Assessing VTE Risk After Treatment for Isolated Superficial Vein Thrombosis

Patients who received anticoagulation treatment for high-risk isolated superficial vein thrombosis (iSVT) still exhibited a “substantial” risk of VTE later on, though their risk of bleeding events was low, according to a recent study.

The study was published in the Journal of Thrombosis and Haemostasis and led by Camilla Tøvik Jørgensen, of the Department of Emergency Medicine at the Østfold Hospital in Sarpsborg, Norway.

Available data on the long-term risk of venous thromboembolism (VTE) following anticoagulant treatment for high-risk isolated superficial vein thrombosis (iSVT) is sparse, according to the study.  To characterize VTE risk, the authors reviewed patients with iSVT in the Norwegian database, TROLL, and established a significant risk of VTE.

Investigators reviewed TROLL records and identified 229 patients with high-risk iSVT (defined as a thrombus length ≥5cm) who received anticoagulant treatment between January 2014 and December 2021. The primary endpoints were cumulative incidence of VTE, recurrence of iSVT, and cumulative incidences of major bleeding and clinically relevant nonmajor bleeding (CRNMB) events.

VTE Risk Remains High After Anticoagulation Therapy

The cohort had a median age of 60 years (interquartile range, 48-71), was 55% female, and had no active cancer or history of VTE or iSVT. Overall, 74% of patients received direct oral anticoagulants (DOACs), of which 79% received a dose of rivaroxaban 10 mg daily, and 26% received low-molecular weight heparin.

Based on their analysis, the authors reported the cumulative incidence of VTE following iSVT was 4.6% (95% CI, 2.5-8.3) at one year and 15.9% (95% CI, 10.8-22.9) at five years. Likewise, the incidence of iSVT recurrence was 6.5% (95% CI, 3.9-10.7) at one year and 15.9% (95% CI, 10.8-23.1) at five years.

Finally, the overall 45-day cumulative incidences of major bleeding and CRNMB events were 0.4% (95% CI, 0.06-3.06) and 1.8% (95% CI, 0.7-4.6), respectively. Researchers noted there were no major bleeding events among patients who received DOACs.

Reference

Jørgensen CT, Brækkan SK, Førsund E, et al. Incidence of VTE, recurrence, and bleeding after isolated superficial vein thrombosis – findings from the TROLL registry. J Thromb Haemost. 2023;S1538-7836(23)00786-9. doi:10.1016/j.jtha.2023.10.017

Related: Study Links LMWH to Lower Risk of VTE in Patients With Severe Blunt Trauma