Drug therapy for improving walking distance in intermittent claudication: a systematic review and meta-analysis of robust randomised controlled studies.

OBJECTIVES: To evaluate the efficacy of pharmacological interventions in improving walking capacity and health-related quality of life for people with intermittent claudication. DATASOURCES: We searched Medline, EMBASE, Cochrane library and relevant websites for studies published from the start of the databases to February 2009. In addition, reference lists were manually searched.

REVIEW METHODS: Based upon a power calculation, only robust (n>56), peer-reviewed, double-blinded, randomised and placebo-controlled trials were included. The main outcomes evaluated were maximal walking distance (MWD) and pain-free walking distance on a treadmill. Random models were used in the statistical analysis, and chi-square test were used to test for heterogeneity.

RESULTS: Among 220 trials, only 43 trials fulfilled the quality criteria. Treatment periods, follow-up and treadmill protocols varied substantially. Vasodilator agents and phosphodiesterase inhibitors show robust significant results compared to placebo, but the improvements in MWD are modest. The highest benefit was caused by lipid-lowering agents, which in mean gained above 160 m in MWD, while the other agents only improved MWD about 50 m.

CONCLUSION: Several drugs have shown to improve MWD, but with limited benefits. Statins seem to be the most efficient drug at the moment.