D-dimer Levels During and After Anticoagulation in Patients With a Previous Venous Thromboembolism: Effects on the Risk of Recurrence

This study has been completed.
Italian Federation of Anticoagulation Clinics (FCSA)
Information provided by (Responsible Party):
ClinicalTrials.gov Identifier:
First received: December 13, 2005
Last updated: August 31, 2012
Last verified: August 2012

The results of the Prolong study, currently submitted for publication, show that patients with a first unprovoked venous thromboembolic event who have altered D-dimer levels, measured one month after anticoagulation with vitamin K antagonists is stopped, have a high rate of recurrences (about 14%) and a prolongation of anticoagulation is effective in reducing significantly this rate. Those patients with normal D-dimer (about 60% of all patients examined) have a low rate of recurrences (about 5%) and likely a prolongation of anticoagulation in all these patients cannot be recommended.

In line with these results, the Prolong-Two study aims at assessing the predictive role for recurrence of D-dimer levels measured: a) during anticoagulation, b) one month after its withdrawal and c) periodically during follow up.

Patients with a first unprovoked venous thromboembolism (including proximal deep vein thrombosis of a leg and/or pulmonary embolism) which are treated with vitamin K antagonists for not less than 6 months are considered for the study. D-dimer assay is performed during anticoagulation and patients with altered results continue the anticoagulation for 6 more months. Those with normal D-dimer stop the anticoagulant treatment and are again examined one month later. Anticoagulation is resumed for 6 more months in those patients with abnormal D-dimer results but is permanently stopped in those with a normal assay. The latter patients are examined and D-dimer assay performed again every two months to evaluate the natural history of the assay after anticoagulation is stopped and the possible predictive value for recurrence of a change of the assay during follow-up from normal to abnormal results.

Condition Phase
Deep Vein Thrombosis
Pulmonary Embolism
Phase 4

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: A Multicentre, Prospective, Observational Study on the Predictive Role for Recurrence of D-dimer Levels Measured During and After Anticoagulation in Patients With a First Venous Thromboembolism Episode (the PROLONG-II Study)

Resource links provided by NLM:

Further study details as provided by St. Orsola Hospital:

Biospecimen Retention:   Samples Without DNA

Plasma samples for D-dimer assays or other coagulation tests

Enrollment: 355
Study Start Date: August 2005
Study Completion Date: December 2008
Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)

Ages Eligible for Study:   18 Years to 82 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Subjects with a single previous idiopathic venous thromboembolic event who stop anticoagulation


Inclusion Criteria

  • Age > 18 years
  • After a first documented idiopathic proximal deep vein thrombosis and/or pulmonary embolism
  • After at least 6 months of oral anticoagulation
  • After written informed consent

Exclusion Criteria:

  • Age > 82 y
  • Recurrent venous thromboembolism
  • If the Venous thromboembolism occurred:
  • during pregnancy or puerperium
  • after recent (i.e. within three months) fracture or plaster casting of a leg,
  • after immobilization with confinement to bed for three consecutive days after surgery with general anesthesia lasting longer than 30 minutes
  • Patients with:
  • active cancer
  • antiphospholipid antibody syndrome
  • antithrombin deficiency
  • serious liver disease or renal insufficiency (creatininemia > 2 mg/dL),
  • other indications for anticoagulation or contraindications for this treatment
  • limited life expectation
  • Patients who live too far from the clinical center
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00266045

Dept. Angiology & Blood Coagulation; Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi
Bologna, BO, Italy, 40138
Sponsors and Collaborators
St. Orsola Hospital
Italian Federation of Anticoagulation Clinics (FCSA)
Study Chair: Gualtiero Palareti, MD Dept. Angiology & Blood Coagulation, University Hospital S. Orsola-Malpighi, Bologna
  More Information

No publications provided by St. Orsola Hospital

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: GUALTIERO PALARETI, Prof. Gualtiero Palareti, St. Orsola Hospital
ClinicalTrials.gov Identifier: NCT00266045     History of Changes
Other Study ID Numbers: PROLONG-TWO STUDY
Study First Received: December 13, 2005
Last Updated: August 31, 2012
Health Authority: Italy: National Monitoring Centre for Clinical Trials - Ministry of Health

Keywords provided by St. Orsola Hospital:
Deep Vein Thrombosis
Pulmonary Embolism
Duration of Anticoagulation
Vitamin K Antagonists

Additional relevant MeSH terms:
Pulmonary Embolism
Venous Thrombosis
Venous Thromboembolism
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Lung Diseases
Respiratory Tract Diseases
Disease Attributes
Pathologic Processes

ClinicalTrials.gov processed this record on April 17, 2014