Contemporary clinical and economic outcomes among oral anticoagulant treated and untreated elderly patients with atrial fibrillation: Insights from the United States Medicare database

Abstract

Background Oral anticoagulants (OACs) mitigate the risk of stroke in atrial fibrillation (AF) patients. Objective Elderly AF patients who were treated with OACs (apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin) were compared against AF patients who were not treated with OACs with respect to their clinical and economic outcomes. Methods Newly diagnosed AF patients were identified between January 2013 and December 2017 in the Medicare database. Evidence of an OAC treatment claim on or after the first AF diagnosis was used to classify patients into treatment-defined cohorts, and these cohorts were further stratified based on the initial OAC prescribed. The risks of stroke/systemic embolism (SE), major bleeding (MB), and death were analyzed using inverse probability treatment weighted time-dependent Cox regression models, and costs were compared with marginal structural models. Results The two treatment groups were composed of 1,421,187 AF patients: OAC treated (N = 583,350, 41.0% [36.4% apixaban, 4.9% dabigatran, 0.1% edoxaban, 26.7% rivaroxaban, and 31.9% warfarin patients]) and untreated (N = 837,837, 59.0%). OAC-treated patients had a lower adjusted risk of stroke/SE compared to untreated patients (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.68–0.72). Additionally patients receiving OACs had a lower adjusted risk of death (HR: 0.56; 95% CI: 0.55–0.56) and a higher risk of MB (HR: 1.57; 95% CI: 1.54–1.59) and this trend was consistent across each OAC sub-group. The OAC-treated cohort had lower adjusted total healthcare costs per patient per month ($4,381 vs $7,172; p < .0001). Conclusion For the OAC-treated cohort in this elderly US population, stroke/SE and all-cause death were lower, while risk of MB was higher. Among OAC treated patients, total healthcare costs were lower than those of the untreated cohort.

Anticoagulation-Associated Bleeding in Patients Screened for Atrial Fibrillation versus Usual Care—A Post Hoc Analysis from the LOOP Study

“…Our findings indicate a larger increase in OAC-mediated bleeding risk, despite a lower mean age and lighter comorbidity burden compared to the American cohort. The percentage of AF-patients treated with OAC in the American cohort was low (41 %) compared to the current study (87.1%), and yet the registry reported a significantly lower all-cause and inpatient medical cost for OAC-treated AF patients compared to their non-treated cohort 23 . With the expected surge in AF prevalence 3,24,25 this underlines that a suited screening strategy is needed to identify and treat AF to mitigate mortality, morbidity and health care expenses 26,27 .…”

“… 21 22 An American observational study used OAC as a time-dependent exposure in an older AF population and found an increased risk of major bleeding after OAC initiation (HR: 1.57; 95%CI: 1.54–1.59). 23 Our findings indicate a larger increase in OAC-mediated bleeding risk, despite a lower mean age and lighter comorbidity burden compared with the American cohort. The percentage of AF patients treated with OAC in the American cohort was low (41%) compared with the current study (87.1%), and yet the registry reported a significantly lower all-cause and inpatient medical cost for OAC-treated AF patients compared with their nontreated cohort.…”

“…The percentage of AF patients treated with OAC in the American cohort was low (41%) compared with the current study (87.1%), and yet the registry reported a significantly lower all-cause and inpatient medical cost for OAC-treated AF patients compared with their nontreated cohort. 23 With the expected surge in AF prevalence, 3 24 25 this underlines that a suited screening strategy is needed to identify and treat AF to mitigate mortality, morbidity, and health care expenses. 26 27 But before this, evidence is needed with regard to OAC treatment in subclinical AF.…”

“…Our results confirm that older individuals in this population are particularly at risk of major bleeding besides the increased risk of thromboembolic events, as previous studies have reported in OAC-treated patients 21,22 . An American observational study used OAC as a time-dependent exposure in an older AF population, and found an increased risk of major bleeding after OAC initiation (HR 1.57 95%CI 1.54-1.59) 23 . Our findings indicate a larger increase in OAC-mediated bleeding risk, despite a lower mean age and lighter comorbidity burden compared to the American cohort.…”

Addressing Undertreatment of Atrial Fibrillation With Community Pharmacists

“…Older age, female sex, and Black race were factors associated with OAC nonuse. 2 The news was slightly better in the Veterans Health Administration (VHA), 3 where OAC nonuse increased from 52% to 65.1% of eligible patients with AF between 2014 and 2018. Patients from racial and ethnic minority groups were less likely to receive OAC than their White counterparts.…”