title: Bleeding risk comparing targeted low-dose heparin with bivalirudin in patients undergoing percutaneous coronary intervention: results from a propensity score-matched analysis of the Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) registry.
abstract: BACKGROUND
  Prior randomized trials have shown reduced bleeding with bivalirudin compared with unfractionated heparin (UFH) in patients undergoing percutaneous coronary intervention (PCI). However, it is not known if this benefit is also present when UFH doses are more tightly controlled (as measured by activated clotting time, ACT).
  
  
  RESULTS
  Patients enrolled in the EVENT (Evaluation of Drug-Eluting Stents and Ischemic Events) registry, were divided into 3 groups, based on the antithrombotic drug used during PCI (UFH monotherapy, UFH+glycoprotein IIb-IIIa receptor inhibitor [GPI], or bivalirudin alone). Propensity score matching was used to adjust for measured covariates (89 variables) and to compare bivalirudin versus UFH monotherapy and bivalirudin versus UFH+GPI groups. The UFH groups were stratified based on ACT achieved (optimal ACT defined as 250-300 for UFH monotherapy and 200-250 when GPI was also used). The primary bleeding outcome was in-hospital composite bleeding, defined as events of access site bleeding, Thrombolysis In Myocardial Infarction major/minor bleeding, or transfusion. Primary (in-hospital death/myocardial infarction) and secondary ischemic outcomes (death/MI/unplanned repeat revascularization at 12 months) were also evaluated. Propensity score matching yielded 3022 patients for the UFH monotherapy versus bivalirudin comparison and 3520 patients for the UFH+GPI versus bivalirudin comparison. Bivalirudin use was associated with numerically lower bleeding rates at all categories of achieved ACT when compared with UFH (low, optimal, high ACT: 2.5% versus 4.7%, 1.9% versus 6.0%, 3.1% versus 4.8%, respectively) or heparin+GPI groups (low, optimal, high ACT: 0.0% versus 2.7%, 2.7% versus 5.2%, 2.4% versus 6.1%, respectively) and was not associated with any statistically significant increase in either primary or secondary ischemic outcomes.
  
  
  CONCLUSIONS
  Among unselected patients undergoing PCI, bivalirudin use during PCI was associated with a lower risk of bleeding at all comparator ACT levels without an increase in ischemic outcomes.
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, New York University School of Medicine, 530 First Avenue, New York, NY 10016, USA. sripalbangalore@gmail.com
authors.forename: Sripal
authors.initials: S
authors.lastname: Bangalore
authors.forename: David J
authors.initials: DJ
authors.lastname: Cohen
authors.forename: Neal S
authors.initials: NS
authors.lastname: Kleiman
authors.forename: Tal
authors.initials: T
authors.lastname: Regev-Beinart
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Rao
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pencina
authors.forename: Laura
authors.initials: L
authors.lastname: Mauri
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D054796:Drug Dosage Calculations; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D006470:Hemorrhage; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects; D006629:Hirudins / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000008:administration & dosage / Q000009:adverse effects; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors; D057216:Propensity Score; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000009:adverse effects; D012306:Risk; D016019:Survival Analysis; D016896:Treatment Outcome; D014914:Whole Blood Coagulation Time
chemical_list: D005343:Fibrinolytic Agents; D006629:Hirudins; D010446:Peptide Fragments; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011994:Recombinant Proteins; D006493:Heparin; C074619:bivalirudin