Anatomical Predictors of Venous Thromboembolism Recurrence after Isolated Superficial Vein Thrombosis

Background: Isolated superficial vein thrombosis (iSVT) (i.e. without concurrent deep-vein thrombosis or pulmonary embolism) is a frequent event. Its clinical significance and management are controversial. Data on long-term follow-up are scarce and the impact of anatomical characteristics of iSVT on the risk of venous thromboembolism (VTE) (DVT and/or PE) recurrence has not been assessed.

Objective: To determine the impact of anatomical characteristics of iSVT on the long-term risk of VTE recurrence.

Methods: Using data from the The OPTIMEV (OPTimisation de l’Interrogatoire dans l’_evaluation du risque throMbo-Embolique Veineux) study, a prospective, observational, multicenter study, we assessed at 3 years in patients recruited for an objectively confirmed iSVT i) cumulative rates of DVT, PE and SVT recurrences using the Kaplan-Meier method; and ii) anatomical predictors of VTE recurrence (SVT involving the sapheno-femoral junction (i.e. ≤3 cm), SVT of the trunk of the great saphenous vein, bilateral SVT, SVT occurring in a varicose vein (i.e. C≥2 according to CEAP classification) using a Cox multivariable model adjusted for age, sex, cancer and personal history of VTE. At baseline, all patients with SVT underwent a complete bilateral swhole leg ultrasound to exclude concurrent DVT and during follow-up, all suspected VTE recurrences were confirmed/ruled out with objective tests. All recurrences were centrally adjudicated by the study’s expert committee.

Results: Among the 479 recruited patients with iSVT, 12.5% (n=60) had a thrombotic recurrence during the 3 years of follow-up. Cumulative rates of recurrence as a PE, DVT and iSVT were 1.9%, 4.8% and 5.8%, respectively. In multivariate analysis, a thrombus involving the sapheno-femoral junction at baseline independently increased the risk of VTE recurrence (HR=3.34 [1.5-7.2]). Presence of varicose veins also increased the risk but this result did not reach statistical significance (HR=1.8 [0.9 – 3.9], p=0.11).

Conclusion: In an unselected population of patients with iSVT, long-term risk of VTE recurrence is substantial. Involvement of the sapheno-femoral junction is a strong independent predictor of VTE during the subsequent 3 years. Our results suggest the need for more aggressive management and follow-up of patients with iSVT exhibiting this anatomical characteristic.