Stroke Prevention with Oral Anticoagulants: Summary of the Evidence and Efficacy Measures as an Aid to Treatment Choices

Risk Factors of Ischemic Stroke in Patients With Atrial Fibrillation After Transcatheter Aortic Valve Implantation from the Randomized ENVISAGE-TAVI AF Trial

In patients with prevalent or incident atrial fibrillation (AF) after successful transcatheter aortic valve implantation (TAVI) enrolled in the EdoxabaN Versus standard of care and theIr effectS on clinical outcomes in pAtients havinG undergonE Transcatheter Aortic Valve Implantation - in Atrial Fibrillation (ENVISAGE-TAVI AF) trial, the incidence of ischemic stroke (IS) and any stroke was numerically less in the edoxaban group than in the vitamin K antagonist (VKA) group. The present study aimed to identify risk factors associated with IS in an on-treatment subanalysis in patients from ENVISAGE-TAVI AF who received ≥1 dose of edoxaban or VKA. Baseline patient characteristics were compared in patients with and those without IS. Numerical variables were compared using a 1-way analysis of variance; categorical variables were compared using Fisher's exact test. Stepwise Cox regression determined patient characteristics associated with the first IS event. Of 1,377 patients, 41 (3.0%) experienced an IS, and 1,336 (97.0%) did not; baseline demographics and clinical characteristics were well balanced between groups. Most ISs occurred within 180 days of TAVI for edoxaban (57.9%) and VKA (68.2%). The rate of IS was 2.0/100 person-years for edoxaban versus 2.7/100 person-years for VKA. Independently associated with IS were history of systemic embolic events (hazard ratio 2.96, 95% confidence interval 1.26 to 7.00, p = 0.01) and pre-TAVI use of VKAs (hazard ratio 2.17, 95% confidence interval 1.12 to 4.20, p = 0.02). In conclusion, although the overall incidence of IS was small for patients with AF on edoxaban or VKA after successful TAVI, patients with a history of systemic embolic events or pre-TAVI use of VKAs may be at greater risk of IS after TAVI.

Increasing the reach: optimizing screening for atrial fibrillation-the STROKESTOP III study

AIMS

Atrial fibrillation (AF) is the most common type of cardiac arrythmia and is an important risk factor for ischaemic stroke. Many cases of AF remain undiagnosed due to its paroxysmal, intermittent, and often asymptomatic nature. Early detection of AF through screening and initiation of treatment with oral anticoagulants can prevent stroke, increase life expectancy, and decrease the cost of healthcare for the society. However, participation has been low in previous AF screening studies employing population screening. The aim of this study is to determine whether opportunistic screening is a superior method to increase participation in comparison to population screening. We hypothesize that opportunistic screening will significantly increase participation.

METHODS AND RESULTS

In our study, STROKESTOP III, a randomized prospective cohort study, we compare two different methods of AF screening in high-risk individuals: population screening vs. opportunistic screening. Sixteen different primary clinics in Värmland, Sweden, serving 75-76-year-old individuals (n = 2954), will be randomized to either population screening or opportunistic screening. The individuals will be instructed to record electrocardiogram (ECG) for 30 s, 3 times daily for 2 weeks, using a handheld one-lead ECG device. Patients with detected AF will be referred to their primary healthcare physician and offered treatment. The main objective of the study is to determine the rate of participation in opportunistic screening in comparison to population screening.

CONCLUSIONS

The STROKESTOP III study will provide valuable information on which screening method to use for improved participation in atrial fibrillation screening.

Factor Xa inhibitors versus warfarin in patients with non-valvular atrial fibrillation and diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Background

Patients with non-valvular atrial fibrillation with diabetes face increased stroke and cardiovascular risks. This study compares factor Xa inhibitors and warfarin using data from randomized controlled trials (RCTs).

Methods

MEDLINE, Embase, and Cochrane CENTRAL databases were searched for RCTs comparing the risk of efficacy and safety of any factor Xa inhibitors with dose-adjusted warfarin by diabetes status. Incidence of stroke/systemic embolism, major bleeding, intracranial hemorrhage, ischemic stroke, all-cause mortality, risk of hemorrhagic stroke, and myocardial infarction were among the outcomes of interest. A generic inverse-weighted random-effects model was used to calculate hazard ratios (HRs) with 95 percent confidence intervals (CIs).

Results

After applying exclusion criteria, four RCTs containing 19 818 patients were included in the analysis. Compared with warfarin, meta-analysis showed statistically significant reduction in incidence of stroke/systemic embolism (HR 0.80 [95% CI 0.69-0.92]; P=0.002), intracranial hemorrhage (HR 0.49 [95% CI 0.37-0.65]; P<0.001), and risk of hemorrhagic stroke (HR 0.37 [95% CI 0.20-0.66]; P=0.001) in patients on factor Xa inhibitors. However, there was no discernible difference between two treatment arms in incidence of major bleeding (HR 0.93 [95% CI 0.84-1.04]; P=0.19), ischemic stroke (risk ratio (RR) 0.90 [95% CI 0.73-1.12; P=0.34), myocardial infarction (RR 0.88 [95% CI 0.67-1.15]; P=0.35), and all-cause mortality (RR 0.89 [95% CI 0.79-1.01]; P=0.06).

Conclusion

Factor Xa inhibitors show a favorable balance between efficacy and safety compared with warfarin, which is consistent across a wide range of patients with atrial fibrillation known to be at high risk for both ischemic and bleeding events.

The Effects of Tranexamic Acid in Breast Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Tranexamic acid (TXA) is used in trauma and surgical settings. Its role in reducing postoperative blood loss in breast surgery remains unclear. The primary objective of this study was to determine the effect of TXA on postoperative blood loss in breast surgery.

METHODS

Searches of the PubMed, Ovid MEDLINE, Embase, CINAHL, and Cochrane Central Register of Controlled Trials databases were performed from inception to April 3, 2020. Inclusion criteria were any retrospective reviews, prospective cohort studies, and randomized controlled trials that administered TXA (topical or intravenously) in the context of breast surgery. Quality of studies were evaluated using the risk of bias in randomized trials tool and the risk of bias in nonrandomized studies of interventions tool. Data were pooled, and a meta-analysis was performed.

RESULTS

In total, seven studies were included, representing 1226 patients (TXA, 632 patients; control, 622 patients). TXA was administered as follows: topically (20 mL of 25 mg/mL TXA intraoperatively; n =258 patients), intravenously (1 to 3 g perioperatively; n = 743 patients), or both (1 to 3 g daily up to 5 days postoperatively; n = 253 patients). TXA administration reduced hematoma formation in breast surgery (risk ratio, 0.48; 95% CI, 0.32 to 0.73), with no effect on drain output (mean difference, -84.12 mL; 95% CI, -206.53 to 38.29 mL), seroma formation (risk ratio, 0.92; 95% CI, 0.60 to 1.40), or infection rates (risk ratio, 1.01; 95% CI, 0.46 to 2.21). No adverse effects were reported.

CONCLUSION

The use of TXA in breast surgery is a safe and effective modality with low-level evidence that it reduces hematoma rates without affecting seroma rates, postoperative drain output, or infection rates.

Oral anticoagulation use in non-valvular atrial fibrillation patients in rural setting

Background

The 2019 ACC/AHA/HRS guidelines established direct oral anticoagulants (DOACs) as first line therapy over warfarin for non-valvular atrial fibrillation (AF).

Methods

Ambulatory clinic patients with non-valvular AF or atrial flutter seen between 10/1/2019-7/12/2020 included. High-risk AF defined as males CHA2DS2-VASc score ≥2 and females ≥3. Patients were separated into: warfarin, DOAC, or no oral anticoagulation (OAC). ATRIA bleed score calculated. A provider survey assessing knowledge and barriers to anticoagulation completed via REDCap between 3/5-4/16/2020.

Results

Of 12,014 subjects with AF, 8,032 were high risk (mean age 75.9 ± 9.8 years; 57.5% male). There were 4,619 (57.1%) ≥ 75 years and 63.4% were rural dwelling. There was no significant difference between the number of subjects on anticoagulation before and after the guideline publication (75.6% vs. 75.7%, p = 0.79). Warfarin use decreased 2.3% over 1 year (39.3% to 37.0%), while DOACs increased 2.4% (36.2% to 38.7%, p < 0.001 for both). At 1-year, age, male gender, CHA2DS2-VASc score 4-6, hypertension, stroke and cardiology consult increased prescription of OAC (p<0.05). Vascular disease, high risk ATRIA bleed, renal disease, prior hemorrhage, and left atrial appendage occlusion were associated with decreased OAC use (p < 0.05). Left atrial appendage occlusion device use was low (<1%). In a survey, majority of providers noted bleeding risk (35.1%) and cost (25.0%) to be the biggest barriers to DOAC use.

Conclusions

The new guidelines caused a slight increase in DOACs over time. Significant barriers to DOAC use exist in rural areas; one in four high risk AF patient remains without OAC therapy.

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

INTRODUCTION

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

OBJECTIVES

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

DESIGN

Scoping review.

DATA SOURCES

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

RESULTS

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

CONCLUSIONS

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

Astrocytes Protect Human Brain Microvascular Endothelial Cells from Hypoxia Injury by Regulating VEGF Expression

Hypoxic-ischemic stroke has been associated with changes in neurovascular behavior, mediated, in part, by induction of the vascular endothelial growth factor (VEGF). The objective of this study was to investigate the effects of human astrocytes on the proliferation, apoptosis, and function of human microvascular endothelial cells (hBMEC) in vitro. Human microvascular endothelial cells (hBMEC) and human normal astrocytes (HA-1800) were used to establish in vitro cocultured cell models. The coculture model was used to simulate hypoxic-ischemic stroke, and it was found that astrocytes could promote hBMEC proliferation, inhibit apoptosis, reduce cell damage, and enhance antioxidant capacity by activating the VEGF signaling pathway. When VEGF is knocked out in astrocytes, the protective effect of astrocytes on hBMEC was partially lost. In conclusion, our study confirms the protective effect of hBMEC and laid a foundation for the study of hypoxic-ischemic stroke.

Causes and Trends of Disabilities in Community-Dwelling Stroke Survivors: A Population-Based Study

Many stroke survivors live with disabilities in the community. This study aimed to investigate the causes and trends of disabilities among community-dwelling stroke survivors. A total of 1547 community-dwelling stroke survivors ≥ 19 years were identified using the Korea National Health and Nutrition Examination Survey (KNHANES) database from 2007 to 2018. We analyzed the causes and trends of disabilities in strokes survivors using complex-samples procedures. During 2007-2018, 38.0% of stroke survivors were found to have disabilities. Stroke itself was the most common cause of disabilities (21.3%). Musculoskeletal (back or neck problems, 7.0%; arthritis, 5.7%; and leg pain excluding arthritis, 2.3%), sensory (visual problems, 3.6%; and auditory problems, 1.4%), and medical problems (diabetes 2.6%; hypertension, 2.3%; heart disease, 1.5%) accounted for the rest of the other causes of disabilities. Upon analyzing the trends, we found that both the proportion of stroke survivors with disabilities and that of stroke survivors with stroke-related disabilities decreased from KNHANES IV (2007-2009) to V (2010-2012). After 2010-2012, the proportion of both groups stayed constant. The burden of disabilities in non-hospitalized stroke survivors has decreased but still remains high. Attention is warranted because many other problems than a stroke can cause disabilities in community-dwelling stroke survivors.

Antiplatelet and Antithrombotic Therapy in Type I Diabetes Mellitus: Update on Current Data

Diabetes mellitus type 1 (T1DM) is an autoimmune disease characterized by a markedly elevated cardiovascular (CV) risk due to premature atherosclerosis. Previous studies have shown that intense glycemic control reduces the incidence of CV disease. Antiplatelet therapy is considered to be a very important therapy for secondary prevention of recurrent atherothrombotic events in patients with DM, while it may be considered for primary prevention in individuals with T1DM with additional CV risk factors. The aim of the present review is to summarize existing literature data regarding the thrombotic risk in T1DM patients and discuss current treatment strategies.

Incidence, persistence, and clinical relevance of iatrogenic atrial septal defects after percutaneous left atrial appendage occlusion

OBJECTIVE

To investigate the rate and clinical impact of a persisting iatrogenic atrial septal defect (iASD) after percutaneous left atrial appendage occlusion (LAAO).

BACKGROUND

Percutaneous LAAO is an alternative to oral anticoagulation (OAC) for the prevention of ischemic stroke and systemic embolism in patients with atrial fibrillation (AF). Data regarding incidence and persistence of iASD after LAAO procedures and its clinical relevance is scarce.

METHODS

We retrospectively analyzed 144 patients that underwent LAAO at our center between 2009 and 2020 who had at least one follow-up including transesophageal echocardiography (TEE). Baseline clinical, procedural data and echocardiographic characteristics in patients with and without evidence of an iASD were compared. We furthermore determined the rate of iASD persistence over time and evaluated outcomes of patients with and without spontaneous iASD closure.

RESULTS

After a median of 92 days (IQR 75-108 days) after LAAO, 50 patients (50/144, 34.7%) showed evidence of an iASD. Patients with iASD had higher CHADS-VASc-scores (4.9±1.5 vs 4.2±1.2, p = 0.03), larger left atrial volumes (80.5±30.5 ml vs 67.1±19.7 ml, p = 0.01) and were more likely to have relevant mitral regurgitation (≥° II) (46.0% vs 12.3%, p = 0.001). LAAO procedures took longer (50.1±24.3 vs 41.1±17.8 min, p = 0.06) in patients with a persisting iASD. Furthermore, larger device sizes were implanted (24.3±3.4 mm vs 22.1±2.8 mm, p = 0.03). The presence of an iASD had no impact on RV dysfunction, thromboembolism or mortality. Spontaneous closure of an iASD was documented in 52.0% (26/50). Hereby, similar risk factors were identified for the persistence of an iASD in follow-up.

Economic burden of rivaroxaban and warfarin among nonvalvular atrial fibrillation patients with obesity and polypharmacy

Aim: Evaluate healthcare resource utilization (HRU) and costs associated with rivaroxaban and warfarin among nonvalvular atrial fibrillation (NVAF) patients with obesity and polypharmacy. Materials & methods: IQVIA PharMetrics^® Plus (January 2010-September 2019) data were used to identify NVAF patients with obesity (BMI ≥30 kg/m²) and polypharmacy (≥5 medications) initiated on rivaroxaban or warfarin. Weighted rate ratios and cost differences were evaluated post-treatment initiation. Results: Rivaroxaban was associated with significantly lower rates of HRU, including hospitalization (rate ratio [95% CI]: 0.83 [0.77, 0.92]). Medical costs were reduced in rivaroxaban users (difference [95% CI]: -US$6868 [-US$10,628, -US$2954]), resulting in significantly lower total healthcare costs compared with warfarin users (difference [95% CI]: -US$4433 [-US$8136, -US$582]). Conclusion: Rivaroxaban was associated with lower HRU and costs compared with warfarin among NVAF patients with obesity and polypharmacy in commercially insured US patients.

Comparative Effectiveness and Safety of Rivaroxaban and Warfarin Among Nonvalvular Atrial Fibrillation (NVAF) Patients with Obesity and Polypharmacy in the United States (US)

Introduction

Current evidence indicates that rivaroxaban may be a safe and effective alternative to warfarin among patients with nonvalvular atrial fibrillation (NVAF) and obesity. However, evidence regarding the impact of polypharmacy is limited in this population. The present study evaluated the effectiveness and safety of rivaroxaban versus warfarin among NVAF patients with obesity and polypharmacy in the US.

Methods

De-identified health insurance claims data from the IQVIA PharMetrics^® Plus data (01/2010–09/2019) were used to identify NVAF patients with obesity (BMI ≥ 30 kg/m²) and polypharmacy (≥ 5 medications) initiated on rivaroxaban or warfarin. Inverse probability of treatment weighting (IPTW) was used to adjust for imbalances between groups. Study outcomes were evaluated up to 36 months post-treatment initiation and included the composite of stroke or systemic embolism (stroke/SE) and major bleeding. Subgroup analyses were conducted stratified by polypharmacy category (5–9 or ≥ 10 medications). Outcomes were assessed using Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (CIs).

Results

A total of 7000 and 3920 NVAF patients with obesity and polypharmacy were initiated on rivaroxaban and warfarin, respectively. At 36 months of follow-up, rivaroxaban was associated with a 29% lower risk of stroke/SE relative to warfarin (HR 0.71, 95% CI 0.57, 0.90). Major bleeding risk was not significantly different among rivaroxaban- compared to warfarin-treated patients (HR 0.85, 95% CI 0.70, 1.03). Subgroup analyses yielded results that were largely consistent with the overall polypharmacy analysis.

Conclusions

These results suggest that rivaroxaban is an effective and safe treatment option among NVAF patients with obesity and polypharmacy in a commercially-insured US population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01746-2.

Surgical Treatment of Atrial Fibrillation

The surgical treatment of atrial fibrillation (AF) has evolved significantly over the last 20 years and even more so in the last 5 years. There are now many clinically successful surgical procedures focused on eliminating AF and AF-related stroke. This review discusses the current types of surgical AF procedures, including minimally invasive and hybrid, and may assist clinicians in understanding the various surgical AF options available to patients today.

Healthcare resource utilization and costs of rivaroxaban versus warfarin among non-valvular atrial fibrillation (NVAF) patients with obesity in a US population

AIM

To assess the real-world healthcare resource utilization (HRU) and costs of patients with non-valvular atrial fibrillation (NVAF) and obesity newly initiated on rivaroxaban or warfarin in the US.

METHODS

This retrospective study used IQVIA PharMetrics Plus data (01/2010-09/2019) to evaluate patients (≥18 years) with NVAF and obesity (body mass index ≥30 kg/m²) initiated on rivaroxaban or warfarin (on or after 01/2013). Inverse probability of treatment weighting (IPTW) was used to adjust for confounding between cohorts. HRU and costs were assessed post-treatment initiation. Weighted cohorts were compared using Poisson regression models and cost differences, with 95% confidence intervals (CIs) and p values generated using non-parametric bootstrap procedures.

RESULTS

After IPTW, 10,555 and 5,080 patients were initiated on rivaroxaban and warfarin, respectively (mean age: 59 years). At 12 months follow-up, the rivaroxaban cohort had lower all-cause HRU, including fewer hospitalizations (rate ratio [RR]: 0.80, 95% CI: 0.74, 0.87), emergency room visits (RR: 0.89, 95% CI: 0.83, 0.97), and outpatient visits (RR: 0.72, 95% CI: 0.69, 0.77; all p < .05). Medical costs were also reduced in the rivaroxaban cohort (mean difference: -$6,759, 95% CI: -$9,814, -$3,311) due to reduced hospitalization costs (mean difference: -$5,967, 95% CI: -$8,721, -$3,327), resulting in lower total all-cause healthcare costs compared to the warfarin cohort (mean difference: -$4,579, 95% CI: -$7,609, -$1,052; all p < .05). The rivaroxaban cohort also had lower NVAF-related HRU and medical costs driven by lower hospitalization at 12 months post-treatment initiation. HRU and cost reductions associated with rivaroxaban persisted up to 36 months of follow-up.

LIMITATIONS

Claims data may have contained inaccuracies and obesity was classified based on ICD diagnosis codes given that patient BMI values were not available.

CONCLUSIONS

Rivaroxaban was associated with reduced HRU and costs compared to warfarin among NVAF patients with obesity in a real-world US setting.

High Frequency of Anticoagulation Management Errors Preceding Ischemic Strokes in Atrial Fibrillation

BACKGROUND AND AIMS

Anticoagulants are recommended to prevent cardioembolic stroke in most patients with atrial fibrillation (AF). Management errors with anticoagulation and use of aspirin instead of anticoagulants have been documented worldwide, especially with vitamin K antagonists. We assessed the rate of anticoagulant mismanagement errors in patients admitted with ischemic stroke, and the clinical correlates with stroke outcomes in the era of non-vitamin K oral anticoagulants.

METHODS

We performed a retrospective analysis of patients admitted with ischemic stroke and history of AF to a single-centre tertiary hospital stroke unit in Melbourne, Australia, between January 2016 and June 2019. We assessed management errors as defined using European Heart Rhythm Association criteria with anticoagulation in the two weeks prior to the index stroke.

RESULTS

A total of 306 patients with AF and ischemic stroke were included, of whom 196 (64%) had management errors. Patients with management errors were older (median age 84 versus 81 years [p=0.002]) and more often female (53% verse 38% [p=0.02]). Of those with management errors, 74 (37%) were not prescribed any anticoagulation despite increased stroke risk and absence of contraindications and 40 (20%) had anticoagulation inappropriately ceased. Mortality at 3-months was 32% in those with management errors, compared to 17% in the appropriately anticoagulated group (p=0.005).

CONCLUSIONS

Inappropriate management of anticoagulants is present in the majority of acute ischemic stroke in the 2 weeks preceding the event and is linked to higher mortality. Improved anticoagulation practice has the potential to substantially reduce stroke rates in patients with AF. This article is protected by copyright. All rights reserved.

Healthcare costs of NVAF patients treated with rivaroxaban and apixaban in the US

OBJECTIVES

To provide the most current assessment of real-world healthcare resource utilization (HRU) and costs among patients with non-valvular atrial fibrillation (NVAF) who newly initiated rivaroxaban and apixaban using a large US database.

MATERIAL AND METHODS

A retrospective weighted cohort design was used with healthcare insurance claims from the Optum Clinformatics Data Mart databases (January 2012-December 2018). The index date was defined as the first dispensing of rivaroxaban or apixaban. Adult NVAF patients with an index date on or after 1 January 2016, ≥ 12 months of continuous eligibility before the index date and ≥ 1 month after, and without prior use of oral anticoagulant were included. The observation period spanned from the index date to the earliest of the end of data availability, end of insurance coverage, or death. Inverse probability of treatment weighting (IPTW) was used to adjust for differences in baseline characteristics between cohorts. All-cause healthcare resource utilization (HRU), including hospitalization, emergency room, and outpatient visits, and healthcare costs, including medical and pharmacy costs, were evaluated from the payer's perspective during the observation period up to 18 and 24 months, separately.

RESULTS

In total, 23,822 rivaroxaban and 53,666 apixaban users were included. After weighting, all baseline characteristics were well balanced between cohorts (mean age: 73.8 years, female: 46.6% in both cohorts). Up to 18 months of follow-up, rivaroxaban users incurred significantly lower total healthcare costs compared to apixaban users (cost difference = -$1,121; p = 0.020), driven by significantly lower rates of outpatient hospital visits and associated costs (cost difference = -$1,579; p < 0.001). Similar results were found in the analysis conducted for up to 24 months of follow-up (total cost difference = ‒$1,111; p = 0.020).

CONCLUSIONS

In this large retrospective analysis, patients with NVAF initiated on rivaroxaban incurred significantly lower healthcare costs compared to those initiated on apixaban, which were primarily driven by significantly lower outpatient visits and costs during the 18- and 24-month follow-up periods.

Cost-effectiveness analysis of apixaban compared to other direct oral anticoagulants for prevention of stroke in Austrian atrial fibrillation patients

OBJECTIVES

Several direct oral anticoagulants (DOACs) have been approved by the European Medicines Agency since 2008. The aim of the present cost-effectiveness-analysis was to analyze apixaban compared to other DOACs and vitamin K antagonists (warfarin) in Austria.

METHODS

A cost-utility-model was developed to simulate lifetime-costs and quality-adjusted-life-years of DOACs and warfarin, based on a published Markov-Model and 23 randomized trials with 94,656 atrial-fibrillation (AF) patients. Each year, a patient has a probability of suffering a clinically relevant (extracranial) bleed, an intracranial hemorrhage (ICH), an ischemic stroke or a myocardial infarction (MI), remaining healthy, or deceasing. Direct-costs (2018€) were derived from published sources from the payer's perspective.

RESULTS

In the base-case, warfarin had the lowest cost of 12,968 € (95%-CI±593 €) followed by apixaban (15,269 €±661 €), edoxaban (15,534 €±641 €), dabigatran (15,687 €±667 €), and rivaroxaban (17,522 €±764 €). Apixaban had the highest quality-adjusted-life-years estimate at 5.45 (SD, 0.06). In a Monte-Carlo probabilistic sensitivity analysis, apixaban was cost-effective vs. edoxaban, dabigatran, warfarin, and rivaroxaban in 85.6%, 79.0%, 76.4%, and 61.2% of the simulations, respectively.

CONCLUSION

In patients with AF and an increased risk of stroke, prophylaxis with apixaban was highly cost-effective from the perspective of the Austrian health-care system.

Examining the evidence for PFO closure and novel oral anticoagulants for treatment of cryptogenic stroke

Introduction: There has been considerable study assessing the treatment of cryptogenic stroke (CS) recently. This review examines the role of patent foramen ovale (PFO) closure in CS, while also discussing the evidence for alternative medical therapies in disease treatment.Areas covered: PFO closure for treatment of CS has been assessed in 6 randomized controlled trials (RCTs). This review summarizes the background, results and limitations of these trials. Methodological and treatment-related differences in RCTs provide potential explanations for the discordance in outcomes observed between older (CLOSURE, PC, RESPECT-Early) and newer PFO closure trials (RESPECT-Late, CLOSE, REDUCE, DEFENSE-PFO). With regards to medical therapy for CS, two RCTs (NAVIGATE ESUS and RE-SPECT ESUS) did not show any benefit in recurrent stroke prevention with the use of novel oral anticoagulants (NOAC) compared with aspirin. Marked differences in baseline characteristics and rates of recurrent stroke between PFO closure and NOAC trials underlie the heterogeneous nature of CS.Expert commentary: In young patients with CS, PFO closure reduces the risk of recurrent stroke, with newer RCTs emphasizing the importance of identifying those with 'high-risk' PFO and the need for continued antiplatelet therapy. Additionally, treatment for CS should not be uniform but directed at disease-specific pathologies.

Long noncoding RNA XIST participates hypoxia-induced angiogenesis in human brain microvascular endothelial cells through regulating miR-485/SOX7 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) X-inactive specific transcript (XIST) has identified to involve into the tumor cell angiogenesis. However, whether XIST contributes to Human Brain Microvascular Endothelial Cells (HBMEC) angiogenesis as well as potential mechanisms are largely unclear.

METHODS

The expression of XIST, miR-485-3p and SRY-box 7 (SOX7) in HBMEC were altered by transfection. The cell viability, cell migration and tube formation of HBMEC were measured, respectively. The cross-regulations between XIST, miR-485-3p, SOX7, and vascular endothelial growth factor (VEGF) signaling pathway were investigated by RT-qPCR and Western blot assay.

RESULTS

In this study, we characterized the upregulation of XIST in HBMEC under hypoxia condition. Meanwhile, XIST silencing impaired hypoxia-induced cell proliferation, migration and tube formation. Besides, our integrated experiments identified that XIST may competitively bind with miR-485-3p and then modulate the derepression of downstream target SRY-box 7 (SOX7). Mechanically, knockdown of XIST impaired hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis and subsequent suppression of VEGF signaling pathway.

CONCLUSION

Altogether, the present study suggested that XIST is required to maintain VEGF signaling expression in HBMEC under hypoxia condition and plays a vital role in hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis.