Anticoagulation and All-Cause Mortality in Adults Aged 80 Years and Older with Atrial Fibrillation: A Retrospective Cohort Study

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• Picked for Internal Medicine (paper of the day, 29 October 2026): Anticoagulation trade-offs in very elderly patients with atrial fibrillation

Abstract

BACKGROUND: The benefits and risks of anticoagulation therapy in patients aged ≥ 80 years with atrial fibrillation (AF) remain underexplored, as this population is underrepresented in randomized clinical trials. We evaluated mortality and bleeding outcomes associated with anticoagulation use in this population. DESIGN: We conducted a retrospective cohort study using MDClone, a synthetic electronic health record database from a large US health system, including 45,305 patients aged ≥ 80 years with AF after excluding those with mitral stenosis, mechanical heart valves, cirrhosis, or end-stage renal disease. Patients were categorized as continued, initiated, discontinued, or never anticoagulated. The primary outcome was all-cause mortality at 30 days, 6 months, 1 year, and 5 years; secondary outcomes were ischemic stroke, gastrointestinal bleeding (GIB), and intracranial hemorrhage (ICH). To address immortal time bias, the primary analysis used a time-varying Cox model, complemented by a 90-day landmark analysis and propensity score matching. KEY RESULTS: Patients who continued anticoagulation had lower 1-year mortality than those never anticoagulated (8.7% vs 17.7%; p < 0.001). In the time-varying Cox model, anticoagulation was associated with a 25% lower hazard of mortality (HR 0.75, 95% CI 0.71-0.79). Compared with continued anticoagulation, mortality was higher among patients who initiated (HR 1.51, 95% CI 1.38-1.66), discontinued (HR 1.64, 95% CI 1.49-1.81), or never received anticoagulation (HR 2.22, 95% CI 2.05-2.41), and persisted after propensity score matching. At 5 years, mortality converged across groups. GIB was more frequent in anticoagulated patients (continued 13.0%, initiated 11.9%), whereas ICH rates were low and comparable across groups (1.3-1.6%, p = 0.129). CONCLUSIONS: Among patients aged ≥ 80 years with AF, anticoagulation therapy was associated with lower all-cause mortality despite an increase in gastrointestinal bleeding. These findings support continued anticoagulation in appropriately selected elderly patients, rather than withholding therapy on the basis of age alone.

Abstract as published, via PubMed.