Rivaroxaban real-world evidence: Validating safety and effectiveness in clinical practice

Clinical outcomes in patients receiving edoxaban or phenprocoumon for prevention of stroke in atrial fibrillation: a German real-world cohort study

Background

Appropriate and timely anticoagulant therapy with vitamin K antagonists (VKAs) or non-vitamin K oral antagonists (NOACs) is essential for stroke prevention in non-valvular atrial fibrillation (NVAF). Comparative data regarding effectiveness and safety for edoxaban vs phenprocoumon, the predominant VKA in Germany, are scarce.

Objectives

The study evaluates effectiveness and safety of edoxaban vs phenprocoumon in NVAF patients in a German real-world setting.

Methods

German statutory health insurance claims data of the Institute for Applied Health Research Berlin (InGef) Research Database from 2014 until 2019 were analyzed. In NVAF patients, new users of edoxaban and phenprocoumon were compared to assess effectiveness (stroke/systemic embolism (SE)) and safety (bleeding) during therapy. Hazard ratios (HR) were estimated through multiple outcome-specific cox proportional hazard models adjusting for baseline characteristics. Outcomes of geriatric patients were analyzed in subgroup analyses.

Results

Between 2015 and 2018, 7,975 and 13,319 NVAF patients newly initiated treatment with edoxaban or phenprocoumon. After adjusting for baseline confounders, the risk of stroke/SE (HR: 0.85, 95% CI: 0.70–1.02) was numerically but not significantly lower, while the risk of major bleeding (HR: 0.69, 95% CI: 0.58–0.81) was significantly lower for edoxaban. In the geriatric subgroups, homogenous results compared to the main analysis were obtained.

Conclusion

The results of this real-world analysis indicated better effectiveness and safety outcomes in patients with NVAF initiating edoxaban treatment compared to phenprocoumon. The findings confirm that the beneficial effects observed in the pivotal ENGAGE AF-TMI 48 trial can also be achieved in real-world use of edoxaban.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00395-x.

EA3: A softmax algorithm for evidence appraisal aggregation

Real World Evidence (RWE) and its uses are playing a growing role in medical research and inference. Prominently, the 21st Century Cures Act—approved in 2016 by the US Congress—permits the introduction of RWE for the purpose of risk-benefit assessments of medical interventions. However, appraising the quality of RWE and determining its inferential strength are, more often than not, thorny problems, because evidence production methodologies may suffer from multiple imperfections. The problem arises to aggregate multiple appraised imperfections and perform inference with RWE. In this article, we thus develop an evidence appraisal aggregation algorithm called EA³. Our algorithm employs the softmax function—a generalisation of the logistic function to multiple dimensions—which is popular in several fields: statistics, mathematical physics and artificial intelligence. We prove that EA³ has a number of desirable properties for appraising RWE and we show how the aggregated evidence appraisals computed by EA³ can support causal inferences based on RWE within a Bayesian decision making framework. We also discuss features and limitations of our approach and how to overcome some shortcomings. We conclude with a look ahead at the use of RWE.

Thromboembolic and bleeding events with rivaroxaban in clinical practice in Spain: impact of inappropriate doses (the EMIR study)

Aim: To analyze the frequency and variables related to inappropriate rivaroxaban dosage in clinical practice and its impact on outcomes after 2 years. Materials & methods: Postauthorization, observational, multicenter study, in which atrial fibrillation patients, treated with rivaroxaban ≥6 months were included. Results: A total of 1421 patients (74.2 ± 9.7 years, CHA₂DS₂-VASc 3.5 ± 1.6) were included. Overall, 22.9% received rivaroxaban 15 mg. The proper dose of rivaroxaban was taken by 83.3% (9.7% underdosed, 7.0% overdosed). Older age and renal insufficiency were associated with inadequate rivaroxaban dosage. There was a trend toward higher all-cause mortality among underdosed patients (adjusted hazard ratio 1.39; 95% CI 0.75-2.58), and more bleedings in overdosed patients (2.29 vs 0.80 events/100 patient-years; p = 0.14). Conclusion: In clinical practice, rivaroxaban is properly dosed in most patients.

Risk of Stroke Outcomes in Atrial Fibrillation Patients Treated with Rivaroxaban and Warfarin

OBJECTIVES

In a previous real-world study, rivaroxaban reduced the risk of stroke overall and severe stroke compared with warfarin in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study was to assess the reproducibility in a different database of our previously observed results (Alberts M, et al. Stroke. 2020;51:549-555) on the risk of severe stroke among NVAF patients in a different population treated with rivaroxaban or warfarin.

MATERIAL AND METHODS

This retrospective cohort study included patients from the IBM® MarketScan® Commercial and Medicare databases (2011-2019) who initiated rivaroxaban or warfarin after a diagnosis of NVAF, had ≥6 months of continuous health plan enrollment, had a CHA₂DS₂-VASc score ≥2, and had no history of stroke or anticoagulant use. Patient data were assessed until the earliest occurrence of a primary inpatient diagnosis of stroke, death, end of health plan enrollment, or end of study. Stroke severity was defined by National Institutes of Health Stroke Scale (NIHSS) score, imputed by random forest model. Cox proportional hazard regression was used to compare risk of stroke between cohorts, balanced by inverse probability of treatment weighting.

RESULTS

The mean observation period from index date to either stroke, or end of eligibility or end of data was 28 months. Data from 13,599 rivaroxaban and 39,861 warfarin patients were included. Stroke occurred in 272 rivaroxaban-treated patients (0.97/100 person-years [PY]) and 1,303 warfarin-treated patients (1.32/100 PY). Rivaroxaban patients had lower risk for stroke overall (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.76-0.88) and for minor (NIHSS 1 to <5; HR, 0.83; 95% CI, 0.74-0.93), moderate (NIHSS 5 to <16; HR, 0.88; 95% CI, 0.78-0.99), and severe stroke (NIHSS 16 to 42; HR, 0.44; 95% CI, 0.22-0.91).

CONCLUSIONS

The results of this study in a larger population of NVAF patients align with previous real-world findings and the ROCKET-AF trial by showing improved stroke prevention with rivaroxaban versus warfarin across all stroke severities.

Effectiveness and Safety of Oral Anticoagulants in Older Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background and Objective

Atrial fibrillation (AF), the most common cardiac arrhythmia, typically increases with age. Oral anticoagulants (OACs) are the cornerstone of treatment to reduce the associated risk for systemic thromboembolism. Four large randomized controlled trials (RCTs) have shown that non-vitamin K antagonist oral anticoagulants (NOACs) are non-inferior to vitamin K antagonists (VKAs) in preventing stroke and systemic embolism, as well as regarding their risk for major bleeding. However, as vulnerable geriatric patients with AF were largely underrepresented in these trials, physicians are faced with the challenge of choosing the right anticoagulant for geriatric patients in real-life clinical practice. In this vulnerable patient group, NOACs tend to be underused or underdosed due to concerns of excessive fall-related intracranial bleeding, cognitive impairment, multiple drug-drug interactions, low body weight or impaired renal function. As life expectancy continues to rise worldwide, the number of geriatric patients substantially increases. Therefore, there is an urgent need for a critical appraisal of the added value of NOACs in geriatric patients with AF at high thromboembolic and bleeding risk.

Methods and Results

This systematic review provides an overview of the literature on the impact of increased age (≥75 years), multimorbidity, polypharmacy, increased falling risk, frailty and dementia on the effectiveness and safety of NOACs as compared to VKAs, after searching the Medline database. Moreover, a meta-analysis on the impact of increased age ≥75 years old was performed after pooling results from 6 post hoc analyses of RCTs and 6 longitudinal observational cohort studies, highlighting the superior effectiveness (hazard ratio (HR) 0.83, 95% confidence interval (CI) [0.74–0.94] for stroke/SE; HR 0.77, 95%CI [0.65–0.92] for mortality) and non-inferior safety (HR 0.93, 95%CI [0.86–1.01] for major bleeding; HR 0.58, 95%CI [0.50–0.67] for intracranial bleeding; HR 1.17, 95%CI [0.99–1.38] for gastrointestinal bleeding) of NOACs versus VKAs in older AF patients.

Conclusion

Across geriatric subgroups, apixaban was consistently associated with the most favourable benefit-risk profile and should therefore be preferred in geriatric patients with AF. However, research gaps on the impact of increased falling risk, frailty and baseline dementia were identified, requiring careful consideration while awaiting more results.

Awareness, Knowledge, and Utility of RCT Data vs RWE: Results From a Survey of US Cardiologists: Real-world Evidence in Clinical Decision Making

Real-world evidence (RWE) provides a potential rich source of additional information to the body of data available from randomized clinical trials (RCTs), but there is a need to understand the strengths and limitations of RWE before it can be applied to clinical practice. To gain insight into current thinking in clinical decision making and utility of different data sources, a representative sampling of US cardiologists selected from the current, active Fellows of the American College of Cardiology (ACC) were surveyed to evaluate their perceptions of findings from RCTs and RWE studies and their application in clinical practice. The survey was conducted online via the ACC web portal between 12 July and 11 August 2017. Of the 548 active ACC Fellows invited as panel members, 173 completed the survey (32% response), most of whom were board certified in general cardiology (n = 119, 69%) or interventional cardiology (n = 40, 23%). The survey results indicated a wide range of familiarity with and utilization of RWE amongst cardiologists. Most cardiologists were familiar with RWE and considered RWE in clinical practice at least some of the time. However, a significant minority of survey respondents had rarely or never applied RWE learnings in their clinical practice, and many did not feel confident in the results of RWE other than registry data. These survey findings suggest that additional education on how to assess and interpret RWE could help physicians to integrate data and learnings from RCTs and RWE to best guide clinical decision making.

GARFIELD-AF: a worldwide prospective registry of patients with atrial fibrillation at risk of stroke

The Global Anticoagulant Registry in the Field-Atrial Fibrillation (GARFIELD-AF) examined real-world practice in a total of 57,149 (5069 retrospective, 52,080 prospective) patients with newly diagnosed AF at risk of stroke/systemic embolism, enrolled at over 1000 centers in 35 countries. It aimed to capture data on AF burden, patients' clinical profile, patterns of clinical practice and antithrombotic management, focusing on stroke/systemic embolism prevention, uptake of new oral anticoagulants, impact on death and bleeding. GARFIELD-AF set new standards for quality of data collection and analysis. A total of 36 peer-reviewed articles were already published and 73 abstracts presented at international congresses, covering treatment strategies, geographical variations in baseline risk and therapies, adverse outcomes and common comorbidities such as heart failure. A risk prediction tool as well as innovative observational studies and artificial intelligence methodologies are currently being developed by GARFIELD-AF researchers. Clinical Trial Registration: NCT01090362 (ClinicalTrials.gov).

Efficacy and Safety of Rivaroxaban versus Warfarin for the Treatment of Acute Pulmonary Embolism: A Real-World Study

Background

Pulmonary embolism (PE) is a life-threatening disease. Target-specific anticoagulant rivaroxaban is a direct factor Xa inhibitor that can be safely used without laboratory monitoring.

Objective

To investigate the efficacy and safety of rivaroxaban versus warfarin for the treatment of acute pulmonary thromboembolism in real-world clinical practice.

Method

This was a semiretrospective, semiprospective, and real-world trial involving 128 patients with acute symptomatic pulmonary embolism with or without active tumor or frailty. We compared rivaroxaban to the standard therapy consisting of low-molecular-weight heparin combined with warfarin. The primary efficacy outcome was absorption of thrombus. The principal safety outcome was bleeding episode.

Results

There was no significant difference in thrombus absorption between rivaroxaban and standard therapy after 3-month treatment (P = 0.798, 95% confidence interval (CI) 0.686 to 1.336) or more than 6-month treatment (P = 0.534, 95% confidence interval (CI) 0.795 to 1.556). There was no decline in efficacy (including computed tomographic pulmonary angiography and recurrence) when the rivaroxaban dose was reduced to 10 mg once daily after 3 months of administration. The ratio of patients without bleeding was 48.84% for rivaroxaban and 19.05% for standard therapy (P = 0.001). There was no significant difference in rivaroxaban monotherapy subgroups (including frail patients, tumor patients, and thrombolysis or nonthrombolysis at intermediate-high-risk patients).

Conclusion

In this real-world study, the efficacy and safety of rivaroxaban alone was not different to standard therapy for pulmonary emboli absorption. With an extension in treatment duration, the rivaroxaban regimen had a higher efficacy and safety than standard therapy and there was no decline in treatment efficacy when the rivaroxaban dose was reduced to 10 mg once daily.

Healthcare resource utilization and costs among nonvalvular atrial fibrillation patients initiating rivaroxaban or warfarin in skilled nursing facilities: a retrospective cohort study

Objective: Atrial fibrillation (AF) is present in up to 17% of patients in skilled nursing facilities (SNFs). This study compared healthcare resource utilization (HRU) and costs between AF patients initiating rivaroxaban or warfarin in SNFs.Methods: Using de-identified claims from Optum Clinformatics Extended Data Mart (1 January 2013 to 31 December 2017), this retrospective cohort study indexed AF patients with first SNF admission during which rivaroxaban or warfarin was initiated within 3 days of admission. To adjust for selection bias, inverse probability of treatment weighting (IPTW) was applied for baseline characteristics. Logistic regression and generalized linear models were used to compare HRU and costs.Results: 519 rivaroxaban and 1129 warfarin patients met inclusion criteria. After IPTW, the cohorts were well balanced for baseline characteristics. The average length of index SNF stay was 32.07 and 37.44 days for rivaroxaban and warfarin patients, respectively. During SNF stay, rivaroxaban patients had 27% lower odds of hospitalization (p < .0001), 2.7 fewer international normalized ratio (INR) tests per-patient-per-month (PPPM; p < .001), and 2.3 fewer pathology/laboratory encounters PPPM (p < .0001) than warfarin patients. All-cause healthcare costs were $2638 lower with rivaroxaban versus warfarin (p < .0001) during the index SNF stay, with lower medical costs (p < .0001) but higher pharmacy costs (p < .0001). Total all-cause healthcare costs 100 days post-index SNF were $8746 lower with rivaroxaban versus warfarin (p < .0001).Conclusions: In the SNF setting, AF patients treated with rivaroxaban had 5-day shorter length of stay, lower HRU, and lower all-cause total and medical costs compared to warfarin, despite higher treatment costs. These findings may help inform clinical decision-making to reduce economic burden.

Impact of direct oral anticoagulant off-label doses on clinical outcomes of atrial fibrillation patients: A systematic review

AIMS

Worldwide observational studies are evidencing discordance between guidelines and real-world practice regarding direct oral anticoagulant drug (DOAC) doses. This systematic review summarizes and evaluate DOACs use in real-world practice.

METHODS

This review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines searching PubMed (MEDLINE) and Medscape databases.

RESULTS

Data from 75 studies showed that most of the patients treated with DOACs for stroke prevention in atrial fibrillation received doses in accordance to the guidelines. However, a significant number of patients received off-label doses (25-50% in most of the studies evaluated). DOAC overdosing was associated with increased all-cause mortality and worse bleeding events while underdosing was associated with increased cardiovascular hospitalization and, particularly for apixaban, with a nearly 5-fold increased risk of stroke.

CONCLUSION

Patients prescribed with off-label DOAC doses did not receive the full benefit of anticoagulation and presented an increased risk of stroke, bleeding and/or adverse effects.

Risks of Stroke and Mortality in Atrial Fibrillation Patients Treated With Rivaroxaban and Warfarin

Background and Purpose- Oral anticoagulation therapy is standard of care for patients with nonvalvular atrial fibrillation to prevent stroke. This study compared rivaroxaban and warfarin for stroke and all-cause mortality risk reduction in a real-world setting. Methods- This retrospective cohort study (2011-2017) included de-identified patients from the Optum Clinformatics Database who started treatment with rivaroxaban or warfarin within 30 days following initial diagnosis of nonvalvular atrial fibrillation. Before nonvalvular atrial fibrillation diagnosis, patients had 6 months of continuous health plan enrollment and CHA₂DS₂-VASc score ≥2. Stroke severity was determined by the National Institutes of Health Stroke Scale, imputed based on machine learning algorithms. Stroke and all-cause mortality risks were compared by treatment using Cox proportional hazard regression, with inverse probability of treatment weighting to balance cohorts for baseline risk factors. Stratified analysis by treatment duration was also performed. Results- During a mean follow-up of 27 months, 175 (1.33/100 patient-years [PY]) rivaroxaban-treated and 536 (1.66/100 PY) warfarin-treated patients developed stroke. The inverse probability of treatment weighting model showed that rivaroxaban reduced stroke risk by 19% (hazard ratio [HR], 0.81 [95% CI, 0.73-0.91]). Analysis by stroke severity revealed risk reductions by rivaroxaban of 48% for severe stroke (National Institutes of Health Stroke Scale score, 16-42; HR, 0.52 [95% CI, 0.33-0.82]) and 19% for minor stroke (National Institutes of Health Stroke Scale score, 1 to <5; HR, 0.81 [95% CI, 0.68-0.96]), but no difference for moderate stroke (National Institutes of Health Stroke Scale score, 5 to <16; HR, 0.93 [95% CI, 0.78-1.10]). A total of 41 (0.31/100 PY) rivaroxaban-treated and 147 (0.44/100 PY) warfarin-treated patients died poststroke, 12 (0.09/100 PY) and 67 (0.20/100 PY) of whom died within 30 days, representing mortality risk reductions by rivaroxaban of 24% (HR, 0.76 [95% CI, 0.61-0.95]) poststroke and 59% (HR, 0.41 [95% CI, 0.28-0.60]) within 30 days. Conclusions- After the initial diagnosis of atrial fibrillation, patients treated with rivaroxaban versus warfarin had significant risk reduction for stroke, especially severe stroke, and all-cause mortality after a stroke. Findings from this observational study may help inform anticoagulant choice for stroke prevention in patients with nonvalvular atrial fibrillation.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Exposure to vitamin k antagonists and kidney function decline in patients with atrial fibrillation and chronic kidney disease

BACKGROUND

Exposure to vitamin K antagonists (VKA) has been suggested to accelerate progression of chronic kidney disease (CKD) but robust clinical data are currently lacking.

METHODS

We retrospectively evaluated the impact of VKA exposure on kidney function in patients with atrial fibrillation (AF) and CKD stage 3/4. Patients were prospectively followed within a primary care electronic database (median follow-up of 1.45 years). The kidney function trajectory over time, defined as the annualized change in estimated glomerular filtration rate (eGFR), was analyzed with linear mixed-effects regression including propensity score adjustment.

RESULTS

14 432 patients (median age 78 years, median CHA 2 DS 2-VASc score 4 points) contributed 97 792 eGFR measurements (mean 6.8 measurements/patient; range: 1-197). Mean baseline eGFR was 50.3 mL/min/1.73 m2; and declined by 1.10 mL/min/1.73 m2/year (95% CI: 0.91-1.28, P < 0.0001). In 7409 patients with VKA exposure, CKD progression was significantly faster compared to patients without VKA exposure (5-year absolute eGFR loss from baseline: 6.0 mL/min/1.73 m2 vs 4.5 mL/min/1.73 m2, for an absolute 5-year excess eGFR decline with VKA exposure of 1.5 mL/min/1.73 m2 (95% CI: 0.4-2.7, P = 0.002). These results prevailed upon adjusting for CHA 2 DS 2-VASc score and other potential imbalances in prognostic variables, and in several sensitivity analyses. In the group without documented VKA exposure, 1775 VKA patients (24%) and 1012 patients (14%) developed a 30% decline in eGFR during follow-up (P < 0.0001).

CONCLUSIONS

In patients with AF and CKD, VKA use is associated with accelerated eGFR decline. Within the limitations of a retrospective analysis, this finding supports the "VKA-renal-calcification hypothesis." However, although statistically significant, the excess loss in eGFR over 5 years with VKA was modest.

Real World Comparison of Rivaroxaban and Warfarin in Korean Patients with Atrial Fibrillation: Propensity Matching Cohort Analysis

Rivaroxaban has emerged as a potential alternative to warfarin for the prevention of thromboembolism in patients with atrial fibrillation (AF). However, there has been concern for the risk of major bleeding, especially in Asian patients. We investigated the efficacy and safety of rivaroxaban compared to warfarin in Korean real world practice. A total of 2,208 consecutive non-valvular AF patients were divided into the Warfarin group (n=990) and the Rivaroxaban group (n=1218). Propensity matched 1-year clinical outcomes were compared (Warfarin, n=804; Rivaroxaban, n=804). The efficacy outcome was defined as stroke/systemic embolism (SE). The safety outcome was major bleeding. The primary net clinical benefit (NCB) was defined as the composite of stroke/SE, major bleeding, and all-cause mortality. Secondary, NCB was defined as the composite of stroke, SE, and major bleeding. Rivaroxaban had the similar efficacy in terms of thromboembolic event prevention [hazard ratio (HR) 0.69, 95% confidence interval (CI) 0.37-1.32, p=0.266] compared to warfarin. Rivaroxaban significantly lowered the risk of major bleeding [HR 0.41, 95% CI 0.22-0.76, p=0.004]. Primary NCB was significantly low in the rivaroxaban group [HR 0.54, 95% CI 0.36-0.81, p=0.003]. Secondary NCB was also low in the rivaroxaban group [HR 0.62, 95% CI 0.40-0.99, p=0.041]. Both rivaroxaban 15 mg and 20 mg groups had similar efficacy and significantly lower risks of major bleeding as well as primary and secondary NCB compared to the warfarin group. In patients with non-valvular AF, rivaroxaban had a similar efficacy to warfarin in Korean real world practice. However, rivaroxaban had better safety and net clinical outcomes compared to warfarin.

Pharmacogenetic studies with oral anticoagulants. Genome-wide association studies in vitamin K antagonist and direct oral anticoagulants

Oral anticoagulants (OAs) are the recommended drugs to prevent cardiovascular events and recurrence in patients with atrial fibrillation (AF) and cardioembolic stroke. We conducted a literature search to review the current state of OAs pharmacogenomics, focusing on Genome Wide Association Studies (GWAs) in patients treated with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs).

VKAs: Warfarin, acenocoumarol, fluindione and phenprocoumon have long been used, but their interindividual variability and narrow therapeutic/safety ratio makes their dosage difficult. GWAs have been useful in finding genetic variants associated with VKAs response. The main genes involved in VKAs pharmacogenetics are: VKORC1, CYP2C19 and CYP4F2. Variants in these genes have been included in pharmacogenetic algorithms to predict the VKAs dose individually in each patient depending on their genotype and clinical variables.

DOACs: Dabigatran, apixaban, rivaroxaban and edoxaban have been approved for patients with AF. They have stable pharmacokinetics and do not require routine blood checks, thus avoiding most of the drawbacks of VKAs. Except for a GWAs performed in patients treated with dabigatran, there is no Genome Wide pharmacogenomics data for DOACs. Pharmacogenomics could be useful to predict the better clinical response and avoid adverse events in patients treated with anticoagulants, identifying the most appropriate anticoagulant drug for each patient. Current pharmacogenomics data show that the polymorphisms affecting VKAs or DOACs are different, concluding that personalized medicine based on pharmacogenomics could be possible. However, more studies are required to implement personalized medicine in clinical practice with OA and based on pharmacogenetics of DOACs.

Fitting the right non-vitamin K antagonist oral anticoagulant to the right patient with non-valvular atrial fibrillation: an evidence-based choice

Atrial fibrillation (AF) is the most prevalent arrhythmia and is associated with an increased risk of ischemic stroke (IS) and systemic embolism (SE). Stroke prevention is a key element for the overall management of AF patients. The non-vitamin K antagonist oral anticoagulants (NOACs), such as dabigatran, rivaroxaban, apixaban and edoxaban, are at least as effective as warfarin in reducing IS/SE with a lower rate of major bleeding. Various analyses from the large Phase III randomized trials demonstrated different efficacy and safety of NOACs in specific subgroups of patients. The randomized trials are supplemented by effectiveness and safety data from real-world observational cohorts following the availability of these drugs for use in everyday clinical practice. Given the clinical heterogeneity of AF patients, the available data from trials and real-world studies allow us to fit the right NOAC to the particular patient's characteristics, with the aim of optimizing outcomes for the individual patient. This review article aims to provide a summary of the evidence on the performance of NOACs in AF patients with specific clinical characteristics. Evidence-based suggestions are presented to provide a simple and viable strategy for clinicians for the choice of a particular NOAC. KEY MESSAGE Given the different performance of the new-oral anticoagulants in patients with the different clinical situation, evidence-based choice of fitting the right new-oral anticoagulants to the patients is provided in this review article.

Role of rivaroxaban in the management of atrial fibrillation: insights from clinical practice

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and it leads to significant morbidity and mortality, predominantly from ischemic stroke. Vitamin K antagonists, mainly warfarin, have been used for decades to prevent ischemic stroke in AF, but their use is limited due to interactions with food and other drugs, as well as the requirement for regular monitoring of the international normalized ratio. Rivaroxaban, a direct factor Xa inhibitor and the most commonly used non-vitamin K oral anticoagulant, avoids many of these challenges and is being prescribed with increasing frequency for stroke prevention in non-valvular AF. Randomized controlled trial (RCT) data from the ROCKET-AF(Rivaroxaban once daily oral direct Factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and embolism trial in atrial fibrillation) trial have shown rivaroxaban to be non-inferior to warfarin in preventing ischemic stroke and systemic embolism and to have comparable overall bleeding rates. Applicability of the RCT data to real-world practice can sometimes be limited by complex clinical scenarios or multiple comorbidities not adequately represented in the trials. Available real-world evidence in non-valvular AF patients with comorbidities - including renal impairment, acute coronary syndrome, diabetes mellitus, malignancy, or old age - supports the use of rivaroxaban as safe and effective in preventing ischemic stroke in these subgroups, though with some important considerations required to reduce bleeding risk. Patient perspectives on rivaroxaban use are also considered. Real-world evidence indicates superior rates of drug adherence with rivaroxaban when compared with vitamin K antagonists and with alternative non-vitamin K oral anticoagulants - perhaps, in part, due to its once-daily dosing regimen. Furthermore, self-reported quality of life scores are highest among patients compliant with rivaroxaban therapy. The generally high levels of patient satisfaction with rivaroxaban therapy contribute to overall favorable clinical outcomes.

Long-term bleeding risk prediction in ‘real world’ patients with atrial fibrillation: Comparison of the HAS-BLED and ABC-Bleeding risk scores

Risk scores in patients with atrial fibrillation (AF) based on clinical factors alone generally have only modest predictive value for predicting high risk patients that sustain events. Biomarkers might be an attractive prognostic tool to improve bleeding risk prediction. The new ABCBleeding score performed better than HAS-BLED score in a clinical trial cohort but has not been externally validated. The aim of this study was to analyze the predictive performance of the ABC-Bleeding score compared to HAS-BLED score in an independent “real-world” anticoagulated AF patients with long-term follow-up. We enrolled 1,120 patients stable on vitamin K antagonist treatment. The HAS-BLED and ABC-Bleeding scores were quantified. Predictive values were compared by c-indexes, IDI, NRI, as well as decision curve analysis (DCA). Median HAS-BLED score was 2 (IQR 2–3) and median ABC-Bleeding was 16.5 (IQR 14.3–18.6). After 6.5 years of follow-up, 207 (2.84%/year) patients had major bleeding events, of which 65 (0.89%/year) had intracranial haemorrhage (ICH) and 85 (1.17%/year) had gastrointestinal bleeding events (GIB). The c-index of HAS-BLED was significantly higher than ABC-Bleeding for major bleeding (0.583 vs 0.518; p=0.025), GIB (0.596 vs 0.519; p=0.017) and for the composite of ICH-GIB (0.593 vs 0.527; p=0.030). NRI showed a significant negative reclassification for major bleeding and for the composite of ICH-GIB with the ABC-Bleeding score compared to HAS-BLED. Using DCAs, the use of HAS-BLED score gave an approximate net benefit of 4% over the ABC-Bleeding score. In conclusion, in the first “real-world” validation of the ABC-Bleeding score, HAS-BLED performed significantly better than the ABC-Bleeding score in predicting major bleeding, GIB and the composite of GIB and ICH.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Progressively Worsening Premature Coronary Artery Disease: Adding Anticoagulation Stabilizes–Reverses Clinical Symptomatic Disease Progression in Thrombophilic–Atherothrombotic Patients: A Pilot Study

In 35 patients with 116 severe premature cardiovascular disease (CVD) events (median age: 48 years), 14 having worsening CVD despite maximal intervention, we evaluated thrombophilia and speculated that anticoagulation might arrest–reverse progressive thrombophilic–atherothrombotic CVD. Thrombophilia–hypofibrinolysis in the 35 patients was compared to 110 patients with venous thromboembolism (VTE) without CVD and to 110 healthy normal controls. Efficacy–safety of anticoagulation was prospectively assessed in 14 of the 35 patients whose CVD worsened over 2 years despite maximal medical–surgical intervention. At entry on maximally tolerated lipid-lowering therapy, median low-density lipoprotein was 88 mg/dL. Measures of thrombophilia–hypofibrinolysis in the 35 cases differed from 110 VTE controls only for the lupus anticoagulant, present in 6 (21%) of 28 cases versus 4 (4%) of 91 VTE controls ( P = .01), and for high anticardiolipin antibodies (ACLAs) immunoglobulin G, 5 (14%) of 35 cases versus 4 of 108 VTE controls (4%), P = .04. The 14 patients who were anticoagulated differed from 110 VTE controls only for the lupus anticoagulant, 38% versus 4%, P = .001, and for high lipoprotein (a), 46% versus 17%, P = .028, respectively. The 14 patients with atherothrombosis having inexorably worsening CAD despite maximal medical–surgical therapy were anticoagulated for 6.5 years (median), with clinical CVD progression arrested in 12 (86%), and all 12 became asymptomatic. In the 35 patients with premature CVD, thrombophilia was pervasive, comparable to or more severe than in VTE controls without CVD. When CVD progressively worsens despite maximal intervention, thrombophilia and atherosclerosis (atherothrombosis) are commonly concurrent, and the downhill course of CVD may be arrested–stabilized by anticoagulation.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

Direct oral anticoagulant reversal: how, when and issues faced

INTRODUCTION

The number of atrial fibrillation (AF) patients requiring thrombo-prophylaxis with oral anticoagulation is greatly increasing. The introduction of non-vitamin K oral anticoagulants (NOACs) in addition to standard therapy with dose-adjusted warfarin has increased the therapeutic options for AF patients. Despite a generally better safety profile of the NOACs, the risk of major bleedings still persists, and the management of serious bleeding is a clinical challenge. Areas covered: In the current review, risk of major bleeding in patients taking NOACs and general approaches to manage bleeding depending on severity, with a particular focus on specific reversal agents, are discussed. Expert commentary: Due to short half-life of NOACs compared to warfarin, discontinuation of drug, mechanical compression, and volume substitution are considered to be sufficient measures in most of bleeding cases. In case of life-threatening bleeding or urgent surgery, hemostasis can be achieved with non-specific reversal agents (prothrombin complex concentrates) in patients treated with factor Xa inhibitor until specific antidotes (andexanet α and ciraparantag) will receive approval. Thus far, idarucizumab has been the only reversal agent approved for dabigatran.

Comparative effectiveness of rivaroxaban in the treatment of nonvalvular atrial fibrillation

Rivaroxaban is a direct oral anticoagulant (DOAC) approved for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, a common arrhythmia. In this review, we summarize the effectiveness of rivaroxaban versus warfarin and the DOACs dabigatran, apixaban and edoxaban. The primary focus is on primary evidence from clinical trials, indirect comparison studies and real-world studies. While there are gaps in the literature, the evidence thus far indicates that rivaroxaban is superior to warfarin and similar to dabigatran, apixaban and edoxaban for the prevention of stroke or systemic embolism in patients with nonvalvular atrial fibrillation, although rivaroxaban may be associated with an elevated bleeding risk compared with other DOACs.

Switching, Adverse Effects and Use of Over-the-Counter Analgesics among Users of Oral Anticoagulants: A Pharmacy-based Survey

Oral anticoagulants are widely used but information on important aspects in that respect is not available from medical registers or clinical databases. Therefore, we conducted a survey including patients filling a prescription for oral anticoagulants at two large Danish community pharmacies. We collected information concerning the patients' knowledge of their anticoagulant treatment including prior drug switching. Further, patients were asked about use of over-the-counter analgesics, adverse effects and how the treatment affected their everyday life. Among 335 eligible patients, 301 (90%) agreed to participate. Atrial fibrillation was the most common indication (65%), and most patients filled a prescription for a non-vitamin K antagonist oral anticoagulant (NOAC) (58%). Among the 12% (n = 35) of participants who had switched oral anticoagulant treatment, 69% had switched from a vitamin K antagonist (VKA) to a NOAC. Switching was most frequently caused by inconvenience (34%) and adverse effects (23%). Although half of all patients had recently bought over-the-counter analgesics, purchase of ibuprofen and aspirin was rare (6%). More VKA users than NOAC users felt limited in their everyday life because of anticoagulant treatment (18% versus 9%). Among non-incident NOAC users, 21% had experienced adverse effects during their current treatment. Based on first-hand information from a large sample of anticoagulant users, we conclude that the main drug-related issues leading to anticoagulant switching and perceived limitations in everyday life were inconvenience and adverse effects. This varied between drug groups. Further, use of NSAIDs obtained over the counter was rare.

Recent advances in the understanding and management of atrial fibrillation: a focus on stroke prevention

Atrial fibrillation (AF) is associated with an increased risk of stroke compared with the general population. It is anticipated that by 2030 an estimated 14-17 million patients will be diagnosed with this most prevalent arrhythmia within the European Union. AF-related stroke confers a higher mortality and morbidity risk, and thus early detection and assessment for the initiation of effective stroke prevention with oral anticoagulation (OAC) is crucial. Recent guidelines point to the use of non-vitamin K antagonist OACs (NOACs) where appropriate in stroke prevention of patients with non-valvular AF. At present, there are four NOACS available, with no direct head-to-head comparisons to suggest the superiority of one drug over another. Simple and practical risk assessment tools have evolved over the years to facilitate stroke and bleeding risk assessment in busy clinics and wards to aid decision-making. At present, the CHA ₂DS ₂VASc (congestive heart failure, hypertension, age 65-74/>75, diabetes mellitus, stroke/transient ischemic attack/thromboembolism, vascular disease, female sex) score is recommended by many international guidelines as a simple and practical method of assessing stroke risk in such patients. Alongside this, use of the HAS BLED (hypertension systolic blood pressure >160 mmHg, abnormal liver/renal function [with creatinine ≥200 μmol/L], stroke, bleeding history or predisposition, labile international normalized ratio [range <60% of the time], elderly [>65], concomitant drugs/alcohol) score aims to identify patients at high risk of bleeding for more regular review and follow-up and draws attention to potentially reversible bleeding risk factors. The aim of this review article is to provide an overview of recent advances in the understanding and management of AF with a focus on stroke prevention.

Efficacy and safety of the target-specific oral anticoagulants for stroke prevention in atrial fibrillation: the real-life evidence

The aim of our article is to provide a concise review for clinicians entailing the main studies that evaluated the efficacy and safety of target-specific oral anticoagulants (TSOAs) for thromboembolic stroke prevention in the real-world setting. Atrial fibrillation (AF) is one of the most common supraventricular arrhythmias that requires anticoagulation therapy to prevent stroke and systemic embolism. TSOAs, dabigatran, apixaban and rivaroxaban have become available as an alternative to warfarin anticoagulation in nonvalvular atrial fibrillation (NVAF). Randomized clinical trials showed non-inferior or superior results in efficacy and safety of the TSOAs compared with warfarin for stroke prevention in NVAF patients. For this reason, the 2012 update to the European Society of Cardiology guidelines for the management of AF recommends TSOAs as broadly preferable to vitamin K antagonists (VKAs) in the vast majority of patients with NVAF [Camm et al. 2012]. Although the clinical trial results and the guideline's indications, there is a need for safety and efficacy data from unselected patients in everyday clinical practice. Recently, a large number of studies testing the efficacy and the safety of TSOAs in clinical practice have been published. The aim of our article is to provide a concise review for clinicians, outlining the main studies that evaluated the efficacy and safety of TSOAs for thromboembolic stroke prevention in the real-world setting.