Fox, Keith A.A.

Background Guidelines for patients with atrial fibrillation (AF) at high thromboembolic risk recommend oral anticoagulants (OACs) for preventing stroke and systemic embolism (SE). The reasons for guideline non-adherence are still unclear. Aim The aim is to identify clinical, demographic and non-patient characteristics associated with withholding OAC in patients with AF at high stroke risk. Methods Patients in the Global Anticoagulant Registry in the FIELD-AF, newly diagnosed with AF between March 2010 and August 2016, and with CHA2DS2-VASc Score≥2 (excluding sex), were grouped by OAC treatment at enrolment. Factors associated with OAC non-use were analysed by multivariable logistic regression. Results Of 40 416 eligible patients, 12 126 (30.0%) did not receive OACs at baseline. Globally, OAC prescription increased over time, from 60.4% in 2010–2011 to 74.7% in 2015–2016. Country of enrolment was the major predictor for OAC withholding (χ2−df=2576). Clinical predictors of OAC non-use included type of AF (χ2−df=404), history of bleeding (χ2−df=263) and vascular disease (χ2−df=99). OACs were used most frequently around the age of 75 years and decreasingly with younger as well as older age beyond 75 years (χ2−df=148). Non-cardiologists (χ2−df=201) and emergency room physicians (χ2−df=14) were less likely to prescribe OACs. OAC prescription correlated positively with country health expenditure. Conclusions Approximately one out of three AF patients did not receive OAC, while eligible according to the guidelines. Country of enrolment was the major determinant of anticoagulation strategy, while higher country health expenditure was associated with lower likelihood of withholding anticoagulation.

AbstractBackgroundAn unmet need exists to reliably predict the risk of intracranial hemorrhage (ICH) in patients with atrial fibrillation (AF) treated with oral anticoagulants (OACs).HypothesisAn externally validated model improves ICH risk stratification.MethodsIndependent factors associated with ICH were identified by Cox proportional hazard modeling, using pooled data from the GARFIELD‐AF (Global Anticoagulant Registry in the FIELD‐Atrial Fibrillation) and ORBIT‐AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registries. A predictive model was developed and validated by bootstrap sampling and by independent data from the Danish National Patient Register.ResultsIn the combined training data set, 284 of 53 878 anticoagulated patients had ICH over a 2‐year period (0.31 per 100 person‐years; 95% confidence interval [CI]: 0.28–0.35). Independent predictors of ICH included: older age, prior stroke or transient ischemic attack, concomitant antiplatelet (AP) use, and moderate‐to‐severe chronic kidney disease (CKD). Vitamin K antagonists (VKAs) were associated with a significantly higher risk of ICH compared with non‐VKA oral anticoagulants (NOACs) (adjusted hazard ratio: 1.61; 95% CI: 1.25–2.08; p = .0002). The ability of the model to discriminate individuals in the training set with and without ICH was fair (optimism‐corrected C‐statistic: 0.68; 95% CI: 0.65–0.71) and outperformed three previously published methods. Calibration between predicted and observed ICH probabilities was good in both training and validation data sets.ConclusionsAge, prior ischemic events, concomitant AP therapy, and CKD were important risk factors for ICH in anticoagulated AF patients. Moreover, ICH was more frequent in patients receiving VKA compared to NOAC. The new validated model is a step toward mitigating this potentially lethal complication.

The management of atrial fibrillation (AF), the most common sustained arrhythmia, impacts healthcare resource utilization (HCRU). This study aims to estimate global resource use in AF patients, using the GARFIELD-AF registry. A prospective cohort study was conducted to characterize HCRU in AF patients enrolled in sequential cohorts from 2012 to 2016 in 35 countries. Components of HCRU studied were hospital admissions, outpatient care visits, and diagnostic and interventional procedures occurring during follow-up. AF-related HCRU was reported as the percentage of patients demonstrating at least one event and was quantified as rate-per-patient-per-year (PPPY) over time. A total of 49,574 patients was analyzed, having an overall median follow-up of 719 days. Almost all patients (99.5%) had at least one outpatient care visit, while hospital admissions were the second most frequent medical contact, with similar proportions in North America (37.5%) and Europe (37.2%), and slightly higher in the other GARFIELD-AF countries (42.0%; namely Australia, Egypt, and South Africa). Asia and Latin America showed lower percentages of hospitalizations, outpatient care visits, and diagnostic and interventional procedures. Analyses of GARFIELD-AF highlighted the vast AF-related HCRU, underlying significant geographical differences in the type, quantity, and frequency of AF-related HCRU. These differences were likely attributable to health service availability and differing models of care.

Abstract Background Many patients with atrial fibrillation (AF) have comorbid vascular disease. The effects of oral anticoagulation (OAC) in AF patients with vascular disease, however, have not been widely studied. Purpose To investigate the impact of OAC in AF patients with (Vasc) or without (nVasc) concomitant vascular disease. Methods GARFIELD-AF is the largest multinational, prospective AF registry. The study comprised 51,574 GARFIELD-AF patients with newly diagnosed AF, 13,365 Vasc and 38,209 nVasc patients. All patients who reported coronary artery disease, aortic or peripheral artery disease, acute coronary syndromes, myocardial infarction, stenting, or coronary artery bypass graft were classified as having vascular disease. Adjusted hazard ratios were obtained via Cox proportional-hazards models to quantify the association of vascular disease with selected endpoints. Comparative effectiveness analyses were restricted to patients enrolled from April 2013-September 2016 (when NOACs became widely available) and who were eligible for anticoagulation (CHA2DS2-VASc ≥2 excl. gender). To evaluate the safety and efficacy of different anticoagulation strategies in Vasc and nVasc patients, propensity score using an overlap weighting scheme was applied. Weights were applied to Cox proportional-hazards models to estimate the effects of OAC vs No OAC and NOAC vs VKA. Results Vasc patients were older (median (Q1; Q3): 72.0 (65.0; 79.0) vs 70.0 (62.0; 78.0) and more often male (62.0 vs 53.6%). Vasc patients had a higher rate of comorbidities including heart failure, hypertension, and diabetes. Vasc patients received less OAC (62.8 vs 68.3%). NOACs were less common compared with nVasc patients (23.8% vs 28.7%) but a similar proportion of VKAs was observed in both (39.0% vs 39.6%). Antiplatelet monotherapy was more common in Vasc (31%) than nVasc (18%) patients. At 2-years, Vasc was associated with a higher risk of all-cause (HR [95% CI]: 1.30 [1.16–1.47]) and cardiovascular mortality (1.59 [1.28–1.97]). OACs significantly lowered the risk of all-cause mortality and stroke in nVasc patients (0.72 [0.63–0.82] and 0.64 [0.49–0.84], respectively), but not in nVasc patients. OACs led to a numerical increase in major bleeding in Vasc patients (1.32 [0.90–1.93]) and a significant increase in major bleeding in nVasc patients (1.40 [1.03–1.90]) (Figure 1). Compared with VKAs, NOACs did not significantly improve the risk of outcomes in nVasc patients. In Vasc patients however, NOACs significantly lowered the risk of all-cause mortality (0.74 [0.61–0.90]) and major bleeding (0.45 [0.29–0.70]) compared with VKAs (Figure 2). Conclusion AF patients with vascular disease have worse long-term outcomes than those without. They receive less often OAC, specifically NOAC, and more antiplatelet agents. The beneficial effects of NOAC over VKA are much more pronounced in patients with than in those without vascular disease. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the Thrombosis Research Institute (London, UK).

Objective While greater body mass index (BMI) is associated with increased risk of developing atrial fibrillation (AF), the impact of BMI on outcomes in newly diagnosed AF is unclear. We examine the influence of BMI on outcomes and whether this is modified by sex and evaluate the effect of non-vitamin K oral anticoagulants (NOACs) in patients with high BMI. Methods GARFIELD-AF is a prospective registry of 52 057 newly diagnosed AF patients. The study population comprised 40 482 participants: 703 underweight (BMI <18.5 kg/m 2 ), 13 095 normal (BMI=18.5–24.9 kg/m 2 ), 15 043 overweight (BMI=25.0–29.9 kg/m 2 ), 7560 obese (BMI=30.0–34.9 kg/m 2 ) and 4081 extremely obese (BMI ≥35.0 kg/m 2 ). Restricted cubic splines quantified the association of BMI with outcomes. Comparative effectiveness of NOACs and vitamin K antagonists (VKAs) by BMI was performed using propensity score overlap-weighted Cox models. Results The median age of participants was 71.0 years (Q1; Q3 62.0; 78.0), and 55.6% were male. Those with high BMI were younger, more often had vascular disease, hypertension and diabetes. Within 2-year follow-up, a U-shaped relationship between BMI and all-cause mortality was observed, with BMI of ~30 kg/m 2 associated with the lowest risk. The association with new/worsening heart failure was similar. Only low BMI was associated with major bleeding and no association emerged for non-haemorrhagic stroke. BMI was similarly associated with outcomes in men and women. BMI did not impact the lower rate of all-cause mortality of NOACs compared with VKAs. Conclusions In the GARFIELD-AF registry, underweight and extremely obese AF patients have increased risk of mortality and new/worsening heart failure compared with normal or obese patients.

Abstract Introduction Non-vitamin-K oral anticoagulants (NOACs) were recommended in preference to oral vitamin K antagonists (VKAs) in the 2020 updated guidelines for stroke prevention in atrial fibrillation (AF), from the European Society of Cardiology (ESC). Rivaroxaban is a NOAC that is approved in many countries worldwide for reducing the risk of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (AF). Purpose To explore the baseline characteristics, dosing and 2-year outcomes of patients with AF treated with rivaroxaban. Methods RIVaroxaban Evaluation in Real Life setting (RIVER) is a prospective international, multicenter registry of patients with newly diagnosed non-valvular AF treated with rivaroxaban for the prevention of thromboembolic stroke and at least one investigator-determined risk factor for stroke. Results A total of 5043 patients were enrolled into RIVER between January 2015 and June 2017. Mean (SD) age at diagnosis was 69.5 (11.0) years and 55.7% were males. Caucasian patients represented the largest proportion of patients in RIVER (80.3%), followed by Asians (5.5%) and hispanic/latino (3.7%). Almost all patients (98.5%) were prescribed a single daily dose of rivaroxaban, most commonly 20 mg (77.3%) and 15 mg (20.4%), while a 10 mg dose was prescribed in only 2.3% of patients. During the 2-year follow-up, the rates (95% CI) of all-cause mortality, stroke/SE, and major bleeding were 2.75 (2.43 to 3.12), 0.89 (0.72; 1.11), and 1.26 (1.05 to 1.52) per 100 person years, respectively (Figure 1). The most common cardiovascular cause of death was congestive heart failure (30.4%) and myocardial infarction (11.4%). Leading non-cardiovascular causes of death were malignancy (27.4%), respiratory failure (18.9%) and infections/sepsis (13.2%). Over 2 years, 710 (14.1%) of patients discontinued rivaroxaban. The corresponding proportions at 6 months and 1 year were 7.8% and 10.8%, respectively. Out of all the patients who discontinued, 62 (8.7%) restarted rivaroxaban during their follow-up (Table 1). Conclusion During 2 years of follow up in the international, prospective RIVER registry, rivaroxaban treatment for AF was associated with low rates of stroke or major bleeding. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by an unrestricted research grant from Bayer AG, Berlin, Germany, to TRI, London, UK. This work is supported by KANTOR CHARITABLE FOUNDATION for the Kantor-Kakkar Global Centre for Thrombosis Science.

Abstract Introduction Rivaroxaban is recommended as an option for anticoagulation in patients with nonvalvular atrial fibrillation (AF) with one or more risk factors for stroke. The approved/recommended rivaroxaban dose for stroke prevention in patients with atrial fibrillation (AF) is solely based on renal function: 20 mg once daily (od) for patients with a creatinine clearance [CrCl] ≥50 ml/min and 15 mg od in patients with CrCl 15–49 mL/min). Purpose To assess the patterns of rivaroxaban prescription as per the creatinine clearances levels and to assess the impact of the rivaroxaban dosing on the rate of events at 2-year follow-up in patients with AF. Methods RIVaroxaban Evaluation in Real Life setting (RIVER) is a prospective international registry of patients with newly diagnosed non-valvular AF treated with rivaroxaban for the prevention of thromboembolic stroke and at least one investigator-determined risk factor for stroke. Adjusted hazard ratios (HRs) were obtained through Cox proportional-hazard model. Results Among 3402 patients with normal renal function (CrCl ≥50 mL/min), 82.1% were prescribed the recommended rivaroxaban dose of 20 mg (od) at baseline. Among 524 patients with moderate or severe renal impairment (CrCl 15–50 mL/min), 55.3% patients received rivaroxaban 15 mg (od), 39.9% received 20 mg (od) and 4.2% 10 mg (od). Non-recommended dosing was rare in patients younger than 70 (13.5%) but more frequent in older patients (28.8%). Non-recommended low dosing was more frequent in Asians (38.9%), compared to non-Asian patients (13.8%). Regarding clinical outcomes, adjusted hazards ratios (HR, presented with 95% confidence intervals) showed that the non-recommended low dosing (&lt;20 mg od) was associated with higher risk of non-cardiovascular mortality (HR 2.09 (1.16–3.77)) in patients with normal renal function. The non-recommended high dosing (&gt;15 mg od) was associated with lower risk of all-cause mortality (HR 0.63 (0.42–0.93)) and cardiovascular mortality (HR 0.32 (0.13–0.77)) and higher risk of major bleeding (HR 2.86 (1.49–5.50)) in patients with moderate to severe renal impairment (figure 1 and 2). Conclusion In patients with normal renal function, non-recommended low dose rivaroxaban was associated with increased cardiovascular mortality without reducing the risk of major bleeding compared to recommended dosing. In patients with CrCl &lt;50 ml/min, non-recommended high dose rivaroxaban was associated with reduced cardiovascular mortality but at the cost of increased major bleeding. These observational data largely support the reduction of rivaroxaban dosing according to renal function but educational strategies are needed to ensure that rivaroxaban is used appropriately. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by an unrestricted research grant from Bayer AG, Berlin, Germany, to TRI, London, UK, which sponsors the RIVER registry. This work is supported by KANTOR CHARITABLE FOUNDATION for the Kantor-Kakkar Global Centre for Thrombosis Science.

Objectives This study evaluated the comparative effectiveness of vitamin K antagonists (VKAs), direct thrombin inhibitors (DTIs) and factor Xa inhibitors (FXaI) in patients with atrial fibrillation (AF) at risk of stroke in everyday practice. Methods Data from patients with AF and Congestive heart failure, Hypertension, Age 75 years, Diabetes mellitus, prior Stroke, TIA, or thromboembolism, Vascular disease, Age 65-74 years, Sex category (CHA2DS2-VASc) score ≥2 (excluding gender) in the Global Anticoagulant Registry in the FIELD–Atrial Fibrillation registry were analysed using an improved method of propensity weighting, overlap weights and Cox proportional hazards models. Results All-cause mortality, non-haemorrhagic stroke/systemic embolism (SE) and major bleeding over 2 years were compared in 25 551 patients, 7162 (28.0%) not treated with oral anticoagulant (OAC) and 18 389 (72.0%) treated with OAC (FXaI (41.8%), DTI (11.4%) and VKA (46.8%)). OAC treatment compared with no OAC treatment was associated with decreased risk of all-cause mortality (HR 0.82 (95% CI 0.74 to 0.91)) and non-haemorrhagic stroke/SE (HR 0.71 (95% CI 0.57 to 0.88)) but increased risk of major bleeding (HR 1.46 (95% CI 1.15 to 1.86)). Non-vitamin K antagonist oral anticoagulant (NOAC) use compared with no OAC treatment was associated with lower risks of all-cause mortality and non-haemorrhagic stroke/SE (HR 0.67 (95% CI 0.59 to 0.77)) and 0.65 (95% CI 0.50 to 0.86)) respectively, with no increase in major bleeding (HR 1.10 (95% CI 0.82 to 1.47)). NOAC use compared with VKA use was associated with lower risk of all-cause mortality and major bleeding (rates/100 patient-years 3.6 (95% CI 3.3 to 3.9) vs 4.8 (95% CI 4.5 to 5.2) and 1.0 (95% CI 0.9 to 1.1) vs 1.4 (95% CI 1.2 to 1.6); HR 0.79 (95% CI 0.70 to 0.89) and 0.77 (95% CI 0.61 to 0.98) respectively), with similar risk of non-haemorrhagic stroke/SE (rates/100 patient-years 0.8 (95% CI 0.7 to 0.9) versus 1.0 (95% CI 0.8 to 1.1); HR 0.96 (95% CI 0.73 to 1.25). Conclusion Important benefits in terms of mortality and major bleeding were observed with NOAC versus VKA with no difference among NOAC subtypes. Trial registration number NCT01090362.