Oral anticoagulants for primary prevention, treatment and secondary prevention of venous thromboembolic disease, and for prevention of stroke in atrial fibrillation: systematic review, network meta-analysis and cost-effectiveness analysis

Ischemic stroke subtypes: risk factors, treatments, and 1-month prognosis - The Lille, France Stroke Registry

OBJECTIVES

First, this registry-based study aimed to comprehensively analyze patients' medical histories and treatments based on ischemic strokes' etiology. We focused on the management of atrial fibrillation among patients diagnosed with cardioembolic stroke. Then, our objective was to identify prognostic factors associated with 28-day mortality.

MATERIALS AND METHODS

All ischemic strokes occurring in adults between 2014 and 2021 in Lille, France, were categorized using the TOAST classification. Comparative analyses of patients' medical characteristics were conducted across subtypes. Survival rates within 28 days post-stroke were assessed, and factors influencing mortality were identified using a multivariate Cox model.

RESULTS

1912 ischemic strokes were recorded, due to cardioembolism (36%), large-artery atherosclerosis (9%), small-artery occlusion (9%), other determined causes (6%), or undetermined causes (39%). The median NIHSS score after cardioembolic stroke (6, IQR: 3-13) was twice that after small-artery occlusion (3, IQR: 2-5). Among patients with cardioembolic stroke, 26% were diagnosed post-admission with atrial fibrillation. For the 42% diagnosed pre-admission, only 54% had prior prescriptions for oral anticoagulants. Reperfusion therapies were administered in 21% of cases, with significant variations across subtypes. Mortality rates were higher after cardioembolic strokes (17%) than after small-artery occlusions (3%). Prognostic factors included etiology, high NIHSS score, atrial fibrillation, and previous heparin prescription.

CONCLUSIONS

While atrial fibrillation was underdiagnosed and undertreated, patients with cardioembolic stroke exhibited high severity and elevated mortality rates. Etiology emerged as an independent predictor of early mortality, regardless of NIHSS score upon admission. These findings underscore the importance of targeted prevention to improve patient outcomes after ischemic stroke.

Immunomodulation by xylan and carrageenan-type polysaccharides from red seaweeds: Anti-inflammatory, wound healing, cytoprotective, and anticoagulant activities

The immunomodulatory properties of the polysaccharides (carrageenan, xylan) from Chondrus crispus (CC), Ahnfeltiopsis devoniensis (AD), Sarcodiotheca gaudichaudii (SG) and Palmaria palmata (PP) algal species were studied. Using RAW264.7 macrophages, we investigated the proliferation and migration capacity of different extracts along with their immunomodulatory activities, including nitric oxide (NO) production, phagocytosis, and secretion of pro-inflammatory cytokines. Polysaccharides from C. crispus and S. gaudichaudii effectively mitigated inflammation and improved scratch-wound healing. Polysaccharide fractions extracted under cold conditions (25 °C), including CC-1A, SG-1A and SG-1B stimulated cell proliferation, while fractions extracted under hot conditions (95 °C), including CC-3A, CC-2B and A. devoniensis (AD-3A), inhibited cell proliferation after 48 h. Furthermore, RAW264.7 cells treated with the fractions CC-3A, AD-1A, and SG-2A significantly reduced LPS-stimulated NO secretion over 24 h. Phagocytosis was significantly improved by treatment with C. crispus (CC-2B, CC-3B) and A. devoniensis (AD-3A) fractions. RAW264.7 cells treated with the CC-2A and SG-1A fractions showed elevated TGF-β1 expression without affecting TNF-α expression at 24 h. Polysaccharide fractions of A. devoniensis (ι/κ hybrid carrageenan; AD-2A, AD-3A) showed the highest anti-coagulation activity. CC-2A and SG-1A fractions enhanced various bioactivities, suggesting they are candidates for skin-health applications. The carrageenan fractions (CC-3A: λ-, μ-carrageenan, SG-2A: ν-, ι-carrageenan) tested herein showed great potential for developing anti-inflammatory and upscaled skin-health applications.

Telestroke for acute ischaemic stroke: A systematic review of economic evaluations and a de novo cost-utility analysis for a middle income country

INTRODUCTION

Telemedicine can alleviate the problems faced in rural settings in providing access to specialist stroke care. The evidence of the cost-effectiveness of this model of care outside high-income countries is limited. This study aimed to conduct: (a) a systematic review of economic evaluations of telestroke and (b) a cost-utility analysis of telestroke, using China as a case study.

METHODS

We systematically searched Embase, Medline Complete and Cochrane databases. Inclusion criteria: full economic evaluations of telemedicine/telestroke networks examining the use of thrombolysis in patients with acute ischaemic stroke, published in English. A cost-utility analysis was undertaken using a Markov model incorporating a decision tree to simulate the delivery of telestroke for acute ischaemic stroke in rural China, compared to no telestroke from a societal and healthcare perspective. One-way deterministic sensitivity analyses and probabilistic sensitivity analyses were performed to test the robustness of results.

RESULTS

Of 559 publications found, eight met the eligibility criteria and were included in the systematic review (two cost-effectiveness analyses and six cost-utility analyses, all performed in high-income countries). Telestroke was a cost-saving/cost-effective intervention in five out of the eight studies. In our modelled analysis for rural China, telestroke was the dominant strategy, with estimated cost savings of Chinese yuan 4,328 (US$627) and additional 0.0925 quality-adjusted life years per patient. Sensitivity analyses confirmed the base case results.

DISCUSSION

Consistent with published economic evaluations of telestroke in other jurisdictions, telestroke represents a cost-effective solution to enhance stroke care in rural China.

Efficacy and Safety of Direct Oral Anticoagulants (DOACs) Versus Warfarin in Atrial Fibrillation Patients with Prior Stroke: a Systematic Review and Meta-analysis

BACKGROUND

The purpose of this meta-analysis was to compare efficacy and safety of direct oral anticoagulants (DOACs) to warfarin for secondary stroke prevention among adult patients with atrial fibrillation and prior stroke.

METHODS

Major repositories were screened for randomized controlled trials (RCTs), RCT subgroups, and observational studies (OBSs, divided in claims and non-claims). Occurrences of ischemic stroke or transient ischemic attack, systemic embolism, all-cause mortality, intracranial hemorrhage (ICH), and major bleeding were outcomes of interest. Hazard ratios (HRs) and their confidence intervals (95%CIs) were pooled using random-effects models for each study design. Claims studies were analyzed separately from non-claims, while RCT subgroups were grouped with OBSs (non-claims) as the randomization was broken.

RESULTS

Of 8647 articles, 20 were included (one RCT, six RCT subgroups, nine claims, and four non-claims). Comparing DOACs to warfarin, pooled HRs (95%CI) were consistently in favor of DOACs although some did not reach statistical significance: for ischemic stroke, 0.84 (0.66-1.07) in claims; 0.90 (0.77-1.06) in non-claims and RCT subgroups; for systemic embolism, 0.77 (0.62-0.96) in claims; 0.86 (0.77-0.96) in non-claims and RCT subgroups; for all-cause mortality, 0.57 (0.33-0.99) in claims; 0.87 (0.79-0.96) in non-claims and RCT subgroups; for ICH, 0.72 (0.39-1.33) in claims; 0.51 (0.38-0.67) in non-claims and RCT subgroups; and for major bleeding, 0.86 (0.71-1.03) in claims; 0.90 (0.76-1.08) for non-claims and RCT subgroups.

CONCLUSION

DOACs were associated with better efficacy and safety profiles than warfarin in atrial fibrillation patients with prior stroke, more specifically a lower risk of systemic embolism, all-cause mortality, and ICH.

Effect of an herbal medicine, Chunghyul-dan, on prevention of recurrence in patients with ischemic stroke: A retrospective cohort study

Research indicates that Chunghyul-dan (CHD), a herbal medicine, has an inhibitory effect on stroke recurrence in small vessel disease. Recent studies have suggested that CHD might also act on large arteries. This study aimed to verify the preventive effect of CHD on strokes of all the Trial of Org 10172 in Acute Stroke Treatment (TOAST) causative classifications. We retrospectively analyzed 2 years of medical records of patients with ischemic stroke treated with CHD, 600 mg once daily, in combination with antiplatelet or anticoagulant agents. The prevalence of stroke recurrence in 2 years was analyzed. Stroke recurrence was defined as new neurological symptoms with corresponding brain imaging results. Nine of the 202 patients (4.46%) had recurrent ischemic stroke. Four occurred within 180 days, 3 between 180 and 365 days, and 2 between 365 and 730 days. All had only 1 recurrence. The recurrence rates were 1.12%, 5%, and 5.48% for small vessel occlusion, cardioembolism, and large vessel atherosclerosis, respectively. There were no adverse effects. These results suggest that CHD could inhibit ischemic stroke recurrence of all TOAST causative categories. A randomized controlled trial is needed to confirm this hypothesis.

Antithrombotic Effects of the Novel Small-Molecule Factor XIa Inhibitor Milvexian in a Rabbit Arteriovenous Shunt Model of Venous Thrombosis

Background  Factor XIa (FXIa) is an emerging therapeutic target, and FXIa inhibition is a promising mechanism to improve therapeutic index over current anticoagulants. Milvexian (BMS-986177/JNJ-70033093) is an oral small-molecule FXIa inhibitor. Objective  Milvexian's antithrombotic efficacy was characterized in a rabbit arteriovenous (AV) shunt model of venous thrombosis and compared with the factor Xa inhibitor apixaban and the direct thrombin inhibitor dabigatran. Methods  The AV shunt model of thrombosis was conducted in anesthetized rabbits. Vehicle or drugs were administered as intravenous bolus plus a continuous infusion. Thrombus weight was the primary efficacy endpoint. Ex vivo activated partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin time (TT) were measured as the pharmacodynamic responses. Results  Milvexian dose dependently reduced thrombus weights by 34.3 ± 7.9, 51.6 ± 6.8 ( p  < 0.01; n  = 5), and 66.9 ± 4.8% ( p  < 0.001; n  = 6) versus vehicle at 0.25 + 0.17, 1.0 + 0.67, and 4.0 ± 2.68 mg/kg bolus + mg/kg/h infusion, respectively. Ex vivo clotting data supported a dose-dependent prolongation of aPTT (with 1.54-, 2.23-, and 3.12-fold increases from baseline upon the AV shunt start), but no changes in PT and TT. Dose-dependent inhibition in thrombus weight and clotting assays was also demonstrated for both apixaban and dabigatran as the references for the model validation. Conclusion  Results demonstrate that milvexian is an effective anticoagulant for prevention of venous thrombosis in the rabbit model, which supports the utility of milvexian in venous thrombosis, as seen in the phase 2 clinical study.

Economic and Health Value of Delaying Atrial Fibrillation Progression Using Radiofrequency Catheter Ablation

BACKGROUND

Radiofrequency catheter ablation (RFCA) is an established treatment for atrial fibrillation (AF) refractory to antiarrhythmic drugs. The economic value of RFCA in delaying disease progression has not been quantified.

METHODS

An individual-level, state-transition health economic model estimated the impact of delayed AF progression using RFCA versus antiarrhythmic drug treatment for a hypothetical sample of patients with paroxysmal AF. The model incorporated the lifetime risk of progression from paroxysmal AF to persistent AF, informed by data from the ATTEST (Atrial Fibrillation Progression Trial). The incremental effect of RFCA on disease progression was modeled over a 5-year duration. Annual crossover rates were also included for patients in the antiarrhythmic drug group to mirror clinical practice. Estimates of discounted costs and quality-adjusted life years asssociated with health care utilization, clinical outcomes, and complications were projected over patients' lifetimes.

RESULTS

From the payer's perspective, RFCA was superior to antiarrhythmic drug treatment with an estimated mean net monetary benefit per patient of $8516 ($148-$16 681), driven by reduced health care utilization, cost, and improved quality-adjusted life years. RFCA reduced mean (95% CI) per-patient costs by $73 (-$2700 to $2200), increased mean quality-adjusted life years by 0.084 (0.0-0.17) and decreased the mean number of cardiovascular-related health care encounters by 24%.

CONCLUSIONS

RFCA is a dominant (less costly and more effective) treatment strategy for patients with AF, especially those with early AF for whom RFCA could delay progression to advanced AF. Increased utilization of RFCA-particularly among patients earlier in their disease progression-may provide clinical and economic benefits.

A Real-World Cost-Effectiveness Analysis of Rivaroxaban versus Vitamin K Antagonists for the Treatment of Symptomatic Venous Thromboembolism: Lessons from the REMOTEV Registry

Background and objectives: Venous thromboembolism (VTE) represents a health and economic burden with consequent healthcare resource utilization. Direct oral anticoagulants (DOACs) have emerged as the mainstay option for VTE treatment but few data exist on their cost-effectiveness as compared to the standard therapy (vitamin K antagonists (VKAs)). This study aimed to assess the cost-effectiveness of rivaroxaban compared to VKAs in VTE treatment by calculating the incremental cost effectiveness ratio (ICER). Materials and methods: We conducted a prospective observational study based on the REMOTEV registry, including patients hospitalized for VTE from 23 October 2013 to 31 July 2015, to evaluate the impact of the anticoagulant treatment (DOACs versus VKAs) on 6-month complications: major or clinically relevant non-major bleeding, VTE recurrence and all-cause death. Rivaroxaban was the only DOAC prescribed in this study. The ICER was calculated as the difference in costs divided by the difference in effectiveness. Results: Among the 373 patients included, 279 were treated with rivaroxaban (63.1 ± 17.9 years old; 49% men) and 94 with VKAs (71.3 ± 16.6 years old; 46% men). The mean cost was EUR 5662 [95% CI 6606; 9060] for rivaroxaban and EUR 7721 [95% CI 5130; 6304] for VKAs, while effectiveness was 0.0586 95% CI [0.0114; 0.126] for DOACs and 0.0638 [95% CI 0.0208; 0.109] for VKAs. The rivaroxaban treatment strategy was dominant with costs per patient EUR 2059 lower [95% CI -3582; -817] and a higher effectiveness of 0.00527 [95% CI -0.0606; 0.0761] compared to VKAs. Conclusions: This study provides real-world evidence that rivaroxaban is not only an efficient and safe alternative to VKAs for eligible VTE patients, but also cost-saving.

Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation: A Systematic Review of Economic Evaluations

OBJECTIVES

Several studies have evaluated the economic evaluation of a group of medications known as novel oral anticoagulant drugs (NOACs) in recent years. The aim of this study is to review and systematically analyze the cost-utility studies results of warfarin compared with other NOAC drugs in atrial fibrillation patients.

METHODS

A systematic review was performed to identify all studies evaluating the NOAC medications in comparison with warfarin. For this purpose, PubMed, Cochrane Library, ISI Web of Science, and Scopus were searched from 2013 to 2022. Articles were independently screened with inclusion criteria, and full texts were reviewed. First, the Consolidated Health Economic Evaluation Reporting Standards checklist was used to evaluate the quality of the articles. Then, the costs and outcomes of the studies were analyzed, and findings were appraised critically.

RESULTS

A total of 84 costs-per-quality-adjusted life-year (QALY) cases were extracted from the studies in which the share of rivaroxaban, edoxaban, apixaban, and dabigatran were 31%, 13%, 29%, and 27%, respectively. The median cost per QALY of rivaroxaban, edoxaban, apixaban, and dabigatran was 21 910$/QALY, 22 096$/QALY, 17 765$/QALY, and 24 161$/QALY, respectively. Subgroup analysis based on perspective showed that dabigatran had the highest incremental cost-effectiveness ratio (ICER) and edoxaban had the lowest ICER value. Edoxaban and apixaban had the highest and the lowest cost per QALY from an insurance perspective, respectively.

CONCLUSION

Despite the differences and variations in the economic evaluation studies of NOAC drugs, these drugs have shown acceptable cost-effectiveness in developed and developing countries. Among NOAC drugs, apixaban has the lowest ICER and the highest cost-effectiveness.

Risks and benefits of oral anticoagulants for stroke prophylaxis in atrial fibrillation according to body mass index: Nationwide cohort study of primary care records in England

BACKGROUND

Direct oral anticoagulants (DOACs) are effective and safe alternatives to warfarin for stroke prophylaxis for atrial fibrillation (AF). Whether this extends to patients at the extremes of body mass index (BMI) is unclear.

METHODS

Using linked primary and secondary data, Jan 1, 2010 to Nov 30, 2018, we included CHA₂DS₂-VAS_C score ≥3 in women and ≥2 in men with AF treated with oral anticoagulants (OACs). Outcomes were ischaemic stroke, major bleeding and all-cause mortality by World Health Organisation BMI classification. Patients who received warfarin were propensity score matched (1:1 ratio) with those who received DOACs and the association of time-varying OAC exposure on outcomes quantified using Cox proportional hazards models.

FINDINGS

We included 29,135 (22,818 warfarin, 6317 DOAC); 585 (2.0%) underweight, 8427 (28.9%) normal weight, 10,705 (36.7%) overweight, 5910 (20.3%) class I obesity and 3508 (12.0%) class II/III obesity. Patients treated with DOACs were older and more comorbid. After 3.7 (SD 2.5) years follow up, there was no difference in risk of ischaemic stroke and major bleeding by BMI category between DOACs and warfarin. Normal weight, overweight and obese class I patients had higher risk of all-cause mortality when treated with DOACs compared with warfarin (HR: 1.45 [95% CI 1.24-1.69], p < 0.001; 1.41 [95% CI 1.19-1.66], p < 0.001; and 1.90 [95% CI 1.50-2.39], p < 0.001), an effect not observed after DOACs became the most common OAC prescription. Amongst underweight patients OAC exposure was associated with greater harm from bleeding than benefit from stroke prevention (benefit to harm ratio, 0.35 [95% CI 0.26-0.44]).

INTERPRETATION

In patients with AF in each BMI classification we found no difference in ischaemic stroke and bleeding risk for DOACs compared with warfarin. Underweight patients experienced divergent risk-benefit patterns from oral anticoagulation compared with other BMI categories.

FUNDING

None.

Perceptions of patients and healthcare providers on patient education to improve oral anticoagulant management

RATIONALE AND OBJECTIVES

Education of patients is thought to be key to high-quality oral anticoagulant (OAC) medication management. Theoretically, improving patients' knowledge should improve their self-management skills and adherence. The study's objective was to explore the opinions of healthcare providers and patients on the desired content and format of patient education on OACs, in addition to perceived barriers to high-quality patient education.

METHODS

We applied qualitative descriptive methods in a focus group study on OAC management. Five focus group discussions were conducted in two health regions in Southwestern Ontario from 2017 to 2018 with 19 patients, 7 caregivers and 16 healthcare providers (physicians, nurses and pharmacists). During the focus groups, participants discussed their experiences with OAC education and made suggestions about the content and format for patient education on OACs. Transcripts were analysed using conventional content analysis.

RESULTS

We identified the five themes of patient education on OAC management: content of OAC education (rationale, risk and appropriate drug administration methods), the best times for providing OAC education (time of OACs initiation along with continuing education), preferred education delivery strategies (case management targeted patient information summaries from authoritative sources such as Thrombosis Canada and video education), patient and community pharmacist engagement in OAC education, and perceived barriers to optimal patient education (patients depending too much on their healthcare providers for advice, the limited time patients spend with healthcare providers, gaps in clear communication between providers and the lack of a nationally or provincially coordinated OAC management programme).

CONCLUSION

Our findings suggest that patients, caregivers and healthcare providers support the need for education on OACs, including for patients taking DOACs. Specific important content and proper education format are needed. The optimal combination of content, format, duration, timing and sources for OAC education requires further research.

Oral anticoagulants: a systematic overview of reviews on efficacy and safety, genotyping, self-monitoring, and stakeholder experiences

BACKGROUND

This systematic overview was commissioned by England's Department of Health and Social Care (DHSC) to assess the evidence on direct (previously 'novel') oral anticoagulants (OACs), compared with usual care, in adults, to prevent stroke related to atrial fibrillation (AF), and to prevent and treat venous thromboembolism (VTE). Specifically, to assess efficacy and safety, genotyping, self-monitoring, and patient and clinician experiences of OACs.

METHODS

We searched MEDLINE, Embase, ASSIA, and CINAHL, in October, 2017, updated in November 2021. We included systematic reviews, published from 2014, in English, assessing OACs, in adults. We rated review quality using AMSTAR2 or the JBI checklist. Two reviewers extracted and synthesised the main findings from the included reviews.

RESULTS

We included 49 systematic reviews; one evaluated efficacy, safety, and cost-effectiveness, 17 assessed genotyping, 23 self-monitoring or adherence, and 15 experiences (seven assessed two topics). Generally, the direct OACs, particularly apixaban (5 mg twice daily), were more effective and safer than warfarin in preventing AF-related stroke. For VTE, there was little evidence of differences in efficacy between direct OACs and low-molecular-weight heparin (prevention), warfarin (treatment), and warfarin or aspirin (secondary prevention). The evidence suggested that some direct OACs may reduce the risk of bleeding, compared with warfarin. One review of genotype-guided warfarin dosing assessed AF patients; no significant differences in stroke prevention were reported. Education about OACs, in patients with AF, could improve adherence. Pharmacist management of coagulation may be better than primary care management. Patients were more adherent to direct OACs than warfarin. Drug efficacy was highly valued by patients and most clinicians, followed by safety. No other factors consistently affected patients' choice of anticoagulant and adherence to treatment. Patients were more satisfied with direct OACs than warfarin.

CONCLUSIONS

For stroke prevention in AF, direct OACs seem to be more effective and safer than usual care, and apixaban (5 mg twice daily) had the best profile. For VTE, there was no strong evidence that direct OACs were better than usual care. Education and pharmacist management could improve coagulation control. Both clinicians and patients rated efficacy and safety as the most important factors in managing AF and VTE.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017084263-one deviation; efficacy and safety were from one review.

Network Meta-analysis on Disconnected Evidence Networks When Only Aggregate Data Are Available: Modified Methods to Include Disconnected Trials and Single-Arm Studies while Minimizing Bias

BACKGROUND

Network meta-analysis (NMA) requires a connected network of randomized controlled trials (RCTs) and cannot include single-arm studies. Regulators or academics often have only aggregate data. Two aggregate data methods for analyzing disconnected networks are random effects on baseline and aggregate-level matching (ALM). ALM has been used only for single-arm studies, and both methods may bias effect estimates.

METHODS

We modified random effects on baseline to separate RCTs connected to and disconnected from the reference and any single-arm studies, minimizing the introduction of bias. We term our modified method reference prediction. We similarly modified ALM and extended it to include RCTs disconnected from the reference. We tested these methods using constructed data and a simulation study.

RESULTS

In simulations, bias for connected treatments for ALM ranged from -0.0158 to 0.051 and for reference prediction from -0.0107 to 0.083. These were low compared with the true mean effect of 0.5. Coverage ranged from 0.92 to 1.00. In disconnected treatments, bias of ALM ranged from -0.16 to 0.392 and of reference prediction from -0.102 to 0.40, whereas coverage of ALM ranged from 0.30 to 0.82 and of reference prediction from 0.64 to 0.94. Under fixed study effects for disconnected evidence, bias was similar, but coverage was 0.81 to 1.00 for reference prediction and 0.18 to 0.76 for ALM. Trends of similar bias but greater coverage for reference prediction with random study effects were repeated in constructed data.

CONCLUSIONS

Both methods with random study effects seem to minimize bias in treatment connected to the reference. They can estimate treatment effects for disconnected treatments but may be biased. Reference prediction has greater coverage and may be recommended overall.

HIGHLIGHTS

Two methods were modified for network meta-analysis on disconnected networks and for including single-arm observational or interventional studies in network meta-analysis using only aggregate data and for minimizing the bias of effect estimates for treatments only in trials connected to the reference.Reference prediction was developed as a modification of random effects on baseline that keeps analyses of trials connected to the reference separately from those disconnected from the reference and from single-arm studies. The method was further modified to account for correlation in trials with more than 2 arms and, under random study effects, to estimate variance in heterogeneity separately in connected and disconnected evidence.Aggregate-level matching was extended to include trials disconnected from the reference, rather than only single-arm studies. The method was further modified to separately estimate treatment effects and heterogeneity variance in the connected and disconnected evidence and to account for the correlation between arms in trials with more than 2 arms.Performance was assessed using a constructed data example and simulation study.The methods were found to have similar, and sometimes low, bias when estimating the relative effects for disconnected treatments, but reference prediction with random study effects had the greatest coverage.The use of reference prediction with random study effects for disconnected networks is recommended if no individual patient data or alternative real-world evidence is available.

Long term follow up of direct oral anticoagulants and warfarin therapy on stroke, with all-cause mortality as a competing risk, in people with atrial fibrillation: Sentinel network database study

Background

We investigated differences in risk of stroke, with all-cause mortality as a competing risk, in people newly diagnosed with atrial fibrillation (AF) who were commenced on either direct oral anticoagulants (DOACs) or warfarin treatment.

Methods and results

We conducted a retrospective cohort study of the Oxford Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) database (a network of 500 English general practices). We compared long term exposure to DOAC (n = 5,168) and warfarin (n = 7,451) in new cases of AF not previously treated with oral anticoagulants. Analyses included: survival analysis, estimating cause specific hazard ratios (CSHR), Fine-Gray analysis for factors affecting cumulative incidence of events occurring over time and a cumulative risk regression with time varying effects.We found no difference in CSHR between stroke 1.08 (0.72–1.63, p = 0.69) and all-cause mortality 0.93 (0.81–1.08, p = 0.37), or between the anticoagulant groups. Fine-Gray analysis produced similar results 1.07 (0.71–1.6 p = 0.75) for stroke and 0.93 (0.8–1.07, p = 0.3) mortality. The cumulative risk of mortality with DOAC was significantly elevated in early follow-up (67 days), with cumulative risk decreasing until 1,537 days and all-cause mortality risk significantly decreased coefficient estimate:: -0.23 (-0.38–0.01, p = 0.001); which persisted over seven years of follow-up.

Conclusions

In this large, contemporary, real world primary care study with longer follow-up, we found no overall difference in the hazard of stroke between warfarin and DOAC treatment for AF. However, there was a significant time-varying effect between anti-coagulant regimen on all-cause mortality, with DOACs showing better survival. This is a key methodological observation for future follow-up studies, and reassuring for patients and health care professionals for longer duration of therapy

Impact of the COVID-19 pandemic on England's national prescriptions of oral vitamin K antagonist (VKA) and direct-acting oral anticoagulants (DOACs): an interrupted time series analysis (January 2019-February 2021)

BACKGROUND

Direct-acting oral anticoagulants (DOACs) were developed as an alternative to warfarin to treat and prevent thromboembolism, including stroke prevention in non-valvular atrial fibrillation patients. The COVID-19 pandemic could increase the risk of stroke and/or the risk of bleeding in patients due to nonadherence or sub/supra-optimal dosing.

OBJECTIVE

To investigate DOAC prescription trends in England's community settings during the complete first wave of COVID-19 pandemic.

METHODS

Descriptive and interrupted time series (ITS) analyses were conducted to examine the prescription patterns of DOACs (dabigatran, rivaroxaban, apixaban and edoxaban) and warfarin for primary care patients in the English Prescribing Dataset from January 2019 to February 2021, with March 2020 as the cut-off point.

RESULTS

A 19% increase in mean DOAC's accompanied with 20% warfarin prescriptions decline was observed. ITS modelling showed an increase in DOAC prescription volume in March 2020 (+7 million items, p = 0.008). The pre-existing upward trend in DOAC prescriptions slowed during the period (-427,000 items, p = 0.007). Apixaban was the most frequently used DOAC and had the largest step-change in March 2020 (+5 million items, p = 0.010). The mean monthly combined cost of DOACs and warfarin was higher during the period. DOAC prescription trends were consistent across England's regions. Conclusion: The overall oral anticoagulants use in this period was lower than expected, indicating a medical needs gap, possibly due to adherence issues. The potential clinical and logistical consequences warrant further study to identify contributing factors and mitigate avoidable risks.

[Time in therapeutic range and incidence of warfarin complications in a 20-year retrospective cohort]

Objetivo

Caracterizar el tiempo en rango terapéutico (TTR) y estimar la tasa de incidencia de complicaciones (PTIRc) en adultos con protocolo de warfarina.

Diseño

Cohorte retrospectiva basada en registros médicos de pacientes mayores de 18 años entre 1996 a 2016 y seguidos al menos tres meses.

Emplazamiento

Unidad de Hematología de un centro especializado cardiovascular venezolano.

Participantes

Registros médicos electrónicos.

Mediciones principales

TTR y PTIRc. Las variables fueron: sexo, analfabetismo funcional, ocupación, international normalized ratio (INR) y tiempo de seguimiento, que fueron analizados con TTR and PTIRc mediante modelos de logística binomial y regresión de Poisson, respectivamente.

Resultados

Un total de 2.770 pacientes fueron seguidos durante 1.201.380 días; el 42,3% tuvieron un TTR < 65% y el 3,5% tuvieron indicación de INR 2,5-3,5. El 61,8% presentaron complicaciones. La PTIRc fue de 6,84/100 personas-mes (IC 95%: 6,56-7,15). TTR < 65% mostró OR ajustadas significativas con analfabetismo funcional e INR 2,5-3,5, mientras que para la mayor PTIRc se encontró un RR significativo en los dos factores mencionados, menor tiempo de seguimiento, TTR < 65% y en mujeres.

Conclusiones

A pesar de nuevos tratamientos anticoagulantes, la warfarina es útil. A medida que aumentó el tiempo de seguimiento el control fue mejor y la velocidad de aparición de complicaciones disminuyó; sin embargo, las condiciones que mostraron menor TTR y mayor velocidad de aparición de complicaciones requieren una profunda revisión del seguimiento, de manera especial en pacientes con analfabetismo funcional.

Incremental net monetary benefit of direct oral anticoagulants for the prevention of venous thromboembolism after total knee or hip replacement: A systematic review and meta-analysis

INTRODUCTION

This meta-analysis was conducted to quantitatively pool the incremental net benefit (INB) of using direct oral anticoagulants (DOACs) for the prevention of venous thromboembolism (VTE) in patients undergoing total knee or hip replacements (TKR or THR).

MATERIALS AND METHODS

We performed a comprehensive search in several databases published before June 2021. Studies were included if they were cost-effectiveness analyses reporting cost per quality-adjusted life-year or life-year of DOACs compared to low molecular-weight heparins (LMWHs) or other anticoagulant agents for the prevention of VTE after TKR or THR. Risk of bias was also assessed using the biases in economic studies (ECOBIAS) checklist. Various monetary units were converted to purchasing power parity, adjusted to 2020 US dollars. The INBs were pooled across studies using a random-effects model, stratified by high-income countries (HICs) and low- and middle-income countries (LMICs). Heterogeneity was assessed using the I² statistic.

RESULTS

A total of 49 comparisons (TKR = 25 and THR = 24) from 16 studies was included. In HICs, DOACs were cost-effective compared to LMWHs from the health care system/payer perspective for the prevention of VTE after both TKR and THR with corresponding INBs (95 % CI; I²) of $231.91 ($178.71, $285.11; 0 %) and $254.99 ($159.20, $350.77; 27.79 %), respectively. In LMICs, DOACs were not cost-effective compared to LMWHs for both TKR and THR with the INBs of $94.13 (-$40.21, $228.47; 97.04 %) and $80.55 (-$157.37, $318.47; 99.78 %), respectively. No evidence of small-study effects was identified in any analyses. The cost-effectiveness of using DOACs for TKR and THR in HICs was robust across a series of sensitivity analyses.

CONCLUSIONS

DOACs were cost-effective as compared to LMWHs for VTE prophylaxis following TKR and THR surgeries in HICs. Further studies from LMICs are warranted.

The Effect of Switching From Warfarin to Novel Oral Anticoagulants on Patients’ Satisfaction and the Travel Burden in a Rural Setting

Introduction: New oral anticoagulants (NOACs) have shown comparable efficacy to warfarin in the treatment of patients with venous thromboembolism (VTE), stroke and atrial fibrillation (AF). Various studies on quality-of-life improvement in rural patients following the switch from vitamin K antagonists (VKAs) to NOACs have produced inconclusive results. The aim of the study is to assess the impact of switching from warfarin to NOACs on remotely living patients’ quality of life and the burden of travel.

Methods: A questionnaire was provided to the patient by their pharmacists. The questionnaire assessed their travel burden and their level of satisfaction with their treatment.

Results: The switch from warfarin to NOACs reduced the burden of travel in 75% of patients. A total of 66% of patients were hesitant about the efficacy of their warfarin treatment. The inconvenience caused due to international normalized ratio (INR) monitoring was reduced in 83% of patients; 70% and 72% of patients strongly agreed that NOACs improved their adherence and treatment satisfaction, respectively. The average number of patients’ travels for INR testing for warfarin monitoring was 7.27 trips/year. The average number of trips made by the patient to obtain their NOACs and warfarin scripts was 2.1 and 4.81 trips/year, respectively.

Conclusion: The switch from warfarin, a VKA, to NOACs in patients who live in remote areas without medical services improved their quality of life, decreased their travel burden, and increased their treatment satisfaction and adherence. Switching to NOACs reduced the number of trips travelled by patients to obtain their anticoagulation scripts and/or to adjust their doses.

Deprescribing in Palliative Cancer Care

The aim of palliative care is to maintain as high a quality of life (QoL) as possible despite a life-threatening illness. Thus, the prescribed medications need to be evaluated and the benefit of each treatment must be weighed against potential side effects. Medications that contribute to symptom relief and maintained QoL should be prioritized. However, studies have shown that treatment with preventive drugs that may not benefit the patient in end-of-life is generally deprescribed very late in the disease trajectory of cancer patients. Yet, knowing how and when to deprescribe drugs can be difficult. In addition, some drugs, such as beta-blockers, proton pump inhibitors, anti-depressants and cortisone need to be scaled down slowly to avoid troublesome withdrawal symptoms. In contrast, other medicines, such as statins, antihypertensives and vitamins, can be discontinued directly. The aim of this review is to give some advice according to when and how to deprescribe medications in palliative cancer care according to current evidence and clinical praxis. The review includes antihypertensive drugs, statins, anti-coagulants, aspirin, anti-diabetics, proton pump inhibitors, histamin-2-blockers, bisphosphonates denosumab, urologicals, anti-depressants, cortisone, thyroxin and vitamins.

Real-world evidence comparing oral anticoagulants in non-valvular atrial fibrillation: a systematic review and network meta-analysis

Aim: To compare real-world effectiveness/safety of non-vitamin K antagonist oral anticoagulants and vitamin K antagonists among patients with non-valvular atrial fibrillation. Materials & methods: A systematic review of electronic databases yielded 7661 citations published from January 2013 to January 2020. Fifty-five studies were included in Bayesian network meta-analyses of hazard ratios. Results & conclusion: In comparison with vitamin K antagonists, apixaban, dabigatran and rivaroxaban were associated with a reduced risk of stroke or systemic embolism, ischemic stroke, intracranial hemorrhage and all-cause mortality. Apixaban, dabigatran and edoxaban, but not rivaroxaban, were associated with a reduced risk of major bleeding. This study confirmed the effectiveness and safety of non-vitamin K antagonist oral anticoagulants for the treatment of non-valvular atrial fibrillation in real-world settings, consistent with clinical trial evidence.

Non-vitamin K antagonist oral anticoagulants in venous thromboembolism patients: a meta-analysis of real-world studies

Background

The real-world studies on recurrent venous thromboembolism (VTE) and bleeding events of non-vitamin K antagonist oral anticoagulants (NOACs) in VTE patients have reported conflicting findings. Our study aimed to provide the direct comparison evidence of different NOACs for VTE patients in clinical practice settings.

Methods

Search of the medical literature was conducted using PubMed, Web of Science, EMBASE, Clinical Trials.gov, and the Cochrane Library from inception to March 22, 2021. Among the 19,996 citations retrieved, a total of 63,144 patients from 6 studies were analyzed. Clinical outcomes included recurrent VTE, death, and different bleeding events.

Results

Adjusted hazard ratio (HR) analysis suggested that apixaban had significant lower bleeding riskthan rivaroxaban (major, minor and any bleeding: HR = 0.61, 0.56, 0.70; p = 0.008, < 0.0001, 0.006, respectively), but no statistics difference found in recurrent VTE events (HR = 1.02, 95% confidence interval (CI) 0.71–1.47, p = 0.93). There was no significant difference of major bleeding between dabigatran and rivaroxaban (odds ratios (OR) = 0.41, 95% CI 0.09–1.90, p = 0.25), apixaban and dabigatran (OR 0.64, 95% CI 0.15–2.72, p = 0.83). No significant difference was found in the comparison of edoxaban and other NOACs in VTE recurrence, major bleeding and composite outcome.

Conclusions

In the prevention of bleeding events, apixaban was associated with a lower risk than rivaroxaban, but equivalent efficacy for different NOACs in prevention of recurrent VTE. Evidence generated from the meta-analysis based on real-world data can help to guide selection between apixaban and rivaroxaban in routine clinical practice.

Trial registration: This systematic review and meta-analysis were conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis and Meta-analysis of Observational Studies in Epidemiology statements and was registered with PROSPERO (CRD42019140553).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02550-8.

Use of Apixaban in Atrial Fibrillation With Ritonavir-Boosted Antiretroviral Therapy: A Case Report

PURPOSE

Direct oral anticoagulants (DOACs) pose a challenge when given with potent CYP3A4 and P-gp inhibitors, such as the commonly prescribed pharmacokinetic booster ritonavir. As per the manufacturer, apixaban offers a dose reduction when administered concurrently with ritonavir; thus, we explore the clinical indication and safety of apixaban when given with ritonavir-boosted highly active antiretroviral therapy (HAART) in an HIV patient.

SUMMARY

We describe a 73-year-old male with extensive cardiac history, including a past medical history of resolved left ventricular thrombus, newly diagnosed non-valvular atrial fibrillation treated with warfarin, and HIV infection treated with ritonavir-boosted HAART. The patient presented to the emergency department with bleeding from multiple sites, necessitating the use of vitamin K. Consequently, his hospital course was complicated by episodes of minor bleeding and labile INR. Due to the complicated nature of his condition and the potential for drug-drug interactions (DDIs), he was transitioned from warfarin to apixaban. Since there is little readily available data to support the use of rivaroxaban and dabigatran with ritonavir, our patient was safely started on dose-reduced apixaban for stroke prophylaxis in atrial fibrillation due to the predictable nature of apixaban pharmacokinetics and proven superiority regarding adverse effects, as compared to other DOACs.

CONCLUSION

Dose-reduced apixaban is a safe and viable choice in patients with atrial fibrillation warranting stroke prophylaxis while concurrently receiving ritonavir-boosted HAART.

The economic and health burden of stroke among younger adults in Australia from a societal perspective

Background

To estimate the short term (5 years) and long term (30 years) economic burden of stroke among younger adults (18–64 years), and to calculate the loss of health-related quality of life in these individuals, in Australia.

Methods

A Markov microsimulation model was built to simulate incidence of stroke among younger adults in Australia. Younger adults with stroke commenced in the model via health states defined by the modified Rankin Scale at 12 months from the AVERT study (A Very Early Rehabilitation Trial), and transitioned through these health states. Costs in Australian dollars (AUD) were measured from a societal perspective for a 2018 reference year and categorised into medical, non-medical and indirect costs. Probabilistic sensitivity analyses were performed to test the robustness around the cost of illness estimates. The loss of health-related quality of life due to stroke among younger adults was calculated by determining the difference in estimated quality-adjusted life years (QALYs) between the stroke population and the general population. This was determined by multiplying the predicted remaining life years for the modelled stroke cohort and the age-matched general population, by their corresponding age-dependent utilities.

Results

The economic burden of stroke among younger adults was estimated to be AUD2.0 billion over 5 years, corresponding to a mean of $149,180 per stroke patient. Over 30 years, the economic impact was AUD3.4 billion, equating to a mean of $249,780 per case. Probabilistic sensitivity analyses revealed a mean cost per patient of $153,410 in the short term, and a mean cost per patient of $273,496 in the long term. Compared to the age-matched general population, younger adults with stroke experienced a loss of 4.58 life years and 9.21 QALYs.

Conclusions

The results of our study suggests high economic and health burden of stroke among younger adults and highlights the need for preventive interventions targeting this age group.

Trial registration

ACTRN12606000185561, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12400-5.

Assessment of Anti-Xa activity in patients receiving concomitant apixaban with strong p-glycoprotein inhibitors and statins

WHAT IS KNOWN AND OBJECTIVES

Although the apixaban Food and Drug Administration (FDA) package insert recommends dose reduction in patients administered dual strong inhibitors of p-glycoprotein (P-gp) and cytochrome P-450 (CYP) 3A4, there are limited published data regarding potential drug-drug interactions between apixaban (Eliquis) and common p-glycoprotein (P-gp) and CYP3A4 inhibitors co-administered with statins. The aim of this study was to investigate the degree of elevation relative to apixaban serum peak and trough concentration after the co-administration of amiodarone, diltiazem and statins (atorvastatin, rosuvastatin and simvastatin).

METHODS

Patients prescribed apixaban 5mg twice daily for at least one week were identified from the anticoagulation clinic database and contacted for potential enrolment. A total of 117 volunteers were enrolled with eight excluded due to discontinued use, resulting in 109 volunteers (44 females and 65 males delineated into age groups 40-64 and ≥65 years old) completing the observational study. Fifty-five volunteers were administered apixaban without the P-gp inhibitors amiodarone or diltiazem, with or without statins (atorvastatin, rosuvastatin and simvastatin). Fifty-four volunteers were administered apixaban with either amiodarone or diltiazem, with or without statins (atorvastatin, rosuvastatin or simvastatin). Peak and trough concentrations were assessed for each patient utilizing an apixaban anti-Xa assay.

RESULTS

Of the combinations studied, the mean apixaban trough concentration upon co-administration of amiodarone without a statin was elevated compared to apixaban alone (experimental 156.83 +/- 79.59 ng/ml vs. control 104.09 +/- 44.56 ng/ml; p = 0.04). The co-administration of diltiazem and rosuvastatin, and the administration of amiodarone without a statin led to greater than 1.5-fold increase in apixaban concentrations (peak experimental 315.19 +/- 157.53 ng/ml vs control 207.6 +/- 83.38 ng/ml; p = 0.08 and trough experimental 182.03 +/- 95.93 ng/ml vs control 112.32 +/- 37.78 ng/ml; p = 0.17) suggesting the need to assess dose adjustment for patients per the FDA package insert. In addition, the aggregated mean peak (p = 0.0056) and trough (p = 0.0089) elevation of CYP3A4 experimental groups (atorvastatin and simvastatin) co-administered apixaban and diltiazem were statistically significant compared with the aggregated non-CYP3A4 control groups (no statin and rosuvastatin).

WHAT IS NEW AND CONCLUSION

Herein, we report novel data regarding peak and trough apixaban concentrations after concomitant administration of P-gp and CYP3A4 inhibitors (amiodarone or diltiazem) co-administered with statins (atorvastatin, rosuvastatin or simvastatin). Providers should consider utilizing the apixaban anti-Xa assay or comparative heparin anti-Xa assay to determine if patients require dose reduction to decrease adverse events in high-risk patients prescribed apixaban and concomitant p-glycoprotein and CYP3A4 inhibitors amiodarone or diltiazem with and without a CYP3A4 or non-3A4 statin.

Cost-effectiveness analysis of apixaban versus vitamin K antagonists for antithrombotic therapy in patients with atrial fibrillation after acute coronary syndrome or percutaneous coronary intervention in Spain

BACKGROUND/OBJECTIVE

AUGUSTUS trial demonstrated that, for patients with atrial fibrillation (AF) having acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI), an antithrombotic regimen with apixaban and P2Y12 resulted in less bleeding, fewer hospitalizations, and similar ischemic events than regimens including a vitamin K antagonist (VKA), aspirin, or both. This study objective was to evaluate long-term health and economic outcomes and the cost-effectiveness of apixaban over VKA, as a treatment option for patients with AF having ACS/PCI.

METHODS

A lifetime Markov cohort model was developed comparing apixaban versus VKA across multiple treatment strategies (triple [with P2Y12 + aspirin] or dual [with P2Y12] therapy followed by monotherapy [apixaban or VKA]; triple followed by dual and then monotherapy; dual followed by monotherapy). The model adopted the Spanish healthcare perspective, with a 3-month cycle length and costs and health outcomes discounted at 3%.

RESULTS

Treatment with apixaban resulted in total cost savings of €883 and higher life years (LYs) and quality-adjusted LYs (QALYs) per patient than VKA (net difference, LYs: 0.13; QALYs: 0.11). Bleeding and ischemic events (per 100 patients) were lower with apixaban than VKA (net difference, -13.9 and -1.8, respectively). Incremental net monetary benefit for apixaban was €3,041, using a willingness-to-pay threshold of €20,000 per QALY. In probabilistic sensitivity analysis, apixaban was dominant in the majority of simulations (92.6%), providing additional QALYs at lower costs than VKA.

CONCLUSIONS

Apixaban was a dominant treatment strategy than VKA from both the Spanish payer's and societal perspectives, regardless of treatment strategy considered.

Evolution of Antithrombotic Management of Atrial Fibrillation After Percutaneous Coronary Intervention Over 10 Years and Guidelines Uptake

Background

The management of atrial fibrillation and/or flutter (AF) patients requiring percutaneous coronary intervention (PCI) has evolved significantly. The Canadian Cardiovascular Society AF guidelines, last updated in 2020, seek to aid physicians in balancing both bleeding and thrombotic risks.

Methods

A tertiary academic centre registry of patients with AF who had PCI was examined for the antithrombotic therapy at discharge in 4 time periods (cohort 2010–2011; cohort 2014–2015; cohort 2017; cohort 2019). Discharge prescription patterns were compared among the cohorts, using the χ² test. In addition, antithrombotic management in cohorts 2017 and 2019 were compared to guideline-expected therapy, using the χ² test.

Results

A total of 576 AF patients undergoing PCI were included. Clinical and procedural characteristics were similar among cohorts, except for an increase in drug-eluting stent use in the most recent cohort (94% vs 99%; P = 0.04). The rate of oral anticoagulation increased over time (75% vs 89%; P < 0.01), driven primarily by an increase in direct oral anticoagulants prescription (63% vs 84%; P < 0.01). In contrast to previous cohorts, there was no significant difference between the observed and the guideline-expected anticoagulation rate in cohort 2019 (89% vs 94%; P = 0.23).

Conclusions

A combination of expert guidance and educational initiatives in the past decade contributed to dramatic changes in the management of patients with AF undergoing PCI.

A Patient Decision Aid for Anticoagulation Therapy in Patients With Nonvalvular Atrial Fibrillation: Development and Pilot Study

Background

Atrial fibrillation (AF) is one of the most common predisposing factors for ischemic stroke worldwide. Because of this, patients with AF are prescribed anticoagulant medications to decrease the risk. The availability of different options for oral anticoagulation makes it difficult for some patients to decide a preferred choice of medication. Clinical guidelines often recommend enhancing the decision-making process of patients by increasing their involvement in health decisions. In particular, the use of patient decision aids (PDAs) in patients with AF was associated with increased knowledge and increased likelihood of making a choice. However, the majority of available PDAs are from Western countries.

Objective

We aimed to develop and pilot test a PDA to help patients with nonvalvular AF choose an oral anticoagulant for stroke prevention in the local setting. Outcomes were (1) reduction in patient decisional conflict, (2) improvement in patient knowledge, and (3) patient and physician acceptability.

Methods

We followed the International Patient Decision Aid Standards (IPDAS) to develop a mobile app–based PDA for anticoagulation therapy in patients with nonvalvular AF. Focus group discussions identified decisional needs, which were subsequently incorporated into the PDA to compare choices for anticoagulation. Based on recommendations, the prototype PDA was rendered by at least 30 patients and 30 physicians. Decisional conflict and patient knowledge were tested before and after the PDA was implemented. Patient acceptability and physician acceptability were measured after each encounter.

Results

Anticoagulant options were compared by the PDA using three factors that were identified (impact on stroke and bleeding risk, and price). The comparisons were presented as tables and graphs. The prototype PDA was rendered by 30 doctors and 37 patients for pilot testing. The mean duration of the encounters was 15 minutes. The decisional conflict score reduced by 35 points (100-point scale; P<.001). The AF knowledge score improved from 10 to 15 (P<.001). The PDA was acceptable for both patients and doctors.

Conclusions

Our study showed that an app-based PDA for anticoagulation therapy in patients with nonvalvular AF (1) reduced patient decisional conflict, (2) improved patient knowledge, and (3) was acceptable to patients and physicians. A PDA is potentially acceptable and useful in our setting. A randomized controlled trial is warranted to test its effectiveness compared to usual care. PDAs for other conditions should also be developed.

Multilevel and Quasi Monte Carlo Methods for the Calculation of the Expected Value of Partial Perfect Information

The expected value of partial perfect information (EVPPI) provides an upper bound on the value of collecting further evidence on a set of inputs to a cost-effectiveness decision model. Standard Monte Carlo estimation of EVPPI is computationally expensive as it requires nested simulation. Alternatives based on regression approximations to the model have been developed but are not practicable when the number of uncertain parameters of interest is large and when parameter estimates are highly correlated. The error associated with the regression approximation is difficult to determine, while MC allows the bias and precision to be controlled. In this article, we explore the potential of quasi Monte Carlo (QMC) and multilevel Monte Carlo (MLMC) estimation to reduce the computational cost of estimating EVPPI by reducing the variance compared with MC while preserving accuracy. We also develop methods to apply QMC and MLMC to EVPPI, addressing particular challenges that arise where Markov chain Monte Carlo (MCMC) has been used to estimate input parameter distributions. We illustrate the methods using 2 examples: a simplified decision tree model for treatments for depression and a complex Markov model for treatments to prevent stroke in atrial fibrillation, both of which use MCMC inputs. We compare the performance of QMC and MLMC with MC and the approximation techniques of generalized additive model (GAM) regression, Gaussian process (GP) regression, and integrated nested Laplace approximations (INLA-GP). We found QMC and MLMC to offer substantial computational savings when parameter sets are large and correlated and when the EVPPI is large. We also found that GP and INLA-GP were biased in those situations, whereas GAM cannot estimate EVPPI for large parameter sets.

Healthcare and Economic Impact of Lung Perfusion Scintigraphy in Patients Affected by Acute Pulmonary Embolism

Acute pulmonary embolism (APE) is a cardiovascular emergency, representing the main cause of mortality, morbidity, and hospitalisation in Europe. We aim to evaluate the economic and healthcare impact of lung perfusion scintigraphy (LPS) used in patients with suspected APE, in the event of non-conclusive or contraindicated computed tomography pulmonary angiography (CTPA). We considered two alternative healthcare processes for APE diagnosis, with and without LPS. We performed a cost analysis with the aim of evaluating the average direct healthcare costs for diagnosis, risk assessment, and treatment of APE. We used data from a monocentric trial. Our economic model showed that the strategy with LPS was preferable in terms of costs. The average per-patient costs for the diagnosis and treatment of the acute phase of PE in low-risk patients with a non-conclusive or not-executable CTPA, with and without LPS, are EUR 2145.25 and EUR 4912.45, respectively. LPS is a simple, quick, and economic examination, useful in this setting of patients not only for an early diagnosis but also to exclude APE, demonstrating an advantage in terms of healthcare resources. To the best of our knowledge, this study is the first to analyse the economic and healthcare impact of the use of LPS in the diagnostic pathway of suspected APE.

Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke: a systematic review and economic evaluation

BACKGROUND

Cryptogenic stroke is a stroke for which no cause is identified after standard diagnostic tests. Long-term implantable cardiac monitors may be better at diagnosing atrial fibrillation and provide an opportunity to reduce the risk of stroke recurrence with anticoagulants.

OBJECTIVES

The objectives were to assess the diagnostic test accuracy, clinical effectiveness and cost-effectiveness of three implantable monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] in patients who have had a cryptogenic stroke and for whom no atrial fibrillation is detected after 24 hours of external electrocardiographic monitoring.

DATA SOURCES

MEDLINE, EMBASE, The Cochrane Library, Database of Abstracts of Reviews of Effects and Health Technology Assessment databases were searched from inception until September 2018.

REVIEW METHODS

A systematic review was undertaken. Two reviewers agreed on studies for inclusion and performed quality assessment using the Cochrane Risk of Bias 2.0 tool. Results were discussed narratively because there were insufficient data for synthesis. A two-stage de novo economic model was developed: (1) a short-term patient flow model to identify cryptogenic stroke patients who have had atrial fibrillation detected and been prescribed anticoagulation treatment (rather than remaining on antiplatelet treatment) and (2) a long-term Markov model that captured the lifetime costs and benefits of patients on either anticoagulation or antiplatelet treatment.

RESULTS

One randomised controlled trial, Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL-AF) (Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, et al. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med 2014;370:2478-86), was identified, and no diagnostic test accuracy study was identified. The CRYSTAL-AF trial compared the Reveal™ XT (a Reveal LINQ predecessor) (Medtronic plc) monitor with standard of care monitoring. Twenty-six single-arm observational studies for the Reveal devices were also identified. The only data for BioMonitor 2-AF or Confirm Rx were from mixed population studies supplied by the companies. Atrial fibrillation detection in the CRYSTAL-AF trial was higher with the Reveal XT than with standard monitoring at all time points. By 36 months, atrial fibrillation was detected in 19% of patients with an implantable cardiac monitor and in 2.3% of patients receiving conventional follow-up. The 26 observational studies demonstrated that, even in a cryptogenic stroke population, atrial fibrillation detection rates are highly variable and most cases are asymptomatic; therefore, they probably would not have been picked up without an implantable cardiac monitor. Device-related adverse events, such as pain and infection, were low in all studies. The de novo economic model produced incremental cost effectiveness ratios comparing implantable cardiac monitors with standard of care monitoring to detect atrial fibrillation in cryptogenic stroke patients based on data for the Reveal XT device, which can be related to Reveal LINQ. The BioMonitor 2-AF and Confirm RX were included in the analysis by making a strong assumption of equivalence with Reveal LINQ. The results indicate that implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold. When each device is compared incrementally, BioMonitor 2-AF dominates Reveal LINQ and Confirm RX.

LIMITATIONS

The cost-effectiveness analysis for implantable cardiac monitors is based on a strong assumption of clinical equivalence and should be interpreted with caution.

CONCLUSIONS

All three implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold, compared with standard of care monitoring, for cryptogenic stroke patients with no atrial fibrillation detected after 24 hours of external electrocardiographic monitoring; however, further clinical studies are required to confirm their efficacy in cryptogenic stroke patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018109216.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 5. See the NIHR Journals Library website for further project information.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Patients Aged 80 Years and Older

The effectiveness of direct oral anticoagulants (DOAC) is non-inferior to vitamin K antagonists (VKA) to treat atrial fibrillation and venous thromboembolism (VTE). In this cross-sectional study, we compared older persons taking DOACs to those taking VKAs. We included ambulatory individuals ≥80 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for a medical prescription in September 2017. The demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs were compared in the DOAC group and VKA group. Of the 3190 included individuals, 1279 (40%) were prescribed DOACs and 1911 (60%) VKAs. Individuals taking VKAs were older than those taking DOACs (87.11 vs. 86.35 years). In the DOAC group, there were more women (51.92% vs. 48.25%) (p = 0.043), less RCD (89.60% vs. 92.73%) (p = 0.002), less VTE (1.80% vs. 6.59%), less severe heart failure (58.09% vs. 67.87%), less severe hypertension (18.22% vs. 23.60%), less severe kidney diseases (1.49% vs. 3.82%), and fewer drugs per prescription (6.15 vs. 6.66) (p < 0.01 for all). The DOAC group were also less likely to be taking angiotensin receptor blockers (10.79% vs. 13.97%), furosemide (40.81% vs. 49.66%) or digoxin (10.32% vs. 13.66%) than the VKA group (p = 0.009, p < 0.001, and p = 0.005). DOACs were less prescribed than VKAs. Individuals taking VKAs were older and had more severe comorbidities and more drugs per prescription than those taking DOACs.

Cost-Effectiveness Analysis of Rivaroxaban Plus Aspirin Compared with Aspirin Alone in Patients with Coronary and Peripheral Artery Diseases in Italy

BACKGROUND

Rivaroxaban is a selective inhibitor of coagulation factor Xa and its combination with aspirin showed better outcomes in the prevention of recurrent cardiovascular disease than aspirin alone.

OBJECTIVE

This analysis aimed to economically compare the cost effectiveness of rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily) with aspirin alone in patients with coronary artery disease (CAD) or peripheral artery disease (PAD) and related subgroups.

METHODS

The analysis simulates the perspective of the Italian National Healthcare Service and used a state-transition decision Markov model. Clinical efficacy data and health events risks were gathered from the COMPASS trial. Health outcomes and costs (in Euros) were evaluated over a lifetime horizon and were discounted at 3.5% per annum. Direct healthcare costs entered the analysis. Results were expressed in terms of incremental cost-effectiveness ratio (ICER), defined as cost per quality-adjusted life-year (QALY) gained. One-way deterministic and probabilistic sensitivity analyses were performed.

RESULTS

For the CAD or PAD population, rivaroxaban plus aspirin was more effective and costly compared with aspirin alone. Incremental costs and efficacy produced an ICER of €16,522 per QALY gained. Analyses found similar trends for the PAD and CAD groups, with respective ICERs of €8003 and €18,599, while ICERs for the other groups were lower than €13,000 per QALY. Sensitivity analyses confirmed these findings.

CONCLUSION

Compared with aspirin alone, rivaroxaban plus aspirin is cost effective in preventing recurrent cardiovascular events in all patients with CAD or PAD, from the Italian perspective. These results could help clinicians and decision makers to develop improved strategies for cardiovascular disease prevention.

Cost-Effectiveness of Direct Non-Vitamin K Oral Anticoagulants Versus Vitamin K Antagonists for the Management of Patients with Non-Valvular Atrial Fibrillation Based on Available "Real-World" Evidence: The Italian National Health System Perspective

BACKGROUND AND OBJECTIVE

The increasing availability of real-world evidence (RWE) about safety and effectiveness of direct non-vitamin K oral anticoagulants (DOACs) for the management of atrial fibrillation (AF) offers the opportunity to better understand the clinical and economic implications of DOACs versus vitamin K antagonists (VKAs). The objective of this study was to compare the economic implications of DOACs and VKAs using data from real-world evidence in patients with AF.

METHODS

A Markov model simulating the lifetime course of patients diagnosed with non-valvular AF was used to evaluate the cost-effectiveness of DOACs (i.e., rivaroxaban, dabigatran and apixaban) versus VKAs from the Italian National Health System (INHS) perspective. The model was made up of data from the literature and a meta-analysis of RWE on the incidence of stroke/systemic embolism (SE), major bleeding (MB), intracranial haemorrhage (ICH) and all-cause mortality (ACM); direct costs included drug costs, costs for drug monitoring, and management of events from official national lists. One-way and probabilistic sensitivity analyses (PSA) were used to assess the robustness of the results.

RESULTS

Results from the meta-analysis showed that apixaban had a high probability of being the most effective for stroke/SE, MB and ACM. Despite their higher acquisition costs, the cost-effectiveness analysis showed all DOACs involved a saving when compared with VKAs, with per-patient savings ranging between €4647 (rivaroxaban) to €6086 (apixaban). Moreover, all DOACs indicated a gain both in quality-adjusted life-years and life-years. According to PSA, findings related to apixaban were consistent, while for dabigatran and rivaroxaban PSA revealed a higher degree of uncertainty.

CONCLUSIONS

The beneficial effect of DOACs on containing events showed in RWE had the potential to offset drug-related costs, thus improving the sustainability of treatment for non-valvular AF in daily clinical practice.

Direct oral anticoagulants in point-of-care monitoring: an ex-vivo study

BACKGROUND

Anticoagulatory activity of direct oral anticoagulants (DOACs) is not routinely measurable by point-of-care monitoring. Thus, the aim of this study was to evaluate the influence of dabigatran/rivaroxaban on point-of-care testing.

METHODS

Samples from 34 participants under DOAC therapy were drawn at two time points. Before ingestion and two-to-three hours afterwards. Thrombelastometric (ROTEM) and aggregometric (Multiplate) measurements were performed. Dabigatran and rivaroxaban plasma levels were determined.

RESULTS

Dabigatran and rivaroxaban plasma levels showed significant correlations with clotting time (CT) in EXTEM (r=0.765, P<0.0001; r=0.689, P<0.0001) and INTEM (r=0.792, P<0.0001; r=0.595, P<0.001). A positive correlation was identified between dabigatran ingestion and maximum-clot-firmness (MCF) (r=0.354, P<0.05) in the EXTEM test, pronounced in the absence of concomitant antiplatelet therapy (r=0.709, P<0.05). EXTEM-MCF positively correlated with the TRAP test in aggregometry (0.662, P<0.05), an effect not observed in patients treated with antiplatelet therapy.

CONCLUSIONS

Prolongation of CT-EXTEM and CT-INTEM indicates delayed initiation of clot formation. The CT-EXTEM seems to facilitate qualitative monitoring of dabigatran. In contrast, qualitative monitoring of rivaroxaban by CT-EXTEM may be limited as rivaroxaban may affect the measurement at therapeutic plasma levels. It seems that clot formation is faster/firmer in the presence of increased dabigatran plasma levels. This can be attributed to a non-dose-dependent effect via increased fibrin polymerization and second to a dose-dependent effect via increased platelet sensitivity to thrombin.

The affordability of adding a direct-acting oral anticoagulant to the national list of essential medicine for patients with non-valvular atrial fibrillation in Thailand: a budget impact analysis

BACKGROUND

Atrial fibrillation (AF) can lead to a significant health and economic burden to society. This study aimed to assess the net budget impact of direct-acting oral anticoagulants (DOACs) instead of warfarin for stroke prevention in patients with non-valvular AF from the payer's perspective.

METHODS

A budget model over a 5-year period was used. Dabigatran 150 mg, dabigatran 110 mg, apixaban 5 mg, rivaroxaban 20 mg, edoxaban 60 mg, and edoxaban 30 mg were included. Inputs were retrieved from published literature. Adoption rate of DOACs started at 5% and subsequently had a 5% increase in each year. Net budget impact (NBI) and sensitivity analyses were performed.

RESULTS

The average NBI over the 5-year horizon for all DOACs ranged from 12.3 M USD to 13.9 M USD. Dabigatran 150 mg had the highest NBI, while edoxaban 30 mg had the lowest NBI. The average NBI/patient/year ranged from 63.03 USD - 70.75 USD.

CONCLUSIONS

Of all DOACs, edoxaban 30 mg, apixaban 5 mg, and edoxaban 60 mg are the top 3 lowest NBI. Together with cost-effectiveness evidence, those DOACs should be considered to be listed on the National List of Essential Medicine in Thailand.

Impact of different anticoagulation management strategies on outcomes in atrial fibrillation: Dutch and Belgian results from the GARFIELD-AF registry

BACKGROUND

The uptake rate of non-vitamin K oral anticoagulants (NOAC) for the treatment of non-valvular atrial fibrillation (AF) was far lower in the Netherlands (NL) compared to Belgium (BE). Also, patients on VKA in NL were treated with a higher target international normalized ratio (INR) range of 2.5 to 3.5.

OBJECTIVES

To explore the effect of these differences on thromboembolism (TE) and bleeding.

METHODS

Data from the GARFIELD-AF registry was used. Patients with new-onset AF and ≥1 investigator-determined risk factor for stroke were included between 2010 and 2016. Event rates from 2 years of follow-up were used.

RESULTS

In NL and BE, 1186 and 1705 patients were included, respectively. Female sex (42.3% vs 42.2%), mean age (70.7 vs 71.3 years), CHA2 DS2 -VASc (3.1 vs 3.1), and HAS-BLED score (1.4 vs 1.5) were comparable between NL and BE. At diagnosis in NL vs BE, 72.1% vs 14.6% received vitamin K antagonists (VKA) and 17.8% vs 65.5% NOACs, varying greatly across cohorts. Mean INR was 2.9 (±1.0) and 2.4 (±1.0) in NL and BE, respectively. Event rates per 100 patient-years in NL and BE, respectively, of all-cause mortality (3.38 vs 3.90; hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.65-1.15), ischemic stroke/TE (0.82 vs 0.72; HR 1.14, 95% CI 0.62-2.11), and major bleeding (2.06 vs 1.54; HR 1.33, 95% CI 0.89-1.99) did not differ significantly.

CONCLUSIONS

In GARFIELD-AF, despite similar characteristics, patients on anticoagulants were treated differently in NL and BE. Although the rate of major bleeding was 33% higher in NL, variations in bleeding, mortality, and TE rates were not statistically significant.

Oral Anticoagulants Preference in Hospitalized Patients with Acute Deep Vein Thrombosis or Non-Valvular Atrial Fibrillation

(1) Aim: The aim of this study was to assess the preferences of oral anticoagulants (OA) in patients diagnosed with deep vein thrombosis (DVT) of lower limbs or non-valvular atrial fibrillation (AF) requiring anticoagulation for medium/long term. (2) Materials and methods: the study included consecutive patients admitted with a diagnosis of either acute DVT of lower limbs (without signs of pulmonary embolism) or non-valvular AF who required oral anticoagulation, in a time frame of 18 months from January 2017 until June 2018. The following data were recorded: demographic variables, comorbidities (ischemic heart disease, arterial hypertension, heart failure, stroke, peripheral artery disease, diabetes mellitus, obesity), type and dose of OA (acenocoumarol, dabigatran, apixaban, rivaroxaban), complications due to the use of OA. (3) Results: AF patients were older and had considerably more cardiovascular comorbidities than DVT patients. Vitamin K antagonists (VKA) were more likely to be administered in patients with AF, as they had indication for indefinite anticoagulation. VKA were more frequently prescribed in patients with ischemic heart disease, heart failure, and diabetes compared with DVT patients. Moreover, complications related to OA use were more frequent in the VKA group. Almost half of patients with acute DVT (48.5%) were treated with direct OA (DOAC) rather than VKA, and only a quarter of AF patients (24.8%) were treated with DOACs.

Cost-Effectiveness of Extended and One-Time Screening Versus No Screening for Non-Valvular Atrial Fibrillation in the USA

BACKGROUND

There is limited evidence on the clinical and cost benefits of screening for atrial fibrillation (AF) with electrocardiogram (ECG) in asymptomatic adults.

METHODS

We adapted a previously published Markov model to evaluate the clinical and economic impact of one-time screening for non-valvular AF (NVAF) with a single 12-lead ECG and a 14-day extended screening with a hand-held ECG device (Zenicor single-lead ECG, Z14) compared with no screening. Clinical events considered included ischemic stroke, systemic embolism, major bleeds, myocardial infarction, and death. Epidemiology and effectiveness data for extended screening were from the STROKESTOP study. Risks of clinical events in NVAF patients were derived from ARISTOTLE. Analyses were conducted from the perspective of a third-party payer, considering a population with undiagnosed NVAF, aged 75 years in the USA. Costs and utilities were discounted at a 3% annual rate. Parameter uncertainty was formally considered via deterministic and probabilistic sensitivity analyses (DSA and PSA). Structural uncertainty was assessed via scenario analyses.

RESULTS

In a hypothetical cohort of 10,000 patients followed over their lifetimes, the number of additional AF diagnoses was 54 with 12-lead ECG and 255 with Z14 compared with no screening. Both screening strategies led to better health outcomes (ischemic strokes avoided: ECG 12-lead, 9.8 and Z14, 42.2; quality-adjusted life-years gained: ECG 12-lead, 31 and Z14, 131). Extended screening and one-time screening were cost effective compared with no screening at a willingness-to-pay (WTP) threshold of $100,000 per QALY gained ($58,728/QALY with ECG 12-lead and $47,949/QALY with Z14 in 2016 US dollars). ICERs remained below $100,000 per QALY in all DSA, most PSA runs, and in all scenario analyses except for a scenario assuming low anticoagulation persistence.

CONCLUSIONS

Our analysis suggests that, screening the general population at age 75 years for NVAF is cost effective at a WTP threshold of $100,000. Both extended screening and one-time screening for NVAF are expected to provide health benefits at an acceptable cost.

A Systematic Review of Network Meta-Analyses and Real-World Evidence Comparing Apixaban and Rivaroxaban in Nonvalvular Atrial Fibrillation

There is no direct evidence comparing the 2 most commonly prescribed direct oral anticoagulants, apixaban and rivaroxaban, used for stroke prevention in nonvalvular atrial fibrillation (NVAF). A number of network meta-analyses (NMAs) of randomized control trials and real-world evidence (RWE) studies comparing the efficacy, effectiveness, and safety of apixaban and rivaroxaban have been published; however, a comprehensive evidence review across the available body of evidence is lacking. In this study, we aimed to systematically review and evaluate the clinical outcomes of apixaban and rivaroxaban using a combination of data gleaned from both NMAs and RWE studies. The review identified 21 NMAs and 5 RWE studies. The data demonstrated that apixaban was associated with fewer major bleeding events compared to rivaroxaban. There was no difference in the efficacy/effectiveness profiles between these treatments. Bleeding is a serious complication of anticoagulation therapy for the management of NVAF, and is associated with increased rates of hospitalization, morbidity, mortality, and health-care expenditure. The majority of studies in this comprehensive evidence review suggests that apixaban has a lower risk of major bleeding events compared to rivaroxaban in patients with NVAF.

MOdified DIagnostic strateGy to safely ruLe-out pulmonary embolism In the emergency depArtment: study protocol for the Non-Inferiority MODIGLIANI cluster cross-over randomized trial

Introduction

In the work-up strategy for pulmonary embolism (PE) in the ED, the recently introduced YEARS rule allows the raising of the D-dimer threshold to 1000 ng/ml in patients with no signs of deep venous thrombosis and no hemoptysis and in whom PE is not the most likely diagnosis. However, this decision rule has never been prospectively compared to the usual strategy. Furthermore, it is unclear if the YEARS rule can be used on top of the Pulmonary Embolism Rule-out Criteria (PERC). We aim to assess the non-inferiority of YEARS compared to current guidelines to rule out PE among PERC-positive ED patients with suspicion of PE.

Methods/design

The MODIGLIANI study is a multicenter, European, non-inferiority, cluster-randomized, two periods cross-over, controlled trial. Each center will be randomized for the sequence of two 4-month periods: intervention (MOdified Diagnostic Strategy: MODS) followed by control (usual care), or control followed by intervention with 1 month of “wash-out” between the two periods. In the control period, the threshold will be as usual (500 ng/ml for patients aged 50 years or younger and age × 10 for older patients). In the MODS period, the threshold of D-dimers to rule out PE will be raised to 1000 ng/ml if no item of the YEARS score is present or will remain unchanged otherwise. Patients will be included if they have a suspicion of PE, defined as chest pain, dyspnea, or syncope. Non-inclusion criteria comprise a high clinical probability of PE or PERC-negative patients with low clinical probability.

Ethics and dissemination

The study has received the following approvals: Comité de protection des personnes Ile de France XI (France) and Comité de Ética de la Investigación con medicamentos del Hospital Clínic de Barcelona (Spain). Results will be made available to all included participants and other researchers.

Trial registration

ClinicalTrials.gov, NCT04032769. Registered on 24 July 2019.

DOACs Versus VKAs in Older Adults Treated for Acute Venous Thromboembolism: Systematic Review and Meta-Analysis

BACKGROUND/OBJECTVES

Four direct-acting oral anticoagulants (DOACs) are currently approved by the Food and Drug Administration for the treatment of venous thromboembolism (VTE). Limited efficacy and safety data are available for their use in older adults (aged ≥75 years).

METHODS

Medline, Cochrane Central Register of Controlled Trials, Embase, EBSCO, Web of Science, and CINAHL databases were searched for trials comparing DOACs with vitamin K antagonists (VKAs) for the treatment of VTE in older adults from inception through January 1, 2020. Meta-analysis was performed to assess the combined endpoint of recurrent VTE and related deaths and bleeding events (composite of major and clinically relevant nonmajor bleeding). The Mantel-Haenszel relative risk (RR) random effects model was used to pool results across studies.

RESULTS

Six randomized controlled trials at low risk of bias met criteria for inclusion with a total of 3,665 patients aged 75 years and older with follow-up of 24 weeks or longer. Data for bleeding events were not available for dabigatran. Overall, DOACs had an improved efficacy over VKAs (RR = .56; 95% confidence interval [CI] = .38-.82). There was no statistically significant difference in the safety outcomes (RR = .77; 95% CI = .56-1.05). No significant heterogeneity was observed for efficacy outcome, and only moderate heterogeneity was observed for safety outcome.

CONCLUSION

In older adults with VTE, DOACs appear to improve rates of recurrent VTE and VTE-related deaths compared with VKAs with similar bleeding outcomes.

Uptake of direct oral anticoagulants in primary care: an ecological and economic study

Background

Clinical trials indicate that direct oral anticoagulants (DOACs) are as effective as warfarin at preventing ischaemic stroke. It is unclear, however, whether relative changes in DOAC uptake have affected clinical and economic outcomes in practice.

Aim

To investigate variations in DOAC uptake and the relationship with hospital admissions and cost.

Design & setting

An ecological study using electronic administrative records from England, April 2012 to March 2017.

Method

Multivariable regression was used to model practice variation in DOAC prescribing, and the relationship with clinical and economic outcomes.

Results

In quarter 1 of 2017, 55.0% of the 2 695 262 patients dispensed an anticoagulant were given a DOAC. There was a two-fold difference in odds of dispensing DOACs between clinical commissioning groups (CCGs) between those with the highest and lowest usage of these drugs. Increases in the relative uptake of DOACs were not associated with hospital admissions for ischaemic stroke (adjusted incidence rate ratio [IRR] = 1.00; 95% confidence intervals [CI] = 0.999 to 1.001), nor gastrointestinal or intracranial bleeds (IRR = 1.001; 95% CI = 1.000 to 1.002). In 2017, quarter 1, CCGs spent £9247 (inter-quartile range £7751 to £10 853) per 1000 patients on anticoagulants. The marginal effect of a 5% increase in DOAC uptake was associated with a £17.95 (£8.75 to £27.15) increase in total costs, per 1000 patient population.

Conclusion

There were significant differences in the relative uptake of DOACs across practices, with greater costs but no reduction in hospital admissions in those with higher levels of dispensing. Findings indicate that clinical and economic benefits of DOACs identified by clinical trials are not realised in practice.

Prevention and treatment of venous thromboembolism in hospital and the community: a research programme including the ExACT RCT

Background

Deep-vein thrombosis and pulmonary embolism, collectively known as venous thromboembolism when clots are formed in the venous circulation, are common disorders that are often unprovoked (i.e. there is no obvious reason for the clot occurring). Some people, after having an unprovoked clot, are at a high risk of developing another, or at risk of developing a secondary clot, most importantly in the lungs. Furthermore, in the long term, some patients will develop circulation problems known as post-thrombotic syndrome. The aim of this programme was to improve the understanding of both the prevention and the treatment of thrombosis in people at the highest risk of recurrence.

Objectives

To clarify if it is possible to identify those people at the highest risk of having a recurrent venous thromboembolism, and if it is possible to prevent this happening by giving anticoagulation treatment for longer. To clarify if it is possible to identify those people at the highest risk of developing post-thrombotic syndrome. To document the current knowledge level about prevention and treatment of venous thromboembolism. To find what the barriers are to implementing measures to prevent venous thromboembolism. To find the most cost-effective means of treating venous thromboembolism.

Design

Mixed methods, comprising a randomised controlled trial, qualitative studies, cost-effectiveness analyses and questionnaire studies, including patient preferences.

Setting

UK general practices and hospitals, predominantly from the Midlands and Shropshire.

Participants

Adults attending participating anticoagulation clinics with a diagnosis of first unprovoked deep-vein thrombosis or pulmonary embolism, and health-care professionals, patients and other stakeholders who were involved in the prevention and treatment of venous thromboembolism.

Intervention

Extended treatment with oral anticoagulation therapy (2 years) versus standard care (treatment with oral anticoagulation therapy for at least 3 months).

Results

Work package 1 demonstrated that extended anticoagulation for up to 2 years was clinically effective and cost-effective in reducing the incidence of recurrent venous thromboembolism, with a small increase in the risk of bleeding. There was no difference in post-thrombotic syndrome incidence or severity, or quality of life, between those undergoing the extended treatment and those receiving the standard care. Work package 2 identified five common themes with regard to the prevention of hospital-acquired thrombosis: communication, knowledge, role of primary care, education and training, and barriers to patient adherence. Work package 3 suggested that extended anticoagulation with novel oral anticoagulants was cost-effective only at the £20,000-per-quality-adjusted life-year level for a recurrence rate of between 17.5% and 22.5%, depending on drug acquisition costs, while identifying a strong patient preference for extended anticoagulation based on a fear of recurrent venous thromboembolism.

Limitations

The major limitation was the failure to reach the planned recruitment target for work package 1.

Conclusions

Extended anticoagulation with warfarin for a first unprovoked venous thromboembolism is clinically effective and cost-effective and is strongly preferred by patients to the alternative of not having treatment. There are significant barriers to the implementation of preventative measures for hospital-acquired thrombosis. Further research is required on identifying patients in whom it is safe to discontinue anticoagulation, and at what time point following a first unprovoked venous thromboembolism this should be done.

Trial registration

Current Controlled Trials ISRCTN73819751 and EudraCT 2101-022119-20.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 8, No. 5. See the NIHR Journals Library website for further project information.

Web search popularity, publicity, and utilization of direct oral anticoagulants in the United States, 2008-2018: A STROBE-compliant study

We aimed to study the changing popularity of oral anticoagulants and the potential association between media coverage and real-world utilization practice, using time series analysis.In this STROBE-compliant study, we used Google Trends data to study public interest for direct oral anticoagulants (DOACs) (dabigatran, rivaroxaban, apixaban, and edoxaban) and warfarin in the United States (10-year coverage, beginning July 1st, 2008 ending June 30th, 2018). We validated our findings on a sample of 50 consecutive datasets (accumulated between July 6th, 2018 and October 19th, 2018), using the same search criteria. We used the LexisNexis Academic database to quantify monthly media coverage for DOACs and explored its association with interest by the public, using the cross-correlation coefficient function. Finally, we studied the association between public interest and real-world utilization data, including published US-wide data on ambulatory anticoagulation visits.The approval of dabigatran in 2010 marked an increasing public interest for DOACs. Dabigatran exhibited a steep rise early after Food and Drug Administration approval that peaks in 2011, to be surpassed sequentially by rivaroxaban (2012) and apixaban (2014). Apixaban has outperformed its competitors in popularity since mid-2017, and, by the end of the observation period, was close to warfarin that is on first place. Media coverage was low before approval of the first oral DOAC (dabigatran), increased thereafter (median 13 news articles per month vs 64, P < .001), with peaks on the approval dates (81 vs 48, P = .003). Media coverage had a weak immediate impact on DOACs public interest and public interest patterns preceded changes in ambulatory anticoagulation visits by up to 5 months.For a long-run observation period, a single Google Trends search will suffice to produce robust estimations of the relative popularity between treatment options, such as oral anticoagulants. Media coverage has limited immediate impact and relative public interest is a potential lead indicator of changes in actual utilization.

Comparative effectiveness and safety of oral anticoagulants for atrial fibrillation: A retrospective cohort study

Oral anticoagulants (OACs) are high-priority medications, frequently used with clinically important benefit and serious harm. Our objective was to compare the safety and effectiveness of direct-acting oral anticoagulants (DOACs) versus warfarin in a population where anticoagulation management and DOACs were readily available. A retrospective cohort study of all adults living in British Columbia with a diagnosis of atrial fibrillation and a first prescription for an OAC was conducted. Co-primary outcomes were ischemic stroke and systemic embolism, and major bleeding. Secondary outcomes included a net clinical outcome composite and analysis of discontinuation, switching, and key subgroups. We estimated the effects of treatment using time-to-event models with high-dimensional propensity score adjustment to control confounding. After adjustment for prescribing bias, a cohort (n = 20,113, 43.8% female, mean age 72.4 years) with a mean follow-up of 18.1 months showed that patients taking warfarin tended to be poorer, sicker, and less likely to have a cardiologist prescriber. Outcome event rates were not significantly different for DOACs compared to warfarin [adjusted rate ratio of 1.15 (0.91, 1.46) for systemic embolism, 0.94 (0.82, 1.08) for major bleeding, and 0.98 (0.90, 1.06) for net clinical outcome]. Only the effect of age on net clinical outcome met our strict criteria for predicting which group might be superior. Switch of drug class was associated with increased risk of events (p < 0.003). In this population, we found no difference in important clinical outcomes between warfarin and DOACs. Switching compared to not switching was associated with harm.

Efficacy and Safety of Direct Oral Anticoagulants in Elderly Patients With Atrial Fibrillation: A Network Meta-Analysis

Background: Direct oral anticoagulants (DOACs) have been widely used in patients with atrial fibrillation (AF) for antithrombotic prophylaxis, which were shown to have a favorable risk–benefit profile. However, there are no guidelines for the use of DOACs in elderly patients (aged ≥75 years) with AF, which creates uncertainty about the optimal antithrombotic treatment in these patients.

Methods: After comprehensively searching Embase, PubMed, and Cochrane databases, five phase III randomized controlled trials involving 28,137 elderly participants were included in this study. The efficacy outcome was stroke or systemic embolism, and the safety outcome was major bleeding. We conducted a network meta-analysis by using a Bayesian random-effect model for the first time to evaluate the efficacy and safety of main DOACs (apixaban, edoxaban, rivaroxaban, and dabigatran) and warfarin in elderly patients with AF. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were used to assess the effect of drugs on efficacy and safety. The rank probabilities were used to reflect the hierarchy of drugs, and a larger rank probability value symbolized a better rank of drugs.

Results: In the prophylaxis of stroke or systemic embolism, apixaban was found to be the best among DOACs compared to warfarin (HR, 0.71; 95% CI: 0.33–1.50), though this finding was not statistically significant. Apixaban ranked the best (rank probabilities, 41.2%) in efficacy of drugs, followed by rivaroxaban, edoxaban, dabigatran, and warfarin (rank probabilities, 31.8, 15.9, 10.9, and 0.2%, respectively). In reducing the risk of major bleeding, apixaban was found to be the best among DOACs too, compared to warfarin (HR, 0.64; 95% CI: 0.33–1.30), though this finding was not statistically significant. In safety, apixaban ranked the best (rank probabilities, 71.4%), followed by edoxaban, dabigatran, warfarin, and rivaroxaban (rank probabilities, 21.0, 5.8, 0.9, and 0.8%, respectively).

Conclusions: DOACs showed a lower incidence of stroke/systemic embolism and major bleeding compared with warfarin in antithrombotic therapy in elderly patients (aged ≥75 years), with apixaban being the best of those interventions. Therefore, apixaban should be given priority as an anticoagulant in stroke prevention for elderly patients with AF.

A consultant-led anticoagulation review of all patients in one clinical commissioning group to prevent atrial fibrillation related stroke

OBJECTIVE

Ensuring patients with Atrial fibrillation (AF) are appropriately anticoagulated across NHS Bedfordshire Clinical Commissioning Group (BCCG) with the primary goal of reducing AF-related strokes.

METHODS

With Inspira Health, BCCG adopted the Primary Care Atrial Fibrillation (PCAF) Service which is led by Consultant Cardiologists. PCAF uses retrospective clinical audit to identify patients who require prospective face-to-face review on the need for anticoagulation.

RESULTS

34 GP practices participated covering a 376 311 population (80% of BCCG). 12 573 patients' medical records were audited. The initial AF register was 7301 patients (AF prevalence 1.9%) and an additional 265 patients were identified through AF casefinder resulting in an AF prevalence of 2.0%. From 7566 patients with AF, 5831 were already on anticoagulants (77.1%), with 50.5% (n = 2947) on VKA medications and 49.5% (n = 2884) on direct oral anticoagulants (DOACs). Of the DOAC patients, 595 (20.6%) required dosage review or up to date blood tests. Case notes were reviewed for 1735 patients not on anticoagulation, with 901 (51.9%) patients deemed not eligible for anticoagulation. This left 834 (48.1%) patients who were eligible for, but not on, anticoagulation. A further 407 (13.8%) patients currently taking VKA medications were deemed sup-optimal with regards to INR control with TTR < 65%. In total 1241 patients were invited for review by a Consultant Cardiologist at their local GP practice, with an attendance rate of 90%. From all face to face and virtual consultations, 908 patients had anticoagulants prescribed, changed, management of INRs improved or were in the process of being anticoagulated at the time of follow-up. From this we would expect 36.3 AF related strokes prevented and a cost saving to the NHS of £470 200 per year.

CONCLUSION

Through comprehensive audit, BCCG have been able to ensure that patients with AF are appropriately anticoagulated in 80% of their catchment population. This has improved anticoagulation to prevent AF-related stroke.