A feasibility double-blind randomized placebo-controlled trial of extracorporeal shockwave therapy as a novel treatment for intermittent claudication.

BACKGROUND: Intermittent claudication is the most common symptom of peripheral arterial disease. Previous research has suggested that extracorporeal shockwave therapy (ESWT) may induce angiogenesis in treated tissue. The objective of this feasibility pilot trial was to assess the safety, tolerability, and efficacy of ESWT as a novel treatment.

METHODS: Patients with unilateral claudication were randomized to receive ESWT or sham treatment to the calf muscle three times per week for 3 weeks. Primary outcomes were pain-free walking distance (PFWD) and maximum walking distance (MWD). Secondary outcomes included safety and tolerability of ESWT treatment, ankle-brachial index before and after exercise, and quality of life assessed using generic (36-Item Short Form Health Survey, EuroQol-5 Dimension 3-Level) and disease-specific (Vascular Quality of Life) instruments. Participants were assessed at baseline and 4, 8, and 12 weeks after treatment. Feasibility outcomes included recruitment and attendance rates for treatment and follow-up.

RESULTS: Thirty patients were recruited in total. Statistically significant (P < .05) improvements at all time points were observed in the active treatment group for both MWD and PFWD compared with the sham treatment group. PFWD improved by 276% in the active group and MWD improved by 167% in the active group at 12 weeks after treatment. There were no immediate or delayed treatment safety concerns or documented adverse effects of treatment with ESWT in this trial.

CONCLUSIONS: ESWT is safe and well tolerated when it is applied to the calf and demonstrated significant improvements in walking distances. Current conservative management of intermittent claudication includes supervised exercise. The early results with ESWT as an alternative, noninvasive treatment option show great potential. The mechanism of action, durability of the clinical effect, and cost-effectiveness of ESWT for claudication require further investigation.