title: Apixaban for the Secondary Prevention of Thrombosis Among Patients With Antiphospholipid Syndrome: Study Rationale and Design (ASTRO-APS).
abstract: BACKGROUND
  Antiphospholipid syndrome (APS) is an acquired thrombophilia characterized by thrombosis, pregnancy morbidity, and the presence of characteristic antibodies. Current therapy for patients having APS with a history of thrombosis necessitates anticoagulation with the vitamin K antagonist warfarin, a challenging drug to manage. Apixaban, approved for the treatment and prevention of venous thrombosis with a low rate of bleeding observed, has never been studied among patients with APS.
  
  
  OBJECTIVE
  We report study rationale and design of Apixaban for the Secondary Prevention of Thrombosis Among Patients With Antiphospholipid Syndrome (ASTRO-APS), a prospective randomized open-label blinded event pilot study that will randomize patients with a clinical diagnosis of APS receiving therapeutic anticoagulation to either adjusted-dose warfarin or apixaban 2.5 mg twice a day. We aim to report our ability to identify, recruit, randomize, and retain patients with APS randomized to apixaban compared with warfarin. We will report clinically important outcomes of thrombosis and bleeding. All clinical outcomes will be adjudicated by a panel blinded to the treatment arm. A unique aspect of this study is the enrollment of patients with an established clinical diagnosis of APS. Also unique is our use of electronic medical record interrogation techniques to identify patients who would likely meet our inclusion criteria and use of an electronic portal for follow-up visit data capture.
  
  
  CONCLUSIONS
  ASTRO-APS will be the largest prospective study to date comparing a direct oral anticoagulant with warfarin among patients with APS for the secondary prevention of thrombosis. Our inclusion criteria assure that outcomes obtained will be clinically applicable to the routine management of patients with APS receiving indefinite anticoagulation.
authors.affiliation: Intermountain Medical Center, Murray, UT, USA Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA scott.woller@imail.org.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Woller
authors.affiliation: Intermountain Medical Center, Murray, UT, USA Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Stevens
authors.affiliation: Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Kaplan
authors.affiliation: Intermountain Medical Center, Murray, UT, USA Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: D Ware
authors.initials: DW
authors.lastname: Branch
authors.affiliation: Intermountain Medical Center, Murray, UT, USA.
authors.forename: Valerie T
authors.initials: VT
authors.lastname: Aston
authors.affiliation: Division of Statistics, Intermountain Medical Center, Murray, UT, USA.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Wilson
authors.affiliation: Intermountain Medical Center, Murray, UT, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Gallo
authors.affiliation: Intermountain Medical Center, Murray, UT, USA.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Johnson
authors.affiliation: Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rondina
authors.affiliation: Department of Medical Informatics, Intermountain Healthcare, Murray, UT, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Lloyd
authors.affiliation: Department of Medical Informatics, Intermountain Healthcare, Murray, UT, USA Department of Biomedical Informatics, University of Utah, Salt Lake City, UT, USA.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Evans
authors.affiliation: Intermountain Medical Center, Murray, UT, USA Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: C Gregory
authors.initials: CG
authors.lastname: Elliott
mesh_terms: D000284:Administration, Oral; D000328:Adult; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000188:drug therapy; D011720:Pyrazoles / Q000008:administration & dosage* / Q000009:adverse effects; D011728:Pyridones / Q000008:administration & dosage* / Q000009:adverse effects; D013927:Thrombosis / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D014812:Vitamin K / Q000037:antagonists & inhibitors / Q000097:blood; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D011720:Pyrazoles; D011728:Pyridones; D014812:Vitamin K; C522181:apixaban; D014859:Warfarin
keywords: anticoagulants; deep venous thrombosis; lupus inhibitor; pulmonary embolism; stroke; venous thromboembolism