Almost 1 in 3 High-Risk AFib Patients Not Receiving Anticoagulation

An analysis of data from nearly half a million patients with atrial fibrillation who received treatment in care centers across the US over a decade suggests in 1 in 3 high-risk patients with atrial fibrillation was not receiving any anticoagulants.

Results of the study, which leveraged data from within the Cerner Real World Data database, suggest overall rate of anticoagulation rose from 56.3% to 64.7%, with marked increases in use of direct oral anticoagulants (DOACs) compared with warfarin, but investigators note specific subgroups

“Despite increasing use of DOACs, nearly 1 in 3 patients with AF and elevated CHA2DS2‐VASc score remains on no anticoagulation. Regardless of agent chosen, significant room for improvement remains in improving stroke prevention in patients with AF,” wrote investigators.

With the introduction of DOACs into the clinician’s armamentarium and, later, clinical guidelines, management of most patients with nonvalvular atrial fibrillation underwent a major change. No longer was warfarin, a long-time staple, recommended for stroke prevention, with DOACs given the nod from major professional organizations, including the American Heart Association, American College of Cardiology, and Heart Rhythm Society. Despite this change being reflected in guidelines more than half a decade ago, concern has grown over the optimal adoption of guideline recommendations and prescribing practices among patients with nonvalvular atrial fibrillation.

With this in mind, investigators from the University of Texas Southwestern Medical Center, Duke Clinical Research Institute, and the University of Texas, designed the current study to provide an overview of changes in DOAC use using contemporary data obtained from the Corner Real World Data database. A large deidentified database from participating health systems using Cerner's electronic health record platform, Cerner Real World Data provided investigators with information to a cohort of 699,954 adults with at least 1 diagnosis of atrial fibrillation between January 1, 2011, and December 31, 2020. Investigators limited their analyses to individuals aged 40 years or older with 2 or more diagnoses of atrial fibrillation at least 1 month apart at any point in the past from an inpatient or outpatient visit.

After further excluding those with a CHA₂DS₂‐VASc score below 2, those with a mechanical valve, and those without longitudinal follow‐up data, investigators identified a cohort of 436,864 from 88 care centers across the US for inclusion in their analyses.

This cohort had a median age of 78.3 (IQR, 71.3-84.5) years, 47.5% were female. In regard to race and ethnicity, 87.7% were White, 6.2% were Black, and 6.1% identified as other or unknown. Among the 436,864 included in the study, 76.0% (n=331,842) had at least 1 encounter after 2019. Among these patients, 17.0% (n=56,512) were on warfarin, 46.8% (n=155,371) were on a DOAC, and 36.1% (n=119,959) were on no anticoagulation. Compared to those on warfarin, DOAC users were younger (median age, 77.1 vs 79.2 years), more likely to be female (48.0% versus 44.8%), and less likely to be White (87.4% vs 89.6%).

Upon analysis, investigators overall anticoagulation rates increased from 56.3% to 64.7% from 2011 to 2020. During this time period, DOAC use increased from 4.7% to 47.9% and warfarin use declined from 52.4% to 17.7%. Further analysis demonstrated increases in DOAC use was similar across age, sex, and race and ethnicity groups.

However, investigators noted significant variability in DOAC prescribing by health system. In 2020, the median health‐system‐level proportion of patients with AF on a DOAC was 49% (IQR, 40%–54%). Among the hospitals in the highest quartile of DOAC use more than 54% were on a DOAC while fewer than 33% those in the lowest quartile were on a DOAC in 2020.

“While DOACs are now much more commonly used than warfarin in patients with AF at risk for stroke, DOAC use did not overtake warfarin use for more than half a decade after the first DOAC reached the market. At a population level, patient‐level differences did not appear to drive differences in DOAC use,” concluded investigators. “Substantial variability in the proportion of patients receiving a DOAC between health systems and lack of large patient‐level differences in those receiving warfarin versus DOACs suggests that provider and health‐system‐level factors are responsible for the majority of ongoing warfarin use.”

This study, “Trends in Oral Anticoagulant Use Among 436 864 Patients With Atrial Fibrillation in Community Practice, 2011 to 2020,” was published in the Journal of the American Heart Association.