Risk Factors for Venous Thromboembolism in the Community

Sponsor
Mayo Clinic (Other)
Overall Status
Completed
CT.gov ID
NCT00011180
Collaborator
National Heart, Lung, and Blood Institute (NHLBI) (NIH)
385
1
97
4

Study Details

Study Description

Brief Summary

To evaluate the trends in the incidence of venous thromboembolism, to determine the risk factors for venous thromboembolism in patients with medical and surgical illness, and to evaluate the efficacy of the anticoagulant therapy in reducing venous thromboembolism.

Condition or Disease Intervention/Treatment Phase

    Detailed Description

    BACKGROUND:

    Venous thromboembolism (VTE) occurs frequently among patients hospitalized for major surgery or hospitalized for a medical illness primarily due to prolonged duration of immobilization. However, many patients undergo major surgery without any occurrence of VTE. Standard prophylactic therapy after surgery is heparin, which reduces the risk of VTE. However, heparin is associated with bleeding complications. Thus, it would be desirable to identify patients at high risk for VTE who might benefit the most from heparin therapy. An important focus of the study is to look at genetic factors which might play an important role in VTE incidence.

    DESIGN NARRATIVE:

    The study is a population based, retrospective case and case-control investigation of the genetic and environmental determinants of venous thromboembolism in the Rochester Minnesota Olmsted County population. The first five years of the study had three specific aims. The first specific aim was to update the 1966-1995 inception cohort to include Olmsted County residents with VTE during the five year period, 1996-2000. The second aim was to extend the analysis of risk factors for VTE by identifying two Olmsted County residents (controls) without VTE matched by age and gender to each definite or probable case within the 1996-2000 cohort, and to obtain plasma and genomic DNA from all cases and controls and perform a case-control study. The third specific aim was to evaluate the efficacy of anticoagulant therapy to prevent VTE recurrence.

    The study was extended through March, 2009 to investigate trends in the incidence of venous thromboembolism, new risk factors including lipid-lowering, beta-blocker, and ACE-inhibitor therapies, and introduction of low molecular weight heparin (LMWH) therapy.

    Study Design

    Study Type:
    Observational
    Actual Enrollment :
    385 participants
    Observational Model:
    Case-Control
    Time Perspective:
    Retrospective
    Official Title:
    Subtherapeutic Heparin Anticoagulation as a Predictor of Recurrent Venous Thromboembolism: A Population-Based Cohort Study
    Study Start Date :
    Apr 1, 2001
    Actual Primary Completion Date :
    May 1, 2009
    Actual Study Completion Date :
    May 1, 2009

    Arms and Interventions

    Arm Intervention/Treatment
    Incident Cohort with VTE

    Olmsted County, Minnesota residents with with a first-lifetime deep vein thrombosis (DVT) or pulmonary embolism (PE) during the five year period, 1996-2000.

    Controls without VTE

    Two Olmsted County, Minnesota residents without venous thromboembolism (VTE) were matched by age and gender to each definite or probable case of VTE within the 1996-2000 cohort.

    Outcome Measures

    Primary Outcome Measures

    1. Mean time interval between commencing unfractionated heparin therapy and achieving a therapeutic activated partial thromboplastin time (aPTT) [Day 1 in hospital]

      The time interval (minutes) was measured retrospectively, using the electronic medical record for each subject.

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    N/A and Older
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    No

    No eligibility criteria

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Mayo Clinic Rochester Minnesota United States 55905

    Sponsors and Collaborators

    • Mayo Clinic
    • National Heart, Lung, and Blood Institute (NHLBI)

    Investigators

    • Principal Investigator: John Heit, MD, Mayo Clinic

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    Responsible Party:
    , ,
    ClinicalTrials.gov Identifier:
    NCT00011180
    Other Study ID Numbers:
    • 864-98
    • R01HL066216
    First Posted:
    Feb 13, 2001
    Last Update Posted:
    Dec 6, 2012
    Last Verified:
    Dec 1, 2012

    Study Results

    No Results Posted as of Dec 6, 2012