Prevalence of Post-Thrombotic Syndrome in Deep-Vein Thrombosis (DVT) Patients Treated With Dabigatran

Study Overview
=================
Brief Summary
-----------------
The primary objective in this cross-sectional study is to assess the prevalence of post-thrombotic syndrome (PTS) in the two treatment arms of the RE-COVER studies (warfarin versus dabigatran). PTS will be assessed by the recently developed Patient Reported Villalta (PRV) Score. Secondary objectives: to assess in both treatment arms the Prevalence of recurrent venous thromboembolism (VTE) after the discontinuation of study treatment. Prevalence of PTS determined by the standard Villalta score. Health related Quality of Life (HRQoL).

Detailed Description
-----------------
In the RE-COVER- and RE-COVER II studies, 5109 patients with deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) were randomized to receive 6 months of treatment with either dabigatran (150 mg twice daily) or warfarin (once daily to maintain international normalized ratio (INR) 2.0-3.0). All patients received an initial 5-7 day phase of parenteral anticoagulant treatment. The studies were designed as double blind, double dummy trials. RE-COVER was conducted between April 2006 to November 2008 and RE-COVER II between June 2008 and October 2010; they were completed in 2009 and 2011, respectively. A substantial number of patients are expected to have developed post-thrombotic syndrome (PTS). However, since dabigatran provides a stable level of anticoagulation throughout the treatment period and knowing that the quality of anticoagulation is an important factor in the development of PTS, we anticipate that a lower rate of PTS will be seen in the dabigatran treated patients compared to warfarin. Patients will be interviewed and examined by the investigator if they accept to attend a clinic visit. Otherwise, a telephone interview will be performed if the patient refuses to meet up. PTS will be determined using Patient Reported Villalta (PRV) Score form. However, those who will meet for consultation will in addition be assessed for PTS by the standard Villalta score. The primary endpoint will be the prevalence of PTS determined by Patient Reported Villalta (PRV) score. The secondary endpoints are 1- objectively verified DVT or PE after the discontinuation of treatment, 2- prevalence of PTS determined by the standard Villalta score, 3- health related quality of life (HRQOL) determined by EQ-5D (www.euroqol.org) and Venous Insufficiency Epidemiological and Economic Study quality of life and symptom (VEINES-QOL/Sym) questionnaires. The investigators will recruit the subpopulation of patients who were included into the RE-COVER studies in the Norway, Sweden and Canada.

Official Title
-----------------
The Prevalence of Post-Thrombotic Syndrome in Deep-Vein Thrombosis (DVT) Patients Treated With Dabigatran- a Cross-Sectional Assessment of RE-COVER Study Patients

Conditions
-----------------
Postthrombotic Syndrome

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with DVT (±PE) treated in the RE-COVER studies. Signed written informed consent. Exclusion Criteria: Patients who refuse to participate Deceased patients
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Dabigatran<br>In the RE-COVER- and RE-COVER II studies, one group of DVT and/or PE patients were randomized to receive 6 months of treatment with dabigatran (150 mg twice daily). All patients received an initial 5-7 day phase of parenteral anticoagulant treatment. | |
| Warfarin<br>In the RE-COVER- and RE-COVER II studies, the other group of DVT and/or PE patients were randomized to receive 6 months of treatment with warfarin (once daily to maintain international normalized ratio (INR) 2.0-3.0). All patients received an initial 5-7 day phase of parenteral anticoagulant treatment. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-thrombotic syndrome (PTS) | The primary objective is to assess the prevalence of PTS in a subgroup of patients in the two treatment arms of the RE-COVER studies assessed by Patient Reported Villalta (PRV) Score. | April 2016 - December 2017 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recurrent venous thromboembolism | Prevalence of recurrent VTE after the discontinuation of study treatment in a subgroup of patients in the two treatment arms of the RE-COVER studies. | April 2016 - December 2017 | 
| Post-thrombotic syndrome (PTS) determined by the standard Villalta score | Prevalence of PTS determined by the standard Villalta score in a subgroup of patients in the two treatment arms of the RE-COVER studies. | April 2016 - December 2017 | 
| Generic health related Quality of Life (HRQoL) | Generic health related Quality of Life (HRQoL) assessed by the EQ-5D in a subgroup of patients in the two treatment arms of the RE-COVER studies. | April 2016 - December 2017 | 
| Disease specific health related Quality of Life (HRQoL) | Disease specific health related Quality of Life (HRQoL) assessed by the VEINES-QOL/Sym score in a subgroup of patients in the two treatment arms of the RE-COVER studies. | April 2016 - December 2017 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Postthrombotic Syndrome, Venous Thrombosis, Quality of Life, Hemorrhage, Recurrence