WARP (warfarin thromboprophylaxis)
Trial question
What is the role of warfarin thromboprophylaxis in cancer patients with central venous catheters?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
39.0% female
61.0% male
N = 812
812 patients (313 female, 499 male).
Inclusion criteria: patients aged ≥ 16 years with cancer receiving chemotherapy through central venous catheters.
Key exclusion criteria: contraindication to warfarin; patient on warfarin therapy; pregnancy or lactation.
Interventions
N=408 warfarin (an oral daily dose of warfarin).
N=404 no warfarin (no treatment with warfarin).
Primary outcome
Catheter-related thrombotic events
6%
6%
6.0 %
4.5 %
3.0 %
1.5 %
0.0 %
Warfarin
No
warfarin
No significant
difference ↔
No significant difference in catheter-related thrombotic events (6% vs. 6%; RR 0.99, 99% CI 0.57 to 1.72).
Secondary outcomes
No significant difference in thrombotic events (7% vs. 9%; RR 0.78, 95% CI 0.5 to 1.24).
No significant difference in total major bleeding (1.73% vs. 0.25%; RR 6.93, 95% CI 0.86 to 56.08).
No significant difference in thrombotic events and major bleeding events (9% vs. 10%; RR 0.94, 95% CI 0.61 to 1.44).
Conclusion
In patients aged ≥ 16 years with cancer receiving chemotherapy through central venous catheters, warfarin was not superior to no warfarin with respect to a catheter-related thrombotic events.
Reference
Annie M Young, Lucinda J Billingham, Gulnaz Begum et al. Warfarin thromboprophylaxis in cancer patients with central venous catheters (WARP): an open-label randomised trial. Lancet. 2009 Feb 14;373(9663):567-74.
Open reference URL