Racial/Ethnic Disparities in Atrial Fibrillation Treatment and Outcomes among Dialysis Patients in the United States
Authors: Waddy Salina P. , Solomon Allen J. , Becerra Adan Z. , Ward Julia B. , Chan Kevin E. , Fwu Chyng-Wen , Norton Jenna M. , Eggers Paul W. , Abbott Kevin C. , Kimmel Paul L. 
Published: February 2020

Significance Statement
Reduced likelihood of anticoagulant use among patients on hemodialysis with ESKD and atrial fibrillation may contribute to higher stroke rates, especially among racial/ethnic minority patients. In a retrospective cohort study, the authors identified patients with ESKD who initiated hemodialysis, determined which patients subsequently developed atrial fibrillation, and followed them for 1 year for all-cause stroke and other outcomes. Compared with white patients, racial/ethnic minority patients were more likely to experience stroke but less likely to fill a warfarin prescription. Additional analysis suggested that achieving warfarin distribution equal to that for white patients would prevent 7%, 10%, and 12% of excess strokes among black, Hispanic, and Asian patients, respectively. Identifying and addressing barriers to maximizing appropriate anticoagulation treatment may help reduce disparities in stroke among patients on hemodialysis with atrial fibrillation.

Background
Because stroke prevention is a major goal in the management of ESKD hemodialysis patients with atrial fibrillation, investigating racial/ethnic disparities in stroke among such patients is important to those who could benefit from strategies to maximize preventive measures.

Methods
We used the United States Renal Data System to identify ESKD patients who initiated hemodialysis from 2006 to 2013 and then identified those with a subsequent atrial fibrillation diagnosis and Medicare Part A/B/D. Patients were followed for 1 year for all-cause stroke, mortality, prescription medications, and cardiovascular disease procedures. The survival mediational g-formula quantified the percentage of excess strokes attributable to lower use of atrial fibrillation treatments by race/ethnicity.

Results
The study included 56,587 ESKD hemodialysis patients with atrial fibrillation. Black, white, Hispanic, and Asian patients accounted for 19%, 69%, 8%, and 3% of the population, respectively. Compared with white patients, black, Hispanic, or Asian patients were more likely to experience stroke (13%, 15%, and 16%, respectively) but less likely to fill a warfarin prescription (10%, 17%, and 28%, respectively). Warfarin prescription was associated with decreased stroke rates. Analyses suggested that equalizing the warfarin distribution to that in the white population would prevent 7%, 10%, and 12% of excess strokes among black, Hispanic, and Asian patients, respectively. We found no racial/ethnic disparities in all-cause mortality or use of cardiovascular disease procedures.

Conclusions
Racial/ethnic disparities in all-cause stroke among hemodialysis patients with atrial fibrillation are partially mediated by lower use of anticoagulants among black, Hispanic, and Asian patients. The reasons for these disparities are unknown, but strategies to maximize stroke prevention in minority hemodialysis populations should be further investigated.