title: The FReedom from Ischemic Events-New Dimensions for Survival (FRIENDS) registry: design of a prospective cohort study of patients with advanced peripheral artery disease.
abstract: BACKGROUND
  Advanced lower extremity peripheral artery disease (PAD), whether presenting as acute limb ischemia (ALI) or chronic critical limb ischemia (CLI), is associated with high rates of cardiovascular ischemic events, amputation, and death. Past research has focused on strategies of revascularization, but few data are available that prospectively evaluate the impact of key process of care factors (spanning pre-admission, acute hospitalization, and post-discharge) that might contribute to improving short and long-term health outcomes.
  
  
  METHODS
  The FRIENDS registry is designed to prospectively evaluate a range of patient and health system care delivery factors that might serve as future targets for efforts to improve limb and systemic outcomes for patients with ALI or CLI. This hypothesis-driven registry was designed to evaluate the contributions of: (i) pre-hospital limb ischemia symptom duration, (ii) use of leg revascularization strategies, and (iii) use of risk-reduction pharmacotherapies, as pre-specified factors that may affect amputation-free survival. Sequential patients would be included at an index "vascular specialist-defined" ALI or CLI episode, and patients excluded only for non-vascular etiologies of limb threat. Data including baseline demographics, functional status, co-morbidities, pre-hospital time segments, and use of medical therapies; hospital-based use of revascularization strategies, time segments, and pharmacotherapies; and rates of systemic ischemic events (e.g., myocardial infarction, stroke, hospitalization, and death) and limb ischemic events (e.g., hospitalization for revascularization or amputation) will be recorded during a minimum of one year follow-up.
  
  
  CONCLUSIONS
  The FRIENDS registry is designed to evaluate the potential impact of key factors that may contribute to adverse outcomes for patients with ALI or CLI. Definition of new "health system-based" therapeutic targets could then become the focus of future interventional clinical trials for individuals with advanced PAD.
authors.forename: Hong H
authors.initials: HH
authors.lastname: Keo
authors.forename: Sue
authors.initials: S
authors.lastname: Duval
authors.forename: Iris
authors.initials: I
authors.lastname: Baumgartner
authors.forename: Niki C
authors.initials: NC
authors.lastname: Oldenburg
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jaff
authors.forename: JoAnne
authors.initials: J
authors.lastname: Goldman
authors.forename: James M
authors.initials: JM
authors.lastname: Peacock
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Tretinyak
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Henry
authors.forename: Russell V
authors.initials: RV
authors.lastname: Luepker
authors.affiliation: Vascular Medicine Program, Lillehei Heart Institute and Cardiovascular Division, University of Minnesota Medical School, Minneapolis, MN, USA. hirsc005@umn.edu.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Hirsch
mesh_terms: D015331:Cohort Studies; D005500:Follow-Up Studies; D033062:Friends; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000401:mortality*; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000401:mortality*; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends