Abstract
Background: Oral anticoagulants (OACs) reduce stroke risk in atrial fibrillation (AF) patients. Little is known about the prescription patterns of OAC prescription and outcomes in AF patients among different age groups. The primary objectives of this study were to examine the association of age with likelihood of OAC prescription and with risk of major bleeding (MB), stroke and systemic embolism (SE) among newly diagnosed AF patients.
Methods: Newly diagnosed AF patients age ≥18 with a CHA2DS2-VASc score ≥2 were identified from the IQVIA PharMetrics database (January 1, 2013 – April 30, 2021). Age was categorized as 18-64, 65-74, 75+ years, and patients were further characterized as receiving an OAC prescription versus not. Multivariable logistic regression was used to estimate odds ratios for OAC prescription. Multivariable Cox models were used to estimate hazard ratios of MB and stroke/SE. Models were adjusted for demographics, comorbidities, and medication use.
Results: A total of 244,507 AF patients were identified, of whom 145,117 (59.4%) did not have a claim for an OAC and 99,390 (40.6%) were prescribed an OAC during the study identification period. Patients aged 65-74 (OR 1.44 [95% CI 1.40, 1.48]) and 75+ (OR 1.50 [95% CI 1.45, 1.57]) had higher likelihoods of receiving an OAC prescriptions compared to patients aged 18-64. Patients aged 65-74 had an 18% higher risk of MB (95% CI [1.14, 1.21]) and 75+ had a 46% higher risk of MB (95% CI [1.42, 1.50]). Older ages were also significantly associated with a 50% (95% CI (1.42, 1.58)) and 136% higher risk (95% CI [2.24, 2.48]) of GI bleeds in ages 64-75 and 75+, respectively. Results for intracranial and other bleeds were similar. Patients aged 65-74 also had a 16% higher risk (95% CI (1.11, 1.22)), and 75+ had a 67% higher risk (95% CI [1.60, 1.75]), of any stroke outcome. Age 75+ was also associated with a 32% higher risk (95% CI [1.16, 1.50]) of hemorrhagic stroke. Results for ischemic stroke and SE were similar.
Conclusion: After adjusting for demographics, comorbidities and medication use, older AF patients had higher likelihoods of receiving an OAC prescription and were at significantly higher risk for adverse outcomes compared to younger AF patients.
