Anticoagulants (heparin, low molecular weight heparin and oral anticoagulants) for intermittent claudication

Abstract

Background: Anticoagulant treatment for intermittent claudication might improve functional capacity, and prevent acute cardiovascular complications caused by peripheral obstructive arterial disease.

Objectives: To assess the effects of anticoagulant drugs (heparin, low molecular weight heparin (LMWH) and oral anticoagulants) in patients with intermittent claudication (Fontaine stage II) in terms of improving walking capacity (pain-free walking distance or absolute walking distance), mortality, cardiovascular events, ankle/brachial pressure index, progression to surgery, amputation-free survival and side effects of these drugs.

Search strategy: Randomised trials of anticoagulants for intermittent claudication were sought using the search strategy described by the Cochrane Peripheral Vascular Diseases Review Group. Additional trials were sought through: reference lists resulting from this search; recent conference proceedings; contact with authors of published trials and pharmaceutical companies producing anticoagulants.

Selection criteria: All randomised trials of anticoagulants used to treat patients with intermittent claudication.

Data collection and analysis: Thirteen trials were initially considered eligible for inclusion in the review. Two studies evaluated oral anticoagulants, five evaluated standard heparin, and six evaluated LMWHs. Only three studies (two evaluating oral anticoagulants, one evaluating heparin) met the high quality methodological inclusion criteria and were included in the primary analysis. Four other studies were included in the sensitivity analysis. The reviewers extracted the data independently.

Main results: No significant difference was observed between heparin treatment and control groups for pain-free walking distance or maximum walking distance at the end of treatment. There were no data to indicate that LMWHs benefit walking distance. Revascularisation or amputation-free survival rates were reported in one study only with a five year follow-up. No study reported a significant effect on overall mortality or cardiovascular events and the pooled odds ratios were not significant for these outcomes either. Major and minor bleeding events were significantly more frequent in the group treated with oral anticoagulants compared to control, with a non-significant increase in fatal bleeding events. No major bleeding events were reported in the study evaluating heparin, while a non-significant increase in minor bleeding events was reported.

Reviewer's conclusions: No benefit of heparin, LMWHs or oral anticoagulants has been established for intermittent claudication. An increased risk of major bleeding events has been observed especially with oral anticoagulants. The use of anticoagulants for intermittent claudication cannot be recommended at this stage.