Association of stroke and bleed events in non-valvular atrial fibrillation patients with direct oral anticoagulant prescriptions in NHS England between 2013 and 2016

Effectiveness and safety of oral anticoagulant therapy in a real-world cohort with atrial fibrillation: The SIESTA-A study protocol

INTRODUCTION

Oral anticoagulants (OACs) are first-line drugs for stroke prevention in patients with atrial fibrillation (AF). The introduction of new lines of therapy with direct oral anticoagulants (DOACs) has led to a decreased use of vitamin K antagonists (VKAs). Comparative analyses of DOACs in clinical trials are scarce and the comparator has mostly been warfarin. Their impact on health outcomes in observational studies has not always been consistent. The aim of this study is to evaluate the effectiveness and safety of DOACs and VKAs in patients with AF using Real-World Data (RWD).

METHODS AND ANALYSIS

Population-based retrospective cohort study using RWD from actual practice. Period: January 2012-December 2020. Inclusion criteria: patients with AF who had not taken OACs in the previous 12 months. Exclusion criteria: <40 years, with severe mitral stenosis, or valvular heart disease or aortic and/or mitral valve procedures. Data source: The Andalusian Population Health Database, Spain. Outcome measures: a) Effectiveness: ischaemic stroke, transient ischaemic attack, systemic and pulmonary embolism, and death; b) Safety: gastrointestinal and intracranial haemorrhaging; Independent variables: age, sex, comorbidities, medication and health resource use, CHA2DS2-VASC, HAS-BLED, and analytical tests. Statistical analysis: crude incidence analysis, survival models, Kaplan-Meier, Cox regression analysis adjusted for possible confounding and paired analysis by propensity score matching.

Managing stroke risk in patients with atrial fibrillation: a cross-sectional analysis of socio-demographic inequalities in a London borough

BACKGROUND

Stroke prevention is essential for patients with atrial fibrillation (AF), but some receive sub-optimal management. We reviewed those with a recorded AF diagnosis assessed with CHA2DS2-VASc stroke risk score (SRS) and socio-demographic determinants of anticoagulation prescribing. The objective was to compare with national guidance recommendations, which recommend anticoagulant therapy for SRS ≥ 2, to determine if there were inequalities in management.

METHODS

A cross-sectional design was used to analyze records from all (n = 41) general practices in one London borough. Patients were excluded if they were <18 years, had AF resolved or diagnosed < 3 months. Logistic regression identified socio-demographic factors associated with high SRS and anticoagulant prescribing.

RESULTS

Of 2913 patients, 2885 (99.0%) had an SRS, and 2411 (83.6%) a score ≥ 2 and 82.9% (1999 of 2411) were prescribed anticoagulation. Women (compared with men), Black and Mixed/Multiple ethnic groups (compared with White), and those living in most deprived areas (compared with least) were more likely to have a score ≥ 2. Patients with a high SRS from Black and Mixed/Multiple ethnic groups and aged 18-74 years were less likely to be prescribed anticoagulation.

CONCLUSION

We found evidence of age and ethnic inequity in anticoagulation prescribing for stroke prevention in patients with AF.

Association Between Use of Pharmacokinetic-Interacting Drugs and Effectiveness and Safety of Direct Acting Oral Anticoagulants: Nested Case-Control Study

Concomitant use of direct oral anticoagulants (DOACs) and medications with inhibition/induction effect on P-gp/CYP3A might increase risk of bleeding/treatment failure, respectively. We designed a nested case-control study within a Clalit cohort of patients with atrial fibrillation (AF) and a cohort of patients with venous thromboembolism, new users of a DOAC (January 1, 2010 to August 24, 2020). Propensity scores were constructed from demographic/clinical characteristics, and medications at cohort entry. Each case of: (i) serious bleeding event; (ii) stroke/systemic emboli (SE) in patients with AF; (iii) recurrent thromboembolism in patients with thromboembolism, was matched by age, sex, length of follow-up, year of cohort entry, DOAC type, and DOAC indication, to up to 20 controls. Within 89,284 patients with AF and venous thromboembolism and 126,302 patient-years of follow-up, there were 1,587 serious bleeding events. Risk of serious bleeding increased in association with concurrent prescription of P-gp/CYP3A4 inhibitors. Specifically, higher bleeding risk was associated with dabigatran-verapamil, rivaroxaban-verapamil, and rivaroxaban-amiodarone concurrent prescriptions: adjusted odds ratios (ORs) 2.29 (1.13-4.60), 2.18 (1.07-4.40), and 1.68 (1.14-2.49), respectively. There were 1,116 events of stroke/SE, in 79,302 DOAC-treated patients with AF and 118,124 patient-years of follow-up. Concomitant use of phenytoin, carbamazepine, valproic acid, or levetiracetam was associated with risk for stroke/SE: adjusted OR 2.18 (1.55-3.10). Risk of recurrent venous thromboembolism could not be assessed due to the low number of cases. Concurrent prescriptions of dabigatran or rivaroxaban with verapamil, and of rivaroxaban with amiodarone, are associated with increased risk for serious bleeding. Higher risk for stroke/SE in patients with AF is associated with concurrent prescriptions of DOACs with phenytoin, carbamazepine, valproic acid, or levetiracetam.

Impact of prescription patterns of antithrombotic treatment on atrial fibrillation-related ischemic stroke

OBJECTIVE

To analyze the temporal trends of atrial fibrillation (AF)-related ischemic stroke (IS) and their relationship with the prescription patterns of antithrombotic treatment from 2013 to 2019 in the Health Assistance Area of a regional hospital.

METHODS

First, a retrospective ecological study of aggregate data to analyze the annual incidence of IS between 2013 and 2019 was performed. Second, we selected those patients diagnosed with AF between 2013 and 2019 and performed a retrospective longitudinal study to assess the role of antithrombotic therapy in the development of AF-related IS.

RESULTS

During this period, whereas the annual incidence of IS remained stable (from 1.3 in 2013 to 1.2 cases per 1000 inhabitants in 2019; adjusted P for trend .829), the annual incidence of AF-related IS decreased over time (from 23.8 to 18.8 cases per 1000 inhabitants, respectively; adjusted P for trend .001). Among AF patients, the use of direct oral anticoagulants increased from 5.5% to 46.8%, while the prescription of antiplatelets and vitamin K antagonists decreased from 21.9% to 6.0% and from 63.8% to 36.1%, respectively. Overall, the use of oral anticoagulants increased from 69.3% to 82.9%; p < .001. Patients under antiplatelet agents had a higher probability of presenting IS than those patients taking oral anticoagulants, either vitamin K antagonists or direct oral anticoagulants (adjusted OR 1.89; 95% CI 1.52-2.37; p < .001).

CONCLUSIONS

The prescription of oral anticoagulants, particularly direct oral anticoagulants, has increased from 2013 to 2019 in our Health Assistance Area. This increase might partially explain the reduction in AF-related IS.