Long-Term Post Thrombotic Syndrome Assessment (CELEST Long Term).

Determine the Proportion of Patients With Disabling Post Thrombotic Syndrome (Moderate or Severe) in the Long Term Within the Cohort of Patients Who Participated in the Trial CELEST Therapy.

The CELEST Long term is a prospective study, assessing the very long term risk of post thrombotic syndrome (PTS) in patients enrolled in the CELEST double-blind RCT. All patients enrolled in CELEST RCT will benefit from a 7-year follow-up visit conducted over the phone. The primary objective is to assess the proportion of patients with moderate-severe PTS assessed with the patient reported Villalta score and the 2 main secondary objectives are to assess predictors of moderate to severe PTS and the impact of initial compression stockings strength (25mmHg vs. 35mmHg) on the development of moderate-severe PTS. Up to 288 patients may participate.

The investigators believe that this study has the potential to significantly improve the knowledge on the epidemiology of burdensome PTS and on the impact of different initial compression stockings strengths on the risk of PTS.

The CELEST double blind RCT demonstrated that 25mmHg elastic compression stockings (ECS) were non inferior to 35mmHg ECS to prevent post thrombotic syndrome (PTS) 2 years after a first proximal deep vein thrombosis (DVT). Likely because of lack of statistical power the investigators were not able to demonstrate that 25mmHg ECS were superior in the overall RCT population and that 35mmHg ECS were superior in patients optimally adherent to ECS. Furthermore, few data are available on the very long term (>5 years).

The CELEST Long term is a prospective study, assessing the very long term risk of PTS in patients enrolled in the CELEST RCT. All patients enrolled in CELEST RCT and willing to participate are eligible and will benefit from a 7-year follow-up visit conducted over the phone.

Primary objective is to assess the proportion of patients with moderate-severe PTS defined as a patient reported Villalta score (PRVS) ≥10 or a venous leg ulcer ipsilateral to index DVT. Secondary objectives include predictors of moderate to severe PTS, impact of initial ECS strength on the development of moderate-severe PTS, impact of anticoagulant treatment (type and duration) on the development of moderate to severe PTS, proportion of PTS (defined as PRVS≥5 or ipsilateral leg ulcer) and impact of PTS on patient's QOL. Study should last 1 year and up to 288 patients may participate.

The investigators believe that this study has the potential to significantly improve the knowledge on the epidemiology of burdensome PTS and on the impact of different initial CE strengths on the risk of PTS.

Inclusion Criteria:

• Patients enrolled and followed in the CELEST RCT*

Exclusion Criteria:

• Patients who withdrew consent or died during the 2-year follow-up of the CELEST RCT.

• Patients who decline or are unable to participate (including severe memory loss issues) to the long-term follow-up

  • CELEST RCT main inclusion/exclusion criteria were: adult (>18 years at time of enrolment) patients first unilateral acute symptomatic proximal lower limb DVT