Oral Anticoagulant Initiation in Patients With Kidney Failure on Hemodialysis Newly Diagnosed With Atrial Fibrillation (2007-2020): An Observational Study of Trends and Disparities.

RATIONALE & OBJECTIVE: Atrial fibrillation (AF) is common in patients with kidney failure on hemodialysis (HD), but few patients receive oral anticoagulant (OAC) treatment. Availability of direct-target OACs starting in 2010 may have induced greater OAC initiation, but this has not been systematically studied.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS: Using Medicare fee-for-service billing claims (2006-2020), we identified previously OAC-naïve HD patients newly-diagnosed with AF between January 1, 2007, and October 1, 2020.

EXPOSURES

Calendar year; race/ethnicity.

OUTCOMES

OAC initiation within 90 days from AF diagnosis (any; specific agent).

ANALYTICAL APPROACH

We estimated initiation risk ratios for each calendar year compared with the referent cohort, 2007, using unadjusted and multivariable-adjusted modified Poisson regression. We also determined differences by racial/ethnic group in OAC initiation, as well as any changes in these disparities over time.

RESULTS

Among 82,389 HD patients newly-diagnosed with AF, 20,002 (24.3%) initiated new OAC treatment within 90 days: 20.5% in 2007 and 34.1% in 2020. Direct-target OACs accounted for 81.0% of OAC initiations in 2020. Adjusted regression models estimated that OAC initiation remained essentially unchanged between 2007 and 2013, but thereafter increased toward a demographics-adjusted risk ratio of 1.61 (95% CI: 1.50-1.73) in 2020. Compared with non-Hispanic Whites, the rates of OAC initiation were 15% (95% CI, 12%-17%) lower among Black patients, 29% (95% CI, 24%-34%) lower among Asian patients, and 22% (95% CI, 19%-25%) lower among Hispanic patients. These disparities were not found to have differed across time (  = 0.75).

LIMITATIONS

Lack of clinical detail to firmly establish contraindications to OAC initiation.

CONCLUSIONS

While rates of OAC initiation among patients on HD with newly-diagnosed AF increased in recent years, predominantly driven by increased use of apixaban, OAC initiation rates remained low, at 34% of patients in 2020. Compared with non-Hispanic White patients, OAC initiation remained consistently lower in patients of other race and ethnic groups.