title: Association of Preceding Antithrombotic Treatment With Acute Ischemic Stroke Severity and In-Hospital Outcomes Among Patients With Atrial Fibrillation.
abstract: Antithrombotic therapies are known to prevent stroke for patients with atrial fibrillation (AF) but are often underused in community practice.
  
  
  
  To examine the prevalence of patients with acute ischemic stroke with known history of AF who were not receiving guideline-recommended antithrombotic treatment before stroke and to determine the association of preceding antithrombotic therapy with stroke severity and in-hospital outcomes.
  
  
  
  Retrospective observational study of 94 474 patients with acute ischemic stroke and known history of AF admitted from October 2012 through March 2015 to 1622 hospitals participating in the Get With the Guidelines-Stroke program.
  
  
  
  Antithrombotic therapy before stroke.
  
  
  
  Stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS; range of 0-42, with a higher score indicating greater stroke severity and a score ≥16 indicating moderate or severe stroke), and in-hospital mortality.
  
  
  
  Of 94 474 patients (mean [SD] age, 79.9 [11.0] years; 57.0% women), 7176 (7.6%) were receiving therapeutic warfarin (international normalized ratio [INR] ≥2) and 8290 (8.8%) were receiving non-vitamin K antagonist oral anticoagulants (NOACs) preceding the stroke. A total of 79 008 patients (83.6%) were not receiving therapeutic anticoagulation; 12 751 (13.5%) had subtherapeutic warfarin anticoagulation (INR <2) at the time of stroke, 37 674 (39.9%) were receiving antiplatelet therapy only, and 28 583 (30.3%) were not receiving any antithrombotic treatment. Among 91 155 high-risk patients (prestroke CHA2DS2-VASc score ≥2), 76 071 (83.5%) were not receiving therapeutic warfarin or NOACs before stroke. The unadjusted rates of moderate or severe stroke were lower among patients receiving therapeutic warfarin (15.8% [95% CI, 14.8%-16.7%]) and NOACs (17.5% [95% CI, 16.6%-18.4%]) than among those receiving no antithrombotic therapy (27.1% [95% CI, 26.6%-27.7%]), antiplatelet therapy only (24.8% [95% CI, 24.3%-25.3%]), or subtherapeutic warfarin (25.8% [95% CI, 25.0%-26.6%]); unadjusted rates of in-hospital mortality also were lower for those receiving therapeutic warfarin (6.4% [95% CI, 5.8%-7.0%]) and NOACs (6.3% [95% CI, 5.7%-6.8%]) compared with those receiving no antithrombotic therapy (9.3% [95% CI, 8.9%-9.6%]), antiplatelet therapy only (8.1% [95% CI, 7.8%-8.3%]), or subtherapeutic warfarin (8.8% [95% CI, 8.3%-9.3%]). After adjusting for potential confounders, compared with no antithrombotic treatment, preceding use of therapeutic warfarin, NOACs, or antiplatelet therapy was associated with lower odds of moderate or severe stroke (adjusted odds ratio [95% CI], 0.56 [0.51-0.60], 0.65 [0.61-0.71], and 0.88 [0.84-0.92], respectively) and in-hospital mortality (adjusted odds ratio [95% CI], 0.75 [0.67-0.85], 0.79 [0.72-0.88], and 0.83 [0.78-0.88], respectively).
  
  
  
  Among patients with atrial fibrillation who had experienced an acute ischemic stroke, inadequate therapeutic anticoagulation preceding the stroke was prevalent. Therapeutic anticoagulation was associated with lower odds of moderate or severe stroke and lower odds of in-hospital mortality.
authors.affiliation: Department of Neurology, Duke University Medical Center, Durham, North Carolina2Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xian
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Emily C
authors.initials: EC
authors.lastname: O'Brien
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Li
authors.initials: L
authors.lastname: Liang
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Haolin
authors.initials: H
authors.lastname: Xu
authors.affiliation: Harvard Medical School, Massachusetts General Hospital, Cambridge.
authors.forename: Lee H
authors.initials: LH
authors.lastname: Schwamm
authors.affiliation: University of California, Los Angeles.
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.affiliation: Heart and Vascular Center, Brigham and Women's Hospital, Boston, Massachusetts6Harvard Medical School, Boston, Massachusetts.
authors.forename: Deepak L
authors.initials: DL
authors.lastname: Bhatt
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Smith
authors.affiliation: University of Texas Southwestern Medical Center, Dallas.
authors.forename: DaiWai M
authors.initials: DM
authors.lastname: Olson
authors.affiliation: Patient investigator, Amherst, New York.
authors.forename: Lesley
authors.initials: L
authors.lastname: Maisch
authors.affiliation: Patient investigator, Richland Hills, Texas.
authors.forename: Deidre
authors.initials: D
authors.lastname: Hannah
authors.affiliation: Patient investigator, Frisco, Texas.
authors.forename: Brianna
authors.initials: B
authors.lastname: Lindholm
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Lytle
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pencina
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Hernandez
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Peterson
mesh_terms: D000208:Acute Disease; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000150:complications*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D017052:Hospital Mortality; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D016017:Odds Ratio; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin