Feasibility study to evaluate cycloidal vibration therapy for the symptomatic treatment of intermittent claudication

Intermittent claudication (IC) is the most common symptom of peripheral arterial disease. Previous research has suggested that cycloidal vibration therapy (CVT) may induce angiogenesis and improvements in circulation. The objective of this feasibility study was to explore trial design and acceptability of the protocol to provide data to estimate the parameters required to design a definitive randomised control trial. This feasibility study specifically aimed to assess recruitment rate; attendance rates at baseline and follow-up; and safety, tolerability, and compliance with therapy device and additionally, to consider the potential efficacy of CVT as a novel treatment for intermittent claudication.

Patients with intermittent claudication (IC) were recruited and CVT was applied at home for 30 min twice a day for a period of 12 weeks. Primary outcomes were pain-free walking time (PFWT) and maximum walking time (MWT) after 12 weeks of treatment. Secondary outcomes included the ankle-brachial index and ankle systolic blood pressure. Participants were assessed during active therapy phase at baseline, week 4, week 8, and week 12.

Thirty-four participants with IC were recruited: 30 (88%) male and 4 (12%) female. The rate of recruitment was 2.4 participants per month from a standard-size district general hospital. No participants left the study during the activity therapy stage, and no participant failed to attend their follow-up appointment. The general compliance with CVT was high. No participants dropped out during the treatment phase. The mean age of all participants was 68 years (IQR 60-75 years). Substantive improvements were seen in a comparison of differences in times to PFWT and MWT, in ABPI, and in systolic leg pressure in the treated leg. There was no evidence of a substantive difference from baseline in systolic leg pressure in the untreated leg. There were no immediate or delated treatment safety concerns of documented adverse effects with the treatment, all patients completed the required 12-week course indicated a high degree of patient acceptability.

The statistically significant and substantive improvements from baseline after 12 weeks observed in PFWT and MWT in participants experiencing IC are comparable to improvements seen from other treatment options such as supervised exercise as reported by Stewart et al. (N Engl J Med 347:1941-1951, 2002). The substantive improvement in systolic leg pressure in the treated leg and the concurrent absence of a substantive change in systolic leg pressure in the untreated leg over the same period suggests a causative effect.This study has provided novel information relating to the number of potential eligible participants for a further research trial and potential association between CVT and improved symptoms. Additionally, it has established that CVT treatment is highly acceptable, as indicated by no participant drop-out in the treatment phase, and may potentially offer an alternative treatment option for patients experiencing IC. Furthermore, this study has assessed the variability of the primary outcome measure which provides vital information needed to calculate sample sizes for any future studies.In conclusion, this study has established the feasibility of using CVT to improve patients' symptoms of IC and provides essential information which will contribute to the design of future research investigating whether the improvements seen are directly related to CVT.