Trends in Use of Oral Anticoagulants in Older Adults With Newly Diagnosed Atrial Fibrillation, 2010-2020

Abstract

ImportanceUndertreatment of older adults with atrial fibrillation with anticoagulation therapy is an important practice gap. It has been posited that the availability of direct oral anticoagulants (DOACs) would improve oral anticoagulant (OAC) initiation in older adults with atrial fibrillation given their superior safety profile compared with warfarin.ObjectivesTo systematically examine trends in OAC initiation and nonadherence in older adults with atrial fibrillation and coexisting geriatric conditions.Design, Setting, and ParticipantsThis retrospective cohort study uses administrative claims data from Optum’s Clinformatics Data Mart from January 1, 2010, to December 31, 2020. Participants included beneficiaries of Medicare Advantage plans aged 65 years and older with atrial fibrillation and elevated risk of ischemic stroke. Data analysis was performed from October 2021 to October 2022.ExposuresCoexisting dementia, frailty, and anemia.Main Outcomes and MeasuresThe primary outcomes were OAC initiation within 12 months after the first diagnosis of atrial fibrillation per year and nonadherence with OAC per year (defined as <80% of proportion of days covered among patients newly started on OAC in each year).ResultsThere were 21 603 to 51 236 patients per year (total for 2010-2020, 381 488 patients) in the OAC-eligible incident AF cohort (mean [SD] age, 77.2 [6.1] to 77.4 [6.8] years; 13 871 [51.8%] to 22 901 [49.8%] women). OAC initiation within 12 months after incident AF increased from 20.2% (5405 of 26 782 patients) in 2010 to 32.9% (7111 of 21 603 patients) in 2020. DOAC uptake increased from 1.1% (291 of 26 782 patients) to 30.9% (6678 of 21 603 patients), and warfarin initiation decreased from 19.1% (5114 of 26 782 patients) to 2.0% (436 of 21 603 patients). Older age (odds ratio [OR], 0.98; 95% CI, 0.98-0.98), dementia (OR, 0.57; 95% CI, 0.55-0.58), frailty (OR, 0.74; 95% CI, 0.72-0.76), and anemia (OR, 0.75; 95% CI, 0.74-0.77) were associated with lower odds of OAC initiation. During the study period, the median (IQR) proportion of days covered increased from 77.6% (41.0%-96.4%) to 90.2% (57.4%-98.6%), and OAC nonadherence decreased from 52.2% (2290 of 4389 patients) to 39.0% (3434 of 8798 patients).Conclusions and RelevanceSince the introduction of DOACs, OAC initiation in older adults with has improved but remained suboptimal in 2020. Additional strategies are needed to improve stroke prophylaxis in all older adults with atrial fibrillation including those with coexisting dementia, frailty, and anemia.

Initiation of oral anticoagulation in US older adults newly diagnosed with atrial fibrillation during hospitalization

“…42 Studies in outpatient populations have found that frailty and geriatric syndromes are associated with decreased rates of anticoagulant prescription among older adults with atrial fibrillation. 5,12,15 Our study extends these findings to the inpatient setting. Although no prior US studies have examined inpatient anticoagulation by geriatric syndrome status, a meta-analysis of three small European studies that included a total of 1204 hospitalized patients found that frail older adults were less likely to receive an anticoagulant.…”

“…Prior estimates using Medicare data have largely focused on the outpatient setting and demonstrate anticoagulant initiation rates for incident atrial fibrillation around 50%. 3,4,12,13,40 One recent study of patients in an integrated health system with incident inpatient atrial fibrillation associated with sepsis reported anticoagulant initiation rates of 20%. 41 Taken together with these studies, our results suggest that patients diagnosed with atrial fibrillation while admitted for other medical conditions-even those at high stroke risk-are infrequently initiated on anticoagulants or discharged with ambulatory cardiac monitors.…”

“…49 Although DOACs have been guideline-recommended therapies for atrial fibrillation since 2014, their recommendation as first-line therapies in 2019 guidelines and increased DOAC penetration in Medicare Part D may have shifted practice patterns since our study year. 2,12,49 However, improved safety profile and increased cost may have had opposing effects on prescription fills. 49 This study has limitations.…”

“…2 Oral anticoagulants are underused among all older adults with atrial fibrillation, with prevalent use estimated at 50%-60%, and even lower use for patients with frailty despite evidence of net benefit in this high-risk group. [3][4][5][6][7][8][9][10][11][12] Hospitalization is a common setting for new atrial fibrillation diagnosis. Patients may be admitted for symptomatic atrial fibrillation or it may be discovered incidentally, driven in part by frequent inpatient use of cardiac monitoring and by acute illness triggering episodes of atrial fibrillation in susceptible and paroxysmal patients.…”

“…National guidelines recommend stroke prevention with oral anticoagulants for patients with atrial fibrillation and at least 2 non‐sex‐related risk factors for stroke, with therapy individualized based on shared decision‐making focused on balancing the risks of thromboembolism and bleeding 2 . Oral anticoagulants are underused among all older adults with atrial fibrillation, with prevalent use estimated at 50%–60%, and even lower use for patients with frailty despite evidence of net benefit in this high‐risk group 3–12 …”