title: Warfarin prevents venous obstruction after cardiac devices implantation in high-risk patients: partial analysis.
abstract: OBJECTIVE
  To evaluate the efficacy of prophylactic use of warfarin in patients with high risk of lead-associated thrombosis.
  
  
  METHODS
  Clinical, prospective, randomized and blinded study, in patients submitted to first transvenous leads implantation with LVEF <0.40 and/or previous ipsilateral temporary pacing. After device implantation, patients were randomly assigned to placebo or warfarin. Periodical clinical and laboratorial evaluations were performed to anticoagulant management. After a six-month period, every patient was submitted to a digital subtraction venography. From February 2004 to November 2006, 101 patients underwent randomization. Baseline characteristics were similar in both groups (P=NS).
  
  
  RESULTS
  Venographic analysis showed 31.4% of venous obstructions in patients assigned to warfarin as compared with 57.1% in patients assigned to placebo (RR= 0.57 [95% CI, 0.33 to 0.98]; P=0.015). In the warfarin group, 72% of the PT/INR tests were in therapeutic INR range. Only one patient required warfarin discontinuation and cross-over to placebo group due to gastrointestinal bleeding.
  
  
  CONCLUSIONS
  These preliminary results showed that the anticoagulation therapy has been safe and reduced the frequency of venous thrombosis after transvenous cardiac devices implantation in high risk patients.
authors.affiliation: Programa de Cirurgia Torácica e Cardiovascular, Heart Institute, Clinics Hospital, Faculty of Medicine-São Paulo, SP, Brazil. katia.regina@incor.usp.br
authors.forename: Kátia Regina da
authors.initials: KR
authors.lastname: Silva
authors.forename: Roberto
authors.initials: R
authors.lastname: Costa
authors.forename: Roberto
authors.initials: R
authors.lastname: Abi Rached
authors.forename: Martino
authors.initials: M
authors.lastname: Martinelli Filho
authors.forename: José Guilherme Mendes Pereira
authors.initials: JG
authors.lastname: Caldas
authors.forename: Francisco César
authors.initials: FC
authors.lastname: Carnevale
authors.forename: Luiz Felipe Pinho
authors.initials: LF
authors.lastname: Moreira
authors.forename: Noedir Antonio Groppo
authors.initials: NA
authors.lastname: Stolf
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000494:pharmacology*; D002304:Cardiac Pacing, Artificial; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control*; D018570:Risk Assessment; D020246:Venous Thrombosis / Q000097:blood / Q000517:prevention & control*; D014859:Warfarin / Q000494:pharmacology*
chemical_list: D000925:Anticoagulants; D014859:Warfarin