Underutilization of anticoagulants in patients with nonvalvular atrial fibrillation in the era of non-vitamin K antagonist oral anticoagulants

Pharmacist-led interventions in optimising the use of oral anticoagulants in patients with atrial fibrillation in general practice in England: a retrospective observational study

BACKGROUND

Oral anticoagulation (OAC) is the mainstay of treatment for the prevention of strokes in patients with atrial fibrillation (AF). Direct oral anticoagulants (DOACs) account for increasing OAC in patients with AF. However, prescribing DOACs for patients with established AF poses various challenges and general practice pharmacists may have an important role in supporting their management.

AIM

To investigate the effectiveness of pharmacist-led interventions in general practice in optimising the use of OAC therapies in AF.

DESIGN & SETTING

A retrospective observational study in general practices in Bradford.

METHOD

The data were collected retrospectively from 1 November 2018-31 December 2019 using electronic health record data. The data were analysed: 1) to identify patients with AF not on OAC; 2) to describe inappropriate DOAC prescriptions; and 3) to calculate HAS-BLED scores.

RESULTS

Overall, 76.3% (n = 470) of patients with AF received OAC therapy, and of these, 63.4% received DOACs. Pharmacist-led interventions increased DOAC prescribing by 6.0% (P = 0.03). Inappropriate DOAC use was identified in 24.5% of patients with AF, with underdosed and overdosed identified in 9.7% and 14.8%, respectively. Post-intervention, inappropriate prescribing was reduced to 1.7%. The mean HAS-BLED score decreased from 3.00 to 2.22 (P<0.01). Successful transition from vitamin K antagonist (VKA) therapy to DOACs was achieved in 25.7% of patients.

CONCLUSION

Pharmacist-led interventions have successfully improved the use of OAC therapies in patients with AF, and effectively managed the bleeding risks and transition from VKA to DOAC therapy, in line with guidelines.

Targeting factor XI and factor XIa to prevent thrombosis

ABSTRACT

Direct oral anticoagulants (DOACs) that inhibit the coagulation proteases thrombin or factor Xa (FXa) have replaced warfarin and other vitamin K antagonists (VKAs) for most indications requiring long-term anticoagulation. In many clinical situations, DOACs are as effective as VKAs, cause less bleeding, and do not require laboratory monitoring. However, because DOACs target proteases that are required for hemostasis, their use increases the risk of serious bleeding. Concerns over therapy-related bleeding undoubtedly contribute to undertreatment of many patients who would benefit from anticoagulation therapy. There is considerable interest in the plasma zymogen factor XI (FXI) and its protease form factor XIa (FXIa) as drug targets for treating and preventing thrombosis. Laboratory and epidemiologic studies support the conclusion that FXI contributes to venous and arterial thrombosis. Based on 70 years of clinical observations of patients lacking FXI, it is anticipated that drugs targeting this protein will cause less severe bleeding than warfarin or DOACs. In phase 2 studies, drugs that inhibit FXI or FXIa prevent venous thromboembolism after total knee arthroplasty as well as, or better than, low molecular weight heparin. Patients with heart disease on FXI or FXIa inhibitors experienced less bleeding than patients taking DOACs. Based on these early results, phase 3 trials have been initiated that compare drugs targeting FXI and FXIa to standard treatments or placebo. Here, we review the contributions of FXI to normal and abnormal coagulation and discuss results from preclinical, nonclinical, and clinical studies of FXI and FXIa inhibitors.

Oral Anticoagulant Use in Patients with Atrial Fibrillation at Low Risk of Stroke and Associated Bleeding Complications

BACKGROUND

The use of oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and low stroke risk might cause more harm than benefit. Little attention has been given to address its prevalence and associated consequences. This study aimed to investigate the prescription rate of OACs, identify associated factors, and describe incident bleeding events in low-risk patients.

METHODS

We included patients with a new diagnosis of AF between 1 January 2011 and 31 December 2018 having a low risk of stroke (CHA2DS2-VASc score of 0 for males and 1 for females) from Australian general practice data (MedicineInsight). Patients were classified as OAC users if there was a recorded prescription of an OAC within 60 days of AF diagnosis, and factors associated with the prescription of an OAC were assessed using logistic regression. Recorded incident bleeding events were identified within 6 months after AF diagnosis or after OAC initiation for OAC non-users and users, respectively. The risk of bleeding was compared between the two groups by adjusting their baseline differences using propensity score matching.

RESULTS

The study included 2810 low-risk patients (62.3% male) with a mean age of 49.3 ± 10.8 years. Of the total, 705 (25.1%) patients had a record of OAC prescription within 60 days of diagnosis of AF. Older age (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.03-1.04) and diagnosis periods (2015-2016 [OR 1.46; 95% CI 1.10-1.94] and 2017-2018 [OR 1.65; 95% CI 1.17-2.23] vs. 2011-2012) were associated with higher odds of OAC initiation. Female sex (OR 0.71; 95% CI 0.59-0.85), higher bleeding risk (ORBIT score; OR 0.80; 95% CI 0.68-0.94), and higher socioeconomic index for areas (SEIFA) quintiles (SEIFA quintiles; 2 [OR 0.65; 95% CI 0.48-0.88], 3 [OR 0.74; 95% CI 0.56-0.98], 4 [OR 0.70; 95% CI 0.52-0.94], 5 [OR 0.69; 95% CI 0.52-0.91] compared with quintile 1) were associated with lower odds of OAC prescription. A total of 52 (in 1.8% of patients) incident bleeds were identified, with 18 (2.6%) among OAC users. The rate of bleeding was not significantly different between users and non-users after matching. However, within OAC users, commencement of OAC was associated with an increased risk of bleeding compared to the period before OAC initiation (p = 0.006).

CONCLUSIONS

One in four patients at low risk of stroke received an OAC within 60 days of AF diagnosis. Older age and the period following the widespread availability of direct-acting OACs were associated with an increased likelihood of OAC prescription. Positively, using OACs was not associated with an increased rate of bleeding compared to non-users.

News at XI: moving beyond factor Xa inhibitors

Oral anticoagulants are a mainstay for the prevention and treatment of arterial and venous thrombosis. Direct oral anticoagulants (DOACs) have replaced vitamin K antagonists for many indications. Currently available DOACs include dabigatran, which inhibits thrombin, and apixaban, edoxaban, and rivaroxaban, which inhibit factor (F) Xa. A new class of DOACs is under development. These new DOACs, which include asundexian and milvexian, inhibit FXIa, which is positioned in the intrinsic pathway of coagulation. Anticoagulants that target FXIa have the potential to be safer than the current DOACs because there is emerging evidence that FXI is essential for thrombosis but mostly dispensable for hemostasis. In addition to the oral inhibitors of FXIa, parenteral inhibitors are also under development. These include fesomersen, an antisense oligonucleotide that reduces the hepatic synthesis of FXI; abelacimab, an antibody that binds to FXI and blocks its activation; and osocimab, an FXIa inhibitory antibody. Focusing on these new agents, this article describes the unmet needs in oral anticoagulation therapy, explains why FXI is a promising target for new oral anticoagulants, reviews phase 2 clinical data on new agents, describes ongoing phase 3 trials, and provides a perspective on the opportunities and challenges for FXI inhibitors.

Utilization of triple antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention

BACKGROUND

Triple antithrombotic therapy (TAT), a combination of an oral anticoagulant and dual antiplatelet therapy (DAPT), is a key treatment for prevention of ischemic events in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). However, TAT is not extensively used because of the risk of bleeding. This study aimed to determine the utilization and influencing factors of TAT using real-world data in the non-vitamin K antagonist oral anticoagulants (NOACs) era.

METHODS

We analyzed National Inpatient Sample data compiled by the Health Insurance Review & Assessment Service (HIRA-NIS) from 2011 to 2020. Patients with AF who underwent PCI with stent implantation and with an increased stroke risk were selected as candidates for TAT therapy. Demographic and clinical factors associated with TAT use were investigated using the chi-squared test and the Student t-test, and influencing factors were identified using multiple logistic regression.

RESULTS

The TAT utilization rate steadily increased from 30.3% in 2011 to 65.4% in 2020 (Cochran-Armitage trend test: p < 0.001) with an average of 45.9%. Positive influencing factors for TAT use were identified as congestive heart failure, history of previous stroke/transient ischemic attack/thromboembolism, valvular heart disease, and year. Negative influencing factors included insurance type (medical aid or Patriots & Veterans Insurance), type of medical institution (general hospitals or primary medical institutions), and comorbidities such as renal disease, liver disease, and history of the previous hemorrhage.

CONCLUSIONS

The utilization of TAT following PCI among high-stroke risk AF patients steadily increased from 2011 to 2020, reaching 65.4% by the end of the study period. However, in 2020, a significant proportion of 29.4% of patients still received DAPT, indicating that many AF patients undergoing PCI did not receive adequate antithrombotic therapy.

Prevalence of Cardio-Embolic Brain Complications in Permanent and Paroxysmal Atrial Fibrillation Patients

Background: Atrial fibrillation (AF) is the most frequent of all cardiac arrhythmias, with an increasing prevalence in the last 20 years. Cardio-embolic brain complications (CEBC) related to AF often occur or recur, even following appropriate treatment. Method: We conducted a retrospective study and analyzed the presence of stroke, dementia, and Parkinson’s disease (PD) in both paroxysmal and permanent AF patients. The records of 1111 consecutive admitted patients with primary diagnosis of AF at the Municipal Emergency University Hospital, Timisoara, between 2015 and 2016 were examined. Statistical analysis was performed on the patients included in the study based on the inclusion and exclusion criteria. Results: A significant statistical difference was noted among the permanent AF group for stroke (48.75% vs. 26.74%, p < 0.001) and dementia (10.25% vs. 3.86%, p < 0.001) compared to paroxysmal AF patients. Permanent AF patients presented a higher risk of developing stroke, dementia, and PD compared to patients with paroxysmal AF. Meanwhile, male gender and an increase in age showed an increase in the odds of having cardio-embolic brain complications in patients with paroxysmal AF. Conclusion: Based on the results obtained, it can be concluded that the risk of cardio-cerebral embolic complications is greater in permanent AF patients compared to paroxysmal AF cases. Ischemic stroke and dementia are more frequent in the permanent AF group, but analyzing the data regarding the age of onset paroxysmal AF is critical due to the fact that it involves a younger population. Prompt diagnosis and treatment can help significantly in saving stroke patients.

Clinical Complexity Domains, Anticoagulation, and Outcomes in Patients with Atrial Fibrillation: A Report from the GLORIA-AF Registry Phase II and III

BACKGROUND

 Clinical complexity is common in atrial fibrillation (AF) patients. We assessed the impact of clinical complexity on oral anticoagulant (OAC) treatment patterns and major adverse outcomes in a contemporary cohort of AF patients.

METHODS

 The GLORIA-AF Phase II and III Registry enrolled newly diagnosed AF patients with at least one stroke risk factor. Among patients with CHA₂DS₂-VASc score ≥2, we defined four domains of perceived clinical complexity: frail elderly (age ≥75 years and body mass index <23 kg/m²), chronic kidney disease (CKD, creatinine clearance <60 mL/min), history of bleeding, and those with ≥2 of the above conditions. We evaluated the associations between clinical complexity domains and antithrombotic treatment prescription, risk of OAC discontinuation, and major adverse outcomes.

RESULTS

 Among the 29,625 patients included (mean age 69.6 ± 10.7 years, 44.2% females), 9,504 (32.1%) presented with at least one complexity criterion. Clinical complexity was associated with lower OAC prescription, with stronger associations in frail elderly (odds ratio [OR]: 0.47, 95% confidence interval [CI]: 0.36-0.62) and those with ≥2 complexity domains (OR: 0.50, 95% CI: 0.44-0.57). Risk of OAC discontinuation was higher among frail elderly (hazard ratio [HR]: 1.30, 95% CI: 1.00-1.69), CKD (HR: 1.10, 95% CI: 1.02-1.20), and those with ≥2 complexity domains (HR: 1.39, 95% CI: 1.23-1.57). Clinical complexity was associated with higher risk of the primary outcome of all-cause death, thromboembolism, and major bleeding, with the highest magnitude in those with ≥2 criteria (HR: 1.63, 95% CI: 1.43-1.86).

CONCLUSION

 In AF patients, clinical complexity influences OAC treatment management, and increases the risk of poor clinical outcomes. These patients require additional efforts, such as integrated care approach, to improve their management and prognosis.