Nonvalvular Atrial Fibrillation and Anticoagulation in the Elderly: A Retrospective Cohort Study

Abstract

Background: Atrial fibrillation (AF) is associated with a substantially increased risk of ischemic stroke and systemic embolism particularly in elderly patients. Understanding real-world patterns of anticoagulation (AC) use in elderly population is critical.

Methods: This is a retrospective, single-center, chart review study that included patients who had nonvalvular AF between 2021 and 2024. Patients were divided into two groups according to age: 50–75 years old and 76–89 years old. Primary endpoint was AC underutilization, which was defined by the presence of all the following conditions: 1) CHA₂DS₂-VASc score > 2; 2) Outcomes Registry for Better Informed Treatment (ORBIT) score ≥ 3; 3) without AC. Secondary endpoint was AC appropriateness, which is defined by the presence of all the following conditions: 1) CHA₂DS₂-VASc > 2; 2) ORBIT < 3; 3) with AC.

Results: A total of 6,386 patients were included. Among them, 3,306 patients were 50–75 years old, and 3,080 patients were 76–89 years old. Patients in age group 76–89 had a 4.547-fold higher odds ratio (OR = 4.547; 95% confidence interval (CI), 3.827–5.403) to have AC underutilization than those in age group 50–75. Patients in age group 76–89 were 108% (OR = 2.077; 95% CI, 1.818–2.374) more likely to have AC appropriateness than those in age group 50–75. History of bleeding (OR = 10.582; 95% CI, 6.467–17.315; P < 0.001) and glomerular filtration rate (GFR) (OR = 0.985; 95% CI, 0.982–0.988; P < 0.001) were independent predictors of appropriateness. Similar, history of bleeding (OR = 2.402; 95% CI, 1.666–3.462; P < 0.001) and GFR (OR = 1.006; 95% CI, 1.001–1.010; P = 0.0185) were also independent predictors of underutilization.

Conclusions: Patients in age group 76–89 were more likely to have AC underutilization than patients in age group 50–75. History of bleeding and GFR were independent predictors of appropriateness and underutilization. These findings highlight the ongoing challenge of balancing stroke prevention and bleeding risk in elderly AF patients and underscore the importance of guideline-directed, individualized AC strategies.