Tinzaparin in intermediate dose for the treatment of superficial vein thrombosis: Results from an observational multicenter study-SeVEN study

Objectives Low-molecular-weight heparins are recommended in the treatment of superficial vein thrombosis but with low grade of evidence. This study was conducted to assess the treatment outcomes of acute superficial vein thrombosis with intermediate dose of Tinzaparin. Methods Retrospective analysis of records from outpatients over a period of 16 months treated in seven centers with Tinzaparin 0.5 ml (10,000 anti-Xa IU) once daily for a period that was at the treating physician's discretion. All the patients were followed up for at least 12 weeks. Results A total of 296 patients (189 females, mean age 57.4 years) were included. Two thirds of the patients (191/296, 64.5%) received treatment for approximately five weeks (mean 36.9 days) and the remaining (105/296, 35.5%) for a shorter period (mean 16.2 days). There was no difference in patients' characteristics between the two treatment duration groups. The presence of thrombus above the knee and restricted daily activity were associated with longer period of treatment. Only one case with minor bleeding was observed. Recurrence of thrombosis over a 12-week follow-up period occurred in 6% (superficial vein thrombosis in 14 (4.7%), deep vein thrombosis in 3 (1%) and thrombus extension in the superficial veins in 1 (0.3%)). Recurrence was not related to the duration of treatment. Conclusions Intermediate dose of Tinzaparin was an effective and safe treatment for superficial vein thrombosis in the setting of real world practice. Location of thrombus and status of patients' mobilization were associated with longer duration of treatment. Future prospective randomized studies are needed to corroborate these findings.