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Prospective Genotyping For Total Hip or Knee Replacement Patients Receiving Warfarin (Coumadin)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Gwen McMillin, University of Utah
ClinicalTrials.gov Identifier:
NCT00634907
First received: February 6, 2008
Last updated: April 25, 2017
Last verified: April 2017
February 6, 2008
April 25, 2017
September 2006
October 2008   (Final data collection date for primary outcome measure)
The Number of Participants With Adverse Events Associated With Warfarin Anticoagulation Following Total Hip and Total Knee Replacement [ Time Frame: 90 days post surgery ]

Adverse events were defined as

  1. Major bleeding: fatal bleeding, bleeding into a critical organ, bleeding that requires hospital admission
  2. Minor bleeding: clinically overt bleeding not meeting criteria for major bleeding
  3. Symptomatic deep vein thrombosis (DVT)
  4. Pulmonary embolism (PE)
Reduction in the number of adverse events associated with warfarin anticoagulation following total hip and total knee replacement [ Time Frame: Time of warfarin initiation to 3 months after completion of warfarin therapy ]
Complete list of historical versions of study NCT00634907 on ClinicalTrials.gov Archive Site
  • Percentage of Determinations in Therapuetic Range (INR 1.8-2.9) [ Time Frame: 2 weeks (knee arthroplasty) or 4 weeks (hip arthroplasty) ]
    Patient response to warfarin was evaluated based on the international normalized ratio (INR), calculated from a prothrombin time blood test. When the INR value was between 1.8 and 2.9, the patient was considered to be "therapeutic." The proportion of INR determinations that fell within the therapeutic range (INR between 1.8-2.9) was calculated, per arm, based on total number of INR determinations that were made during treatment with warfarin.
  • Percentage of Determinations Subtherapeutic (INR<1.8) [ Time Frame: 2 weeks (knee arthroplasty) or 4 weeks (hop arthroplasty) ]
    Patient response to warfarin was evaluated based on the international normalized ratio (INR), calculated from a prothrombin time blood test. When the INR value was less than 1.8, the patient was considered to be "subtherapeutic." The proportion of INR determination that were subtherapeutic was caluculated, per arm, based on the total number of INR determinations that were made during treatment with warfarin.
  • Percentage of Determinations Supratherapeutic (INR>2.9) [ Time Frame: 2 weeks (knee arthroplasty) or 4 weeks (hip arthroplasty) ]
    Patient response to warfarin was evaluated based on the international normalized ratio (INR), calculated from a prothrombin time blood test. When the INR value was greater than 2.9, the patient was considered to be "supratherapeutic." The proportion of INR determinations that were supratherapeutic was calculated, per arm, based on total number of INR determinations that were made during treatment with warfarin.
Improved anticoagulation management in patients on warfarin following total hip and total knee replacement. [ Time Frame: Initiation of warfarin therapy to completion of warfarin therapy ]
Not Provided
Not Provided
 
Prospective Genotyping For Total Hip or Knee Replacement Patients Receiving Warfarin (Coumadin)
Prospective CYP2C9 And VKORC1 Genotyping For Total Hip or Knee Replacement Patients Receiving Warfarin (Coumadin)For Anticoagulation
Several human genes affect how medications are metabolized by the body. It is believed that knowledge of variations of these genes can help health care providers better manage an anticoagulation medicine called warfarin (Coumadin®)and as a result decrease patient problems with bleeding or the development of blood clots. This study was designed to evaluate if genetic testing can improve warfarin initiation better than usual care.
This study was completed in 2008 and was published. Consult the citation link for more details.
Interventional
Not Provided
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: No masking
Primary Purpose: Treatment
  • Venous Thromboembolism
  • Bleeding
  • Genetic: Pharmacogenetic-based warfarin dosing

    Prior to elective joint replacement surgery a blood sample is collected for genetic information(genotyping)which was used for calculating warfarin doses for patients randomized to the cytochrome arm. Outcomes in terms of efficacy, safety, and management of warfarin were compared between this group and the group in which warfarin doses are determined per usual care.

    NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

  • Other: Usual care warfarin dosing

    For patients in arm 2, the control group, warfarin dosing is per usual care. Outcomes in terms of safety, efficacy, and warfarin management was compared to that of patients in the other arm, who receive warfarin dosing based on genotyping.

    NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm as noted above.

  • Experimental: Pharmacogenetic-based warfarin dosing

    Pharmacogenetic-based warfarin dosing: Warfarin dosing based on formula that incorporates genetic testing results.

    NOTE: Standard of care for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm, as noted above.

    Intervention: Genetic: Pharmacogenetic-based warfarin dosing
  • Active Comparator: Standard of care (control)

    Control or "usual care" warfarin dosing

    NOTE: Standard of care ("usual care") for elective knee and hip replacement at our institution is to receive post-operative warfarin thromboprophylaxis. Administration of warfarin was not specific to this study, nor was the duration of prophylaxis, however, warfarin dosing was influenced by the study arm, as noted above.

    Intervention: Other: Usual care warfarin dosing
McMillin GA, Melis R, Wilson A, Strong MB, Wanner NA, Vinik RG, Peters CL, Pendleton RC. Gene-based warfarin dosing compared with standard of care practices in an orthopedic surgery population: a prospective, parallel cohort study. Ther Drug Monit. 2010 Jun;32(3):338-45. doi: 10.1097/FTD.0b013e3181d925bb.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
263
October 2008
October 2008   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Participants were otherwise healthy adults (≥ 18 years of age) who were planning total hip or knee replacement or revision surgery at the University of Utah Hospital, and scheduled a pre-operative office visit at the University of Utah Orthopaedic Center.

Exclusion Criteria:

  • Blood transfusion in previous two weeks
  • Participant is already taking warfarin
  • Pre-operative INR > 4.0
  • Pre-operative bilirubin > 2.4 mg/dL
  • Current active cancer diagnosis with ongoing treatment
  • Concomitant medications known to exert a major interaction with warfarin such as septra, metronidazole, tramadol, amiodarone, ciprofloxacin, or cimetidine.
Sexes Eligible for Study: All
18 Years and older   (Adult, Senior)
No
Contact information is only displayed when the study is recruiting subjects
United States
 
 
NCT00634907
00019469
Yes
Not Provided
No
Not Provided
Gwen McMillin, University of Utah
Gwen McMillin
Not Provided
Principal Investigator: Gwen McMillin, PhD ARUP Laboratories
University of Utah
April 2017

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP