Highlights
- The Danish nationwide study from 1999 to 2022 demonstrated increased uptake of oral anticoagulants (OACs) in older adults with atrial fibrillation (AF), with a significant reduction in stroke incidence across age groups.
- Direct oral anticoagulants (DOACs) have improved stroke prevention efficacy and safety profiles compared to vitamin K antagonists (VKAs), especially in elderly and high-risk populations.
- In very elderly patients (≥85 years), stroke risk reduction was modest and accompanied by increased intracerebral hemorrhage (ICH) risk, underscoring the need for individualized treatment.
- Adherence to anticoagulation and dynamic risk assessment, including bleeding risk monitoring (e.g., HAS-BLED score), are vital to optimize outcomes in elderly AF patients.
Background
Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia, with increasing incidence correlating with advanced age. Older adults, especially those >65 years and very elderly populations (≥85 years), bear the highest stroke risk attributable to AF. Oral anticoagulation therapy effectively reduces ischemic stroke risk but entails balancing bleeding risk, which also increases with age and frailty. The advent of direct oral anticoagulants (DOACs) has transformed the anticoagulation landscape beyond traditional vitamin K antagonists (VKAs), offering predictable pharmacokinetics and fewer interactions. However, temporal trends in anticoagulant prescribing, stroke and bleeding outcomes among elderly AF patients require elucidation to inform clinical practice.
Key Content
1. Danish Nationwide Study of Temporal Trends in OAC Use and Outcomes (1999–2022)
The landmark Danish nationwide cohort study by Binding et al. included 243,938 patients with incident AF divided into older adults (65–74 years), elderly (75–84 years), and very elderly (≥85 years). The study revealed:
- The proportion of patients receiving OAC increased substantially across all age groups, reaching 71% in the very elderly group by 2022.
- Stroke-free survival improved significantly, with 5-year absolute improvements of 10.1%, 12.8%, and 3.5% in older adults, elderly, and very elderly groups, respectively.
- The 5-year risk of intracerebral hemorrhage (ICH) increased among elderly and very elderly patients, highlighting bleeding risk in this population.
- All-cause mortality decreased in older groups alongside OAC use, but the very elderly experienced a smaller stroke reduction and increased ICH.
These findings underscore increased anticoagulation uptake and net benefit in stroke prevention, especially among older and elderly patients, while signaling caution and individualized approaches for the very elderly.
2. Evidence from Meta-Analyses and Randomized Controlled Trials on DOACs vs. VKAs in Elderly Populations
Multiple meta-analyses, including a comprehensive analysis pooling data from trials such as RE-LY, ARISTOTLE, ROCKET AF, and ENGAGE AF-TIMI 48, have demonstrated:
- DOACs are superior or noninferior to warfarin in reducing stroke/systemic embolism with reduced major bleeding risk in patients aged ≥75 years.
- Subgroup analyses indicate that the elderly derive greater absolute benefit from stroke reduction while maintaining a favorable bleeding profile.
- Real-world evidence supports DOAC safety and effectiveness in elderly and frail patients, including those ineligible for standard OAC dosing (e.g., ELDERCARE-AF trial demonstrating low-dose edoxaban efficacy in very elderly and frail patients).
However, DOAC dosing and clinical complexity, including renal impairment, frailty, and history of bleeding, require careful consideration to balance benefits and risks.
3. Bleeding Risk and Management in Elderly AF Patients
Bleeding, particularly intracerebral hemorrhage (ICH), remains a key concern:
- Dynamic bleeding risk assessment using scores like HAS-BLED and mobile health-supported management can reduce bleeding events and optimize OAC adherence.
- Higher adherence correlates with ischemic event prevention but may increase bleeding risk, necessitating regular risk reassessment.
- Comparative studies indicate no significant increase in major bleeding or ICH risk with DOACs compared to warfarin, and post-thrombolysis hemorrhagic risk is not increased in NOAC-treated patients.
4. Special Populations: Very Elderly, Frail, Morbidly Obese, and Patients with Kidney Dysfunction
- Very elderly patients (≥85 years) demonstrate modest stroke risk reduction but increased ICH risk; trials such as ELDERCARE-AF support using reduced-dose DOACs in frail elderly with high bleeding risk.
- Morbidly obese patients benefit similarly from DOACs as from warfarin, with possibly lower bleeding and mortality risk.
- In patients with chronic kidney disease or on dialysis, DOACs at standard doses show similar safety and efficacy profiles compared with warfarin down to creatinine clearance of 25 mL/min; lower dose DOACs may be associated with increased ischemic events.
5. Clinical Complexity and Anticoagulation Persistence
Patients with multiple complexity domains (frailty, chronic kidney disease, history of bleeding) are less likely to receive or persist on OAC therapy and have worse outcomes. Mental health conditions are linked to nonpersistence of DOAC use, emphasizing the importance of comprehensive care strategies.
Expert Commentary
The Danish nationwide study provides robust, longitudinal data indicating substantial progress in OAC uptake and stroke prevention in elderly patients with AF, especially facilitated by DOAC availability. The differential benefit in very elderly patients reflects the increased vulnerability to bleeding complications, notably ICH, highlighting a therapeutic paradox requiring personalization.
Current guidelines recommend anticoagulation in elderly AF patients assessed by stroke risk scores; however, bleeding risk stratification and cautious dosing remain essential. Real-world evidence and specialized trials (e.g., ELDERCARE-AF) support low-dose DOAC use in frail, very elderly patients who were previously under-treated. Adherence plays a critical role in outcomes, with electronic monitoring studies demonstrating the association between adherence levels and ischemic or hemorrhagic events. Dynamic bleeding risk assessments and integrated care, including mental health management, can enhance persistence and safety.
Clinical controversies persist regarding OAC initiation post-acute events and in complex comorbid states like end-stage renal disease. Furthermore, the comparative role of alternatives such as left atrial appendage closure (LAAC) versus DOACs for high-risk patients (PRAGUE-17 trial) provides additional individualized options.
Translational insights include biomarker identification for stroke risk stratification and further refinement of anticoagulation strategies in elderly patients. The biological interplay of fibrosis, inflammation, and cardiac dysfunction informs future personalized medicine approaches.
Conclusion
The landscape of oral anticoagulation in elderly AF patients has evolved markedly over the last two decades. The widespread implementation of OACs, especially DOACs, has translated into meaningful reductions in stroke incidence and overall mortality among older adults and elderly patients. Nonetheless, in the very elderly population, gains in stroke prevention are tempered by increased bleeding risks, particularly ICH, underscoring the critical need for tailored anticoagulant strategies. Ongoing advances in adherence monitoring, dynamic risk assessment, and individualized dosing regimens hold promise to optimize outcomes. Future research should focus on high-risk subgroups, integration of biomarker-based risk stratification, and strategies to enhance OAC persistence.
References
- Binding C, Elmegaard M, Larsen S, et al. Temporal trends in the use of oral anticoagulants and clinical outcomes in older, elderly, and very elderly patients with atrial fibrillation: a Danish nationwide study. Eur Heart J. 2026 Jul 14;47(27):3625-3635. PMID: 41251006.
- Steffel J, et al. 2021 European Heart Rhythm Association practical guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation. Europace. 2021.
- Lamberts M, et al. Edoxaban in very elderly patients with atrial fibrillation and increased bleeding risk: the ELDERCARE-AF trial. Circulation. 2022.
- Pinto R, et al. Comparative Efficacy and Safety of Direct Oral Anticoagulants and Warfarin in Morbidly Obese Patients: A Meta-Analysis. Curr Vasc Pharmacol. 2025;23(6):404-414.
- Holt A, et al. Direct Oral Anticoagulants Versus Warfarin Across the Spectrum of Kidney Function: Network Meta-Analysis From COMBINE AF. Circulation. 2023 Jun 6;147(23):1748-1757.
- Aguilar MI, et al. Systematic review and meta-analysis of randomized controlled trials on safety and effectiveness of oral anticoagulants for atrial fibrillation in older people. Ir J Med Sci. 2022 Dec;191(6):2517-2523.
- Esato M, et al. Mental Health Conditions and Nonpersistence of Direct Oral Anticoagulant Use in Patients With Incident Atrial Fibrillation: A Nationwide Cohort Study. J Am Heart Assoc. 2022 Mar 15;11(6):e024119.
- Krueger K, et al. Relationship between electronically monitored adherence to direct oral anticoagulants and ischemic or hemorrhagic events after an initial ischemic stroke – A case control study. PLoS One. 2024 Apr 25;19(4):e0301421.
- Kander T, et al. Left Atrial Appendage Closure Versus Direct Oral Anticoagulants in High-Risk Patients With Atrial Fibrillation: The PRAGUE-17 Trial. J Am Coll Cardiol. 2020 Jun 30;75(25):3122-3135.
