Rivaroxaban Compared to Placebo for the Treatment of Leg Superficial Vein Thrombosis: A Randomized Trial

A systematic review and meta-analysis for the association between duration of anticoagulation therapy and the risk of venous thromboembolism in patients with lower limb superficial venous thrombosis

OBJECTIVE

The aim of this study was to determine the association between the duration of systemic anticoagulation therapy (ACT) and the risk of further venous thromboembolism (VTE) in patients with superficial venous thrombosis (SVT).

METHODS

A systematic review and meta-analysis were performed using searches of Medline and Cochrane Library databases in September 2023. Papers that provided VTE incidence within mid-term follow-up of ≥45 days in patients who received any ACT were included. Patients were categorized into subgroups according to the course of treatment: (1) no ACT (0 days); (2) ACT of ≤14 days; (3) ACT of 15 to 30 days; (4) ACT of 31 to 45 days; and (5) ACT of >45 days. Reported events were transformed to events per 100 patient-years, and a random-effects model was used to calculate pooled rates for proportions. The primary outcome (VTE) was a combination of SVT progression or recurrence with the occurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE). Secondary outcomes included major and clinically relevant non-major or minor bleeding.

RESULTS

Twenty-four studies (10 randomized controlled trials and 14 cohort studies) combining outcomes in 12,341 patients were included in the quantitative synthesis. Minimum VTE and SVT recurrence or progression rates were observed with the ACT duration of 31 to 45 days of 16.2 (95% confidence interval [CI], 10.4-23.3) and 8.2 (95% CI, 3.1-15.8) events per 100 patient-years, respectively. Minimum DVT and PE rates observed with the treatment duration of 15 to 30 days were 5.5 (95% CI, 2.8-9.1) and 0.9 (95% CI, 0.5-1.3) events per 100 patient-years, respectively. Short-term treatment of ≤14 days was associated with the highest rates of VTE of 59.7 (95% CI, 37.7-86.4), DVT of 13.7 (95% CI, 9.6-18.4), and PE of 3.1 (95% CI, 1.4-5.6) events per 100 patient-years. Major bleeding rates were unrelated to the duration of ACT and did not exceed 0.5 events per 100 patient-years. The highest rate of clinically relevant non-major or minor bleeding was observed with ACT duration of 31 to 45 days of 14.2 (95% CI, 5.5-26.8) events per 100 patient-years. The most common risk factors for VTE included male sex, cancer, personal history of DVT, PE, or SVT, and thrombosis of non-varicose veins.

CONCLUSIONS

Prolonged systemic anticoagulation is associated with the tendency to decrease VTE rates in patients with lower limb SVT.

Superficial Venous Thrombosis: A Comprehensive Review

Superficial venous thrombosis (SVT), an inflammatory-thrombotic process of a superficial vein, is a relatively common event that may have several different underlying causes. This phenomenon has been generally considered benign, and its prevalence has been historically underestimated; the estimated incidence ranges from about 0.3 to 1.5 event per 1000 person-years, while the prevalence is approximately 3 to 11%, with different reports depending on the population studied. However, such pathology is not free of complications; indeed, it could extend to the deep circulation and embolize to pulmonary circulation. For this reason, an ultrasound examination is recommended to evaluate the extension of SVT and to exclude the involvement of deep circulation. Also, SVT may be costly, especially in the case of recurrence. Therefore, accurate management is necessary to prevent sequelae and costs related to the disease. This review aims to analyse the epidemiology of SVT, its complications, optimal medical treatment, and open questions with future perspectives.

Risk of recurrent thromboembolic events according to treatment duration in patients with superficial vein thrombosis treated with intermediate dose of tinzaparin

OBJECTIVES

To evaluate the risk of symptomatic venous thromboembolism (VTE) recurrence at 3 months in relation to treatment duration, according to baseline risk factor profiles, in patients with superficial vein thrombosis (SVT) treated with intermediate dose of tinzaparin.

METHODS

We performed a pooled analysis on individual data from two prospective studies designed to assess the efficacy and safety of tinzaparin in intermediate dose (131 IU/kg) in patients with SVT. Treatment duration was at the treating physician's discretion. All patients were followed up for at least 3 months.

RESULTS

A total of 956 patients (65% female, mean age 58.7 ± 13.7 years) were included. The median treatment duration was 30 days (range, 3-200 days). History of deep vein thrombosis (DVT), location of SVT above the knee, and palpable induration were the only independent factors associated with prolonged treatment duration. During follow-up, 95.9% of patients were event free. Outcomes-related adverse events occurred in 39 (4.1%) patients and their median duration of treatment was 33 days (range, 7-200 days). Recurrent VTE events occurred in 33 patients, including 22 cases of SVT recurrence, 8 cases of DVT, and 1 case of pulmonary embolism. The median time to the event was 29 (6-113) days. Recurrent thromboembolic events were not related to treatment duration as occurred in 17 patients (51.5%) treated up to 30 days and in 16 patients (48.8%) received prolong treatment (p = .46). Length of thrombus at the index event was significantly associated with higher risk for VTE recurrence.

CONCLUSIONS

Intermediate dose of tinzaparin for 30 days is an effective and safe treatment for SVT. The risk of recurrent VTE events may be higher in patients with greater amount of thrombus at index event.