A Cochrane review included 6 studies with a total of 119 subjects. Most of the included patients suffered from either mild or moderate peripheral vascular disease. Studies using selective beta blockers (atenolol, metoprolol) and non-selective beta blockers (propranolol, pindolol) were included. The drugs were administered for a short period of time (10 days to two months), and additional drugs, calcium channel blockers and combined alpha and beta blockers, were also given in some of the trials. Most of the outcome measures were reported in single studies, and thus a meta-analysis was not performed. None of the trials showed a clear worsening effect of beta blockers on time to claudication, claudication and maximal walking distances measured on a treadmill, calf blood flow, calf vascular resistance and skin temperature when compared with placebo. The trials did not report any adverse events or issues regarding taking the medication with the beta blockers studied.
A systematic review including 9 crossover RCTs with a total of 123 subjects was abstracted in DARE. The studies included selective and non-selective beta-blockers and a blocker of both alpha– and beta–adrenergic receptors. The maximal walking distance was shorter in patients receiving beta-blockers compared with control (SMD -0.31, 95% CI -0.58 to -0.04, p=0.03, 3 RCTs), as was the initial claudication distance (=pain-free walking distance), SMD -0.39, 95% CI -0.73 to -0.06, p=0.02 (1 high-quality RCT). Maximum walking distance also appeared to be shorter for patients receiving beta-blockers with ISA, although this was not statistically significant. There was no significant difference between beta-blockers and control for maximal walking time (SMD 0.07, 95% CI -0.24 to 0.37, p=0.67, 4 RCTs) or initial claudication time (SMD 0.12, 95% CI -0.23 to 0.47, p=0.51, 3 RCTs). All these studies were rated as high quality. There was no significant difference between beta-blockers and control for ankle-brachial index, ABI (SMD 0.24, 95% CI -0.30 to 0.78, p=0.39, 1 low-quality RCT with 14 patients) and for calf blood flow at rest (SMD 0.00, 95% CI -0.26 to 0.25, p=0.97, 3 RCTs) or after exercise (SMD -0.23, 95% CI -0.69 to 0.22, p=0.31, 1 high-quality RCT).
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment) and by imprecise results (limited study size for each comparison).