title: [The application of thrombin generation tests to warfarin anticoagulation monitoring].
abstract: OBJECTIVE
  To explore the thrombin generation capacity in patients on warfarin therapy with different prothrombin time international normalized ratio (PT-INR), the capacity in relation to bleeding, and the application of thrombin generation tests to warfarin therapy monitoring.
  
  
  METHODS
  Seventy eight blood samples were taken from patients on warfarin therapy for more than 3 months owing to valve replacement or atrial fibrillation. The patients' case history and PT-INR were collected and thrombin generation tests were performed in all samples.
  
  
  RESULTS
  Patients were ranked into three groups according to different PT-INR. There were 23 patients in group I with PT-INR from 1.51 to 2.00, 39 patients in group II with PT-INR from 2.01 to 3.00, and 16 patients in group III with PT-INR from 3.01 to 4.26. There were significant differences between each two of the three groups in lag time, peak, and ttpeak (time to peak) (P <0.01). There was a significant difference between group I and group II in endogenous thrombin potential (ETP) (P = 0.0001), but not between group II and group III (P= 0.06). Five patients developed bleeding and their ETP was less than 15% of normal control.
  
  
  CONCLUSIONS
  In patients on warfarin therapy, when the PT-INR was more than 3.0, increasing the dose of warfarin doesn' t decrease the thrombin generation, but increase bleeding risk. PT-INR combined with ETP may better reflect patient's coagulation status, therefore be of more significance in preventing bleeding.
authors.affiliation: Clinical Transfusion Department, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Hua-Yun
authors.initials: HY
authors.lastname: Chen
authors.forename: Qiu-Lan
authors.initials: QL
authors.lastname: Ding
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Zhang
authors.forename: Guan-Qun
authors.initials: GQ
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Dai
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Wang
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Xi
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000201:enzymology; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D011517:Prothrombin Time; D013917:Thrombin / Q000096:biosynthesis*; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D013917:Thrombin