Risk Factors for Venous Thromboembolism in the Community
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.
|Study Design:||Observational Model: Case Control
Time Perspective: Retrospective
|Official Title:||Subtherapeutic Heparin Anticoagulation as a Predictor of Recurrent Venous Thromboembolism: A Population-Based Cohort Study|
- Mean time interval between commencing unfractionated heparin therapy and achieving a therapeutic activated partial thromboplastin time (aPTT) [ Time Frame: Day 1 in hospital ] [ Designated as safety issue: No ]The time interval (minutes) was measured retrospectively, using the electronic medical record for each subject.
Biospecimen Retention: Samples With DNA
Plasma and genomic DNA
|Study Start Date:||April 2001|
|Study Completion Date:||May 2009|
|Primary Completion Date:||May 2009 (Final data collection date for primary outcome measure)|
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.
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.
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.
|United States, Minnesota|
|Rochester, Minnesota, United States, 55905|
|Principal Investigator:||John Heit, MD||Mayo Clinic|