To treat or not to treat: a comparative effectiveness analysis of oral anticoagulant outcomes among U.S. nursing home residents with atrial fibrillation

BACKGROUND

Nursing home residents with atrial fibrillation are at high risk for ischemic stroke, but most are not treated with anticoagulants. This study compared the effectiveness and safety between oral anticoagulant (OAC) users and non-users.

METHODS

We conducted a new-user retrospective cohort study by using Minimum Data Set 3.0 assessments linked with Medicare claims. The participants were Medicare fee-for-service beneficiaries with atrial fibrillation residing in US nursing homes between 2011 and 2016, aged ≥ 65 years. The primary outcomes were occurrence of an ischemic stroke or systemic embolism (effectiveness), occurrence of intracranial or extracranial bleeding (safety) and net clinical outcome (effectiveness or safety outcomes). Secondary outcomes included total mortality and a net clinical and mortality outcome. Cox proportional hazards and Fine and Grey models estimated multivariable adjusted hazard ratios (aHRs) and sub-distribution hazard ratios (sHRs).

RESULTS

Outcome rates were low (effectiveness: OAC: 0.86; non-users: 1.73; safety: OAC: 2.26; non-users: 1.75 (per 100 person-years)). OAC use was associated with a lower rate of the effectiveness outcome (sHR: 0.69; 95% Confidence Interval (CI): 0.61-0.77), higher rates of the safety (sHR: 1.70; 95% CI: 1.58-1.84) and net clinical outcomes (sHR: 1.20; 95% CI: 1.13-1.28) lower rate of all-cause mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61), and lower rate of the net clinical and mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61). Warfarin users, but not DOAC users, had a higher rate of the net clinical outcome versus OAC non-users.

CONCLUSIONS

Our results support the benefits of treatment with OACs to prevent ischemic strokes and increase longevity, while highlighting the need to weigh apparent benefits against elevated risk for bleeding. Results were consistent with net favorability of DOACs versus warfarin.

Pharmacist-led interventions in optimising the use of oral anticoagulants in patients with atrial fibrillation in general practice in England: a retrospective observational study

BACKGROUND

Oral anticoagulation (OAC) is the mainstay of treatment for the prevention of strokes in patients with atrial fibrillation (AF). Direct oral anticoagulants (DOACs) account for increasing OAC in patients with AF. However, prescribing DOACs for patients with established AF poses various challenges and general practice pharmacists may have an important role in supporting their management.

AIM

To investigate the effectiveness of pharmacist-led interventions in general practice in optimising the use of OAC therapies in AF.

DESIGN & SETTING

A retrospective observational study in general practices in Bradford.

METHOD

The data were collected retrospectively from 1 November 2018-31 December 2019 using electronic health record data. The data were analysed: 1) to identify patients with AF not on OAC; 2) to describe inappropriate DOAC prescriptions; and 3) to calculate HAS-BLED scores.

RESULTS

Overall, 76.3% (n = 470) of patients with AF received OAC therapy, and of these, 63.4% received DOACs. Pharmacist-led interventions increased DOAC prescribing by 6.0% (P = 0.03). Inappropriate DOAC use was identified in 24.5% of patients with AF, with underdosed and overdosed identified in 9.7% and 14.8%, respectively. Post-intervention, inappropriate prescribing was reduced to 1.7%. The mean HAS-BLED score decreased from 3.00 to 2.22 (P<0.01). Successful transition from vitamin K antagonist (VKA) therapy to DOACs was achieved in 25.7% of patients.

CONCLUSION

Pharmacist-led interventions have successfully improved the use of OAC therapies in patients with AF, and effectively managed the bleeding risks and transition from VKA to DOAC therapy, in line with guidelines.

Direct Oral Anticoagulants in Patients With Cardiac Amyloidosis: A Systematic Review and Meta-Analysis

Background and Objectives

Atrial fibrillation is common in patients with cardiac amyloidosis. However, the optimal anticoagulation strategy to prevent thromboembolic events in patients with cardiac amyloidosis and atrial fibrillation is unknown. This systematic review and meta-analysis compares direct oral anticoagulants (DOACs) vs. vitamin K antagonists (VKAs) in patients with cardiac amyloidosis and atrial fibrillation.

Methods

We performed a systematic literature review to identify clinical studies of anticoagulation therapies for patients with cardiac amyloidosis and atrial fibrillation. The primary outcomes of major bleeding and thrombotic events were reported using random effects risk ratios (RRs) with 95% confidence interval (CI).

Results

Our search yielded 97 potential studies and evaluated 14 full-text articles based on title and abstract. We excluded 10 studies that were review articles or did not compare anticoagulation. We included 4 studies reporting on 1,579 patients. The pooled estimates are likely underpowered due to small sample sizes. There was no difference in bleeding events for patients with cardiac amyloidosis and atrial fibrillation treated with DOACs compared to VKAs with a RR of 0.64 (95% CI, 0.38-1.10; p=0.10). There were decreased thrombotic events for patients with cardiac amyloidosis and atrial fibrillation treated with DOACs compared to VKAs with a RR of 0.50 (95% CI, 0.32-0.79; p=0.003).

Conclusions

This systematic review and meta-analysis suggests that DOACs are as safe and effective as VKAs in patients with cardiac amyloidosis and atrial fibrillation. However, more data are needed to investigate clinical differences in anticoagulation therapy in this patient population.

Efficacy and safety outcomes of patients with atrial fibrillation compared between warfarin and non-vitamin K antagonist oral anticoagulants based on SAMe-TT2R2 score

OBJECTIVES

This study aimed to investigate the efficacy and safety outcomes of patients with atrial fibrillation (AF) compared between those taking warfarin and non-vitamin K antagonist oral anticoagulants (NOACs) based on SAMe-TT2R2 score.

METHODS

AF patients using warfarin or NOACs were enrolled from Thailand's COOL-AF registry. A low SAMe-TT2R2 score was defined as a score of 0-2. The efficacy outcomes were all-cause death, ischemic stroke (IS), transient ischemic attack (TIA), and/or systemic embolization (SE). The safety outcome was major bleeding (MB). The secondary outcome was a combination of cardiovascular (CV) death, IS/TIA/SE, or MB. Cox proportional hazards model was used to compare the event rate between the AF patients taking warfarin and NOACs according to SAMe-TT2R2 score.

RESULTS

A total of 2568 AF patients taking oral anticoagulants were enrolled. Warfarin and NOACs were used in 2340 (91.1%) and 228 (8.9%) patients, respectively. Among overall patients, 305 patients taking warfarin (13.0%) and 21 patients taking NOACs (9.2%) had the efficacy outcome, while 155 patients taking warfarin (6.6%) and 11 patients taking NOACs (4.8%) had the safety outcome. After adjustment for confounders, overall patients taking warfarin had significantly more secondary outcome than those taking NOACs (11.4% vs. 7.5%, respectively; adjusted hazard ratio: 1.74, 95% confidence interval: 1.01-2.99; p = 0.045) regardless of SAMe-TT2R2 score.

CONCLUSIONS

AF patients taking warfarin had a significantly higher CV death or IS/TIA/SE or MB compared to those taking NOACs regardless of SAMe-TT2R2 score. The results of this study do not support the use of SAMe-TT2R2 score to guide OAC selection.

Development of Complementary Encounter and Patient Decision Aids for Shared Decision Making about Stroke Prevention in Atrial Fibrillation

Introduction

Decision aids (DAs) are helpful instruments used to support shared decision making (SDM). Patients with atrial fibrillation (AF) face complex decisions regarding stroke prevention strategies. While a few DAs have been made for AF stroke prevention, an encounter DA (EDA) and patient DA (PDA) have not been created to be used in conjunction with each other before.

Design

Using iterative user-centered design, we developed 2 DAs for anticoagulation choice and stroke prevention in AF. Prototypes were created, and we elicited feedback from patients and experts via observations of encounters, usability testing, and semistructured interviews.

Results

User testing was done with 33 experts (in AF and SDM) and 51 patients from 6 institutions. The EDA and PDA underwent 1 and 4 major iterations, respectively. Major differences between the DAs included AF pathophysiology and a preparation to meet with the clinician in the PDA as well as different language throughout. Content areas included personalized stroke risk, differences between anticoagulants, and risks of bleeding. Based on user feedback, developers 1) addressed feelings of isolation with AF, 2) improved navigation options, 3) modified content and flow for users new to AF and those experienced with AF, 4) updated stroke risk pictographs, and 5) added structure to the preparation for decision making in the PDA.

Limitations

These DAs focus only on anticoagulation for stroke prevention and are online, which may limit participation for those less comfortable with technology.

Conclusions

Designing complementary DAs for use in tandem or separately is a new method to support SDM between patients and clinicians. Extensive user testing is essential to creating high-quality tools that best meet the needs of those using them.

Highlights

First-time complementary encounter and patient decision aids have been designed to work together or separately.User feedback led to greater structure and different experiences for patients naïve or experienced with anticoagulants in patient decision aids.Online tools allow for easier dissemination, use in telehealth visits, and updating as new evidence comes out.

Proportion of Patients on Warfarin Therapy Who Are Eligible for Conversion to a Direct Oral Anticoagulant in the Setting of COVID-19

Background:

Warfarin, a commonly prescribed anticoagulant, requires frequent lab monitoring. Lab monitoring puts patients at risk of COVID-19 exposure and diverts medical resources away from health care systems. Direct oral anticoagulants (DOACs) do not require routine therapeutic monitoring and are indicated first line for nonvalvular atrial fibrillation (NVAF) stroke prevention and venous thromboembolism (VTE) prevention/treatment.

Objective:

The purpose of the study was to determine the proportion of patients who qualify for DOACs and assess for predictors of qualification.

Methods:

This cross-sectional study investigated patients on warfarin managed by Michigan Medicine Anticoagulation Service. Direct oral anticoagulant eligibility criteria were established using apixaban, dabigatran, and rivaroxaban package inserts. Patient eligibility was determined through chart review. The primary outcome was the proportion of patients who qualify for DOACs based on clinical factors. Predictors of DOAC qualification were assessed.

Results:

This study included 3205 patients and found 51.8% (n = 1661) of patients qualified for DOACs. Qualifying patients were older (71.9 vs 59.4 years, P < 0.0001) with a higher CHA₂DS₂ VASc (3.7 vs 3.4, P < 0.0007). The primary disqualifying factor was extreme weight, high and low. Accounting for a patient’s sex and referral source, age > 65 (odds ratio [OR] = 1.9, P < 0.0001) and NVAF indication (OR = 5.6, P < 0.0001) were significant predictors for DOAC qualification.

Conclusion and Relevance:

Approximately 52% of patients on warfarin were eligible for DOACs. This presents an opportunity to reduce patient exposure to health care settings and health care utilization in the setting of COVID-19. Increased costs of DOACs need to be assessed.

Incidence and Risk Factors for Residual Adverse Events Despite Anticoagulation in Atrial Fibrillation: Results From Phase II/III of the GLORIA-AF Registry

Background Residual risk of ischemic stroke despite anticoagulation in patients with atrial fibrillation (AF) represents a significant clinical issue that remains unaddressed. We aimed to evaluate the incidence and risk factors for residual adverse events in AF. Methods and Results Using data from phase II/III of the prospective GLORIA-AF (Global Registry on Long-Term Oral Anti-thrombotic Treatment in Patients With Atrial Fibrillation) registry, we studied anticoagulated patients with newly diagnosed AF and an increased risk of stroke (CHA2DS2-VASc ≥1). The primary outcome of interest was ischemic stroke. Secondary outcomes were all-cause death, cardiovascular death and myocardial infarction. A total of 22 410 patients were included; median age 65 (interquartile range 71-78) and 10 044 (44.8%) were female. During a median follow-up period of 3.0 (interquartile range 2.2-3.1) years, the incidence of ischemic stroke was 0.60 (95% CI, 0.54-0.67) per 100-PYs, all-cause death 3.22 (95% CI, 3.08-3.37) per 100-PYs, cardiovascular death 1.08 (95% CI, 1.00-1.16) per 100-PYs and myocardial infarction 0.59 (95% CI, 0.53-0.66) per 100-PYs. Using multivariable Cox proportional hazards analysis, independent predictors of residual ischemic stroke were age (HR 1.05 [95% CI, 1.03-1.07]), diabetes (HR 1.42 [95% CI, 1.08-1.87]), prior thromboembolism (HR 2.27 [95% CI, 1.73-2.98]) and use of antiarrhythmic drugs (HR 0.66 [95% CI, 0.47-0.92]). The incidence of ischemic stroke was comparable among patients treated with nonvitamin K antagonist oral anticoagulants versus vitamin K antagonist; however, there were differences in the independent predictors between both groups. Conclusions Patients with AF remain at significant residual risk of developing complications including ischemic stroke despite anticoagulation therapy. Further efforts among these patients should be directed at the management of modifiable risk factors that contribute to this risk. Registration URL: http://www.clinicaltrials.gov; Unique identifiers: NCT01468701, NCT01671007 and NCT01937377.

Assessment and Mitigation of Bleeding Risk in Atrial Fibrillation and Venous Thromboembolism: Executive Summary of a European and Asia-Pacific Expert Consensus Paper

While there is a clear clinical benefit of oral anticoagulation in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision for initiating and continuing anticoagulation is often based on a careful assessment of both thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static "one-off" assessment based on baseline factors but is dynamic, being influenced by aging, incident comorbidities, and drug therapies. In this executive summary of a European and Asia-Pacific Expert Consensus Paper, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with a view to summarizing "best practice" when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, and review established bleeding risk factors and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism, are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A Position Paper from the ESC Working Group on Thrombosis, in collaboration with the European Heart Rhythm Association, the Association for Acute CardioVascular Care and the Asia-Pacific Heart Rhythm Society

Whilst there is a clear clinical benefit of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision to initiate and continue anticoagulation is often based on a careful assessment of both the thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static 'one off' assessment based on baseline factors but is dynamic, being influenced by ageing, incident comorbidities, and drug therapies. In this Consensus Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with the view to summarizing 'best practice' when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, review established bleeding risk factors, and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Non-Vitamin K Antagonists Versus Warfarin in Patients with Atrial Fibrillation and Bioprosthetic Valves: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with atrial fibrillation and bioprosthetic valves are at high risk for thromboembolic events. The pooled efficacy and safety of non-vitamin K oral anticoagulants (NOACs), as a class, relative to warfarin in this population is not well-known. We aimed to compare the efficacy and safety of NOACs relative to warfarin in patients with bioprosthetic valves or valve repair.

METHODS

We systematically searched EMBASE, PubMed, and Cochrane databases for randomized controlled trials comparing NOACs to warfarin in patients with atrial fibrillation and bioprosthetic valves or valve repair. We pooled outcomes for stroke or systemic embolism, ischemic stroke, hemorrhagic stroke, and major bleeding.

RESULTS

We included 4 trials with 1379 patients, of whom 723 (52.4%) received a NOAC. Mean follow-up ranged from 90 days to 2.8 years. In the pooled analysis, stroke or systemic embolism was significantly lower in patients treated with NOACs (1.9%) compared with warfarin (3.7%) (odds ratio [OR] 0.43; 95% confidence interval [CI] 0.22-0.85; P = .02). Ischemic stroke (OR 0.72; 95% CI 0.18-2.93), hemorrhagic stroke (OR 0.18; 95% CI 0.03-1.05), cardiovascular death (OR 0.78; 95% CI 0.38-1.62), and all-cause mortality (OR 0.94; 95% CI 0.55-1.62) were not significantly different among groups. Major bleeding was significantly lower in patients treated with NOAC (2.8%) compared with warfarin (4.7%) (OR 0.49; 95% CI 0.28-0.88; P = .02).

CONCLUSIONS

In patients with atrial fibrillation and bioprosthetic valves or valve repair, NOACs are associated with a reduced incidence of thromboembolic events and major bleeding as compared with warfarin. Thus, NOACs may be considered a preferred option for this patient population.

Atrial Fibrillation and Stroke Symptoms in the REGARDS Study

Background

It is unknown if stroke symptoms in the absence of a stroke diagnosis are a sign of subtle cardioembolic phenomena. The objective of this study was to examine associations between atrial fibrillation (AF) and stroke symptoms among adults with no clinical history of stroke or transient ischemic attack (TIA).

Methods and Results

We evaluated associations between AF and self‐reported stroke symptoms in the national, prospective REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort. We conducted cross‐sectional (n=27 135) and longitudinal (n=21 932) analyses over 8 years of follow‐up of REGARDS participants without stroke/transient ischemic attack and stratified by anticoagulant or antiplatelet agent use. The mean age was 64.4 (SD±9.4) years, 55.3% were women, and 40.8% were Black participants; 28.6% of participants with AF reported stroke symptoms. In the cross‐sectional analysis, comparing participants with and without AF, the risk of stroke symptoms was elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (odds ratio [OR], 2.22; 95% CI, 1.89–2.59) or antiplatelet agents only (OR, 1.92; 95% CI, 1.61–2.29) but not for adults with AF taking anticoagulants (OR, 1.08; 95% CI, 0.71–1.65). In the longitudinal analysis, the risk of stroke symptoms was also elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (hazard ratio [HR], 1.41; 95% CI, 1.21–1.66) or antiplatelet agents only (HR, 1.23; 95% CI, 1.04–1.46) but not for adults with AF taking anticoagulants (HR, 0.86; 95% CI, 0.62–1.18).

Conclusions

Stroke symptoms in the absence of a stroke diagnosis may represent subclinical cardioembolic phenomena or “whispering strokes.” Future studies examining the benefit of stroke symptom screening may be warranted.

Residual Stroke Risk in Atrial Fibrillation

AF contributes to increased stroke risk via various mechanisms, including deranged blood constituents, vessel wall abnormalities and abnormal blood flow. This excess risk is frequently managed with anticoagulation therapy, aimed at preventing thromboembolic complications. Yet, a significant proportion of patients with AF remain at high residual stroke risk despite receiving appropriate dose-adjusted anticoagulation. This article explores the residual stroke risk in AF and potential therapeutic options for these patients.

Meta-regression of randomized control trials with antithrombotics: weak correlation between net clinical benefit and all cause-mortality

This study aimed to explore the validity of the use of the net clinical benefit (NCB), i.e. the sum of major bleeding and thrombotic events, as a potential surrogate for all-cause mortality in clinical trials assessing antithrombotics. Published randomized controlled trials testing anticoagulants in the prevention or treatment of venous thromboembolism (VTE) and non-valvular atrial fibrillation (NVAF) were systematically reviewed. The validity of NCB as a surrogate endpoint was estimated by calculating the strength of correlation of determination (R²) and its 95% confidence interval (CI) between the relative risks of NCB and all-cause mortality. Amongst the 125 trials retrieved, the highest R²_trial values were estimated for NVAF (R²_trial = 0.41, 95% CI [0.03; 0.48]), and acute VTE (R²_trial = 0.30, 95% CI [0.04; 0.84]). Conversely, the NCB did not correlate with all-cause mortality in prevention studies with medical (R²_trial = 0.12, 95% CI [0.00; 0.36]), surgical (R²_trial = 0.05, 95% CI [0.00; 0.23]), and cancer patients (R²_trial = 0.006, 95% CI [0.00; 1.00]). A weak correlation between NCB and all cause-mortality was found in NVAF and acute VTE, whereas no correlation was observed in clinical situations where the mortality rate was low. Consequently, NCB should not be considered a surrogate outcome for all cause-mortality in anticoagulation trials.

Explainable Artificial Intelligence Model for Diagnosis of Atrial Fibrillation Using Holter Electrocardiogram Waveforms

Atrial fibrillation is a clinically important arrhythmia. There are some reports on machine learning models for AF diagnosis using electrocardiogram data. However, few reports have proposed an eXplainable Artificial Intelligence (XAI) model to enable physicians to easily understand the machine learning model's diagnosis results.We developed and validated an XAI-enabled atrial fibrillation diagnosis model based on a convolutional neural network (CNN) algorithm. We used Holter electrocardiogram monitoring data and the gradient-weighted class activation mapping (Grad-CAM) method.Electrocardiogram data recorded from patients between January 4, 2016, and October 31, 2019, totaling 57,273 electrocardiogram waveform slots of 30 seconds each with diagnostic information annotated by cardiologists, were used for training our proposed model. Performance metrics of our AI model for AF diagnosis are as follows: sensitivity, 97.1% (95% CI: 0.969-0.972); specificity, 94.5% (95% CI: 0.943-0.946); accuracy, 95.3% (95% CI: 0.952-0.955); positive predictive value, 89.3% (95% CI: 0.892-0.897); and F-value, 93.1% (95% CI: 0.929-0.933). The area under the receiver operating characteristic curve for AF detection using our model was 0.988 (95% CI: 0.987-0.988). Furthermore, using the XAI method, 94.5 ± 3.5% of the areas identified as regions of interest using our machine learning model were identified as characteristic sites for AF diagnosis by cardiologists.AF was accurately diagnosed and favorably explained with Holter ECG waveforms using our proposed CNN-based XAI model. Our study presents another step toward realizing a viable XAI-based detection model for AF diagnoses for use by physicians.

Patient characteristics, adherence, and costs of oral anticoagulation therapy in non-valvular atrial fibrillation using the Dubai Real-World Claims Database

Background:

Non-vitamin K antagonist oral anticoagulants (NOACs) reduce the risk of stroke in patients with non-valvular atrial fibrillation (NVAF) and have better safety profile than vitamin K antagonists (VKAs). However, there is a dearth of quality, real-world, patient data on the use of these drugs to guide healthcare policies in United Arab Emirates (UAE).

Aims and Objectives:

The aim is to address the knowledge gap in demographic and clinical profiles of NVAF patients on NOACs (apixaban, rivaroxaban, and dabigatran) and warfarin in UAE.

Materials and Methods:

This retrospective cohort analysis utilized the Dubai Real-World Claims Database to extract anonymized longitudinal data on NVAF patients with at least one NOAC or warfarin claim between January 2015 and March 2019. Data examined included comorbidities, healthcare resource utilization (HCRU), treatment adherence, and clinical events.

Results:

From 11,086 NVAF patients in the database, 940 patients on oral anticoagulant treatment were selected with mean age of 58.6 ± 14.7 years and 73.7% men. At baseline, the mean CHA₂DS₂-VASc risk score was 2.4, and the mean Deyo–Charlson comorbidity index (CCI) score was 1.6. Most patients (71%) started oral anticoagulation treatment on a standard index dose. High medication possession ratio (MPR) and proportion of days covered (PDC) were observed in 86.8% and 43.1% of the overall cohort. The mean number of HCRU claims and cost during the 180-day follow-up period was 18.5 and 9,747 USD, respectively. Warfarin users accounted for both the highest number of claims and cost, whereas apixaban accounted for the lowest figures. Time to first major bleeding was shorter for warfarin users compared with patients on NOACs. Longer times to first stroke/systemic embolism (SE) were observed for rivaroxaban and warfarin.

Conclusion:

This study provides important comparative insights about comorbidities, adherence, HCRU, and outcome events among NOAC and warfarin users from real-world clinical practice settings.

Atrial Fibrillation and Ischemic Stroke: A Clinical Review

Atrial fibrillation (AF) is an important risk factor for ischemic stroke resulting in a fivefold increased stroke risk and a twofold increased mortality. Our understanding of stroke mechanisms in AF has evolved since the concept of atrial cardiopathy was introduced as an underlying pathological change, with both AF and thromboembolism being common manifestations and outcomes. Despite the strong association with stroke, there is no evidence that screening for AF in asymptomatic patients improves clinical outcomes; however, there is strong evidence that patients with embolic stroke of undetermined source may require long-term monitoring to detect silent or paroxysmal AF. Stroke prevention in patients at risk, assessed by the CHA₂DS₂-VASc score, was traditionally achieved with warfarin; however, direct oral anticoagulants have solidified their role as safe and effective alternatives. Additionally, left atrial appendage exclusion has emerged as a viable option in patients intolerant of anticoagulation. When patients with AF have an acute stroke, the timing of initiation or resumption of anticoagulation for secondary stroke prevention has to be balanced against the risk of hemorrhagic conversion. Multiple randomized clinical trials are currently underway to determine the best timing for administration of anticoagulants following acute ischemic stroke.

Adverse event rates associated with oral anticoagulant treatment early versus later after hospital discharge in older adults: a retrospective population-based cohort study

BACKGROUND

Oral anticoagulants are commonly used high-risk medications, but little is known about their safety in transition from hospital to home. Our objective was to measure the rates of hemorrhage and thromboembolic events among older adults receiving oral anticoagulant treatment early after hospital discharge compared to later.

METHODS

We conducted a retrospective population-based cohort study among Ontario residents aged 66 years or more who started, continued or resumed oral anticoagulant therapy at hospital discharge between September 2010 and March 2015. We calculated the rates of hemorrhage and thromboembolic events requiring hospital admission or an emergency department visit over a 1-year follow-up period, stratified by the first 30 days after discharge and the remainder of the year. We used multivariable regression models, adjusting for covariates, to estimate the effect of sex, prevalent versus incident use, and switching anticoagulants on events.

RESULTS

A total of 123 139 patients (68 408 women [55.6%]; mean age 78.2 yr) were included. About one-quarter (32 563 [26.4%]) had a Charlson Comorbidity Index score of 2 or higher. The rates of hemorrhage and thromboembolic events per 100 person-years were highest during the first 30 days after hospital discharge (25.8, 95% CI 24.8-26.8 and 19.3, 95% CI 18.4-20.2, respectively), falling to 15.7 (95% CI 15.3-16.1) and 6.9 (95% CI 6.6-7.1), respectively, during the subsequent 11 months. Multivariable analysis showed that patients whose anticoagulant was switched in hospital and men had more hemorrhages and thromboembolic events in follow-up.

INTERPRETATION

The first few weeks following hospital discharge represent a very high-risk period for adverse events related to oral anticoagulant treatment among older adults. The results support an intervention trial addressing anticoagulation management in the early postdischarge period.

Anticoagulation with warfarin compared to novel oral anticoagulants for atrial fibrillation in adults with transthyretin cardiac amyloidosis: comparison of thromboembolic events and major bleeding

BACKGROUND

Atrial fibrillation (AF) is common in patients with transthyretin cardiac amyloidosis (ATTR-CA). The optimal strategy to prevent strokes in patients with ATTR-CA and AF is unknown.

OBJECTIVES

To compare outcomes in patients with ATTR-CA and AF treated with warfarin versus novel oral anticoagulants (NOACs).

METHODS

This study was a retrospective analysis of patients with ATTR-CA stratified by presence or absence of AF and anticoagulation therapy. The primary outcome included a time to event analysis for the combined outcomes of stroke, transient ischaemic attack (TIA), major bleed, or death.

RESULTS

Of 290 patients, 217 patients (74.8%) had AF. Of those with AF (n = 217), 78 (35.9%) patients received warfarin compared with 116 (53.5%) patients who received NOACs. There were 17 thrombotic events, all in those diagnosed with AF compared with none in the patients without AF (p = .01). Over a mean follow-up of 2.4 years (range 0.1-12) there was no difference in primary outcome between those with AF treated with warfarin compared with NOACs (p = .35).

CONCLUSION

Patient with ATTR-CA and AF are at increased risk for stroke compared to patients with ATTR-CA and without AF. Thrombotic events and major bleeds did not differ between those who received warfarin and NOACs.

Atrial Fibrillation and Stroke

Atrial fibrillation (AF) is the most common cardiac arrythmia and a major cause of stroke, heart failure, sudden death, and cardiovascular morbidity. AF increases risk of thromboembolic stroke via stasis in the left atrium and subsequent embolization to the brain. In patients with acute ischemic stroke, it is essential that clinicians undertake careful investigation to search for AF. In these patients, up to 23.7% eventually are found to have underlying AF. Oral anticoagulation is effective in prevention of strokes secondary to AF, reducing overall stroke numbers by approximately 64%. Left atrial appendage occlusion is promising for prevention of stroke in AF.

Cost saving analysis of specialized, eHealth-based management of patients receiving oral anticoagulation therapy: Results from the thrombEVAL study

To evaluate the cost-saving of a specialized, eHealth-based management service (CS) in comparison to regular medical care (RMC) for the management of patients receiving oral anticoagulation (OAC) therapy. Costs of hospitalization were derived via diagnosis-related groups which comprise diagnoses (ICD-10) and operation and procedure classification system (OPS), which resulted in OAC-related (i.e. bleeding/ thromboembolic events) and non-OAC-related costs for both cohorts. Cost for anticoagulation management comprised INR-testing, personnel, and technical support. In total, 705 patients were managed by CS and 1490 patients received RMC. The number of hospital stays was significantly lower in the CS cohort compared to RMC (CS: 23.4/100 py; RMC: 68.7/100 py); with the most pronounced difference in OAC-related admissions (CS: 2.8/100 py; RMC: 13.3/100 py). Total costs for anticoagulation management amounted to 101 EUR/py in RMC and 311 EUR/py in CS, whereas hospitalization costs were 3261 [IQR 2857-3689] EUR/py in RMC and 683 [504-874] EUR/py in CS. This resulted in an overall cost saving 2368 EUR/py favoring the CS. The lower frequency of adverse events in anticoagulated patients managed by the telemedicine-based CS compared to RMC translated into a substantial cost-saving, despite higher costs for the specialized management of patients.Trial registration: ClinicalTrials.gov, unique identifier NCT01809015, March 8, 2013.

Neurologic complications of atrial fibrillation: Pharmacologic and interventional approaches to stroke prevention

Atrial fibrillation is a common cardiac arrhythmia that carries a risk of stroke. This is commonly stratified with the CHA₂DS₂-VASc score. Stroke risk can be reduced with anticoagulants or with interventions to close the left atrial appendage, the most common source of left atrial thrombi. While warfarin has been traditionally used as the only oral anticoagulant available, there are several direct oral anticoagulants that compare favorably with respect to both stroke and bleeding risk in randomized controlled trials. Multiple interventional options exist to close the left atrial appendage, but the Watchman device is the only one that compares favorably with warfarin in randomized controlled trials.

Markedly increased risk of postoperative bleeding complications during perioperative bridging anticoagulation in general and visceral surgery

BACKGROUND

Increasing numbers of patients receiving oral anticoagulants are undergoing elective surgery. Low molecular weight heparin (LMWH) is frequently applied as bridging therapy during perioperative interruption of anticoagulation. The aim of this study was to explore the postoperative bleeding risk of patients receiving surgery under bridging anticoagulation.

METHODS

We performed a monocentric retrospective two-arm matched cohort study. Patients that received perioperative bridging anticoagulation were compared to a matched control group with identical surgical procedure, age, and sex. Emergency and vascular operations were excluded. The primary endpoint was the incidence of major postoperative bleeding. Secondary endpoints were minor postoperative bleeding, thromboembolic events, length of stay, and in-hospital mortality. Multivariate analysis explored risk factors of major postoperative bleeding.

RESULTS

A total of 263 patients in each study arm were analyzed. The patient cohort included the entire field of general and visceral surgery including a large proportion of major oncological resections. Bridging anticoagulation increased the postoperative incidence of major bleeding events (8% vs. 1%; p < 0.001) as well as minor bleeding events (14% vs. 5%; p < 0.001). Thromboembolic events were equally rare in both groups (1% vs. 2%; p = 0.45). No effect on mortality was observed (1.5% vs. 1.9%). Independent risk factors of major postoperative bleeding were full-therapeutic dose of LMWH, renal insufficiency, and the procedure-specific bleeding risk.

CONCLUSION

Perioperative bridging anticoagulation, especially full-therapeutic dose LMWH, markedly increases the risk of postoperative bleeding complications in general and visceral surgery. Surgeons should carefully consider the practice of routine bridging.

Prediction and treatment of bleeding in patients under anticoagulant treatment

Major bleeding is a common complication of anticoagulant treatment. Risk assessment tools are relevant in the management of patients with atrial fibrillation and venous thromboembolism. The combination of clinical, biological and genetic markers is incorporated to build predictive scores to help in the decision process about intensity and duration of treatment. The optimal management of bleeding involves the application of predictive scores in combination with anticoagulant reversal strategies.

Direct Oral Anticoagulants in the Treatment of Left Ventricular Thrombus: A Retrospective, Multicenter Study and Meta-Analysis of Existing Data

AIM

To compare the safety and efficacy of direct oral anticoagulants (DOAC) relative to vitamin K antagonists (VKA) for the treatment of left ventricular thrombus (LVT).

METHODS

This retrospective study enrolled patients diagnosed with LVT from 2014-2017. Patient characteristics and outcomes within 12 months of LVT diagnosis were recorded and analyzed. A meta-analysis was also performed by pooling our results with existing data in literature.

RESULTS

14 DOAC and 59 VKA patients were included. Baseline demographic and clinical characteristics were similar except for age. Although more strokes within 12 months occurred in VKA (15%) than in DOAC (0%) patients, this was not statistically significant (P = 0.189). There were no significant differences in outcomes between patients on DOAC and VKA for acute coronary syndrome (ACS) (7%, vs 3.4%, P = .477), LVT resolution (86% vs 76%, P = .499) or bleeding (14% vs 14%, P = 1) within 12 months. The meta-analysis included 6 studies (n = 408 for DOACs; n = 1207 for VKA). There were no significant differences between DOACs versus VKAs with respect to odds for unresolved thrombus (OR 0.61, 95% CI 0.26,1.41), embolic events (OR 1.24, 95% CI 0.90,1.69), embolic events and death (OR 1.10, 95% CI 0.84,1.45) or bleeding events (OR 1.13, 95% CI 0.74,1.72).

CONCLUSIONS

Our study and meta-analysis suggest similar efficacy and safety of DOACs in the treatment of LVT compared to VKA. These findings underscore the need for a randomized controlled trial.

Managing Ischemic Stroke in Patients Already on Anticoagulation for Atrial Fibrillation: A Nationwide Practice Survey

BACKGROUND AND PURPOSE

We sought to understand practice patterns in management of patients who have ischemic stroke while adherent to oral anticoagulation for non-valvular atrial fibrillation (NVAF) in the United States (US).

METHODS

We distributed an iteratively revised online survey to US neurologists in May-June 2019. Survey questions focused on clinicians' practices regarding diagnostic evaluation and secondary prevention after ischemic stroke in patients already on oral anticoagulation for NVAF. Standard descriptive statistics were used to summarize participants' characteristics and responses.

RESULTS

Of the 120 participating clinicians, 79% were attending physicians. Most respondents (66%) were trained in vascular neurology, and 79% were employed in hospital-based, academic settings. For patients with ischemic stroke despite anticoagulation, most respondents indicated that they obtain extracranial and intracranial vessel imaging (72% and 82%, respectively). Most respondents (83%) routinely change therapy to a direct oral anticoagulant (DOAC) for patients experiencing ischemic stroke while on warfarin. In cases of ischemic stroke while on a DOAC, 38% of respondents routinely switch agents, 42% do not routinely switch agents, and 20% routinely add an antiplatelet agent. In this scenario, 83% of respondents who switch agents indicated that the reason was a possible better response to a drug that acts through a different mechanism. The most common reason for not switching while on a DOAC was the lack of randomized trial data.

CONCLUSIONS

There is a high degree of variability in practice patterns among US neurologists caring for patients with ischemic stroke while already on oral anticoagulation for NVAF.

Dabigatran for Japanese Patients with Atrial Fibrillation and Prior Stroke: A Subgroup Analysis of the J-Dabigatran Surveillance Program

BACKGROUND

The study objective was to evaluate long-term safety and effectiveness of dabigatran 110 mg and 150 mg twice daily (bid) in patients with nonvalvular atrial fibrillation (NVAF) with a focus on secondary stroke prevention.

METHODS

In J-Dabigatran Surveillance, 6772 patients newly initiated on dabigatran to prevent ischemic stroke and systemic embolism were enrolled in Japan (1042 sites, December 2011 to November 2013). This subgroup analysis included patients with (1302) and without (5071) previous stroke/transient ischemic attack (TIA). Case report forms were reviewed to determine incidence of outcome events.

RESULTS

In patients with previous stroke/TIA, the incidence rate for recurrent stroke/TIA was 2.48/100 patient-years (ischemic stroke 2.22, hemorrhagic stroke 0.18, TIA 0.12) and for major bleeding was 1.79/100 patient-years, including intracranial bleeding (0.55). Event rates for recurrent stroke/TIA or major bleeding were 1.2% (for both) for patients who started dabigatran less than 30 days after stroke onset and 0.3% (for both) for patients who started dabigatran more than or equal to 30 days after stroke onset, and were independent of dabigatran dose. For patients with previous stroke/TIA, 17% who received 110 mg bid did not meet dose reduction recommendations (DRRs) and 28% who received 150 mg bid met at least 1 DRR, but the dabigatran dose was not reduced. Use of DRRs did not have a major impact on the incidence rates of recurrent stroke/TIA and major bleeding.

CONCLUSION

Findings from this subgroup analysis support the real-world safety and effectiveness of long-term dabigatran in Japan, particularly for patients with NVAF in secondary prevention settings.

Stroke and Bleeding Risk Assessments in Patients With Atrial Fibrillation: Concepts and Controversies

Risk assessments are an important element in the management of patients with atrial fibrillation (AF). In this review, we aim to discuss the concepts and controversies surrounding the various risk factors for stroke and bleeding in AF. Indeed, there are a variety of clinical, electrical, biological, and genetic markers to guide stroke and bleeding risk assessments in AF. The more common factors have been used to formulate risk stratification scores. Some risk factors have shown promise, but others remain less well-defined. Our aim is to discuss concepts and controversies surrounding current evidence of risk factors for stroke and bleeding assessments in AF.

A Novel LC-MS/MS Assay for Quantification of Des-carboxy Prothrombin and Characterization of Warfarin-Induced Changes

Warfarin is a narrow therapeutic index anticoagulant drug and its use is associated with infrequent but significant adverse bleeding events. The international normalized ratio (INR) is the most commonly used biomarker to monitor and titrate warfarin therapy. However, INR is derived from a functional assay, which determines clotting efficiency at the time of measurement and is susceptible to technical variability. Protein induced by vitamin K antagonist-II (PIVKA-II) has been suggested as a biomarker of long-term vitamin K status, providing mechanistic insights about variation in the functional assay. However, the currently available antibody-based PIVKA-II assay does not inform on the position and number of des-carboxylation sites in prothrombin. The assay presented in this paper provides simultaneous quantification of carboxy and des-carboxy prothrombin that are essential for monitoring early changes in INR and, thus, serves as the superior tool for managing warfarin therapy. Additionally, this assay permits the quantification of total prothrombin level, which is affected by warfarin treatment. Prothrombin recovery from plasma was 95% and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was linear (r²  = 0.98) with a dynamic range of 1-100 µg/mL. The assay interday precision was within 20%. A des-carboxy peptide of prothrombin (GNLER) was negatively correlated with active prothrombin (Pearson r = 0.99, P < 0.0001), whereas its association was positively linked with INR values (Pearson r = 0.75, P < 0.015). This novel LC-MS/MS assay for active and inactive prothrombin quantification can be applied to titrate anticoagulant therapy and to monitor the impact of diseases, such as hepatocellular carcinoma on clotting physiology.

Anticoagulation in pulmonary arterial hypertension: a decision analysis

Systemic anticoagulation may be beneficial in pulmonary arterial hypertension, but there is no randomized clinical trial data to guide therapeutic decision making, and current guidelines do not account for patient preferences or quality of life. Decision analytic models to evaluate the potential risks and benefits of systemic anticoagulation in pulmonary arterial hypertension patients, focusing on the benefit in quality-adjusted life years, may be helpful in clarifying this uncertainty. We constructed a 31-state Markov decision analytic model to explore anticoagulation and no anticoagulation strategies. Modeled patient characteristics included gender, use of central catheter-based pulmonary arterial hypertension therapy, type of pulmonary arterial hypertension (idiopathic, idiopathic pulmonary arterial hypertension, or connective-tissue associated, connective tissue disease-pulmonary arterial hypertension), and use of oral contraceptive medication by females. Modeled events included mortality, thromboembolic complications, atrial fibrillation, stroke, and anticoagulation bleeding. Deterministic and probabilistic sensitivity analyses were performed. Anticoagulation was favored in all idiopathic pulmonary arterial hypertension cases, with a gain of 0.43-0.51 quality-adjusted life years, and detrimental in all connective tissue disease-pulmonary arterial hypertension cases, with a loss of 0.66-1.89 quality-adjusted life years. Anticoagulation would need to demonstrate a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better to be favored. In our model, idiopathic pulmonary arterial hypertension patients benefit from anticoagulation in terms of quality-adjusted life years, and connective tissue disease-pulmonary arterial hypertension patients were harmed, with a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better being required to favorably impact quality-adjusted life years. These results suggest that anticoagulation significantly improves quality adjusted life years and should be offered to all idiopathic pulmonary arterial hypertension patients. Shared decision models based on these results may help clarify therapeutic decision-making uncertainty in pulmonary arterial hypertension patients.

Successful Resolution of a Large Left Atrial and Left Atrial Appendage Thrombus with Rivaroxaban

A 79-year-old male was admitted to the hospital for acute exacerbation of heart failure. The patient had history of atrial fibrillation and was planned for cardioversion. Preprocedure transesophageal echocardiogram (TEE) revealed a large multilobulated mobile thrombus in the left atrial appendage. The patient refused warfarin therapy and instead chose to take rivaroxaban. Upon outpatient follow-up, 3 months later, no visible thrombus was appreciated on repeat TEE. This case demonstrates successful resolution of left atrial and left atrial appendage thrombi with the use of rivaroxaban. At present time, limited data is available to support the use of rivaroxaban for treatment of intracardiac thrombi. This case highlights the need for further studies to investigate the outcomes and relative efficiency of use of direct oral anticoagulants (DOACs) in lysis of intracardiac thrombus. The benefits of DOACs compared to the standard of therapy could increase patient compliance, reduce length of stay, and improve treatment efficacy.

Key Enabling Technologies for Point-of-Care Diagnostics

A major trend in biomedical engineering is the development of reliable, self-contained point-of-care (POC) devices for diagnostics and in-field assays. The new generation of such platforms increasingly addresses the clinical and environmental needs. Moreover, they are becoming more and more integrated with everyday objects, such as smartphones, and their spread among unskilled common people, has the power to improve the quality of life, both in the developed world and in low-resource settings. The future success of these tools will depend on the integration of the relevant key enabling technologies on an industrial scale (microfluidics with microelectronics, highly sensitive detection methods and low-cost materials for easy-to-use tools). Here, recent advances and perspectives will be reviewed across the large spectrum of their applications.

Comparison of Clinical Outcomes Among Patients With Atrial Fibrillation or Atrial Flutter Stratified by CHA2DS2-VASc Score

Importance

Current guidelines support treating atrial fibrillation (AF) and atrial flutter (AFL) as equivalent risk factors for ischemic stroke stratified by CHA2DS2-VASc scores, recommending anticoagulation therapy for patients with a CHA2DS2-VASc score of 2 or higher, but some studies found differences in clinical outcomes.

Objective

To investigate differences in clinical outcomes among AF, AFL, and matched control cohorts.

Design, Setting, and Participants

This nationwide cohort study analyzed data from the Taiwan National Health Insurance Research Database from January 1, 2001, through December 31, 2012. Follow-up and data analysis ended December 31, 2012. A total of 219 416 age- and sex-matched individuals participated in the study. Clinical outcomes were compared after stratification by CHA2DS2-VASc score (possible score range, 0-9; higher scores indicate greater risk of ischemic stroke).

Main Outcomes and Measures

Ischemic stroke, heart failure hospitalization, and all-cause mortality among the AF, AFL, and matched control cohorts were analyzed using Cox proportional hazards regression.

Results

This study comprised 188 811 patients in the AF cohort (mean [SD] age, 73.8 [13.4] years; 104 703 [55.5%] male), 6121 patients in the AFL cohort (mean [SD] age, 67.7 [15.8] years; 3735 [61.0%] male), and 24 484 patients in the matched control cohort (mean [SD] age, 67.3 [15.6] years; 14 940 [61.0%] male). The patients with AF were older, were more predominantly female, and had higher CHA2DS2-VASc scores than the patients with AFL and the control participants. After stratification by CHA2DS2-VASc score, the incidence densities (IDs; events per 100 person-years) of ischemic stroke (AF cohort: ID, 3.08; 95% CI, 3.03-3.13; AFL cohort: ID, 1.45; 95% CI, 1.28-1.62; controls: ID, 0.97; 95% CI, 0.92-1.03), heart failure hospitalization (AF cohort: ID, 3.39; 95% CI, 3.34-3.44; AFL cohort: ID, 1.57; 95% CI, 1.39-1.74; controls: ID, 0.32; 95% CI, 0.29-0.35), and all-cause mortality (AF cohort: ID, 17.8; 95% CI, 17.7-17.9; AFL cohort: ID, 13.9; 95% CI, 13.4-14.4; controls: ID, 4.2; 95% CI, 4.1-4.4) were significantly higher in the AF cohort than in the matched control cohort. For the AFL cohort vs the matched control cohort, the incidences of heart failure hospitalization and all-cause mortality were significantly higher across all levels, but the incidence of ischemic stroke was only significantly higher at CHA2DS2-VASc scores of 5 to 9. For the AF cohort vs the AFL cohort, the incidences of ischemic stroke and heart failure hospitalization were significantly higher at a CHA2DS2-VASc score of 1 or higher, but the incidence of all-cause mortality was significantly higher only at CHA2DS2-VASc scores of 1 to 3.

Conclusions and Relevance

This study found different clinical outcomes between patients with AFL and AF and those without AF and AFL. The current recommended level of the CHA2DS2-VASc score in preventing ischemic stroke in patients with AFL should be reevaluated.

Use of non-vitamin K oral anticoagulants in people with atrial fibrillation and diabetes mellitus

AIMS

To examine the efficacy and safety of non-vitamin K oral anticoagulants in people with both atrial fibrillation and diabetes mellitus.

METHODS

We reviewed efficacy and safety data from the warfarin-controlled phase III non-vitamin K oral anticoagulants trials (ARISTOTLE, RE-LY, ROCKET-AF, ENGAGE AF-TIMI 48) and their post hoc analyses with regard to diabetes status. We also reviewed the updated literature regarding this population.

RESULTS

At baseline 20-40% of the participants in the phase III non-vitamin K oral anticoagulants trials had diabetes mellitus at baseline. This population, in comparison with those without diabetes, was more likely to have other comorbidities, such as hypertension and coronary artery disease; thus, their cardiovascular risk was higher. Participants with diabetes had higher rates of stroke and systemic embolism than participants without diabetes. This risk was decreased using non-vitamin K oral anticoagulants, with no significant interaction by diabetic status or the specific drug used. Overall, compared with warfarin, non-vitamin K oral anticoagulants were safe and reduced the incidence of major bleeding in people with atrial fibrillation and diabetes, although the results varied with the different non-vitamin K oral anticoagulants.

CONCLUSIONS

The efficacy and safety of non-vitamin K oral anticoagulants compared with warfarin generally extend to participants with diabetes mellitus, although dedicated randomized trials or real-world data are lacking.

Left Atrial Appendage Occlusion, Shared Decision-Making, and Comprehensive Atrial Fibrillation Management

The epidemic of atrial fibrillation (AF) requires a comprehensive management strategy that uses the full force of available data and technology, including anticoagulation, ablative therapy, and left atrial appendage occlusion. Patient-centered care with an emphasis on shared decision-making is particularly relevant to the authors' understanding of the complexity of AF and has helped them tailor therapy in this ever-growing patient population.

Warfarin Management and Outcomes in Patients with Nonvalvular Atrial Fibrillation Within an Integrated Health Care System

BACKGROUND

Warfarin is a common treatment option to manage patients with nonvalvular atrial fibrillation (NVAF) in clinical practice. Understanding current pharmacist-led anticoagulation clinic management patterns and associated outcomes is important for quality improvement; however, currently little evidence associating outcomes with management patterns exists.

OBJECTIVES

To (a) describe warfarin management patterns and (b) evaluate associations between warfarin treatment and clinical outcomes for patients with NVAF in an integrated health care system.

METHODS

A retrospective cohort study was conducted among NVAF patients with warfarin therapy between January 1, 2006, and December 31, 2011, using Kaiser Permanente Southern California data, and followed until December 31, 2013. Management patterns related to international normalized ratio (INR) monitoring, anticoagulation clinic pharmacist intervention (consultation), and warfarin dose adjustments were investigated along with yearly attrition rates, time-in-therapeutic ranges (TTRs), and clinical outcomes (stroke or systemic embolism and major bleeding). Descriptive statistics and multivariable Cox proportional hazard models were used to determine associations between TTR and clinical outcomes.

RESULTS

A total of 32,074 NVAF patients on warfarin treatment were identified and followed for a median of 3.8 years. About half (49%) of the patients were newly initiating warfarin therapy. INR monitoring and pharmacist interventions were conducted roughly every 3 weeks after 6 months of warfarin treatment. Sixty-three percent of the study population had ≥ 1 warfarin dose adjustments with a mean (SD) of 6.7 (6.3) annual dose adjustments. Warfarin dose adjustments occurred at a median of 1 day (interquartile ranges [IQR] 1-3) after the INR measurement. Yearly attrition rate was from 3.3% to 6.3% during the follow-up, and median (IQR) TTR was 61% (46%-73%). Patients who received frequent INR monitoring (≥ 27 times per year), pharmacist interventions (≥ 24 times per year), or frequently adjusted warfarin dose (≥ 11 times per year) consistently showed poor TTRs (mean TTR for the highest quartiles was 45.3%-48.3%). A higher TTR was associated with a lower risk of clinical outcomes regardless of frequency of INR monitoring, pharmacist interventions, or number of dose adjustments. Patients whose TTRs were < 65%, even with frequent pharmacist interventions, had similar stroke or systemic embolism event rates, as compared with patients with TTRs < 65% and less frequent interventions (1.88 vs. 1.54 stroke or systemic embolism rates per 100 person-years, respectively, P = 0.78). The lowest TTR quartile (< 46%) was associated with a 3 times higher risk of stroke or systemic embolism (hazard ratio [HR] = 3.19, 95% CI = 2.71-3.77) and a 2 times higher risk of major bleeding (HR = 2.10, 95% CI = 1.96-2.24) compared with the highest TTR quartile (≥ 73%).

CONCLUSIONS

Despite close monitoring with timely warfarin dose adjustments, there were still a substantial number of challenging patients whose TTRs were suboptimal despite a higher number of pharmacist interventions. These patients eventually experienced more stroke or systemic embolism and bleeding events among NVAF patients managed by anticoagulation clinics. New individualized treatment or management strategies for patients who are not able to reach optimal therapeutic ranges are necessary to improve outcomes.

DISCLOSURES

This research and manuscript were funded by Bristol-Myers Squibb Company and Pfizer. Authors from Bristol-Myers Squibb Company and Pfizer participated in the design of the study, interpretation of the data, review/revision of the manuscript, and approval of the final version of the manuscript. An received a grant for research support from Bristol-Myers Squibb/Pfizer. Niu, Rashid, and Zheng received a grant from Bristol-Myers Squibb/Pfizer to their institutions for salary reimbursement. Vo, Singh, and Aranda are employed by Bristol-Myers Squibb; Bruno was employed by Bristol-Myers Squibb at the time of this study. Mendes and Dills are employed by Pfizer, and Mendes was a member of the Pfizer Cardiovascular and Metabolic Field Medical Team during the time of this study. Lang, Jazdzewski, and Le have no known conflicts of interest to report. Study concept and design were contributed primarily by An and Rashid, along with the other authors. Niu took the lead in data collection, along with Zheng, and data interpretation was performed by An, along with Mendes and Dills, with assistance from the other authors. The manuscript was written by An and revised by Mendes, Dills, Vo, Singh, Bruno, and Aranda, along with Lang, Le, and Jazdezewski. Part of this study's findings was presented at the CHEST 2015 Annual Meeting in Montreal, Canada, on October 28, 2015.

Vitamin K antagonist therapy: changes in the treated populations and in management results in Italian anticoagulation clinics compared with those recorded 20 years ago

Vitamin K antagonists (VKA) are the most widely used anticoagulants in the world. An appropriate management of treated patients is crucial for their efficacy and safety. The prospective, observational, multicenter, inception-cohort FCSA-START Register, a branch of START Register (NCT02219984) included VKA-treated patients managed by centers of Italian Federation of anticoagulation clinics (AC). Baseline patient characteristics and data during treatment were analyzed and compared with those of ISCOAT study, performed by the Federation and published in 1996/7. 5707 naïve patients [53% males, mean age 73.0 years (28.1% >80 years)], 61.6% treated for atrial fibrillation (AF), and 28.0% for venous thromboembolism were included. During the 8906 patient-years (pt-yrs) of observation, 123 patients had major bleeding (MB) (1.38% pt-yrs; fatal: 0.11% pt-yrs), while non-major clinically relevant bleeds were 144 (1.62% pt-yrs). Bleeding was more frequent in elderly (≥70 years; p = 0.04), and during initial 3-month therapy (p = 0.02). Bleeding rate was 2.5% pt-yrs for temporally related INR results <3.0, increasing to 12.5% for INR ≥ 4.5. Thrombotic events were 47 (0.53% pt-yrs; 4 fatal 0.04% pt-yrs). Compared with ISCOAT-1996/7 results, patients older than 80 y are increased from 8 to 28% (p < 0.01), and those treated for AF are increased from 17 to 61%. The quality of anticoagulation control and incidence of MB are not different. However, thrombotic complications fell drastically from 3.5 to 0.53% pt-yrs (p < 0.01), with lower mortality (p = 0.01). VKA-treated patients monitored in Italian AC have good clinical results, with low bleeding and thrombotic complications rates. Important changes in the treated population and improvement in thrombotic complications are detected compared with the ISCOAT-1996/7 study.

An update on the bleeding risks associated with DOACs

The direct oral anticoagulants (DOACs), also referred to as novel (or non-vitamin K antagonist) oral anticoagulants (NOACs), represent a major development in anticoagulation therapy due to their rapid onset of action, predictable dose-response with fixed doses and limited interactions with food and drugs.^1,2 However, these agents have been in widespread clinical use for less than a decade and, compared with extensive experience with warfarin, there is uncertainty relating to optimal laboratory monitoring of anticoagulation, perioperative management and treatment of bleeding.3 In addition, there is currently only one drug licensed in the UK for rapid reversal of the anticoagulant effect of a DOAC. Here, we review DOAC-related bleeding and the role of drugs to reverse the anticoagulant action of DOACs.

Decision-Making in Clinical Practice: Oral Anticoagulant Therapy in Patients with Non-valvular Atrial Fibrillation and a Single Additional Stroke Risk Factor

Approximately 1 in 3-4 patients presenting with an ischemic stroke will also have atrial fibrillation (AF), and AF-related strokes can be effectively prevented using oral anticoagulant therapy (OAC), either with well-controlled vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs). In addition, OAC use (both VKAs and NOACs) is associated with a 26% reduction in all-cause mortality (VKAs) or an additional 10% mortality reduction with NOACs relative to VKAs. The decision to use OAC in individual AF patient is based on the estimated balance of the benefit from ischemic stroke reduction against the risk of major OAC-related bleeding [essentially intracranial hemorrhage (ICH)]. Better appreciation of the importance of VKAs' anticoagulation quality [a target time in therapeutic range (TTR) of ≥70%] and the availability of NOACs (which offer better safety compared to VKAs) have decreased the estimated threshold for OAC treatment in AF patients towards lower stroke risk levels. Still, contemporary registry-based data show that OAC is often underused in AF patients at increased risk of stroke. The uncertainty whether to use OAC may be particularly pronounced in AF patients with a single additional stroke risk factor, who are often (mis)perceived as having a "borderline" or insufficient stroke risk to trigger the use of OAC. However, observational data from real-world AF cohorts show that the annual stroke rates in such patients are higher than in patients with no additional stroke risk factors, and OAC use has been associated with reduction in stroke, systemic embolism, or death in comparison to no therapy or aspirin, with no increase in the risk of bleeding relative to aspirin. In this review article, we summarize the basic principles of stroke risk stratification in AF patients and discuss contemporary real-world evidence on OAC use and outcomes of OAC treatment in AF patients with a single additional stroke risk factor in various real-world AF cohorts.

D-dimer and the Risk of Stroke and Coronary Heart Disease. The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

D-dimer, a biomarker of coagulation, is higher in blacks than in whites and has been associated with stroke and coronary heart disease (CHD). It was our objective to assess the association of higher D-dimer with stroke and CHD in blacks and whites. REGARDS recruited 30,239 black and white participants across the contiguous US and measured baseline D-dimer in stroke (n=646) and CHD (n=654) cases and a cohort random sample (n=1,104). Cox models adjusting for cardiovascular risk factors determined the hazard ratio (HR) for increasing D-dimer for cardiovascular disease with bootstrapping to assess the difference in HR for CHD versus stroke by race. D-dimer was higher with increasing age, female sex, diabetes, hypertension, pre-baseline cardiovascular disease and higher C-reactive protein (CRP). Accounting for cardiovascular risk factors, each doubling of D-dimer was associated with increased stroke (hazard ratio [HR] 1.15; 95 % confidence interval [CI] 1.01, 1.31) and CHD (HR 1.27; 95 % CI 1.11, 1.45) risk. The difference in the HR between CHD and stroke was 0.20 (95 % CI >0.00, 0.58) for blacks and 0.02 (95 % CI -0.30, 0.27) for whites. CRP mediated 22 % (95 % CI 5 %, 41 %) of the association between D-dimer and CHD and none of the association with stroke. Higher D-dimer increased the risk of stroke and CHD independent of cardiovascular risk factors and CRP, with perhaps a stronger association for CHD versus stroke in blacks than whites. These findings highlight potential different pathophysiology of vascular disease by disease site and race suggesting potential further studies targeting haemostasis in primary prevention of vascular disease.

Administration of Coagulation-Altering Therapy in the Patient Presenting for Oral Health and Maxillofacial Surgery

Oral health care providers are concerned with how to manage patients prescribed coagulation-altering therapy during the perioperative/periprocedural period for dental and oral surgery interventions. Management and recommendation can be based on medication pharmacology and the clinical relevance of coagulation factor levels/deficiencies. Caution should be used with concurrent use of medications that affect other components of the clotting mechanisms; prompt diagnosis and any necessary intervention to optimize outcome is warranted. However, evidence-based data on management of anticoagulation therapy during oral and maxillofacial surgery/interventions is lacking. Therefore, clinical understanding and judgment are needed along with appropriate guidelines matching patient- and intervention-specific recommendations.