Relation of Race, Apparent Disability, and Stroke Risk With Warfarin Prescribing for Atrial Fibrillation in Patients Receiving Maintenance Hemodialysis

Am J Cardiol. 2019 Feb 15;123(4):598-604. doi: 10.1016/j.amjcard.2018.11.020. Epub 2018 Nov 24.

Abstract

Little is known about how warfarin is prescribed for stroke prevention in maintenance dialysis patients with chronic atrial fibrillation (AF). We examined patterns of warfarin use, and associated factors, after AF diagnosis. This retrospective cohort analysis studied US Medicare patients receiving maintenance dialysis January 1, 2008, to June 30, 2010. Demographics, co-morbidity, and a durable medical equipment claims-based disability proxy score predicted warfarin prescription after AF diagnosis. The analysis included 8,964 patients with nonvalvular AF. Compared with nonusers, warfarin users were younger (age 65.4 ± 12.1 vs 67.0 ± 12.9 years) and more likely to be men (54.3% vs 52.8%) and of white race (64.0% vs 59.6%). After adjustment for other factors, nonwhite, versus white, race was associated with significantly less warfarin use within 30 days: odds ratios (ORs), 95% confidence intervals (CIs), were 0.80, 0.71 to 91, for black patients; 0.57, 0.43 to 0.76, for Asians; and 0.74, 0.49 to 1.12, for members of other races. Percentages of patients receiving warfarin decreased as Hypertension Abnormal renal and liver function Stroke-Bleeding Labile INR Elderly Drugs or alcohol (HAS-BLED) bleeding risk score increased (OR 0.82, 95% CI 0.73 to 0.92, HAS-BLED score 3 to 4 versus 2; 0.38, 0.26 to 0.57, score ≥ 5 vs 2). However, as CHA2DS2-Vasc stroke-risk score increased, warfarin use tended to decrease (OR 0.90, 95% CI 0.78 to 1.03, p = 0.13, CHA2DS2-Vasc score 4 versus 1 to 3; 0.69, 0.61 to 0.78, p < 0.0001, score 5 vs 1 to 3). In conclusion, providers appear to weigh bleeding risk more heavily than stroke-prevention potential when prescribing warfarin for maintenance dialysis patients. Racial minorities received warfarin substantially less often than whites, even after accounting for other factors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anticoagulants / therapeutic use*
  • Atrial Fibrillation / complications
  • Atrial Fibrillation / ethnology*
  • Atrial Fibrillation / therapy
  • Chronic Disease
  • Ethnic Groups / statistics & numerical data*
  • European Continental Ancestry Group / statistics & numerical data*
  • Female
  • Humans
  • Kidney Failure, Chronic / complications
  • Kidney Failure, Chronic / ethnology
  • Kidney Failure, Chronic / therapy
  • Male
  • Middle Aged
  • Practice Patterns, Physicians' / statistics & numerical data
  • Renal Dialysis*
  • Retrospective Studies
  • Stroke / epidemiology*
  • United States
  • Warfarin / therapeutic use*
  • Young Adult

Substances

  • Anticoagulants
  • Warfarin