title: Is early anticoagulation with warfarin necessary after bioprosthetic aortic valve replacement?
abstract: OBJECTIVE
  Freedom from anticoagulation is the principal advantage of bioprosthesis; however, the American Heart Association/American College of Cardiology and the American College of Chest Physicians guidelines recommend early anticoagulation with heparin, followed by warfarin for 3 months after bioprosthetic aortic valve replacement. We examined neurologic events within 90 days of bioprosthetic aortic valve replacement at our institution.
  
  
  METHODS
  Between 1993 and 2000, 1151 patients underwent bioprosthetic aortic valve replacement with (641) or without (510) associated coronary artery bypass. By surgeon preference, 624 had early postoperative anticoagulation (AC+) and 527 did not (AC-). In the AC- group, 410 patients (78%) received antiplatelet therapy. Groups were similar with respect to gender (female, 36% AC+ vs 40% AC-, P = .21), hypertension (64% AC+ vs 61%, P = .27), and prior stroke (7.6% AC+ vs 8.5% AC-, P = .54). The AC+ group was slightly younger than the AC- group (median, 76 years vs 78 years, P = .006).
  
  
  RESULTS
  Operative mortality was 4.1% with 43 (3.7%) cerebrovascular events within 90 days. Excluding 18 deficits apparent upon emergence from anesthesia, we found that postoperative cerebrovascular accident occurred in 2.4% of AC+ and 1.9% AC- patients. By multivariable analysis, the only predictor of operative mortality was hypertension ( P < .0001). Postoperative cerebrovascular accident was unrelated to warfarin use ( P = .32). The incidence of mediastinal bleeding requiring reexploration was similar (5.0% vs 7.4%), as were other bleeding complications in the first 90 days (1.1% vs 0.8%). No variables were predictive of bleeding by multivariate analysis.
  
  
  CONCLUSIONS
  Although these data do not address the role of antiplatelet agents, early anticoagulation with warfarin after bioprosthetic aortic valve replacement did not appear to protect against neurologic events.
authors.affiliation: Division of Cardiovascular Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. sundt.thoralf@mayo.edu
authors.forename: T M
authors.initials: TM
authors.lastname: Sundt
authors.forename: K J
authors.initials: KJ
authors.lastname: Zehr
authors.forename: J A
authors.initials: JA
authors.lastname: Dearani
authors.forename: R C
authors.initials: RC
authors.lastname: Daly
authors.forename: C J
authors.initials: CJ
authors.lastname: Mullany
authors.forename: C G A
authors.initials: CG
authors.lastname: McGregor
authors.forename: F J
authors.initials: FJ
authors.lastname: Puga
authors.forename: T A
authors.initials: TA
authors.lastname: Orszulak
authors.forename: H V
authors.initials: HV
authors.lastname: Schaff
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000401:mortality; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology / Q000601:surgery; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D018579:Patient Selection; D011182:Postoperative Care / Q000379:methods*; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin