CACTUS

Incomplete

Righini M, et al. "Anticoagulant therapy for symptomatic calf deep vein thrombosis (CACTUS): a randomised, double-blind, placebo-controlled trial". Lancet Haematology. 2016. 3(12):e556-e562.
PubMed • Full text

Clinical Question

In patients with symptomatic calf deep vein thrombosis, does treatment with LMWH help decrease extension?

Bottom Line

There is no difference between nadroparin and placebo in reducing the risk of extension of calf vein clots into the deeper venous system. Treatment with LMWH did have an increase risk of bleeding. Calf DVTs should not be treated with systemic anticoagulation.

Major Points

There are limited trials studying the need to treat isolated calf DVTs. The CACTUS trial shows that LMWH anticoagulation does not prevent extension of clots compared to placebo. Furthermore, there are increased risks of bleeding with anticoagulation. The ACCP has made guidelines to avoid treating calf DVTs, and using follow-up ultrasound to monitor for extension is an appropriate alternative.

Design

• Randomized, controlled trial
• N=
  • LMWH (n=)
  • Placebo (n=)
• Setting: ## centers in ## countries
• Enrollment: ####-###
• Mean follow-up: ## years
• Analysis: Intention-to-treat
• Primary outcomes:
  • Efficacy: Extension of DVT, contralateral proximal DVT, or symptomatic PE at 42 days
  • Safety: Major or clinically-relevant non-major bleeding at 42 days

Population

Baseline Characteristics

• Demographics: Age ## years, ##% women

Interventions

• Randomized to a group:
  • LMWH - received nadroparin 171 UI/kg daily
  • Placebo

Outcomes

Comparisons are LMWH vs. placebo.

Primary Outcomes

Efficacy - Extension of DVT, contralateral proximal DVT, or symptomatic PE at 42 days

3% vs. 5% (RD -2.1%; 95% CI -7.8 to 3.5; P=0.54)

Safety - Major or clinically-relevant non-major bleeding at 42 days

4% vs. 0% (RD 4.1%; 95% CI 0.4 to 9.2; P=0.0255)