Risk Factors for Venous Thromboembolism in the Community

Cardiovascular Diseases Clinical Trial

Official title:

Subtherapeutic Heparin Anticoagulation as a Predictor of Recurrent Venous Thromboembolism: A Population-Based Cohort Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00011180
• Other study ID #: 864-98
• Secondary ID: R01HL066216
• Status: Completed
• Phase: N/A
• First received: February 13, 2001
• Last updated: December 5, 2012
• Start date: April 2001
• Est. completion date: May 2009

Study information

• Verified date: December 2012
• Source: Mayo Clinic
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Observational

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 385
• Est. completion date: May 2009
• Est. primary completion date: May 2009
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older
• Eligibility: No eligibility criteria

Study Design

Observational Model: Case Control, Time Perspective: Retrospective

Related Conditions & MeSH terms

• Cardiovascular Diseases
• Thromboembolism
• Venous Thromboembolism

Locations

Country	Name	City	State
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (2)

Lead Sponsor	Collaborator
Mayo Clinic	National Heart, Lung, and Blood Institute (NHLBI)

Country where clinical trial is conducted

United States, 

References & Publications (9)

Heit JA, Lahr BD, Petterson TM, Bailey KR, Ashrani AA, Melton LJ 3rd. Heparin and warfarin anticoagulation intensity as predictors of recurrence after deep vein thrombosis or pulmonary embolism: a population-based cohort study. Blood. 2011 Nov 3;118(18):4992-9. doi: 10.1182/blood-2011-05-357343. Epub 2011 Sep 2. — View Citation

Heit JA, O'Fallon WM, Petterson TM, Lohse CM, Silverstein MD, Mohr DN, Melton LJ 3rd. Relative impact of risk factors for deep vein thrombosis and pulmonary embolism: a population-based study. Arch Intern Med. 2002 Jun 10;162(11):1245-8. — View Citation

Heit JA, Petterson TM, Owen WG, Burke JP, DE Andrade M, Melton LJ 3rd. Thrombomodulin gene polymorphisms or haplotypes as potential risk factors for venous thromboembolism: a population-based case-control study. J Thromb Haemost. 2005 Apr;3(4):710-7. — View Citation

Heit JA, Phelps MA, Ward SA, Slusser JP, Petterson TM, De Andrade M. Familial segregation of venous thromboembolism. J Thromb Haemost. 2004 May;2(5):731-6. — View Citation

Heit JA. Mapping out the future in venous thromboembolism and acute coronary syndromes. Semin Thromb Hemost. 2002 Aug;28 Suppl 3:33-9. Review. — View Citation

Heit JA. Perioperative management of the chronically anticoagulated patient. J Thromb Thrombolysis. 2001 Sep;12(1):81-7. Review. — View Citation

Heit JA. Risk factors for venous thromboembolism. Clin Chest Med. 2003 Mar;24(1):1-12. Review. — View Citation

Heit JA. Venous thromboembolism epidemiology: implications for prevention and management. Semin Thromb Hemost. 2002 Jun;28 Suppl 2:3-13. — View Citation

Heit JA. Venous thromboembolism: disease burden, outcomes and risk factors. J Thromb Haemost. 2005 Aug;3(8):1611-7. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mean time interval between commencing unfractionated heparin therapy and achieving a therapeutic activated partial thromboplastin time (aPTT)	The time interval (minutes) was measured retrospectively, using the electronic medical record for each subject.	Day 1 in hospital	No