title: Efficacy and safety of enoxaparin compared with unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention in the Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial.
abstract: BACKGROUND
  Enoxaparin reduces ischemic events more effectively than unfractionated heparin (UFH) in patients treated conservatively for non-ST-segment elevation acute coronary syndrome. The SYNERGY trial compared these agents in high-risk patients undergoing early invasive treatment. Enoxaparin was noninferior to UFH for the 30-day primary end point of death/myocardial infarction (MI), but modestly increased bleeding.
  
  
  RESULTS
  This article compares the outcomes of the 4687 SYNERGY patients (47%) undergoing percutaneous coronary intervention, who were randomized to receive enoxaparin or UFH. Antithrombotic therapy was administered prerandomization in 78%. Crossover (usually in the catheterization laboratory) to the alternative antithrombotic occurred in 14.6% of enoxaparin patients and 2.9% of UFH-treated patients (P < .0001). Stenting was performed in 86.3%. Abrupt vessel closure occurred in 1.3% of enoxaparin patients and 1.7% of UFH-treated patients (P = .318). The rates of death/MI were similar at 30 days (13.1% with enoxaparin vs 14.2% with UFH, P = .289). GUSTO severe bleeding occurred with similar frequency in both groups (1.5% vs 1.6%, P = .688). TIMI major bleeding was more common with enoxaparin (3.7% vs 2.5% with UFH, P = .028). Transfusions were more frequent with enoxaparin than with UFH (6.8% vs 5.4%, P = .047). TIMI major bleeding increased with crossover from enoxaparin to UFH (from 3.7% to 7.8%) and from UFH to enoxaparin (from 2.5% to 8.6%). Statistical adjustment to model reasons for crossover did not affect the overall safety and efficacy outcomes.
  
  
  CONCLUSIONS
  In high-risk patients undergoing early percutaneous coronary intervention for acute coronary syndrome, enoxaparin avoids the need for monitoring and achieves similar effectiveness to UFH but is associated with more bleeding.
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: Neal S
authors.initials: NS
authors.lastname: Kleiman
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Lokhnygina
authors.forename: Karen S
authors.initials: KS
authors.lastname: Pieper
authors.forename: Karen
authors.initials: K
authors.lastname: Chiswell
authors.forename: Marc
authors.initials: M
authors.lastname: Cohen
authors.forename: Robert A
authors.initials: RA
authors.lastname: Harrington
authors.forename: Derek P
authors.initials: DP
authors.lastname: Chew
authors.forename: John L
authors.initials: JL
authors.lastname: Petersen
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Berdan
authors.forename: Philip E G
authors.initials: PE
authors.lastname: Aylward
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Nessel
authors.forename: James J
authors.initials: JJ
authors.lastname: Ferguson
authors.forename: Robert M
authors.initials: RM
authors.lastname: Califf
mesh_terms: D000208:Acute Disease; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001803:Blood Transfusion; D003327:Coronary Disease / Q000628:therapy*; D018592:Cross-Over Studies; D017984:Enoxaparin / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000628:therapy; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D012307:Risk Factors; D013577:Syndrome; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D006493:Heparin