title: Safety and efficacy of switching from either unfractionated heparin or enoxaparin to bivalirudin in patients with non-ST-segment elevation acute coronary syndromes managed with an invasive strategy: results from the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial.
abstract: OBJECTIVE
  The aim of this study was to compare outcomes in patients receiving consistent unfractionated heparin (UFH)/enoxaparin (ENOX) therapy and in those switched at randomization to bivalirudin monotherapy.
  
  
  BACKGROUND
  Crossover between UFH and ENOX has been associated with increased adverse outcomes in patients with acute coronary syndromes. The ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial demonstrated superior net clinical outcomes with similar rates of ischemia and significantly less major bleeding with bivalirudin monotherapy compared with UFH/ENOX plus a glycoprotein (GP) IIb/IIIa inhibitor. It is unknown if these results would be preserved in patients switched from UFH/ENOX to bivalirudin monotherapy.
  
  
  METHODS
  We compared composite ischemia, major bleeding, and net clinical outcomes at 30 days in patients receiving consistent UFH/ENOX therapy and in those switched at randomization from pre-treatment with UFH/ENOX to bivalirudin monotherapy. We also compared outcomes in patients naive to antithrombin therapy who were randomized to UFH/ENOX or bivalirudin monotherapy.
  
  
  RESULTS
  Two thousand one hundred thirty-seven patients received consistent UFH/ENOX (UFH n = 1,294, ENOX n = 843), and 2,078 patients pre-treated with UFH/ENOX were switched to bivalirudin. Patients switching to bivalirudin had similar rates of ischemia (6.9% vs. 7.4%, p = 0.52), less major bleeding (2.8% vs. 5.8%, p < 0.01), and improved net clinical outcomes (9.2% vs. 11.9%, p < 0.01) than those on consistent UFH/ENOX plus a GP IIb/IIIa inhibitor. Patients naive to antithrombin therapy who were administered bivalirudin (n = 1,427) had similar rates of ischemia (6.2% vs. 5.5%, p = 0.47), less major bleeding (2.5% vs. 4.9%, p < 0.001), and similar net clinical outcomes (8.0% vs. 9.4%, p = 0.17) compared with naive patients administered UFH/ENOX plus a GP IIb/IIIa inhibitor (n = 1,462).
  
  
  CONCLUSIONS
  Switching from UFH/ENOX to bivalirudin monotherapy results in comparable ischemic outcomes and an approximately 50% reduction in major bleeding compared with consistent UFH/ENOX plus a GP IIb/IIIa inhibitor. Patients naive to antithrombin therapy administered bivalirudin monotherapy had a significant reduction in bleeding and similar rates of ischemia compared with naive patients initiated with UFH or ENOX plus a GP IIb/IIIa inhibitor.
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand. HarveyW@adhb.govt.nz
authors.forename: Harvey D
authors.initials: HD
authors.lastname: White
authors.forename: Derek P
authors.initials: DP
authors.lastname: Chew
authors.forename: James W
authors.initials: JW
authors.lastname: Hoekstra
authors.forename: Chadwick D
authors.initials: CD
authors.lastname: Miller
authors.forename: Charles V
authors.initials: CV
authors.lastname: Pollack
authors.forename: Frederick
authors.initials: F
authors.lastname: Feit
authors.forename: A Michael
authors.initials: AM
authors.lastname: Lincoff
authors.forename: Michel
authors.initials: M
authors.lastname: Bertrand
authors.forename: Stuart
authors.initials: S
authors.lastname: Pocock
authors.forename: James
authors.initials: J
authors.lastname: Ware
authors.forename: E Magnus
authors.initials: EM
authors.lastname: Ohman
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy* / Q000503:physiopathology / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D017984:Enoxaparin / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use*; D006629:Hirudins / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia; D010446:Peptide Fragments / Q000009:adverse effects / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000187:drug effects; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D006629:Hirudins; D010446:Peptide Fragments; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011994:Recombinant Proteins; D006493:Heparin; C074619:bivalirudin