title: Is early antithrombotic therapy necessary after tissue mitral valve replacement?
abstract: OBJECTIVE
  Patients with prosthetic heart valves have a higher risk of developing valve thrombosis and arterial thromboembolism. Antithrombotic therapy during the early postoperative period after biologic mitral valve replacement (MVR) is controversial. Hence, a retrospective study was conducted to investigate the efficacy of different antithrombotic therapies in patients after MVR with bioprostheses.
  
  
  METHODS
  Between January 2000 and January 2006, a total of 99 patients presenting with preoperative sinus rhythm underwent isolated bioprosthetic MVR. Of these patients, 59 (58%) received a bovine pericardial xenograft, and 40 (42%) a porcine bioprosthesis. The postoperative antithrombotic therapy was prescribed according to the surgeon's preference.
  
  
  RESULTS
  Fifty-one (51%) patients received acetylsalicylic acid (ASA group, 100 mg/day), 12 (13%) did not receive any specific antithrombotic therapy (NT group), and 36 (36%) received a vitamin K antagonist (VKA group, INR 2-3). The primary endpoints were the rate of cerebral ischemic events, bleeding events, and survival. The mean follow up was 23 months (range: 3-68 months). There were five early deaths (5%), and eight late deaths (8%). There were five episodes of cerebral ischemic events; these included three patients (8.3%) in the VKA group, one patient (2.0%) in ASA group, and one patient (8.3%) in the NT group (p = 0.351). Of these episodes, two occurred between 24 h and three months after surgery. Only one (2.8%) episode of major bleeding occurred (in the VKA group), due to poor anticoagulation management.
  
  
  CONCLUSIONS
  Each of the antithrombotic therapies evaluated appeared to be safe. There was no evidence to suggest that any specific antithrombotic therapy would be superior in preventing valve thrombosis in patients undergoing bioprosthetic MVR.
authors.affiliation: Department of Cardiac Surgery, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain. colli.andrea.bcn@gmail.com
authors.forename: Andrea
authors.initials: A
authors.lastname: Colli
authors.forename: Roberto
authors.initials: R
authors.lastname: D'Amico
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Mestres
authors.forename: Jose L
authors.initials: JL
authors.lastname: Pomar
authors.forename: Maria-Luisa
authors.initials: ML
authors.lastname: Cámara
authors.forename: Xavier
authors.initials: X
authors.lastname: Ruyra
authors.forename: Jaume
authors.initials: J
authors.lastname: Mulet
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001241:Aspirin / Q000008:administration & dosage; D001705:Bioprosthesis; D002545:Brain Ischemia / Q000209:etiology / Q000517:prevention & control; D002417:Cattle; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation / Q000401:mortality; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D017410:Practice Guidelines as Topic; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013552:Swine; D013927:Thrombosis / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D014812:Vitamin K; D001241:Aspirin