Contraindications to anticoagulation therapy and eligibility for novel anticoagulants in older patients with atrial fibrillation.
OBJECTIVE
Oral anticoagulation therapy prevents stroke and improves survival in patients with atrial fibrillation, but the therapy is underutilized. We sought to identify the prevalence of contraindications for oral anticoagulation and the proportion of patients potentially eligible for different agents.


METHODS
We identified patients with nonacute atrial fibrillation in a nationally representative 5% sample of 2009 Medicare data. We divided the population into patients ineligible for any oral anticoagulant, patients eligible for warfarin only, and patients eligible for any anticoagulant. We compared patient characteristics and the use of anticoagulation among the subgroups.


RESULTS
Among 86,671 patients with atrial fibrillation, 1872 (2.2%) were ineligible for anticoagulation because of an absolute contraindication, most frequently a history of intracranial hemorrhage (60%). Patients ineligible for any anticoagulant were the same age as the overall group (mean age, 80.5 vs. 80.4 years). However, they had higher rates of dementia (19% vs. 8.6%) and heart failure (59% vs. 43%) and higher mean CHADS2 scores (3.8 vs. 2.8). Of the remaining 84,799 patients eligible for anticoagulation, 7146 (8.4%) were eligible for warfarin only (most commonly because of mechanical heart valves [66%] and end-stage renal disease [12%]). Sixty-five percent of patients eligible for anticoagulation received warfarin, and the proportion was similar for patients with a relatively high risk of bleeding.


CONCLUSIONS
Older adults with atrial fibrillation rarely have absolute contraindications to oral anticoagulation therapy. Among patients without contraindications, most appeared to be eligible for any anticoagulant, and relatively high-risk features appeared not to influence warfarin use.
Duke Clinical Research Institute, Durham, North Carolina, USA.|Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
Benjamin A
http://orcid.org/0000-0002-4729-7820
BA
Steinberg
Duke Clinical Research Institute, Durham, North Carolina, USA.
Melissa A
MA
Greiner
Duke Clinical Research Institute, Durham, North Carolina, USA.
Bradley G
BG
Hammill
Duke Clinical Research Institute, Durham, North Carolina, USA.|Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
Lesley H
LH
Curtis
Framingham Heart Study, Framingham, Massachusetts, USA.|Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA.
Emelia J
EJ
Benjamin
Department of Epidemiology, University of Washington School of Public Health, Seattle, Washington, USA.
Susan R
SR
Heckbert
Duke Clinical Research Institute, Durham, North Carolina, USA.|Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
Jonathan P
JP
Piccini
D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D001777:Blood Coagulation / Q000187:drug effects*; D015897:Comorbidity; D000075202:Contraindications; D004608:Eligibility Determination; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D006278:Medicare; D018579:Patient Selection; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014859:Warfarin / Q000008:administration & dosage
D000925:Anticoagulants; D014859:Warfarin
Atrial fibrillation; Contraindications; Medicarex; Older patients; Oral anticoagulation