistic regression.

RESULTS

We identified 616 incident IS cases in the UK and 643 in the RSD. ORs for IS with any OAC discontinuation were 2.99 (95% CI 2.31 to 3.86, UK) and 2.30 (95% CI 1.79 to 2.95, RSD), for vitamin K antagonist discontinuation they were 2.38 (95% CI 1.72 to 3.30, UK) and 1.83 (95% CI 1.34 to 2.49, RSD), and for non-vitamin K antagonist oral anticoagulant discontinuation they were 4.59 (95% CI 2.97 to 7.08, UK) and 3.37 (95% CI 2.35 to 4.85, RSD). ORs were unaffected by time since discontinuation and duration of use. Annually, up to 987 IS cases in the UK and 132 in Denmark could be preventable if OAC therapy is not discontinued.

CONCLUSIONS

Our results suggest that patients with AF who discontinue OAC therapy have a significant twofold to threefold higher risk of IS compared with those who continue therapy. Addressing OAC discontinuation could potentially result in a significant reduction in AF-attributed IS.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

Safety and efficacy of non-vitamin K antagonist oral anticoagulants for prevention of thromboembolism in adults with systemic right ventricle: Results from the NOTE international registry

BACKGROUND

Patients with systemic right ventricle (sRV), including transposition of great arteries (TGA) after atrial switch procedure and congenitally corrected transposition of great arteries (ccTGA), may require anticoagulation for thromboembolism (TE) prevention. In the absence of data on non-vitamin K antagonist oral anticoagulants (NOACs), vitamin K antagonists (VKAs) remain the agent of choice. We investigated the safety, efficacy and feasibility of NOACs treatment in adults with sRV in a worldwide study.

METHODS

This is an international multicentre prospective study, using data from the NOTE registry on adults with sRV taking NOACs between 2014 and 2019. The primary endpoints were TE and major bleeding (MB). The secondary endpoint was minor bleeding.

RESULTS

A total of 76 patients (42.5 ± 10.0 years, 76% male) with sRV (74% TGA, 26% ccTGA) on NOACs were included in the study. During a median follow-up of 2.5 years (IQR1.5-3.9), TE events occurred in 3 patients (4%), while no MB episodes were reported. Minor bleeding occurred in 9 patients (12%). NOAC treatment cessation rate was 1.4% (95%CI:0.3-4%) during the first year of follow-up. All the patients with TE events had a CHA₂DS₂-VASc score ≥ 2 and impaired sRV systolic function at baseline. The total incidence of major events during follow-up was significantly lower compared to historical use of VKAs or aspirin before study inclusion (1.4% (95%CI:0.29-4%) vs 6,9% (95%CI:2.5-15.2%); p = .01).

CONCLUSIONS

In this prospective study, NOACs appear to be well-tolerated, with excellent efficacy and safety at mid-term in patients with sRV.

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.