Are Cost Benefits of Anticoagulation for Stroke Prevention in Atrial Fibrillation Underestimated?

Favorable prognosis in posterior circulation ischemic stroke: Insights from a nationwide stroke databank

INTRODUCTION

Clinical trials have historically underrepresented patients with posterior circulation ischemic stroke (PCIS). This study aimed to comprehensively assess the clinical characteristics and outcomes of PCIS patients compared to those with anterior circulation ischemic stroke (ACIS).

METHODS

A retrospective analysis was conducted using data from the Japan Stroke Data Bank, encompassing 20 years across 130 stroke centers. The study focused on patients diagnosed with PCIS or ACIS.

RESULTS

Among 37,069 patients reviewed, 7425 had PCIS, whereas 29,644 had ACIS. PCIS patients were younger and had a lower female representation than ACIS patients. Notably, PCIS patients had more favorable outcomes: 71% achieved a modified Rankin Scale of 0-2 or showed no deterioration at discharge (17 days at the median after admission), compared to 60% for ACIS patients (p < 0.001). Factors associated with an unfavorable outcome in the PCIS subgroup were older age, female sex (assigned at birth), history of hypertension, and higher National Institute of Health Stroke Scale (NIHSS) scores at admission. In both sexes, older age and higher NIHSS scores were negatively associated with favorable outcomes.

CONCLUSIONS

PCIS patients demonstrated a more favorable prognosis than ACIS patients. Factors like older age, female sex, and higher NIHSS scores at admission were identified as independent predictors of unfavorable outcomes in PCIS patients. Older age and higher NIHSS scores at admission were common independent negative factors for a favorable outcome regardless of sex.

Effectiveness of Anticoagulants in Reducing Stroke Risk Among Patients With Atrial Fibrillation

Atrial fibrillation (AF) is a type of cardiac arrhythmia causing shortness of breath, lightheadedness, and palpitations. It may go unrecognized and asymptomatic among many patients. AF is not a potentially fatal arrhythmia; its hemodynamic, structural, and hemocoagulative effects have a significant impact on the standard of life, which can lead to various complications such as stroke. A stroke caused by AF leads to additional burdens on both patients and the global economy. Patients with AF can prevent strokes with oral anticoagulants; however, ensuring diligent adherence to medication is crucial for maximizing treatment efficacy. Since they have a lighter treatment load than warfarin, non-vitamin K antagonist oral anticoagulants (NOACs) are also recommended with better hope for medication adherence. Various anticoagulants such as warfarin and ximelagatran, among many more, are prescribed to patients who have the potential to reduce the incidence of stroke as well as alleviate their likelihood of developing other thromboembolic events that can decrease their quality of life. Economic and psychological burdens associated with diminished functionality can be prevented by anticoagulant therapy among AF patients, therefore reducing their economic and social burden. This is due to the negative association between stroke among AF patients and anticoagulation consumption.

Severity of Ischemic Stroke After Left Atrial Appendage Closure vs Nonwarfarin Oral Anticoagulants

BACKGROUND

Strokes after left atrial appendage closure (LAAC) prophylaxis are generally less severe than those after warfarin prophylaxis-thought to be secondary to more hemorrhagic strokes with warfarin. Hemorrhagic strokes are similarly infrequent with direct oral anticoagulant (DOAC) prophylaxis, so the primary subtype after either LAAC or DOAC prophylaxis is ischemic stroke (IS).

OBJECTIVES

The purpose of this study was to compare the severity of IS using the modified Rankin Scale in atrial fibrillation patients receiving prophylaxis with DOACs vs LAAC.

METHODS

A retrospective analysis was performed of consecutive patients undergoing LAAC at 8 centers who developed an IS (ISLAAC) compared with contemporaneous consecutive patients who developed IS during treatment with DOACs (ISDOAC). The primary outcome was disabling/fatal stroke (modified Rankin Scale 3-5) at discharge and 3 months later.

RESULTS

Compared with ISDOAC patients (n = 322), ISLAAC patients (n = 125) were older (age 77.2 ± 13.4 years vs 73.1 ± 11.9 years; P = 0.002), with higher HAS-BLED scores (3.0 vs 2.0; P = 0.004) and more frequent prior bleeding events (54.4% vs 23.6%; P < 0.001), but similar CHA2DS2-VASc scores (5.0 vs 5.0; P = 0.28). Strokes were less frequently disabling/fatal with ISLAAC than ISDOAC at both hospital discharge (38.3% vs 70.3%; P < 0.001) and 3 months later (33.3% vs 56.2%; P < 0.001). Differences in stroke severity persisted after propensity score matching. By multivariate regression analysis, ISLAAC was independently associated with fewer disabling/fatal strokes at discharge (OR: 0.22; 95% CI: 0.13-0.39; P < 0.001) and 3 months (OR: 0.25; 95% CI: 0.12-0.50; P < 0.001), and fewer deaths at 3 months (OR: 0.28; 95% CI: 0.12-0.64; P < 0.001).

CONCLUSIONS

Ischemic strokes in patients with atrial fibrillation are less often disabling or fatal with LAAC than DOAC prophylaxis.

Accuracy, Usability, and Adherence of Smartwatches for Atrial Fibrillation Detection in Older Adults After Stroke: Randomized Controlled Trial

BACKGROUND

Atrial fibrillation (AF) is a common cause of stroke, and timely diagnosis is critical for secondary prevention. Little is known about smartwatches for AF detection among stroke survivors. We aimed to examine accuracy, usability, and adherence to a smartwatch-based AF monitoring system designed by older stroke survivors and their caregivers.

OBJECTIVE

This study aims to examine the feasibility of smartwatches for AF detection in older stroke survivors.

METHODS

Pulsewatch is a randomized controlled trial (RCT) in which stroke survivors received either a smartwatch-smartphone dyad for AF detection (Pulsewatch system) plus an electrocardiogram patch or the patch alone for 14 days to assess the accuracy and usability of the system (phase 1). Participants were subsequently rerandomized to potentially 30 additional days of system use to examine adherence to watch wear (phase 2). Participants were aged 50 years or older, had survived an ischemic stroke, and had no major contraindications to oral anticoagulants. The accuracy for AF detection was determined by comparing it to cardiologist-overread electrocardiogram patch, and the usability was assessed with the System Usability Scale (SUS). Adherence was operationalized as daily watch wear time over the 30-day monitoring period.

RESULTS

A total of 120 participants were enrolled (mean age 65 years; 50/120, 41% female; 106/120, 88% White). The Pulsewatch system demonstrated 92.9% (95% CI 85.3%-97.4%) accuracy for AF detection. Mean usability score was 65 out of 100, and on average, participants wore the watch for 21.2 (SD 8.3) of the 30 days.

CONCLUSIONS

Our findings demonstrate that a smartwatch system designed by and for stroke survivors is a viable option for long-term arrhythmia detection among older adults at risk for AF, though it may benefit from strategies to enhance adherence to watch wear.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03761394; https://clinicaltrials.gov/study/NCT03761394.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1016/j.cvdhj.2021.07.002.

Impact of a dedicated center for atrial fibrillation on resource utilization and costs

BACKGROUND

Atrial fibrillation (AF) affects millions of Americans each year and can lead to high levels of resource utilization through emergency department (ED) visits and inpatient stays.

HYPOTHESIS

We hypothesized that referral of patients to a dedicated Center for AF from the ED would reduce costs of care.

METHODS

The University of Pittsburgh Center for AF serves as a rapid referral center for patients with AF to avoid unnecessary inpatient admissions and provide specialized care. Patients that presented to the ED with AF and met prespecified criteria were directed to rapid outpatient follow-up instead of inpatient admission. The primary outcome of interest was 30-day total costs. Secondary outcomes included outpatient costs, inpatient costs, 90-day costs, and inpatient stay characteristics.

RESULTS

We identified 96 patients (median age 65, 38% women) referred to the center for AF for a new diagnosis of AF between October 2017 and December 2019 and matched 96 control patients. After 30 days of follow-up, patients referred to the center for AF had a lower average cost ($619 vs. $1252, p < 0.001) compared to controls, driven by lower costs of ED care tempered by slightly higher outpatient costs. Thirty-day admissions and lengths of stay were also lower. These differences were persistent at 90 days.

CONCLUSION

Directing patients with AF that present to the ED to follow-up at a dedicated Center for AF significantly reduced overall costs, while reducing subsequent inpatient admissions and total lengths of stay in the hospital.

Cost-effectiveness of targeted screening for non-valvular atrial fibrillation in the United Kingdom in older patients using digital approaches

AIM

Screening for non-valvular atrial fibrillation (NVAF) is key in identifying patients with undiagnosed disease who may be eligible for anticoagulation therapy. Understanding the economic value of screening is necessary to assess optimal strategies for payers and healthcare systems. We evaluated the cost effectiveness of opportunistic screening with handheld digital devices and pulse palpation, as well as targeted screening predictive algorithms for UK patients ≥75 years of age.

METHODS

A previously developed Markov cohort model was adapted to evaluate clinical and economic outcomes of opportunistic screening including pulse palpation, Zenicor (extended 14 days), KardiaMobile (extended), and two algorithms compared to no screening. Key model inputs including epidemiology estimates, screening effectiveness, and risks for medical events were derived from the STROKESTOP, ARISTOTLE studies, and published literature, and cost inputs were obtained from a UK national cost database. Health and cost outcomes, annually discounted at 3.5%, were reported for a cohort of 10,000 patients vs. no screening over a time horizon equivalent to a patient's lifetime, Analyses were performed from a UK National Health Services and personal social services perspective.

RESULTS

Zenicor, pulse palpation, and KardiaMobile were dominant (providing better health outcomes at lower costs) vs. no screening; both algorithms were cost-effective vs. no screening, with incremental cost-effectiveness ratios per quality-adjusted life-year (QALY) of £1,040 and £1,166. Zenicor, pulse palpation, and KardiaMobile remained dominant options vs. no screening in all scenarios explored. Deterministic sensitivity analyses indicated long-term stroke care costs, prevalence of undiagnosed NVAF in patients 75-79 years of age, and clinical efficacy of anticoagulant on stroke prevention were the main drivers of the cost-effectiveness results.

CONCLUSIONS

Screening for NVAF at ≥75 years of age could result in fewer NVAF-related strokes. NVAF screening is cost-effective and may be cost-saving depending on the program chosen.

Retrospective Comparison of Patients ≥ 80 Years With Atrial Fibrillation Prescribed Either an FDA-Approved Reduced or Full Dose Direct-Acting Oral Anticoagulant

Direct-acting oral anticoagulants (DOACs) represent the standard for preventing stroke and systemic embolization (SSE) in patients with atrial fibrillation (AF). There is limited information for patients ≥ 80 years. We report a retrospective analysis of AF patients ≥ 80 years prescribed either a US Food and Drug Administration (FDA)-approved reduced (n = 514) or full dose (n = 199) DOAC (Dabigatran, Rivaroxaban, or Apixaban) between January 1st, 2011 (first DOAC commercially available) and May 31st, 2017. The following multivariable differences in baseline characteristics were identified: patients prescribed a reduced dose DOAC were older (p < 0.001), had worse renal function (p = 0.001), were more often prescribed aspirin (p = 0.004) or aspirin and clopidogrel (p < 0.001), and more often had new-onset AF (p = 0.001). SSE and central nervous system (CNS) bleed rates were low and not different (1.02 vs 0 %/yr and 1.45 vs 0.44 %/yr) for the reduced and full dose groups, respectively. For non-CNS bleeds, rates were 10.89 vs 4.15 %/yr (p < 0.001, univariable) for the reduced and full doses, respectively. The mortality rate was 6.24 vs 1.75 %/yr (p = 0.001, univariable) for the reduced and full doses. Unlike the non-CNS bleed rate, mortality rate differences remained significant when adjusted for baseline characteristics. Thus, DOACs in patients ≥ 80 with AF effectively reduce SSE with a low risk of CNS bleeding, independent of DOAC dose. The higher non-CNS bleed rate and not the mortality rate is explained by the higher risk baseline characteristics in the reduced DOAC dose group. Further investigation of the etiology of non-CNS bleeds and mortality is warranted.

An approach to quantify parameter uncertainty in early assessment of novel health technologies

Health economic modeling of novel technology at the early stages of a product lifecycle has been used to identify technologies that are likely to be cost-effective. Such early assessments are challenging due to the potentially limited amount of data. Modelers typically conduct uncertainty analyses to evaluate their effect on decision-relevant outcomes. Current approaches, however, are limited in their scope of application and imposes an unverifiable assumption, that is, uncertainty can be precisely represented by a probability distribution. In the absence of reliable data, an approach that uses the fewest number of assumptions is desirable. This study introduces a generalized approach for quantifying parameter uncertainty, that is, probability bound analysis (PBA), that does not require a precise specification of a probability distribution in the context of early-stage health economic modeling. We introduce the concept of a probability box (p-box) as a measure of uncertainty without necessitating a precise probability distribution. We provide formulas for a p-box given data on summary statistics of a parameter. We describe an approach to propagate p-boxes into a model and provide step-by-step guidance on how to implement PBA. We conduct a case and examine the differences between the status-quo and PBA approaches and their potential implications on decision-making.

The Potential and Limitations of Mobile Health and Insertable Cardiac Monitors in the Detection of Atrial Fibrillation in Cryptogenic Stroke Patients: Preliminary Results From the REMOTE Trial

Aim

This paper presents the preliminary results from the ongoing REMOTE trial. It aims to explore the opportunities and hurdles of using insertable cardiac monitors (ICMs) and photoplethysmography-based mobile health (PPG-based mHealth) using a smartphone or smartwatch to detect atrial fibrillation (AF) in cryptogenic stroke and transient ischemic attack (TIA) patients.

Methods and Results

Cryptogenic stroke or TIA patients (n = 39) received an ICM to search for AF and were asked to use a blinded PPG-based mHealth application for 6 months simultaneously. They were randomized to smartphone or smartwatch monitoring. In total, 68,748 1-min recordings were performed using PPG-based mHealth. The number of mHealth recordings decreased significantly over time in both smartphone and smartwatch groups (p < 0.001 and p = 0.002, respectively). Insufficient signal quality was more frequently observed in smartwatch (43.3%) compared to smartphone recordings (17.8%, p < 0.001). However, when looking at the labeling of the mHealth recordings on a patient level, there was no significant difference in signal quality between both groups. Moreover, the use of a smartwatch resulted in significantly more 12-h periods (91.4%) that were clinically useful compared to smartphone users (84.8%) as they had at least one recording of sufficient signal quality. Simultaneously, continuous data was collected from the ICMs, resulting in approximately 6,660,000 min of data (i.e., almost a 100-fold increase compared to mHealth). The ICM algorithm detected AF and other cardiac arrhythmias in 10 and 19 patients, respectively. However, these were only confirmed after adjudication by the remote monitoring team in 1 (10%) and 5 (26.3%) patients, respectively. The confirmed AF was also detected by PPG-based mHealth.

Conclusion

Based on the preliminary observations, our paper illustrates the potential as well as the limitations of PPG-based mHealth and ICMs to detect AF in cryptogenic stroke and TIA patients in four elements: (i) mHealth was able to detect AF in a patient in which AF was confirmed on the ICM; (ii) Even state-of-the-art ICMs yielded many false-positive AF registrations; (iii) Both mHealth and ICM still require physician revision; and (iv) Blinding of the mHealth results impairs compliance and motivation.

Shared Decision Making Tools for People Facing Stroke Prevention Strategies in Atrial Fibrillation: A Systematic Review and Environmental Scan

OBJECTIVE

Shared decision making (SDM) tools can help implement guideline recommendations for patients with atrial fibrillation (AF) considering stroke prevention strategies. We sought to characterize all available SDM tools for this purpose and examine their quality and clinical impact.

METHODS

We searched through multiple bibliographic databases, social media, and an SDM tool repository from inception to May 2020 and contacted authors of identified SDM tools. Eligible tools had to offer information about warfarin and ≥1 direct oral anticoagulant. We extracted tool characteristics, assessed their adherence to the International Patient Decision Aids Standards, and obtained information about their efficacy in promoting SDM.

RESULTS

We found 14 SDM tools. Most tools provided up-to-date information about the options, but very few included practical considerations (e.g., out-of-pocket cost). Five of these SDM tools, all used by patients prior to the encounter, were tested in trials at high risk of bias and were found to produce small improvements in patient knowledge and reductions in decisional conflict.

CONCLUSION

Several SDM tools for stroke prevention in AF are available, but whether they promote high-quality SDM is yet to be known. The implementation of guidelines for SDM in this context requires user-centered development and evaluation of SDM tools that can effectively promote high-quality SDM and improve stroke prevention in patients with AF.

Knowledge, attitude, and practice regarding atrial fibrillation among primary care physicians: the potential role of postgraduate training

INTRODUCTION

Atrial fibrillation (AF) is known to lead to stroke and thromboembolism, causing a five-fold increase in the risk of stroke and almost doubling the mortality rate. Optimal anticoagulant therapy is effective in reducing AF-related death. However, prescription of anticoagulants in AF in East Asian countries has been low, ranging from 0.5% to 28%. This study aimed to determine whether vocational training in family medicine improves primary care physicians' knowledge, attitude, and practice in the management of AF.

METHOD

This investigation was a cross-sectional study carried out during centralized workshops for two groups of trainees using a validated questionnaire: (i) junior trainees were newly enrolled postgraduate trainees in the Graduate Certificate in Family Medicine (GCFM) program, and (ii) senior trainees were postgraduate trainees in Advance Training in Family Medicine (ATFM) programs of the Academy of Family Physicians of Malaysia (AFPM).

RESULTS

A total of 223 trainees (127 junior and 96 senior) participated in this study. Only 55.2% of the trainees passed the knowledge test; senior trainees were more likely to pass the knowledge test compared to junior trainees (69.8% vs. 44.1%, p < 0.001). Female trainees were significantly more likely to pass the knowledge test than male trainees. While the attitude of senior and junior trainees was similar, more of the latter group worked in public clinic that provide better support where there is better support for outpatient anticoagulation treatment (e.g., same-day INR test, direct access echocardiogram, and warfarin in in-house pharmacy).

CONCLUSION

Vocational training in family medicine appears to improve primary care physicians' knowledge regarding the management of AF. Better knowledge will help vocationally trained primary care physicians to provide anticoagulation treatment for AF within primary care clinics. More optimal AF management within primary care can take place if the identified barriers are addressed and a shared care plan can be implemented.

Association between P wave polarity in atrial premature complexes and cardiovascular events in a community-dwelling population

OBJECTIVE

To examine the association between polarity of atrial premature complexes (APCs) and stroke.

DESIGN

A prospective study.

SETTING AND PARTICIPANTS

A total of 11 092 participants in the Jichi Medical School cohort study were included after excluding patients with atrial fibrillation. We analysed stroke events in patients with (n=136) and without (n=10 956) APCs. With regard to polarity of APCs, patients were subcategorised into having (1) negative (n=39) or non-negative (n=97) P waves in augmented vector right (aVR), and (2) positive (n=28) or non-positive (n=108) P waves in augmented vector left (aVL).

OUTCOME MEASURES

The primary endpoint was stroke.

RESULTS

Patients with APCs were significantly older than those without APCs (64.1±9.2 vs 55.1±11.6 years, p<0.001). The mean follow-up period was 11.8±2.4 years. Stroke events were observed in patients with (n=13 events) and without (n=411 events) APCs. This difference was significant (log-rank 12.9, p<0.001); however, APCs were not an independent predictor of stroke after adjusting for age, sex, height, body mass index, current drinking, diabetes, systolic blood pressure, prior myocardial infarction, prior stroke and high-density lipoprotein-cholesterol (p=0.15). The incidence of stroke in patients with APCs and non-negative P wave in aVR was significantly higher than in patients without APCs (log-rank 20.1, p<0.001), and non-negative P wave in aVR was revealed to be an independent predictor of stroke (HR 1.84, 95% CI 1.02 to 3.30). The incidence of stroke in patients with APC with non-positive P wave in aVL was also significantly higher than in patients without APC (log-rank 15.3, p<0.001), and non-positive P wave in aVL was an independent predictor of stroke (HR 1.92, 95% CI 1.05 to 3.54).

CONCLUSIONS

The presence of APCs with non-negative P wave in aVR or non-positive P wave in aVL on 12-lead ECG was associated with a higher risk of incident stroke.

Influence of sex on long-term prognosis in patients with atrial fibrillation treated with oral anticoagulants. Results from the prospective, nationwide FANTASIIA study

BACKGROUND

While many risk factors for Atrial Fibrillation (AF) have been identified, there are important differences in their relative impact between sexes. The aim of our study was to investigate the influence of sex as a long-term predictor of adverse events in "real world" AF patients treated with direct oral anticoagulants.

METHODS

The FANTASIIA registry is a prospective, national and multicentric study including outpatients with anticoagulated AF patients. Baseline characteristics and adverse events at 3 years of follow-up were collected and classified by sex. Cox multivariate analysis was performed to investigate the role of sex in major events and composite outcomes.

RESULTS

A total of 1956 patients were included in the study. 43.9% of them were women, with a mean age of 73.8 ± 9.4 years (women were older 76.5 ± 7.9 vs 71.7 ± 10.1, p<0.001). Women had higher rate of cardiovascular risk factors and higher mean of CHA₂DS₂-VASc (4.4 ± 1.4 vs 3.7 ± 1.6, p<0.001) and HAS-BLED (2.1 ± 1.0 vs 1.9 ± 1.1, p<0.001) than men. After 3 years of follow-up, rates of major events were similar in both groups with limit difference for all-cause mortality (4.4%/year in women vs 5.6%/year in men; p = 0.056). However, all the composite events were more frequent in women. We observed in the non-adjusted adverse events lower rate of all-cause mortality (HR 0.62, 95%CI 0.47-0.81; p<0.001), composite 1 outcomes (HR 0.80, 95%CI 0.65-0.98; p = 0.029) and composite 2 (HR 0.77, 95%CI 0.64-0.94; p = 0.010) in women compared with men. In multivariate Cox regression analysis observed that female sex was an independently protector factor for all-cause mortality and for the composite outcomes 1 and 2.

CONCLUSIONS

In this "real world" study of anticoagulated AF patients, women could have a protective role against development of adverse events, mainly on all-cause mortality and combined events.

Convergence of Epicardial and Endocardial RF Ablation for the Treatment of Symptomatic Persistent AF (CONVERGE Trial): Rationale and design

Atrial fibrillation is the most common sustained arrhythmia affecting over 33 million people worldwide. Approximately 70% of AF patients have non-paroxysmal AF. As AF progresses from paroxysmal to non-paroxysmal forms, the prevalence of comorbidities increases. The efficacy of catheter ablation for persistent and long standing persistent (LSP) AF is <40%, often requiring multiple ablation procedures with greater cost and potentially more complications. There is an unmet need to effectively treat such patients. METHODS: CONVERGE is an investigational device exempt, prospective, multi-center, open label 2:1 randomized controlled pivotal study to evaluate the overall success of the Convergent hybrid procedure compared to endocardial catheter ablation for the treatment of symptomatic persistent AF refractory or intolerant to at least one Class I and /or III anti-arrhythmic drug (AAD). A total of 153 subjects at 27 centers are treated in the study. The CONVERGE study is differentiated from other studies currently being conducted on the persistent AF population, because a) there is no time restriction on the duration of diagnosed AF in the patients being studied and b) the trial allows patients with left atrial sizes up to 6 centimeters. The ongoing trials are limited to either 6 months, 12 months or 3-years of continuous AF making CONVERGE the only ablation trial thus far to include a substantial portion of patients with longstanding persistent AF. The convergent procedure involves combination of minimally invasive pericardioscopic epicardial ablation with endocardial left atrial ablation. The primary endpoint is freedom from AF/AFL/AF absent class I/III AAD, except for a previously failed class I/ III AAD with no increase in dosage following 3-months through 12-months. The primary safety endpoint is the incidence of major adverse events from the procedure through 30-days post procedure. CONCLUSION: CONVERGE AF compares the overall success of the Convergent hybrid procedure to endocardial catheter ablation for the treatment of persistent and longstanding persistent AF. By providing objective comparative data, the study aims to provide guidance on the treatment of such patients.

Cost-effectiveness of targeted screening for the identification of patients with atrial fibrillation: evaluation of a machine learning risk prediction algorithm

Aims: As many cases of atrial fibrillation (AF) are asymptomatic, patients often remain undiagnosed until complications (e.g. stroke) manifest. Risk-prediction algorithms may help to efficiently identify people with undiagnosed AF. However, the cost-effectiveness of targeted screening remains uncertain. This study aimed to assess the cost-effectiveness of targeted screening, informed by a machine learning (ML) risk prediction algorithm, to identify patients with AF.Methods: Cost-effectiveness analyses were undertaken utilizing a hybrid screening decision tree and Markov disease progression model. Costs and outcomes associated with the detection of AF compared traditional systematic and opportunistic AF screening strategies to targeted screening informed by a ML risk prediction algorithm. Model analyses were based on adults ≥50 years and adopted the UK NHS perspective.Results: Targeted screening using the ML risk prediction algorithm required fewer patients to be screened (61 per 1,000 patients, compared to 534 and 687 patients in the systematic and opportunistic strategies) and detected more AF cases (11 per 1,000 patients, compared to 6 and 8 AF cases in the systematic and opportunistic screening strategies). The targeted approach demonstrated cost-effectiveness under base case settings (cost per QALY gained of £4,847 and £5,544 against systematic and opportunistic screening respectively). The targeted screening strategy was predicted to provide an additional 3.40 and 2.05 QALYs per 1,000 patients screened versus systematic and opportunistic strategies. The targeted screening strategy remained cost-effective in all scenarios evaluated.Limitations: The analysis relied on assumptions that include the extended period of patient life span and the lack of consideration for treatment discontinuations/switching, as well as the assumption that the ML risk-prediction algorithm will identify asymptomatic AF.Conclusions: Targeted screening using a ML risk prediction algorithm has the potential to enhance the clinical and cost-effectiveness of AF screening, improving health outcomes through efficient use of limited healthcare resources.

Net Clinical Benefit of Left Atrial Appendage Closure Versus Warfarin in Patients With Atrial Fibrillation: A Pooled Analysis of the Randomized PROTECT-AF and PREVAIL Studies

Background

The PROTECT‐AF (Watchman Left Atrial Appendage Closure Technology for Embolic Protection in Patients With Atrial Fibrillation) and PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) trials demonstrated noninferiority of left atrial appendage closure (LAAC) to warfarin for the composite end point of stroke, systemic embolism, or cardiovascular death. This study aims to quantify the net clinical benefit (NCB) of LAAC versus warfarin, accounting for differences in clinical impact of different event types.

Methods and Results

We performed a post hoc analysis of the PROTECT‐AF and PREVAIL trials, which randomized atrial fibrillation patients to LAAC or warfarin in a 2:1 fashion. The trials enrolled patients in the United States and Europe between 2005 and 2012 with paroxysmal, persistent, or permanent atrial fibrillation and CHADS₂ risk scores ≥1. Relative to an index weight for death (1.0), events were assigned weights based on their disabling effect: (1) stroke event weights were based on modified Rankin scores in the base case analyses, and (2) major bleed (0.05) and pericardial effusion (0.05). NCB was calculated as the sum of weight‐adjusted events per 100 patient‐years. Among 1114 randomized subjects, the NCB of LAAC was 1.42% per year (95% CI 0.01–2.82, P=0.04) and a relative risk of 0.74 (95% CI 0.56–1.00). NCB point estimates favored warfarin early in follow‐up, but trended in favor of LAAC after 1 to 2 years. The benefit of LAAC was preserved across subgroups, with particular benefit observed in the subgroup of prior stroke and without diabetes mellitus.

Conclusions

This analysis demonstrates long‐term NCB of LAAC with Watchman over warfarin therapy, as the upfront risk of periprocedural events is counterbalanced over time by reduced bleeding events and mortality.

Clinical Trial Registration

UR: http://www.clinicaltrials.gov. Unique identifiers: NCT01182441 and NCT00129545.

Use of insertable cardiac monitors for the detection of atrial fibrillation in patients with cryptogenic stroke in the United States is cost-effective

Objectives: Atrial fibrillation (AF) is the most common arrhythmia and a major marker of ischemic stroke risk. Early detection is crucial and, once diagnosed, anticoagulation therapy can be initiated to reduce stroke risk. The aim of this study was to assess the cost-effectiveness of employing an insertable cardiac monitor (ICM), BIOMONITOR, for the detection of AF compared to standard of care (SoC) ECG and Holter monitoring in patients with cryptogenic stroke, that is, stroke of unknown origin and where paroxysmal, silent AF is suspected. Materials and methods: A Markov model was developed which consisted of five main health states reflecting the potential lifetime evolution of the AF disease: post cryptogenic stroke (index event), subsequent mild, moderate and severe stroke, and death. Sub-states were included to track a patient's AF diagnostic status and the use of antiplatelet or anticoagulant therapy. AF detection was assumed to result in a treatment switch from aspirin to anticoagulants, except among those with a history of major bleeding. Detection yield and accuracy, clinical actions and treatment effects were derived from the literature and validated by an expert clinician. All relevant costs from a US Medicare perspective were included. Results and conclusions: An ICM-based strategy was associated with a reduction of 37 secondary ischemic strokes per 1000 patients monitored compared with SoC. Total per-patient costs with an ICM were higher (US$90,052 vs. US$85,157) although stroke-related costs were reduced. The use of an ICM was associated with a base-case incremental cost-effectiveness ratio of US$18,487 per life year gained compared with SoC and US$25,098 per quality-adjusted life year gained, below established willingness-to-pay thresholds. The conclusions were found to be robust over a range of input values. From a US Medicare perspective the use of a BIOMONITOR ICM represents a cost-effective diagnostic strategy for patients with cryptogenic stroke and suspected AF.

Stroke Prevention in Atrial Fibrillation: The Role of Oral Anticoagulation

Oral anticoagulation significantly reduces the risk of stroke in patients with atrial fibrillation (AF), and the decision to initiate therapy is based on assessing the patient's yearly risk of stroke. Although warfarin remains the drug of choice in patients with AF and artificial mechanical valves, the novel anticoagulation agents are becoming the drug of choice for all other patients with AF, because of their efficacy, safety, and ease of use. This article summarizes the current evidence for stroke prevention in AF, including valvular AF, subclinical AF, AF in patients with renal insufficiency, as well as stroke prevention around AF cardioversion.

Prevalence and risk factors for atrial fibrillation and its anticoagulant requirement in adults aged ≥40 in Jimma Town, Southwest Ethiopia: A community based cross-sectional study

BACKGROUND

There is no information on the prevalence and incidence of atrial fibrillation in Ethiopia. We aimed to investigate the prevalence, risk factors and anticoagulant requirements of atrial fibrillation in an elderly Jimma population.

METHODS

In a community-based cross-sectional study in 634 adult (≥40 years) Jimma population, we performed cardiovascular health examinations including a 12-lead electrocardiogram to estimate AF prevalence. A standardized questionnaire was used to collect information on medical history, lifestyle and use of medications. Stroke risk stratification was done using CHA2DS2-VASc score. We used logistic regressions to determine the potential risk factors of AF.

RESULTS

The overall prevalence of AF was 4.3%. AF was associated with sex, current smoking, hypertension and BMI. Nineteen out of twenty seven participants with AF were in need of anticoagulation to prevent risk of stroke.

CONCLUSION

The prevalence of AF is high and common risk factors were sex, current smoking, hypertension, and higher BMI in this cohort. More than two-third of study participants with AF were at higher need of oral anticoagulants.

Effects of a reminder to initiate oral anticoagulation in patients with atrial fibrillation/atrial flutter discharged from the emergency department: REMINDER study

CLINICIAN’S CAPSULE

What is known about the topic?

Oral anticoagulation (OAC) reduces stroke risk in patients with atrial fibrillation or flutter; however, initiation rates in patients discharged from the ED are low.

What did this study ask?

Can a simple quality improvement intervention increase the initiation of appropriate OAC in the ED?

What did this study find?

The rate of OAC initiation was increased by 8.5%.

Why does this study matter to clinicians?

This simple intervention is transferrable and therefore can improve patient care.

Risk of cardiovascular events and incident atrial fibrillation in patients without prior atrial fibrillation: Implications for expanding the indications for anticoagulation

BACKGROUND

There is growing interest in the role for non-vitamin K antagonist oral anticoagulants (NOACs) in patients without atrial fibrillation (AF). We aimed to provide a comprehensive assessment of the risks of ischemic stroke, myocardial infarction (MI), AF, and major bleeding in patients without previously diagnosed AF.

METHODS

Using a large US administrative database, we identified 6,495,875 patients ≥50 years between January 1, 2011, and September 30, 2016, who were not diagnosed with AF and were not treated with oral anticoagulants or nonaspirin antiplatelet agents. We assessed the risks by age, sex, the number of risk factors, and the combination of risk factors. We also calculated the number needed to treat or harm based on the untreated risks in our data set and relative risks of NOAC treatment derived from a recent clinical trial.

RESULTS

The event rates were 0.67%/y for ischemic stroke or MI, 0.96%/y for AF, and 0.52%/y for major bleeding. Among patients who had a stroke during follow-up, 84% were not diagnosed with AF at any time, and only 5% were diagnosed with AF before the stroke. Patients who had low number needed to treat for cardiovascular risk reduction (ie, potentially benefiting the most from the addition of NOACs) also had low number needed to harm for major bleeding (ie, facing serious harm).

CONCLUSIONS

Patients without diagnosed AF but with certain risk factors were at a particularly high cardiovascular risk and may require new prevention approaches. In addition to the ongoing trials, future trials in other high-risk populations, for example, diabetes and chronic kidney disease, may be warranted.

Relation of quality of anticoagulation control with different management systems among patients with atrial fibrillation: Data from FANTASIIA Registry

BACKGROUND

Anticoagulation control in patients with atrial fibrillation (AF) has a multidisciplinary approach although is usually managed by general practitioners (GP) or haematologists. The aim of our study was to assess the quality of anticoagulation control with vitamin K antagonists (VKAs) in relation to the responsible specialist in a "real-world" AF population.

METHODS

We consecutively enrolled VKA anticoagulated patients included in the FANTASIIA Registry from 2013 to 2015. We analysed demographical, clinical characteristics and the quality of anticoagulation control according to the specialist responsible (ie GPs or haematologists).

RESULTS

Data on 1584 patients were included (42.5% females, mean age 74.0 ± 9.4 years): 977 (61.7%) patients were controlled by GPs and 607 (38.3%) by haematologists. Patients managed by GPs had higher previous heart disease (53.2% vs 43.3%, P < .001), heart failure (32.9% vs 26.5%, P < .008) and dilated cardiomyopathy (15.2% vs 8.7%, P < .001) with better renal function (69.3 ± 24.7 vs 63.1 ± 21.4 mL/min, P < .001) compared to patients managed by haematologists. There was no difference between groups in the type of AF, CHA₂ DS₂ -VASc or HAS-BLED scores, but patients with electrical cardioversion were more prevalent in GP group. The overall mean time in therapeutic range (TTR) assessed by Rosendaal method was 61.5 ± 24.9%; 52.6% of patients had TTR<65% and 60% of patients had TTR<70%. TTR was significantly lower in patients controlled by haematologists than by GPs (63 ± 24.4 vs 59.2 ± 25.6, P < .005).

CONCLUSIONS

About 60% of AF patients anticoagulated with VKAs had poor anticoagulation control (ie TTR<70%), and their management was only slightly better than when it is managed by general practitioners.

Efficacy and safety of rivaroxaban compared with warfarin in patients with carotid artery disease and nonvalvular atrial fibrillation: Insights from the ROCKET AF trial

BACKGROUND

Atrial fibrillation (AF) increases risk of stroke 5-fold. Carotid artery disease (CD) also augments the risk of stroke, yet there are limited data about the interplay of these 2 diseases and clinical outcomes in patients with comorbid AF and CD.

HYPOTHESIS

Among patients with both AF and CD, use of rivaroxaban when compared with warfarin is associated with a lower risk of stroke.

METHODS

This post hoc analysis from ROCKET AF aimed to determine absolute rates of stroke/systemic embolism (SE) and bleeding, and the efficacy and safety of rivaroxaban compared with warfarin in patients with AF and CD (defined as history of carotid occlusive disease or carotid revascularization [endarterectomy and/or stenting]).

RESULTS

A total of 593 (4.2%) patients had CD at enrollment. Patients with and without CD had similar rates of stroke or SE (adjusted hazard ratio [HR]: 0.99, 95% confidence interval [CI]: 0.66-1.48, P = 0.96), and there was no difference in major or nonmajor clinically relevant bleeding (adjusted HR: 1.04, 95% CI: 0.88-1.24, P = 0.62). The efficacy of rivaroxaban compared with warfarin for the prevention of stroke/SE was not statistically significant in patients with vs those without CD (interaction P = 0.25). The safety of rivaroxaban vs warfarin for major or nonmajor clinically relevant bleeding was similar in patients with and without CD (interaction P = 0.64).

CONCLUSIONS

Patients with CD in ROCKET AF had similar risk of stroke/SE compared with patients without CD. Additionally, there was no interaction between CD and the treatment effect of rivaroxaban or warfarin for stroke prevention or safety endpoints.

The Effect of a Clinical Decision Support System on Improving Adherence to Guideline in the Treatment of Atrial Fibrillation: An Interrupted Time Series Study

To evaluate the effect of a computerized Decision Support System (CDSS) on improving adherence to an anticoagulation guideline for the treatment of atrial fibrillation (AF). This study had an interrupted time series design. The adherence to the guideline was assessed at fortnightly (two weeks) intervals from January 2016 to January 2017, 6 months before and 6 months after intervention. Newly diagnosed patients with AF were included in the offices of ten cardiologists. Stroke and major bleeding risks were calculated by the CDSS which was implemented via a mobile application. Treatment recommendations based on the guideline were shown to cardiologists. The segmented regression model was used to evaluate the effect of CDSS on level and trend of guideline adherence for the treatment of AF. In our analysis, 373 patients were included. The trend of adherence to the anticoagulation guideline for the treatment of AF was stable in the pre-intervention phase. After the CDSS intervention, mean of the adherence to the guideline significantly increased from 48% to 65.5% (P-value < 0.0001). The trend of adherence to the guideline was stable in the post-intervention phase. Our results showed that the CDSS can improve adherence to the anticoagulation guideline for the treatment of AF. Registration ID: IRCT2016052528070N1.

Oral anticoagulation use by patients with atrial fibrillation in Germany

Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder. Oral anticoagulation (OAC) is recommended by guidelines in the presence of a moderate to high risk of stroke. Based on an analysis of claims-based data, the aim of this contribution is to quantify the stroke-risk dependent OAC utilisation profile of German AF patients as well as the possible causes and the associated clinical outcomes of OAC under-use. Our data set was derived from two large mandatory German medical insurance funds. Risk stratification of patients was based on the CHADS2-score and the CHA2DS2-VASc-score. Two different scenarios were constructed to deal with factors potentially disfavouring OAC use. Causes of OAC under-use and its clinical consequences were analysed using multivariate analysis. Observation year was 2008. A total of 183,448 AF patients met the inclusion criteria. This represents an AF prevalence of 2.21%. The average CHADS2-score was 2.8 (CHA2DS2-VASc-score: 4.3). On between 40.5 and 48.7% of the observed patient-days, there was no antithrombotic protection by OAC, other anticoagulants or aspirin. Older female patients with a high number of comorbidities had a higher risk of OAC under-use. Patients who had already experienced a thromboembolic event had a lower risk of OAC under-use. In the observation year, 3,367 patients experienced a stroke (incidence rate 1.8%). In our multi-level Poisson random effects estimate, OAC use decreases the stroke rate by almost 80% (IRR 0.236). In conclusion, OAC under-use is widespread in the German market. It is associated with severe clinical consequences.

Hemoglobin A1c and risk of left atrial thrombus and spontaneous echo contrast in non-valvular atrial fibrillation patients

OBJECTIVES

To evaluate the relationship between hemoglobin A1c (HbA1c) and risk of left atrial thrombus/spontaneous echo contrast (LAT/SEC) in non-valvular atrial fibrillation (AF) patients.

METHODS

In this retrospective study, 1158 consecutive non-valvular AF patients undergoing transesophageal echocardiography prior to radiofrequency catheter ablation or electric cardioversion were enrolled. Baseline characteristics were collected and analyzed.

RESULTS

There were 87 (7.5%) patients with LAT/SEC. The HbA1c levels in the patients with LAT/SEC were significantly higher than that in patients without LAT/SEC (6.13 ± 0.41 vs. 5.89 ± 0.45 μmol/L, P < 0.001). The optimal cut-off point for HbA1c predicting LAT/SEC was 6.1% determined by receiver-operating characteristic curve. The area under the curve is 0.788 (95% confidence interval: 0.764-0.812). HbA1c ≥6.1% was an independent risk factor for LAT/SEC (odds ratio, 1.74; 95% confidence interval, 1.01-2.98; P = 0.045).

CONCLUSIONS

Elevated HbA1c indicated a significantly increased risk for LAT/SEC in non-valvular AF patients. HbA1c might have significance in predicting the risk for prothrombotic state in non-valvular AF patients.

Rationale and design of ASSAF-K (A study of the safety and efficacy of anticoagulant therapy in the treatment of atrial fibrillation in Kanagawa)

Background

Atrial fibrillation (AF) is one of the most prevalent cardiac arrhythmias associated with substantially increased risks of ischemic stroke and thromboembolism. Oral anticoagulants (OACs) are the cornerstone of AF management and effectively prevent AF-related stroke. As new non-vitamin K antagonist OACs (NOACs) have become available, the landscape of stroke prevention in AF has changed. However, there are considerable gaps between daily clinical practice and current guideline-based recommendations for anticoagulant therapy in Japan. Consequently, little is known about the real-world setting and the current use of NOACs, especially by practitioners in Japan.

Methods

We conducted a prospective, observational study in 3847 patients with AF who were enrolled in clinics and hospitals located in Kanagawa Prefecture from September 2013 through March 2015. The participating centers included practitioners (small clinics), medium-sized hospitals, and university hospitals. The primary endpoints were epidemiologic characteristics, status of treatment with anticoagulants and antiplatelet agents, outcomes, and adverse events, including cerebrovascular disease, bleeding, and death.

Results

The mean CHADS2 score was 1.81±1.27, the mean CHADS2-Vasc score was 3.02±1.58, and the mean HAS-BLED score was 2.23±1.06, respectively. The usage rate of warfarin was 44.2% overall, and the usage rate of NOACs was 33.5%.

Conclusions

The results of the study are expected to serve as the basis for providing clinical practice guidance to healthcare institutions in Japan, with the ultimate goals of better characterizing the appropriate use of OACs and providing clinical decision support to physicians to facilitate the design of appropriate therapeutic strategies and the selection of anticoagulants for the management of AF.

Interventional left atrial appendage closure vs novel anticoagulation agents in patients with atrial fibrillation indicated for long-term anticoagulation (PRAGUE-17 study)

Atrial fibrillation (AF), with a prevalence of 1% to 2%, is the most common cardiac arrhythmia. Without antithrombotic treatment, the annual risk of a cardioembolic event is 5% to 6%. The source of a cardioembolic event is a thrombus, which is usually formed in the left atrial appendage (LAA). Prevention of cardioembolic events involves treatment with anticoagulant drugs: either vitamin K antagonists or, recently, novel oral anticoagulants (NOAC). The other (nonpharmacologic) option for the prevention of a cardioembolic event involves interventional occlusion of the LAA.

OBJECTIVE

To determine whether percutaneous LAA occlusion is noninferior to treatment with NOAC in AF patients indicated for long-term systemic anticoagulation.

STUDY DESIGN

The trial will be a prospective, multicenter, randomized noninferiority trial comparing 2 treatment strategies in moderate to high-risk AF patients (ie, patients with history of significant bleeding, or history of cardiovascular event(s), or a with CHA₂DS₂VASc ≥3 and HAS-BLED score ≥2). Patients will be randomized into a percutaneous LAA occlusion (group A) or a NOAC treatment (group B) in a 1:1 ratio; the randomization was done using Web-based randomization software. A total of 396 study participants (198 patients in each group) will be enrolled in the study. The primary end point will be the occurrence of any of the following events within 24months after randomization: stroke or transient ischemic attack (any type), systemic cardioembolic event, clinically significant bleeding, cardiovascular death, or a significant periprocedural or device-related complications.

CONCLUSION

The PRAGUE-17 trial will determine if LAA occlusion is noninferior to treatment with NOAC in moderate- to high-risk AF patients.

CHA2DS2-VASc Scores and Major Bleeding in Patients With Nonvalvular Atrial Fibrillation Who Are Receiving Rivaroxaban

STUDY OBJECTIVE

Assessing stroke risk associated with nonvalvular atrial fibrillation depends on the evaluation of patient characteristics and clinical features. Clinicians must determine that the net clinical benefit from anticoagulation therapy outweighs its risk, namely, bleeding. Risk assessment for stroke is commonly performed by calculating a CHA₂DS₂-VASc (congestive heart failure/left ventricular dysfunction, hypertension, ≥75 years, diabetes mellitus, previous stroke or transient ischemic attack or thromboembolism, vascular disease, aged 65 to 74 years, sex female) score. It is possible that CHA₂DS₂-VASc scores also have a relationship with the incidence of major bleeding. We examined the relationship between CHA₂DS₂-VASc scores and major bleeding in rivaroxaban users with nonvalvular atrial fibrillation.

METHODS

Electronic medical records of more than 10 million patients from the Department of Defense Military Health System were queried to identify patients with nonvalvular atrial fibrillation who received rivaroxaban from January 1, 2013, to June 30, 2015. Baseline characteristics of the study population were described by CHA₂DS₂-VASc scores and major bleeding status; major bleeding incidence was evaluated by CHA₂DS₂-VASc score category and for each CHA₂DS₂-VASc component.

RESULTS

Overall, 44,793 patients met the inclusion criteria for this analysis. The major bleeding incidence rate was 2.84 (95% confidence interval 2.69 to 3.00) per 100 person-years. The incidence of major bleeding increased from 0.30 to 5.40 per 100 person-years among patients with a CHA₂DS₂-VASc score of 0 to 5 or higher, respectively. Fatal outcomes among patients with major bleeding were positively correlated with CHA₂DS₂-VASc scores; patients with higher scores had higher mortality rates. The CHA₂DS₂-VASc component with the highest major bleeding incidence was for vascular disease, 5.69 (95% confidence interval 5.18 to 6.24) per 100 person-years.

CONCLUSION

Higher CHA₂DS₂-VASc scores are associated with increased incidence of major bleeding in nonvalvular atrial fibrillation patients receiving rivaroxaban.

Vitamin K and non-vitamin K antagonist oral anticoagulants for non-valvular atrial fibrillation in real-life

BACKGROUND

Current guidelines recommend vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in patients with non-valvular atrial fibrillation (AF).

METHODS

We compared the clinical features of consecutive in- and out-patients with non-valvular AF newly-treated with NOACs or on treatment with VKAs.

RESULTS

Overall, 1314 patients newly-treated with NOACs and 1024 on treatment with VKAs were included in the study. The mean CHA2DS2-VASc score was 4.3±1.5 and 4.0±1.5 and the mean HAS-BLED score was 2.8±1.2 and 2.2±1.1 in the two groups, respectively (both p<0.001). Hypertension, previous stroke, female gender, vascular diseases and previous bleeding were more prevalent in NOACs patients. Renal failure, age ≥75years and congestive heart failure were more prevalent in VKAs patients. Among NOACs patients, 438 were given dabigatran, 463 rivaroxaban and 413 apixaban (33%, 35% and 31%, respectively). The mean CHA2DS2-VASc and HAS-BLED scores were higher in rivaroxaban or apixaban patients compared with dabigatran (both p<0.001) and VKAs patients (both p<0.001). A lower mean age was observed in patients newly-treated with dabigatran. Patients newly-treated with reduced doses of NOACs (599 patients, 45.5%) had a higher CHA2DS2-VASc (4.8±1.4 vs. 3.9±1.5 vs. 4.0±1.5) and HAS-BLED (2.9±1.1 vs. 2.8±1.2 vs. 2.2±1.1) scores compared with those treated with regular doses of NOACs or VKAs.

CONCLUSION

Patients given rivaroxaban and apixaban in clinical practice have a higher thrombotic and hemorrhagic risk in comparison with patients given dabigatran or VKAs. A considerable proportion of patients receive reduced doses of NOACs.

Using Phase-Based Costing of Real-World Data to Inform Decision-Analytic Models for Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) poses a significant economic burden. An increasing number of interventions for AF require cost-effectiveness analysis with decision-analytic modeling to demonstrate value. However, high-quality cost estimates of AF that can be used to inform decision-analytic models are lacking.

OBJECTIVES

The objectives of this study were to determine whether phase-based costing methods are feasible and practical for informing decision-analytic models outside of oncology.

METHODS

Patients diagnosed with AF between 1 January 2003 and 30 June 2011 in Ontario, Canada were identified based on a hospital admission for AF using administrative data housed at the Institute for Clinical Evaluative Sciences. Patient observations were then divided into phases based on clinical events typically used for decision-analytic modeling (i.e., minor stroke/transient ischemic attack [TIA], moderate to severe ischemic stroke, myocardial infarction, extracranial hemorrhage [ECH], intracranial hemorrhage [ICH], multiple events, death from an event, or death from other causes). First 30-day and greater than 30-day costs of healthcare resources in each health state were estimated based on a validated methodology. All costs are reported in 2013 Canadian dollars (Can$) and from a healthcare payer perspective.

RESULTS

Patients (n = 109,002) with AF who did not experience a clinical event incurred costs of Can$1566 per 30 days, on average. The average 30-day cost of experiencing a fatal clinical event was Can$42,871, but the cost of dying from all other causes was much smaller (Can$12,800). The clinical events associated with the highest short-term costs were ICH (Can$22,347) and moderate to severe ischemic stroke (Can$19,937). The lowest short-term costs were due to minor ischemic stroke/TIA (Can$12,515) and ECH (Can$12,261). Patients who had experienced a moderate to severe ischemic stroke incurred the highest long-term costs.

CONCLUSIONS

Real-world Canadian data and a phase-based costing approach were used to estimate short- and long-term costs associated with AF-related major clinical events. The results of this study can also inform decision-analytic models for AF.

Cost-Effectiveness of Novel Oral Anticoagulants for Stroke Prevention in Non-Valvular Atrial Fibrillation

Recently, novel oral anticoagulants (NOACs) have been approved for stroke prevention in patients with atrial fibrillation (AF). Although these agents overcome some disadvantages of warfarin, they are associated with increased costs. In this review, we will provide an overview of the cost-effectiveness of NOACs for stroke prevention in AF. Our comments and conclusions are limited to studies directly comparing all available NOACs within the same framework. The available cost-effectiveness analyses suggest that NOACs are cost-effective compared to warfarin, with apixaban likely being most favorable. However, significant limitations in these models are present and should be appreciated when interpreting their results.

Establishing Edoxaban’s Role in Anticoagulation

Purpose

This article serves as a review of the current literature regarding the role of edoxaban for the prevention of stroke in patients with nonvalvular atrial fibrillation (AF) and the treatment of venous thromboembolism (VTE).

Summary

Until recent years, oral treatment options for both treatment and prevention of VTE and stroke were limited to warfarin. Dabigatran was the first new oral anticoagulant approved in over 50 years followed by rivaroxaban and apixaban. These new oral anticoagulants offer many benefits over warfarin. Edoxaban is the newest member among the oral anticoagulants and exerts its action by direct inhibition of factor Xa. It may offer some advantages in that it is the second Food and Drug Administration-approved once-daily anticoagulant available and does not interact with the cytochrome P450 (CYP450) system. However, there are concerns in patients with AF and preserved renal function (>95 mL/min), as these cohorts experienced a higher incidence of stroke in trials.

Conclusion

Based on the 3 clinical trials, edoxaban appears to be a safe and effective factor Xa inhibitor in patients with a creatinine clearance of <95 mL/min. It will serve as an alternative anticoagulant for those with a preference for once-daily dosing and/or taking medications that interact with the CYP450 system.

Underuse of anticoagulation in patients with atrial fibrillation

Atrial fibrillation (AF) is a major risk factor for ischemic stroke. Guidelines recommend anticoagulation for patients with intermediate and high stroke risk (CHA2DS2-VASc score ≥ 2). Underuse of anticoagulants among eligible patients remains a persistent problem. Evidence demonstrates that the psychology of the fear of causing harm (omission bias) results in physicians' hesitancy to initiate anticoagulation and an inaccurate estimation of stroke risk. The American Heart Association (AHA) initiated the Get With The Guidelines-AFIB (GWTG-AFIB) module in June 2013 to enhance guideline adherence for treatment and management of AF. Better quality of care for AF patients can be provided by increasing adherence to anticoagulation guidelines and improving patient compliance with anticoagulation therapy through education and established protocols. Nonvitamin K antagonist oral anticoagulants may facilitate better patient adherence due to ease of administration and reduced monitoring burden. In this review, we discuss the reasons for underuse, omission bias contributing to underuse, and different strategies to address this issue.

Atrial Fibrillation Monitoring in Cryptogenic Stroke: the Gaps Between Evidence and Practice

Identifying occult paroxysmal atrial fibrillation as the etiology of cryptogenic stroke has been a top research priority in the past decade. This is because prompt initiation of anticoagulation has significantly decreased subsequent stroke risk. Available evidence suggests that prolonged cardiac monitoring after stroke increases the likelihood of detecting atrial fibrillation. However, further research is required to fill in the gaps in regard to the optimal period of monitoring, candidates for monitoring, etc. Here, we review the current evidence supporting the use of prolonged monitoring for cryptogenic stroke patients and discuss the directions of future research.

Current Antiarrhythmic Therapy for Nonvalvular Atrial Fibrillation in Spain. Data From the FANTASIIA Registry

INTRODUCTION AND OBJECTIVES

Recently, there have been many developments in the management of nonvalvular atrial fibrillation, antiarrhythmic and anticoagulant therapy, and nonpharmacological treatment, but these developments are not applied immediately in clinical practice. The aim of this study was to identify the overall management and antiarrhythmic therapy used in the current general population of patients with nonvalvular atrial fibrillation in Spain.

METHODS

A prospective, observational study of 1318 consecutive anticoagulated patients with nonvalvular atrial fibrillation, recruited between June 2013 and March 2014. We analyzed the patients' general characteristics, management, and antiarrhythmic therapy.

RESULTS

Mean age was 73.8 ± 9.4 years; 42.5% were women. Atrial fibrillation was paroxysmal in 28% of the patients, permanent in 50%, persistent in 17.6%, long-standing persistent in 4.5%, and new-onset in 66 patients (5%). A rhythm control strategy was chosen in 39.4% of the patients and rate control in 60.6%. Beta-blockers were prescribed in 60.2% of the patients, digoxin in 19.5%, and calcium channel antagonists in 10.7%. The antiarrhythmic agents used were amiodarone (12.6%), flecainide (8.9%), propafenone (0.4%), sotalol (0.5%), and dronedarone (2.3%). Cardioversion had been performed previously in 41.9% of the patients, ablation in 3.4%, and atrial appendage closure in 0.2%.

CONCLUSIONS

Currently, patients with nonvalvular atrial fibrillation in Spain are managed mainly with rate control, and beta-blockers in particular. They receive few antiarrhythmic agents and only a very small number of these patients undergo nonpharmacological treatments.

An evidence-based review of edoxaban and its role in stroke prevention in patients with nonvalvular atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the elderly. It is responsible for significant morbidity and mortality from cardioembolic complications like stroke. As a result, atrial fibrillation patients are risk-stratified using the CHADS2 or CHA2DS2-VASc scoring systems. Those at intermediate-to-high risk have traditionally been treated with therapeutic anticoagulation with warfarin for stroke prevention. Although effective, warfarin use is fraught with multiple concerns, such as a narrow therapeutic window, drug-drug and drug-food interactions, and excessive bleeding. Novel oral anticoagulant agents have recently become available as viable alternatives for warfarin therapy. Direct thrombin inhibitor dabigatran and factor Xa inhibitors like rivaroxaban and apixaban have already been approved by the US Food and Drug Administration (FDA) for stroke prevention in patients with nonvalvular atrial fibrillation. Edoxaban is the latest oral direct factor Xa inhibitor studied in the largest novel oral anticoagulant trial so far: ENGAGE AF-TIMI 48. Treatment with a 30 mg or 60 mg daily dose of edoxaban was found to be noninferior to dose-adjusted warfarin in reducing the rate of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, with a lower incidence of bleeding complications and cardiovascular deaths. Edoxaban was recently reviewed by an FDA advisory committee and recommended as a stroke-prophylaxis agent. Once approved, it promises to provide another useful alternative to warfarin therapy.