Lipid-lowering for lower limb atherosclerosis

Abstract

Background: Raised lipid levels, including cholesterol, are important risk factors in the development of lower limb arterial disease (atherosclerosis).

Objectives: The objective of this review was to assess the effects of lipid lowering therapy in patients with lower limb atherosclerosis.

Search strategy: The reviewers searched the Cochrane Peripheral Vascular Diseases Group trials register, Embase, reference lists of relevant articles, and contacted trial investigators in Europe and pharmaceutical companies.

Selection criteria: Randomised trials of lipid-lowering therapy in patients with lower limb atherosclerosis. The main outcomes were mortality, non-fatal events, direct tests of disease progression, indirect measurements of disease, and subjective measures.

Data collection and analysis: Two reviewers extracted data and assessed trial quality independently. The reviewers contacted investigators to obtain information needed for the review that could not be found in published reports.

Main results: There were nine eligible trials, but two were excluded because of poor methodology. The seven remaining trials involved a total of 698 participants from seven different countries. Men and women participated in all but one trial and were generally middle aged to elderly. The follow-up period varied from four months to three years. The overall quality of the included trials was high. The trials were heterogeneous in terms of inclusion criteria, type of drugs used and outcomes measured. Lipid-lowering therapy produced a marked but non-significant reduction in mortality (odds ratio 0.21, 95% confidence interval 0. 03 to 1.17), but little change in non-fatal events (odds ratio 1.21, 95% confidence interval 0.80 to 1.83). In two trials there was a significant overall reduction in disease progression on angiogram (odds ratio 0.47, 95% confidence interval 0.29 to 0.77). The changes in ankle brachial pressure index and walking distance were inconsistent, although trials showed a general improvement in symptoms that could not be combined in a meta-analysis. Side effects were generally mild, with the exceptions of liver toxicity produced by betapyridil and the adverse effect of probucol on lipoprotein profile.

Reviewer's conclusions: Lipid-lowering therapy may be useful in preventing deterioration of underlying disease and alleviating symptoms. These results cannot determine whether one lipid-lowering regimen is better than another.