No head-to-head studies or umbrella meta-analyses assess all the main treatments for VTE against each other.
Long-term LMWH decreases VTE recurrence compared with VKA
Two meta-analyses of RCTs evaluating LMWH and VKA for long-term treatment (3-12 months) of confirmed VTE in patients with cancer found that LMWH didn’t change mortality, but reduced the rate of VTE recurrence compared with VKA (40% relative reduction).1,2 The comparison showed no differences in major or minor bleeding or thrombocytopenia between LMWH and VKA (TABLE1-5).
The studies included patients with any solid or hematologic cancer at any stage and from any age group, including children. Overall, the mean age of patients was in the mid 60s; approximately 50% were male when specified. Investigators rated the evidence quality as moderate for VTE, but low for the other outcomes.1
The most recent meta-analysis of the same RCTs comparing LMWH with VKA evaluated intracranial hemorrhage rates and found no difference.3
Initial therapy with LMWH: A look at mortality
A meta-analysis of RCTs that compared LMWH with UFH/VKA for initial treatment of confirmed VTE in adult cancer patients (any type or stage of cancer, mean ages not specified) found that LMWH reduced mortality by 30%, but didn’t affect VTE recurrence or major bleeding.4
The control groups received UFH for 5 to 10 days and then continued with VKA, whereas the experimental groups received different types of LMWH (reviparin, nadroparin, tinzaparin, enoxaparin) initially and for 3 months thereafter. Investigators rated all studies low quality because of imprecision and publication bias favoring LMWH.
Fondaparinux shows no advantage for initial therapy
The same meta-analysis compared initial treatment with fondaparinux and initial therapy with enoxaparin or UFH transitioning to warfarin.4 It found no differences in any outcomes at 3 months. Investigators rated both studies as low quality for recurrent VTE and moderate for mortality and bleeding.
Continue to: Non-vitamin K oral anticoagulants vs LMWH/VKA or VKA