Strengths and weaknesses of 'real-world' studies involving non-vitamin K antagonist oral anticoagulants.

Randomised controlled trials (RCTs) provide the reference standard for comparing the efficacy of one therapy or intervention with another. However, RCTs have restrictive inclusion and exclusion criteria; thus, they are not fully representative of an unselected real-world population. Real-world evidence (RWE) studies encompass a wide range of research methodologies and data sources and can be broadly categorised as non-interventional studies, patient registries, claims database studies, patient surveys and electronic health record studies. If appropriately designed, RWE studies include a patient population that is far more representative of unselected patient populations than those of RCTs, but they do not provide a robust basis for comparing treatment strategies. RWE studies can have very large sample sizes, can provide information on treatments in patient groups that are usually excluded from RCTs, are generally less expensive and quicker than RCTs, and can assess a broad range of outcomes. Limitations of RWE studies can include low internal validity, lack of quality control surrounding data collection and susceptibility to multiple sources of bias for comparing outcomes. RWE studies can complement the findings from RCTs by providing valuable information on treatment practices and patient characteristics among unselected patients. This information is necessary to guide treatment decisions and for reimbursement and payment decisions. RWE studies have been extensively applied in the postmarketing approval assessment of non-vitamin K antagonist oral anticoagulants since 2010. However, the benefits, costs, limitations and methodological challenges associated with the different types of RWE must be considered carefully when interpreting the findings

The cost-effectiveness of an early interventional strategy in non-ST-elevation acute coronary syndrome based on the RITA 3 trial

The published version of the aritcle can be found at the link below.Background: Evidence suggests that an early interventional strategy for patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) can improve health outcomes but also increase costs when compared with a conservative strategy.Objective: The aim of this study was to assess the cost-effectiveness of an early interventional strategy in different risk groups from a UK health-service perspective.Design: Decision-analytic model based on randomised clinical trial data.Main outcome measures: Costs in UK Sterling at 2003/2004 prices and quality-adjusted life years (QALYs) combined into an incremental cost-effectiveness ratio.Methods: Data from the third Randomised Intervention Trial of unstable Angina (RITA 3) was employed to estimate rates of cardiovascular death and myocardial infarction, costs and health-related quality of life. Cost-effectiveness was estimated over patients' lifetimes within the decision-analytic model.Results: The mean incremental cost per QALY gained for an early interventional strategy was approximately £55000, £22000 and £12000 for patients at low, intermediate and high risk, respectively. The early interventional strategy is approximately 1%, 35% and 95% likely to be cost-effective for patients at low, intermediate and high risk, respectively, at a threshold of £20000 per QALY. The cost-effectiveness of early intervention in low-risk patients is sensitive to assumptions about the duration of the treatment effect.Conclusion: An early interventional strategy in patients presenting with NSTE-ACS is likely to be considered cost-effective for patients at high and intermediate risk, but this is less likely to be the case for patients at low risk

Time-trends and treatment gaps in the antithrombotic management of patients with atrial fibrillation after percutaneous coronary intervention: Insights from the CHUM AF-STENT Registry.

BACKGROUND: The management of atrial fibrillation and flutter (AF) patients undergoing percutaneous coronary intervention (PCI) has undergone a rapid recent evolution. In 2016, the Canadian Cardiovascular Society (CCS) published expert recommendations to help guide clinicians in balancing bleeding and thrombotic risks in these patients. HYPOTHESIS: Antithrombotic regimen prescriptions for AF patients undergoing PCI evolved after the publication of the 2016 CCS AF guidelines. METHODS: A prospective cohort of AF patients undergoing PCI with placement of a coronary stent from a single tertiary academic center was analyzed for the recommended antithrombotic regimen at discharge. Prescribing behavior was compared between three time periods (Cohort A [2010-2011]; Cohort B [2014-2015]; Cohort C [2017]) using the χ2 test. In addition, antithrombotic management in Cohorts B and C were compared to guideline-recommended therapy. RESULTS: A total of 459 patients with AF undergoing PCI were identified. Clinical and procedural characteristics were similar between cohorts, with the exception of an increase in drug-eluting stent (DES) use over time (P < .01). Overall, the rate of oral anticoagulation (OAC) increased over time (P < .01), associated with an increase in nonvitamin K OAC prescription (P < .01) and a concomitant decrease in vitamin K antagonist prescription (P < .01). Despite this, the overall rate of anticoagulation remains below what would be predicted with perfect guideline compliance (75% vs 94%, P < .01). CONCLUSION: There has been a dramatic shift in clinical practice for AF patients requiring PCI, with increases in prescription of OAC even in the context of an increase in the use of DES. However, room for further practice optimization still exists

Evolving quality standards for large-scale registries: the GARFIELD-AF experience.

Aims: Registries have the potential to capture treatment practices and outcomes in populations beyond the constraints of clinical trial settings. The value of data obtained depend critically upon robust quality standards (including source data verification [SDV] and training); features that are commonly absent from registries. This article outlines the quality standards developed for Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF). Methods and Results: GARFIELD-AF comprises ∼57 000 patients prospectively recruited over 6.5 years in 35 countries in five successive cohorts. The registry employs a combination of remote and onsite monitoring to ascertain completeness and accuracy of records and by design, SDV is performed on 20% of cases (i.e. ∼11 400 patients). Four performance measures for ranking sites according to data quality and other performance indicators were evaluated (including data quality for 13 quantifiable variables, late data locking, number of missing critical variables, and history of poor data quality from the previous monitoring phase). These criteria facilitated the identification of sites with potentially suboptimal data quality for onsite monitoring. During early phases of the registry, critical variables for data checking were also identified. SDV using these variables (partial SDV in 902 patients) showed similar concordance to SDV of all fields (110 patients): 94.4% vs. 93.1%, respectively. This standard formed the baseline against which ongoing quality improvements were assessed, facilitating corrective action on data quality issues. In consequence, concordance was improved in the next monitoring phase (95.6%; n = 1172). Conclusion: The quality standards in GARFIELD-AF have the potential to inform a future 'reference' for registries

A nationwide causal mediation analysis of survival following ST-elevation myocardial infarction

Objective: International studies report a decline in mortality following ST-elevation myocardial infarction (STEMI). The extent to which the observed improvements in STEMI survival are explained by temporal changes in patient characteristics and utilisation of treatments is unknown. Methods: Cohort study using national registry data from the Myocardial Ischaemia National Audit Project between first January 2004 and 30th June 2013. 232 353 survivors of hospitalisation with STEMI as recorded in 247 hospitals in England and Wales. Flexible parametric survival modelling and causal mediation analysis were used to estimate the relative contribution of temporal changes in treatments and patient characteristics on improved STEMI survival. Results: Over the study period, unadjusted survival at 6 months and 1 year improved by 0.9% and 1.0% on average per year (HR: 0.991, 95% CI: 0.988 to 0.994 and HR: 0.990, 95% CI: 0.987 to 0.993, respectively). The uptake of primary percutaneous coronary intervention (PCI) (HR: 1.025, 95% CI: 1.021 to 1.028) and increased prescription of P2Y12 inhibitors (HR: 1.035, 95% CI: 1.031 to 1.039) were significantly associated with improvements in 1-year survival. Primary PCI explained 16.8% (95% CI: 10.8% to 31.6%) and 13.2% (9.2% to 21.9%) of the temporal survival improvements at 6 months and 1 year, respectively, whereas P2Y12 inhibitor prescription explained 5.3% (3.6% to 8.8%) of the temporal improvements at 6 months but not at 1 year. Conclusions: For STEMI in England and Wales, improvements in survival between 2004 and 2013 were significantly explained by the uptake of primary PCI and increased use of P2Y12 inhibitors at 6 months and primary PCI only at 1 year. Trial registration number: NCT0374969

Outcomes Associated With Oral Anticoagulants Plus Antiplatelets in Patients With Newly Diagnosed Atrial Fibrillation.

Importance: Patients with nonvalvular atrial fibrillation at risk of stroke should receive oral anticoagulants (OAC). However, approximately 1 in 8 patients in the Global Anticoagulant Registry in the Field (GARFIELD-AF) registry are treated with antiplatelet (AP) drugs in addition to OAC, with or without documented vascular disease or other indications for AP therapy. Objective: To investigate baseline characteristics and outcomes of patients who were prescribed OAC plus AP therapy vs OAC alone. Design, Setting, and Participants: Prospective cohort study of the GARFIELD-AF registry, an international, multicenter, observational study of adults aged 18 years and older with recently diagnosed nonvalvular atrial fibrillation and at least 1 risk factor for stroke enrolled between March 2010 and August 2016. Data were extracted for analysis in October 2017 and analyzed from April 2018 to June 2019. Exposure: Participants received either OAC plus AP or OAC alone. Main Outcomes and Measures: Clinical outcomes were measured over 3 and 12 months. Outcomes were adjusted for 40 covariates, including baseline conditions and medications. Results: A total of 24 436 patients (13 438 [55.0%] male; median [interquartile range] age, 71 [64-78] years) were analyzed. Among eligible patients, those receiving OAC plus AP therapy had a greater prevalence of cardiovascular indications for AP, including acute coronary syndromes (22.0% vs 4.3%), coronary artery disease (39.1% vs 9.8%), and carotid occlusive disease (4.8% vs 2.0%). Over 1 year, patients treated with OAC plus AP had significantly higher incidence rates of stroke (adjusted hazard ratio [aHR], 1.49; 95% CI, 1.01-2.20) and any bleeding event (aHR, 1.41; 95% CI, 1.17-1.70) than those treated with OAC alone. These patients did not show evidence of reduced all-cause mortality (aHR, 1.22; 95% CI, 0.98-1.51). Risk of acute coronary syndrome was not reduced in patients taking OAC plus AP compared with OAC alone (aHR, 1.16; 95% CI, 0.70-1.94). Patients treated with OAC plus AP also had higher rates of all clinical outcomes than those treated with OAC alone over the short term (3 months). Conclusions and Relevance: This study challenges the practice of coprescribing OAC plus AP unless there is a clear indication for adding AP to OAC therapy in newly diagnosed atrial fibrillation

Evaluation of the impact of the GRACE risk score on the management and outcome of patients hospitalised with non-ST elevation acute coronary syndrome in the UK: protocol of the UKGRIS cluster-randomised registry-based trial

Introduction For non-ST-segment elevation acute coronary syndrome (NSTEACS) there is a gap between the use of class 1 guideline recommended therapies and clinical practice. The GRACE risk score is recommended in international guidelines for the risk stratification of NSTEACS, but its impact on adherence to guideline-indicated treatments and reducing adverse clinical outcomes is unknown. The objective of the UKGRIS trial is to assess the effectiveness of the GRACE risk score tool and associated treatment recommendations on the use of guideline-indicated care and clinical outcomes. Methods and Analysis The UK GRACE Risk Score Intervention Study (UKGRIS), a parallel-group cluster randomised registry-based controlled trial, will allocate hospitals in a 1:1 ratio to manage NSTEACS by standard care or according to the GRACE risk score and associated international guidelines. UKGRIS will recruit a minimum of 3000 patients from at least 30 English National Health Service hospitals and collect healthcare data from national electronic health records. The co-primary endpoints are the use of guideline-indicated therapies, and the composite of cardiovascular death, non-fatal myocardial infarction, new onset heart failure hospitalisation or cardiovascular readmission at 12 months. Secondary endpoints include duration of inpatient hospital stay over 12 months, EQ-5D-5L responses and utilities, unscheduled revascularisation and the components of the composite endpoint over 12 months follow-up. Ethics and Dissemination The study has ethical approval (North East - Tyne & Wear South Research Ethics Committee ref: 4/NE/1180). Findings will be announced at relevant conferences and published in peer-reviewed journals in line with the funder’s open access policy. Registration ISRCTN29731761, registered 12th January 2017

International comparison of acute myocardial infarction care and outcomes using quality indicators

Objective: To compare temporal changes in European Society of Cardiology (ESC) acute myocardial infarction (AMI) quality indicator (QI) attainment in the UK and Israel. Methods: Data cross-walking using information from the Myocardial Ischaemia National Audit Project and the Acute Coronary Syndrome in Israel Survey for matching 2-month periods in 2006, 2010 and 2013 was used to compare country-specific attainment of 14 ESC AMI QIs. Results: Patients in the UK (n=17 068) compared with Israel (n=5647) were older, more likely to be women, and had less diabetes, dyslipidaemia and heart failure. Baseline ischaemic risk was lower in Israel than the UK (Global Registry of Acute Coronary Events (GRACE) risk, 110.5 vs 121.0). Overall, rates of coronary angiography (87.6% vs 64.8%) and percutaneous coronary intervention (70.3% vs 41.0%) were higher in Israel compared with the UK. Composite QI performance increased more in the UK (1.0%-86.0%) than Israel (70.2%-78.0%). Mortality rates at 30 days declined in each country, with lower rates in Israel in 2013 (4.2% vs 7.6%). Composite QI adherence adjusted for GRACE risk score was inversely associated with 30-day mortality (OR 0.95; CI 0.95 to 0.97, p<0.001). Conclusions: nternational comparisons of guideline recommended AMI care and outcomes can be quantified using the ESC AMI QIs. International implementation of the ESC AMI QIs may reveal country-specific opportunities for improved healthcare delivery

Ambulatory heart rate range predicts mode-specific mortality and hospitalisation in chronic heart failure

Objective: We aimed to define the prognostic value of the heart rate range during a 24 h period in patients with chronic heart failure (CHF). Methods: Prospective observational cohort study of 791 patients with CHF associated with left ventricular systolic dysfunction. Mode-specific mortality and hospitalisation were linked with ambulatory heart rate range (AHRR; calculated as maximum minus minimum heart rate using 24 h Holter monitor data, including paced and non-sinus complexes) in univariate and multivariate analyses. Findings were then corroborated in a validation cohort of 408 patients with CHF with preserved or reduced left ventricular ejection fraction. Results: After a mean 4.1 years of follow-up, increasing AHRR was associated with reduced risk of all-cause, sudden, non-cardiovascular and progressive heart failure death in univariate analyses. After accounting for characteristics that differed between groups above and below median AHRR using multivariate analysis, AHRR remained strongly associated with all-cause mortality (HR 0.991/bpm increase in AHRR (95% CI 0.999 to 0.982); p=0.046). AHRR was not associated with the risk of any non-elective hospitalisation, but was associated with heart-failure-related hospitalisation. AHRR was modestly associated with the SD of normal-to-normal beats (R2=0.2; p<0.001) and with peak exercise-test heart rate (R2=0.33; p<0.001). Analysis of the validation cohort revealed AHRR to be associated with all-cause and mode-specific death as described in the derivation cohort. Conclusions: AHRR is a novel and readily available prognosticator in patients with CHF, which may reflect autonomic tone and exercise capacity

New AI Prediction Model Using Serial PT-INR Measurements in AF Patients on VKAs: GARFIELD-AF

Aims: Most clinical risk stratification models are based on measurement at a single time-point rather than serial measurements. Artificial intelligence (AI) is able to predict one-dimensional outcomes from multi-dimensional datasets. Using data from Global Anticoagulant Registry in the Field (GARFIELD)-AF registry, a new AI model was developed for predicting clinical outcomes in atrial fibrillation (AF) patients up to 1 year based on sequential measures of prothrombin time international normalized ratio (PT-INR) within 30 days of enrolment. Methods and results: Patients with newly diagnosed AF who were treated with vitamin K antagonists (VKAs) and had at least three measurements of PT-INR taken over the first 30 days after prescription were analysed. The AI model was constructed with multilayer neural network including long short-term memory and one-dimensional convolution layers. The neural network was trained using PT-INR measurements within days 0–30 after starting treatment and clinical outcomes over days 31–365 in a derivation cohort (cohorts 1–3; n = 3185). Accuracy of the AI model at predicting major bleed, stroke/systemic embolism (SE), and death was assessed in a validation cohort (cohorts 4–5; n = 1523). The model’s c-statistic for predicting major bleed, stroke/SE, and all-cause death was 0.75, 0.70, and 0.61, respectively. Conclusions: Using serial PT-INR values collected within 1 month after starting VKA, the new AI model performed better than time in therapeutic range at predicting clinical outcomes occurring up to 12 months thereafter. Serial PT-INR values contain important information that can be analysed by computer to help predict adverse clinical outcomes