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

AbstractObjectivesTo evaluate the efficacy of pharmacological interventions in improving walking capacity and health-related quality of life for people with intermittent claudication.DatasourcesWe 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 methodsBased 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.ResultsAmong 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 160m in MWD, while the other agents only improved MWD about 50m.ConclusionSeveral drugs have shown to improve MWD, but with limited benefits. Statins seem to be the most efficient drug at the moment

Randomized double-blind placebo-controlled crossover study of caffeine in patients with intermittent claudication

Abstract Background Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication. Methods This randomized double-blind placebo-controlled crossover study included 88 patients recruited by surgeons from outpatient clinics. The participants abstained from caffeine for 48 h before each test and then received either a placebo or oral caffeine (6 mg/kg). After 75 min, pain-free and maximal walking distance on a treadmill, perceived pain, reaction times, postural stability, maximal isometric knee extension strength, submaximal knee extension endurance and cognitive function were measured. The analysis was by intention to treat. Results Caffeine increased the pain-free walking distance by 20·0 (95 per cent confidence interval 3·7 to 38·8) per cent (P = 0·014), maximal walking distance by 26·6 (12·1 to 43·0) per cent (P &amp;lt; 0·001), muscle strength by 9·8 (3·0 to 17·0) per cent (P = 0·005) and endurance by 21·4 (1·2 to 45·7) per cent (P = 0·004). However, postural stability was reduced significantly, by 22·1 (11·7 to 33·4) per cent with eyes open (P &amp;lt; 0·001) and by 21·8 (7·6 to 37·8) per cent with eyes closed (P = 0·002). Neither reaction time nor cognition was affected. Conclusion In patients with moderate intermittent claudication, caffeine increased walking distance, maximal strength and endurance, but affected balance adversely. Registration number: NCT00388128 (http://www.clinicaltrials.gov). </jats:sec